Loss in vitamin C contents of some fruit juice namely, orange, lemon, lime and grape stored under different conditions was investigated. The juices from the samples were extracted, stored at room temperature in plastic bottles. The juices were all analyzed for their vitamin C content by oxidation and reduction method. Results revealed that vitamin C concentration is more in orange juice as it is shown in Table 1 and Fig. 1 and 2 compared to grape, lemon and lime juice respectively in this order: at 20 C, 612.15 o > 454.47 > 305.57 > 270.75 ………. 80 C, 550.87 > 380.16 > 248.85 > 222.58 and the rate at which vitamin o C is loss during storage depends on the type of storage method employed, for example, handling and storage; oxygen is the most destructive ingredient in juice, causing degradation of vitamin C. Juice should be discouraged from being display in the hot weather above room temperature in order to maintain production concentration. The citrus fruits were found to follow a similar pattern of loss.

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... Exposure time increase at any fixed heating temperature steadily increased %AA r values. These observations are in agreement with those reported in Igwemmar, Kolawole, and Imran (2013), Njoku, Ayuk, andOkoye (2011), andGabriel et al. (2015). Furthermore, a steady linear decrease in the retention of vitamin was observed with decreasing initial concentration. ...

... Exposure time increase at any fixed heating temperature steadily increased %AA r values. These observations are in agreement with those reported in Igwemmar, Kolawole, and Imran (2013), Njoku, Ayuk, andOkoye (2011), andGabriel et al. (2015). Furthermore, a steady linear decrease in the retention of vitamin was observed with decreasing initial concentration. ...

... When the effect of the initial concentration on %AA r was plotted, faster reduction rate was observed when the initial vitamin content was less. The previous studies reported by Cvetkovic andJokanovic (2009) andNjoku et al. (2011) also showed that lower percentages of ascorbic acid loss were obtained from samples with higher initial AA concentration. deMan (1999) explained that ascorbic acid is the least stable of all vitamins, and that it is easily destroyed in the different unit operations during food processing, which include exposure to oxygen, prolonged heating in the presence of oxygen, and exposure to light. ...

Predictive models for the estimation of residual ascorbic acid (rAA) and ascorbic acid percent change (% AAr) in heat-treated simulated fruit juices were established. The tested ranges of predictor product properties (pH and initial AA level) were based on initial surveys conducted involving processed and freshly squeezed juices, while those of predictor process parameters (heating temperature and treatment time) were based on thermal inactivation of Escherichia coli O157:H7 modeled earlier in our lab. Results showed that both rAA and %AAr data sets had highly significant (P < 0.0001) fit in a linear and quadratic model, respectively. Temperature, time, and initial AA were found significant predictors of rAA. On the other hand, temperature, time, initial AA, temperature2 and initial AA2 were found to be significant predictors of %AAr. Predictive performance indices were within acceptable values, confirming model utility in decision making for a more comprehensive control of juice nutritional functional quality and safety.

... Ascorbic acid is a natural water-soluble vitamin known as Vitamin C (Gao et al., 2010;Njoku et al., 2011). It is an essential nutrient in a human diet, its major role is to maintain connective tissue and bones (Njoku et al., 2011). ...

... Ascorbic acid is a natural water-soluble vitamin known as Vitamin C (Gao et al., 2010;Njoku et al., 2011). It is an essential nutrient in a human diet, its major role is to maintain connective tissue and bones (Njoku et al., 2011). Ascorbic acid is only obtainable in the human diet, it cannot be produced or stored in the human body (Campbell and Campbell Ii, 2016). ...

... Qiushui) during postharvest storage Zhao et al. (2013) Effect of ozone processing on anthocyanins and ascorbic acid degradation of strawberry juice Tiwari et al. (2008) S. Shezi, et al. Scientia Horticulturae 269 (2020) 109397 fibrous tissue, teeth and bones (Njoku et al., 2011;Gorrini et al., 2013). Ascorbic acid serves as an antioxidant since it chemically binds and neutralizes the tissue-damaging effects of substances known as free radicals (Lobo et al., 2010;Njoku et al., 2011;Carocho and Ferreira, 2013). ...

Ozone is a triatomic molecule of oxygen well-known as a powerful disinfectant because of its higher oxidation potential. Ozone has recently gained more interest especially from producers of organic fresh horticultural products. This happened after it was recognized as a generally safe disinfectant of fresh fruits and vegetables. One of the major properties of ozone that makes it an effective postharvest treatment is its ability to disinfect fresh produce effectively without leaving residues on the surface, mainly because it decomposes to form oxygen. Ozone is one of the successful postharvest treatments, however; its mode of action is not well documented. The currently understood mode of action of ozone is linked with antimicrobial properties, however, several studies revealed the biochemical impact of ozone as a postharvest treatment of horticultural fresh produce. Little has been done in terms of critically reviewing the biochemical impact of ozone as a postharvest treatment. Furthermore, among the few reviews on ozone, there is little or no detailed information regarding the effect of ozone on antioxidants, as the major components of the human diet in fruit and vegetables. Therefore, in this review, the mode of action of ozone as a postharvest treatment has been discussed, with a more focus on its biochemical impact on antioxidants as major components of fresh produce diet.

... The highest amount of L-ascorbic acid was obtained from the powder produced at 130 o C (18.86 mg/100g DW). There was no significant difference on L-ascorbic acid contents between powders obtained from 130 o C and 140 o C. Njoku et al., (2011) reported that higher temperature led to the dramatically degradation of Vitamin C content in orange juice. The L -ascorbic acid under high temperature has been susceptible to oxidation (Njoku et al., 2011) or become unstable substances (Pavlovska, Tanevska, 2012); hence, increasing the inlet temperature led to decreasing L-ascorbic acid contents. ...

... There was no significant difference on L-ascorbic acid contents between powders obtained from 130 o C and 140 o C. Njoku et al., (2011) reported that higher temperature led to the dramatically degradation of Vitamin C content in orange juice. The L -ascorbic acid under high temperature has been susceptible to oxidation (Njoku et al., 2011) or become unstable substances (Pavlovska, Tanevska, 2012); hence, increasing the inlet temperature led to decreasing L-ascorbic acid contents. Similar results reported by Bachtira and Sarmidi (1997) whose study found that total Lascorbic acid contents of spray-dried mango powder reduced from 14.34 mg/100g DW to 13.55 mg/100g DW when the temperature increased from 160 o C to 220 o C (Bachtira, Sarmidi, 1997). ...

Application of spray-drying in mango powder production could significantly reduce postharvest loss and diversify products from mango fruit. Five levels of inlet temperature (130 0 C, 140 0 C, 150 0 C, 160 0 C and 170 0 C) and feed flow rate (5 rpm, 6 rpm, 7 rpm, 8 rpm and 9 rpm) were selected for studying influences of spray drying conditions on total phenolic contents (TPCs), total carotenoid contents (TCCs), L-ascorbic acid contents (L-AACs), antioxidant capacities (AC), titratable acidity (TA) and moisture contents (MCs) of Cat Chu mango powder. The inlet temperatures and feed flow rates had opposite effects on TPCs, TCCs, L-AACs, AC, TA and MCs. When increasing the temperatures, TPCs, TCCs, L-AACs, AC, TA and MCs were significantly decreased, whilst accelerating feed flow rates resulted in rising values of those parameters. Increase of the feed flow rates led to reduction of drying duration, the samples would be less heated, resulting in less degradation of antioxidant compounds. The highest TPCs and AC were obtained from samples dried at 130 0 C or at 9rpm. However, due to preventing the biochemical degradation, inlet temperature at 160 o C with feed flow rate at 8 rpm was realized as the most ideal spray-drying condition for producing Cat Chu mango powder that had higher TPCs, TCCs, L-AACs, AC, and TA but lower MCs as compared to the rest ones. High positive correlations between L-ascorbic acid and antioxidant capacity (r = 0.72 and r = 0.70) as compared to those of carotenoids and phenolic compounds, therefore L – ascorbic acid could be considered as the major contributor to antioxidant capacity of Cat Chu mango powder.

... These factors include temperature, type of metal storage container ( each type of metal has a unique standard electrode potential, which determines the rate at which the substance will be reduced or oxidized), and sugar additives (since some sugars may function as a reducing agent). [7][8][9] There are limited investigations published in literature which discuss the influence of such factors on the vitamin C concentration of orange juice. 7,[10][11] Therefore, the aim of this investigation is to determine the relationship between different storage temperatures (5 °C, 10 °C, 20°C, 30°C, and 50°C) and the vitamin C concentration of fresh orange juice. ...

... [7][8][9] There are limited investigations published in literature which discuss the influence of such factors on the vitamin C concentration of orange juice. 7,[10][11] Therefore, the aim of this investigation is to determine the relationship between different storage temperatures (5 °C, 10 °C, 20°C, 30°C, and 50°C) and the vitamin C concentration of fresh orange juice. It also aims to examine the effect of different metal containers (Al, Sn, & Ag) and sugar additives (glucose, lactose, and sucrose) on the vitamin C concentration of orange juice. ...

  • Noor Albusta Noor Albusta
  • Manal Ali

L-ascorbic acid (vitamin C) is an essential dietary nutrient for human beings and provides numerous health benefits. Orange juice is a commonly consumed beverage that is widely known for its vitamin C content. Yet, by its nature, L-ascorbic acid is very unstable, and readily oxidizes to L-dehydroascorbic acid. Once oxidized, its health benefits are lost. Given its unstable nature and oxidative property, many factors may have the potential of affecting the vitamin C concentration of fresh orange juice. These factors include temperature, type of metal storage container, and sugar additive. There are limited investigations published in literature which discuss the influence of such factors on the vitamin C concentration of orange juice. Therefore, the aim of this investigation was to determine the relationship between different storage temperatures and the vitamin C concentration of fresh orange juice. It also aimed to examine the effect of different metal containers and sugar additives on the vitamin C concentration of orange juice. The concentration of L-ascorbic acid was determined via a titration reaction with iodine solution. The results of the investigation have shown that there is a negative relationship between storage temperature and the vitamin C concentration of orange juice. Out of the examined types of metals, aluminum was found to be the most effective in preserving the vitamin C concentration of orange juice. The results also showed that the addition of reducing sugars to orange juice may help in preserving its vitamin C concentration.

... Most of the above vitamin C deficiency diseases are reversible and can be cured by supplementation of vitamin C rich food. Vitamin C is mainly found in fruits and vegetables [12]. Citrus limon L. (lemon) is fruit of the citrus group and rich sources of vitamin C [13]. ...

... Vitamin C is found in foods and supplements. Fruits and vegetables contain a huge vitamin C and that is enough for prevention of Vitamin C related diseases [12,19]. Deficiency of nutrients including vitamin A, vitamin C, vitamin E and other several macro and micro nutrients are significantly associated with wound healing. ...

  • Zubaer Hosen Zubaer Hosen
  • Shahin Afroz Bipasha
  • Sadat Kamal
  • Kaniz Fatema

Vitamin C is an essential dietary component must be ingested for survival. Because of not being produce in the body it must be supplied exogenously by foods and supplements. Citrus limon L. (Lemon) is a citrus fruits, cheap but rich sources of vitamin C. Due to high levels of vitamin C content, it can prevent and cure the vitamin C related disease including gum bleeding, poor wound healing, skin diseases, tiredness, joint pain and edema. A total of 200 people (105 were males and 95 were females) were selected for the study. In order to assess vitamin C status, symptoms like gum bleeding, poor wound healing, hyperkeratosis, excessive tiredness, joint pain and edema were collected by means of a structured questionnaires. People were then divided into two groups randomly. One group was the focus of the lemon supplementation group and another was the non-supplementation group. Then we supplied lemon to the individuals (2piece/day) of lemon supplementation group for 4 months and no lemon was provided to the non-supplementation group during the study period. After four months, we found that symptoms like gum bleeding (92.5%), poor wound healing (89.29%), hyperkeratosis (50%), excessive tiredness (89.83%), joint pain (69.23%) and edema (30%) have been cured in lemon supplementation group. On the other hand, after four months gum bleeding, poor wound healing, hyperkeratosis, excessive tiredness, joint pain and edema in nonsupplementation group have not been cured like lemon supplementation group. The percentages were 20%, 21.05%, 33.33%, 25%, 14.81% and 14.29% respectively.

... The retention of vitamin C is often used as an estimate for the overall nutrient retention of food products because it is highly sensitive to oxidation and leaching into water-soluble media during storage, it begins to degrade immediately after harvest and degrades steadily during prolonged storage [9]. Although the degradation of ascorbic acid is known to be affected by pH, the change in pH during the storage was not significant [10]. ...

... According to many authors, temperature is one of the main factors that significantly influence the stability of vitamin C in solution [12,14,20]. Njoku et al. [19] showed that along with the increase of temperature from 20 o C to 80 o C the amount of vitamin C in fruit's juices decreases significantly reaching minimum value at 80 o C. Suntornsuk et al. [23] proved, that even storing juices at low temperature of 4 o C caused losses in vitamin C concentration. Skalozubova & Reshetova [21] determined amount of vitamin C in infusions made of nettles' leaves with iodimetric titration and titration by 2,6-dichlorophenolindophenol sodium salt. ...

Background: Stinging nettle (Urtica dioica L.) can be found in temperate climate zones of Europe, Africa and America Nettle may be a source of nutritional ingredients, mineral salts, vitamins and antioxidants. Objective: The aim of the study was to determine the effect of temperature and brewing time Urtica dioica L. infusions from different parts of this plant on vitamin C (ascorbic acid) content. Material and methods: Infusions of nettle leaf, stem and root were prepared at room temperature, 50°C, 60°C, 70°C and 80°C for 10 minutes. Leaf infusions were also brewed for 5, 10, 15 and 20 minutes at initial water temperature of 60°C. The amount of vitamin C was determined by the spectrophotometric method. Results: The best temperature of brewing nettle infusions, in terms of vitamin C concentration, is between 50 °C and 60 °C as it is sufficient to extract the substance, yet not high enough to destroy it. Conclusions: The optimal time of brewing appeared to be 10 minutes as the prolonged exposure to high temperature appeared to be detrimental for ascorbic acid as well.

... The results are expressed as mg lycopene equivalent per 100 g of dry weight (mg LE/100 g DW) from the standard curve prepared with lycopene. The amount of ascorbic acid in the sample was determined according to the oxidation-reduction method described by Njoku et al. (2011). It is a direct titration of 10 ml of diluted melon jam with iodine (I 2 ). ...

Melon (Cucumis melo) is a fruit with high market value in Algeria with little details about its quality characteristics. Physico-chemical and microbiological parameters, sensorial profile, antioxidants content and antioxidant activity were evaluated in jam made from Algerian melon fruit (Cucumis melo). For that purpose, special attention was paid to total soluble solids (TSS), titratable acidity (TA), viscocity, total sugars (TS) and others, bioactive compounds and antiradical activity. Results show that jam made from melon had a comparatives physicochemical characteristic to other fruit jams and was highly hygienic with absence of microbiological contamination. wherease, the jam presents a low content of bioactive compounds, but it still remain an important source of antioxidants compounds with antioxidant potential in the diet.

... The content of vitamin C decreased with an increase in the extraction time and temperature. Reports are available on the degradation of ascorbic acid due to prolonged thermal (Njoku, Ayuk, & Okoye, 2011) and ultrasonic treatment (Santhirasegaram, Razali, & Somasundram, 2013). The degradation of vitamin C may be due to vitamin C oxidation during thermal pasteurization (Leskova et al., 2006). ...

The aim of this study was to compare methods for efficient extraction of green tea metabolites. Aqueous green tea leaf powder extracts were prepared by ultra-sonication extraction (UE), agitation extraction (AE), and the conventional extraction method (control) at different temperatures (60, 70, and 80 °C) and times (5-30 min). Compared to the control, both UE and AE techniques significantly increased the yields of polyphenols (three-fold), catechins (two-fold), and flavonoids (two-fold), and resulted in higher antioxidant activity. For both techniques, highest extraction efficiency of bioactive metabolites occurred at 80 °C for 20 min. Caffeine, total free amino acid, vitamin C, and total soluble solid contents were also significantly increased using either technique compared to the control. Thus, AE and UE have similar extraction efficiencies and could be used to prepare antioxidant-rich green tea extract or green tea extract powder.

... A noticeable decline in the ascorbic acid content of muskmelon RTS beverage during six months storage was also noticed by Teotia et al., (1997). Njoku et al., (2011) found significant decrease in ascorbic acid in different fruit juices (orange, lemon, lime and grapes) packaged in plastic bottles and stored at room temperature. ...

... Zinc increases the affinity of haemoglobin for oxygen, participates in taste perception and interacts with a number of hormones[33]. Vitamin C (ascorbic acid) contents of the extracted fruit juice were higher than the values for the manually squeezed grape juice at 28%[28]and grape juice extracted by juice squeezer at 45%[35]. The values were comparable with the study of[4]who reported grape fruit juice with vitamin C content of 54.1% using a screwtype extractor. ...

The juice of grape fruit (Citrus paradisi MacFad) when extracted contains various nutrients and antinutrients. The effect of different extraction methods (hand squeezing, use of blender and use of juice extractor) on these nutrients and antinutrients was investigated in this study. Hand squeezing produced juice with the highest moisture (91.23 ± 0.08%), ash (0.27 ± 0.01%) and protein (1.96 ± 0.02%) contents while the juice extractor had juice with highest carbohydrate content (6.92 ± 0.10%). The minerals were highest in the hand squeezed fruit juice. Calcium content was highest in the grape fruit juice samples and ranged from 2.35 ± 0.02%-2.38 ±0.02%. The vitamin C content was highest (54.31 ± 0.02%) in the juice extracted with the fruit juice extractor. Of all the antinutrients, flavonoids had the highest concentration and ranged from 2.17 ± 0.03 – 2.76 ± 0.03% while pectin had the lowest concentration of 0.002 ± 0.001 –0.006 ± 0.001% in the fruit juice samples. Consumption of grape fruit is advised due to the presence of essential nutrients that possess antioxidant, anti-inflammatory and anti-tumor activities. Extraction of the juice using juice extractor which produced minimal antinutrients and highest Vitamin C is therefore advised.

... Refractive index was recorded and expressed as percentages; measurements were performed at 20°C. Moisture content was determined as described by Lako et al. [7], total sugar and total ash were determined by the method of AFNOR [12], while vitamin C was determined by the methods described by Njoku et al. [13]. Density and conductivity are measured using a densimeter and conductimeter, respectively. ...

  • Benmeziane Farida Benmeziane Farida

Background: fruit juices are a ready and rich sources of vitamins, fiber and minerals for human consumption due to its uses as medecin, food and appetites. Juices are more convenient to consume, and have in general a longer shelf-life than fresh fruit. Objective: The present study was aimed to determine the physicochemical characteristic of some fruit juices including Commercial Grape Nectar (CGN), Fresh Grape Must (FGM) Tangerine Juice Pasteurized in Bath-water (TJPB) and in Micro-wave oven (TJPM) and to determine some bioactive compounds in grape juices. Results: obtained results show that all juices analyzed had relevant physicochemical composition; however, the quantity of analyzed compounds was different in each case. Conclusion: Given the obtained characterization, the beverages analyzed in this work can be considered as good sources of nutritive compounds that are indispensable to healthy feeding habits, thus, their consumption should be stimulated.

... The large volume of fruits and vegetables needed to meet the consumption needs and because they are highly perishable is an issue of great importance for ensuring the quality of the diet throughout the year. Preservation using high temperatures or exposure to oxygen lead to the loss of a significant portion of nutrients, especially vitamins, some of which are destroyed at temperatures above 40 degrees Celsius [8]. Dehydration is one of the oldest forms of conservation of fruits and vegetables and is used in order to reduce both the water content of the products, consequently reducing the activity of microorganisms and their multiplication, and mass and volume products, reducing in this way the costs of packaging, storage and transport [9]. ...

Dehydration is an energy intensive process, a very large portion of the energy used in all industrial processes being used by this process. Between 15 to 20% of the total industrial energy consumption worldwide is used for dehydration, therefore optimization of the design and selection of equipment, process control and rational logistics are important factors for improving this process, thus reducing pollution and increasing the economic throughput. In this we paper analyze a portion of the convective dehydration of apples in order to identify opportunities for process optimization through monitoring and control of essential parameters (temperature, relative humidity and air velocity), as well as providing some automatic control algorithms for the dehydration process.

... The literature on lemon production in Zambia is scanty probably due to little research that has been directed to the citrus fruit. Njoku, Ayuk, & Okoye (2011) found lemons to contain vitamin C, also known as ascorbic acid, only behind oranges and grapes but more than in lime fruits at varying storage temperatures. Vitamin C has antioxidant and therapeutic properties in many organisms. ...

A study was conducted to determine the amount of ascorbic acid in two Citrus limon varieties (Eureka and Lisbon) collected from three agro – ecological regions of Zambia. The ascorbic acid was determined by back titration method. Location and variety of lemon affected the moisture, crude fibre, crude protein, ash, carbohydrates and energy independently while crude protein level in the lemon fruit were influenced by both. Location did affect (P< 0.05) the amount of ascorbic acid in the lemon. However, the amount of vitamin C was not significantly different (P > 0.05) between the lemon varieties. Polynomial regression suggested a linear relationship (Y = 0.086X + 7.617, r = 0.5) between the weight of the Eureka lemon and vitamin C with a lot of variations. It is recommended that the possibilities of using lemons especially Lisbon variety as a source of vitamin C in fish feeds are explored.

... Figure 2 shows the effect of osmotic process conditions on vitamin C. The highest amount of vitamin C (63.43mg/100g) was at 40˚C osmotic solution temperature, 15%w/w of osmotic solution concentration and at 120 min osmotic process duration while the lowest amount of vitamin C (51.23mg/100g) was found to be at 60˚C osmotic solution temperature, 15% w/w osmotic solution concentration and 150 minutes osmotic solution temperature. This observation is in line with what was reported by [16] that exposure to temperature via cooking would not favour vitamin C. Also, [17] reported that there is tendency for vitamin C to degrade steadily during prolonged storage. The fairly high value of the control sample (59.88mg/100g) could mean that the process conditions were not harsh enough to cause a sharp drop in vitamin C. ...

... The values obtained by latter method estimated that ascorbic acid plus dehydroascorbic acid (DHAA) were higher than those found by titration method, which determined only ascorbic acid. The content of vitamin C in citrus fruits by oxidation and reduction method was carried in Nigeria and found that vitamin C concentration is more in orange juice as compared to grape, lemon and lime juice, respectively (Njoku et al., 2011). Another study in Nigeria is carried on quantitative estimation of ascorbic acid levels in matured ripe and unripe sweet oranges, lemons and grapefruits using redox titration involving oxidationreduction conversion of ascorbic acid. ...

  • Huma Tareen
  • Sana Ahmed Sana Ahmed
  • Fariha Mengal
  • Rukshana Taj

The objective of this study was to determine the vitamin C content in artificially prepared juices of orange, grapes, apple and mango juices of two different local companies i.e., Nestle and Shezan from Quetta city of Pakistan by titrimetric method. The method used in the present study was found to be cheap, accurate and could be easily practice in routine analysis. The obtained results of present study indicated that the concentration of vitamin C in Company A (Nestle) was recorded as i.e., 16.2, 9.26, 5.6, 4.8g/l for Orange, red grapes, apple and mango juices, respectively. While the content of vitamin C in company B (Shezan) was noted as7.4, 6.4, 5.04 and 4.06g/l for orange, red grapes, apple and mango juices, respectively. From the obtained results, it has been concluded that the content of Vitamin C was less variable among artificial juices prepared in two different companies selected in the present study. Moreover, it was also observed that the artificial preserved juices contain lesser amounts of vitamin C as compare to freshly prepared juices. Hence, the information provided in the presence study could be useful for the knowledge about the nutritional quality of commercially available packed fruit juices for human health.

... Among artificially ripened banana samples, the kerosene fume-treated ones contained the lowest concentration of vitamin C (175 ppm). According to the ripening chemistry, vitamin C decreases with the increase in temperature (Njoku et al., 2011). Thus, the heat evolved from the kerosene lamp could be a cause of temperature increase which ultimately led to the decrease in vitamin C content of fume-treated samples. ...

In recent years, the use of artificial fruit ripening agents has become prevalent mostly due to the commercial purposes. Different ripening agents are reported to be used to initiate the ripening process in fruits during off-seasons. However, the effects of these agents on the nutritional values of fruits are yet to be fully understood. The purpose of this study is to measure, analyze and compare the nutritional value of naturally and artificially ripened fruits. Bari-1 hybrid banana (Musa Spp.; local name: Sagor Kola) was chosen to carry out the experimental study. Ripe samples were collected directly from orchards or local markets. Additionally, unripe green samples were collected and artificially ripened in the laboratory using artificial ripening agents: ethephon, calcium carbide, ethylene glycol and fume from the kerosene stove. Different nutrition parameters, such as moisture content, total titratable acidity, vitamin C and sugar content were assessed for these banana samples. The assessed parameters of naturally and artificially ripened fruits were compared and analyzed to identify the change in nutritional values and determine the health hazards associated with them. The chemical compositions of artificial ripening agents were also investigated and possible health risks related to the impurities of ripening agents were assessed. Therefore, the key objective of this study is to address the changes in nutritional values and health risks associated with theartificial ripening which will be helpful for the consumers, nutritionists, physicians and other shareholders. Subjects: Food Additives & Ingredients; Food Analysis; Fruit & Vegetables; Nutrition; Food Laws & Regulations Keywords: Artificial fruit ripening; ethephon; kerosene fume; calcium carbide; ethylene glycol

... At the fourth week under the temperature of 28 o C, the fruit has been rotten, so the vitamin C content was not analysed. The vitamin C content of red guava which is storaged at the temperature of 16 o C is higher than the temperature of 28 o C. The declining of vitamin C content can be slowed down in cold temperature storage (Njoku et al. 2011). Fruit coating with various concentrations of chitosan causes the process of fruit"s rind surface covered, so the gas in-and-out is restrainted that the respiration rate declines. ...

  • ENDANG ANGGARWULAN

Anggarwulan E, Mudyantini W, Asiyah IJ. 2015. Chitosan treatment and storage temperature in the retardation of fruit ripening of red guava (Psidium guajava). Nusantara Bioscience 7: 153-159. Guava (Psidium guajava L.) is a thin-skinned tropical fruit which is easy to ripe and rot. The objective of the study is to determine the effect of chitosan coating and storage temperature in restraining the ripening of guava and also to the combination of treatments which could be longest to lengthen its storage period. This study uses Completely Randomized Design, with two factors. The first factor is chitosan concentration of 0, 1, 2, and 3%, while the second factor is the storage temperature in 16°C and 28°C with three repetitions during four weeks. The quality of Psidium guajava which is observed during the storage is weight-loss, water content, fruit texture, reducing sugar content, vitamin C content, pigment rind (chlorophyll and carotenoid), respiration rate, and ethylene content. The treatment of chitosan concentration and the storage temperature of 16oC are able to maintain the fruit hardness, vitamin C content, and chlorophyll content; meanwhile, it shows a decrease in weight-loss, reducing sugar, respiration rate, and ethylene content. The combination of chitosan treatment of 3% with a temperature of 16°C is able to maintain the quality and to lengthen the storage period of Psidium guajava up to four weeks.

... Fruits protect us from many diseases. Citrus fruits contain major quantity of ascorbic acid 1 , which is an essential nutrient 2 and structurally relates to glucose.It is a weak sugar acid 3,4 , found in many vegetables and fruits. Vitamin C helps to make collagen, absorbs iron 5 and neutralizes free radicals. ...

Among all vitamins, vitamin C plays a crucial role in maintaining good health. In the present study ten types of fruits are analyzed to compare ascorbic acid levels and the effect of boiling on its quantity is also determined by colorimetric method .It is concluded that its levels are gradually decreased with increase of boiling time. Cheaply and mostly available fruits have higher concentration of ascorbic acid than other fruits. In Psidium guajana, Citrus aurantium and Phyllanthus emblica the concentration of vitamin C is more. It is concluded that the concentration of ascorbic acid is more in semi-ripened stage of the fruit than ripened and unripened stages of Citrus limon, Citrus aurantifolia and Psidium guajana. But it is more in unripened fruits of Citrus medica and Citrus aurantium. In Psidium cattleianum sabine and Psidium littorale ascorbic acid concentration is more in fully ripened stage.

... Vitamin C levels in citrus fruis depends of many environmental factors like night temperatures during fruit growth (hot tropical regions have lower concentrations of ascorbic acid) [34] , environmental conditions that increase the acidity of the (Table ) contd..... fruits (fruits with higher acidity have higher vitamin C levels) [17], intensity of light during the growing season (fruits with more light exposure have greater vitamin C content) [35], and hydric stress (lower irrigation reduces vitamin C content of the fruit). ...

Citrus are a group of fruit species, quite heterogeneous in many aspects, including chemical composition of the fruit. Since ancient times, some citrus fruits were used to prevent and cure human diseases. In the recent decades, it has been demonstrated that fruits can actually help prevent and cure some diseases and above all, they are essential in a balanced diet. Citrus fruits, as one of the groups of fruit species, with greater importance in the world, have been studied for their effects on human health. Some species of citrus were referred as potential antioxidant based therapy for heart disease, cancer and inflammation. Fruit peels and seeds have also high antioxidant activity. The health benefits of citrus fruit have mainly been attributed to the high level of bioactive compounds, such as phenols (e.g., flavanone glycosides, hydroxycinnamic acids), carotenoids and vitamin C. These compounds are present in the fruit pulp and hence in the juice. But some bioactive compounds can be found in parts of the fruit which usually are not used for human food. The content of bioactive compounds depends on the species and cultivar, but also depends on the production system followed in the orchard. Citrus fruits, their derivatives and their by-products (peel, pulp and oil) are reach in different bioactive compounds and its maturity, postharvest and agroindustry processes influence their composition and concentration. The aim of this chapter was to review the main bioactive compounds of the different components of citrus and their relationship to health.

... Ascorbic acid (2-oxo-L-threo-hexono-1,4-lactone-2,3-endiol, AA) also known as Vitamin C is water-soluble vitamin which is very important because it participates in a great variety of biological events concerning electron transport reaction, hydroxylation, the oxidative catabolism of aromatic acid and so on [1,2]. It is needed by humans to prevent scurvy, a disease of the gums, bones and blood vessels and to increase the body's resistance to infection [3]. Ascorbic acid is a vital vitamin in the diet of humans and has been used for the prevention and treatment of the common cold, mental illness, infertility, cancer (because it has been identified as an in vivo radical scavenger) and AIDS. ...

Ascorbic acid (AA) is a water-soluble vitamin which shows no fluorescence. However, in reaction with iron(III), AA is oxidised to dehydroascorbic acid and iron(III) is reduced to iron(II) which forms a complex with 2,4,6-tripyridyl-S-triazine (TPTZ) in buffered medium. The relative fluorescence intensity of the resulting Fe(TPTZ)22+ complex can be measured at excitation and emission wavelengths of 393 and 790 nm, respectively. Based on this data, a new indirect spectrofluorimetric method for the determination of AA in pharmaceutical samples was proposed. Influence of the reaction conditions, such as acidity of acetic buffer, concentration of TPTZ and iron(III), reaction time and instrumental parameters were investigated in detail. The linear range was from 5.4 × 10−4 to 5.4 × 10−6 mol·L−1 (R = 0.9971). The LOD was 7.7 × 10−7 mol·L−1 and LOQ was 2.3 × 10−4 mol·L−1. Fourteen pharmaceutical samples containing various amounts of AA were analysed. Influences of potential interfering substances were also examined. Analysis of commercial pharmaceutical formulations showed good correlation with the nominal values given by the manufacturers and with the results obtained by a titration method. The proposed method can be applied in routine quality control in the pharmaceutical industry due to its sensitivity, simplicity, selectivity and low cost.

... A noticeable decline in the ascorbic acid content of muskmelon RTS beverage during six months storage was also noticed by Teotia et al., (1997). Njoku et al., (2011) found significant decrease in ascorbic acid in different fruit juices (orange, lemon, lime and grapes) packaged in plastic bottles and stored at room temperature. Similar results for physicochemical changes were earlier observed by Kumar and Manimegalai (2005) in whey-based papaya juice blended ready to serve beverage stored at refrigerated temperature for three months. ...

... Finally, the beverages presented a total degradation of vitamin C after 30 and 15 days for the HHP-treated drinks and after 45 and 60 days of storage for thermal treatment at 4 and 20 • C, respectively. Therefore, the storage temperature was identified as a critical factor affecting vitamin C breakdown, which is in agreement with previous authors [69,70]. In addition, another factor that may contribute to the loss of vitamin C is the mutual degradation between vitamin C and anthocyanins [71,72], as discussed below. ...

The effects of high hydrostatic pressure (HHP) compared to thermal pasteurization (TP) were studied in healthy citrus-maqui beverages. The impact of the processing technologies on the microbiological and phytochemical profile was assessed by applying two HHP treatments at 450 and 600 MPa for 180 s and TP at 85 °C for 15 s. The shelf life under refrigeration (4 °C) and room temperature (20 °C) was monitored for 90 days. All treatments ensured microbiological stability at both storage temperatures. Aside from that, the physicochemical parameters were not significantly different after processing or throughout the storage period. Regarding color parameters, an increase in the reddish coloration was observed during storage for those beverages treated by HHP. In general, phenolic compounds were little affected by the processing technique, even when treatment under HHP was more stable than by TP during storage. On the other hand, vitamin C showed great degradation after processing under any condition. It can be concluded that HHP is an effective alternative to thermal treatments, achieving effective microbial inactivation and extending the shelf life of the juices by contributing to a better preservation of color and bioactive compounds.

... Early harvest or mid harvest fruits of oranges, tangarines and grape fruit had higher ascorbic acid content than late season crop [28]. Losses in ascorbic acid may be due to its sensitivity to oxidation at high temperature [29]. Nagy [30] also reported that ascorbic acid concentration decrease upon fruit maturation and ripening. ...

... Ilic et al. (2015) stated that low light intensity decreases the content of soluble solids, ascorbic acid and pigments (carotenoids) in tomato fruits. Njoku et al. (2011) reported that temperature significantly affects the level of vitamin C in citrus fruits; according to the authors, areas with mild temperatures produce fruits with high ascorbic acid content. In fact, the pepper fruits produced in the field, where the diurnal temperature was lower than the protected environment (Table 1), presented the highest concentrations of vitamin C. Agostini-Costa et al. (2017) working with the Jalapeño pepper type (C. ...

Habanero pepper is known for the diversity of its morphological characteristics and its biochemical attributes. The growth of international demand for this type of pepper is an additional opportunity for Brazilian farmers and processing industries. In order to meet this demand, it is necessary to develop new cultivars with high fruit quality and adaptation to the Brazilian growing conditions. The objective of this study was to carry out a morpho-agronomic and biochemical characterization of new lines of Habanero pepper cultivated in different environments, and to investigate the genotype x environment interaction, aiming to provide subsidies for the registration process of the new cultivars, and their subsequent release. Three advanced endogamic lines and two commercial cultivars, as control, were grown in three different growing environments, two in open field and one in protected environment. The characterization of the lines was based on nine morpho-agronomic and nine biochemical descriptors and field-incidence of the five main virus diseases. The three new lines presented important and desirable characteristics such as high yield, adequate plant size (100.0–150.0 cm) and superior quality of fruits in protected environment (CNPH 15,744); open field cultivation potential with high yield (35.0 to 40.0 t ha⁻¹; CNPH 15,749 and CNPH 15,740); and superiority for fruit characteristics, lower total titratable acidity (15–22 %) and absence of Potato virus Y (CNPH 15,740). CNPH 15,740, CNPH 15,744 and CNPH 15,749 lines present the potential to be submitted to the cultivar registration process, mandatory in the Brazilian agricultural system, and released as new Habanero pepper cultivars developed in and adapted to Brazil, increasing the options for pepper value chain and for intermediate and final consumers. CNPH 15,744 presented unique sensory qualities for a C. chinense Habanero.

... Among strong antioxidants, vitamin C neutralises free radicals in the human organism. However, it is thermally labile and is easily lost during thermal processing (Njoku et al., 2011). Besides vitamin C, the total antioxidant activity of vegetables largely depends on phenol content (Oboh and Rocha, 2008), and beet processing impacts the phenol level in the final product (Ravichandran et al., 2012). ...

In order to popularise organically produced vegetables, two vegetable crops most commonly grown in organic systems in Serbia were studied. This research aimed at investigating differences in phytonutrient content between organically and conventionally produced beet and carrot, in fresh roots, juices pasteurised at different temperatures (70 and 90oC) and dried products. Multivariate analysis (principal component analysis) was used in order to determine the main components accounting for the highest variance, from both systems of production, according to the average content of phytonutrients in beet and carrot. The samples were divided into two clusters, one for carrot and one for beet, each containing two subgroups. The subclusters for beet were: I - BDO, BDC, BJ90C, and BJ90O - dried samples and juices pasteurised at 90oC, from both systems of production; and II - BFC, BFO, BJ70O and BJ70C - fresh beet and pasteurisation at low temperatures. The two sub-clusters for carrot were: I - CDO and CDC - dried samples; and II - pasteurised juices and fresh carrots from both systems of production. In this research, carrot was more stable for processing than beet, as determined for samples from the study area, from both systems of production and for the phytonutrients covered by this research.

... The first research on vitamin C (L-Ascorbic acid (L-3-keto-thero-hexuronic acid-γlactone, Formula 6.18, I)) dates back to 1928 when people were looking for treatment options for scurvy [2][3][4]; therefore, vitamin C is called ascorbic acid differently from the French name (Fr. ascorbine, abbrev. ...

Nowadays, thermal treatments are used for extending the shelf-life of vegetable and fruit products by inactivating microorganisms and enzymes. On the other hand, heat treatments often induce undesirable changes in the quality of the final product, e.g., losses of nutrients, color alterations, changes in flavor, and smell. Therefore, the food industry is opening up to new technologies that are less aggressive than thermal treatment to avoid the negative effects of thermal pasteurization. Non-thermal processing technologies have been developed during the last decades as an alternative to thermal food preservation. Processing changes the structure of fruit and vegetables, and hence the bioavailability of the nutrients contained in them. In this review, special attention has been devoted to the effects of modern technologies of fruit and vegetable processing, such as minimal processing (MPFV), high-pressure processing (HPP), high-pressure homogenization (HPH), ultrasounds (US), pulsed electric fields (PEF), on the stability and bioavailability of vitamin C.

... These effects have been associated to its content in bioactive compounds such as dietary fibers, polyphenols, micronutrients and vitamins, acids, mineral salts and essential oils, many of them having high antioxidant activity (Del Río et al., 2004;Gil-Izquierdo et al., 2004;González-Molina et al., 2010) with the property to reduce oxidative damage in the human body (Abeysinghe et al., 2007). Among other citrus fruits, lemon contains an appreciable amount of ascorbate (Njoku et al., 2011). Humans are unable to synthesize their own AsA supply as they lack a functional gulonolactone oxidase enzyme (Linster and Van Schaftingen, 2007) for the catalysis of the last step in the biosynthetic pathway. ...

Citrus limon (L.) Burm contains many important natural bioactive compounds, such as ascorbic acid, essential oils, and antioxidant substances. An experiment was carried out on four lemon cultivars (Ovale di Sorrento, Sfusato Amalfitano, Femminello Cerza and Femminello Adamo) from Southern Italy to study the changes in physico-chemical properties of juice during fruit ripening. Morphological characteristics of fruits, total soluble solids, pH and titratable acidity, ascorbic acid (AsA), and antioxidant activity (TEAC) of juice were tested. The concentrations of AsA in lemon juice showed significant differences among cultivars and ripening stages, with a steadily decrease along ripening stages: from 31.38 of stage I to 23.71 mg 100 g⁻¹ of stage IV. The juice AsA concentration correlated with the colorimetric parameters of peel: L (r = −0.643), a (r = −0.719) and b (r = −0.654). The cv Ovale di Sorrento showed the highest average AsA concentration (29.91 mg 100 g⁻¹). The level of the total TEAC showed a significant steadily decrease from the first to the fourth ripening stage that on average approached 38 %. Principal component analysis showed that lemon fruits at the ripening stages II and III were highly similar each other and well discriminated from the first and last ripening stages that also performed more distantly each other. The paper provides in-depth knowledge about the trend in AsA content and antioxidant activity of lemon juice across ripening.

... Carotenoid content (µg/mL) was then converted to mg/100 g leaf. Vitamin C content was determined using the iodine titration method (Njoku et al., 2011) with a slight modification. Twenty milliliters of tomato extract was added 25 mL of distilled water and 1 mL of 2% starch indicator solution. ...

  • Nguyen Hoang Loc Nguyen Hoang Loc

The study aimed to evaluate some agrobiological properties of ctb transgenic tomatoes under in vivo condition through physiological and biochemical characteristics relate to fruit yield and quality. Agrobiological parameters are determined by weighing, measuring and counting. Photosynthetic rate was determined via uptake carbon dioxide, the spectrophotometric method used to measure chlorophyll and total carotenoid content, vitamin C was determined using the iodine titration method, reducing sugar was determined by dinitrosalicylic acid, degree Brix was measured using an ATAGO N1 refractometer and total acidity in fruit juice was determined by neutralization method. Study results showed that final harvesting time for all tomatoes were 150 days including transgenic plants and control. Plant height (cm) ranged from 80.3 to 83.6, number of compound leaves from 17.6 to 22, and number of inflorescences from 7.3 to 9.3. The chlorophyll content (mg/g) and the photosynthetic rate (µM CO2/m2/s) peaked at young fruit stage in both transgenic plants and control with values from 0.48 to 0.62 and from 9.08 to 16.77, respectively. The yield, yield components and fruit shape of transgenic plants and control were also similar. Number of fruits ranged from 14.6 to 23, fruit weight (g) ranged from 61.5 to 69.3, and individual yield (kg) varied from 0.99 to 1.53. The main biochemical characteristics of transgenic plants and control were not different, dry matter (%) accounts for 5.45-5.91, reducing sugar (%) of 1.87-2.22, vitamin C (mg/100 g) of 44.01-46.13, acidity (%) of 0.62-0.89, Brix (%) of 5.23-6.01 and carotene (mg/100 g) of 3.01-3.84. In conclusion, six ctb transgenic tomato individuals were able to grow normally under in vivo conditions similar to non-transgenic control plants. Agrobiological properties between transgenic plants and control were insignificantly different with p>0.05.

... Carnitine is essential for transport and transfer of fatty acids into mitochondria, which serve as a source of energy. [4] Latest research show that vitamin C has an important role in the protection of an organism from oxidation stress, and acts as an antioxidant. However, ascorbate, chemical pharmacophore of vitamin C can react with radicals and oxidants in the organism, so it acts as a reduction agent and an antioxidant. ...

  • Tomislav Kraljević
  • Marijana Markovic Boras Marijana Markovic Boras

A reliable and sensitive indirect sequential injection method with spectrophotometric detection for the determination of ascorbic acid in various pharmaceutical preparations is proposed in this paper. The method is based on a redox reaction between ascorbic acid and permanganate in 0.1 mol L-1 sulphuric acid medium. The fading permanganate color as a result of the proposed reaction, was measured at 548 nm. The method involved the injection of 250 μL of ascorbic acid sample or standard, into the holding coil containing potassium permanganate as carrier solution. In the next step the injected volume of standard or sample is dispensed through the detector. This simple two step procedure enables high sample throughput of 240 h-1. The relative standard deviation was calculated to be 0.35 %. The obtained results by the proposed method were found to be in good agreement with the standard titrimetric method. The proposed method is simple and cost-effective and also can be an alternative to more sophisticated methods. The method is suitable for a quick and sensitive quantitative analysis of ascorbic acid in pharmaceutical preparations.

... Previous study reported that ascorbic acid concentration in broccoli stored at 1 C decreased progressively during storage (Serrano et al., 2006). In contrast, the ascorbic acid concentration in citrus fruits (lemon, orange and lime) was higher at 20 C than at 30 C (Njoku et al., 2011). These results indicated that the change in the ascorbic acid concentration in a plant is temperature dependent. ...

Physico-chemical and quality changes in 72 sugar apple (Annona squamosa Linn.) fruits subjected to pre-harvest drought stress were analyzed at harvest and during storage at 10 °C or 15 °C, with 90–95% relative humidity. At harvest, the ascorbic acid, sugar and endogenous abscisic acid concentrations increased while the concentration of the substrate indicating a 50% loss in 2,2-diphenyl-2-picrylhydrazyl scavenging activity (DPPH EC50) decreased in fruit from drought-treated trees compared with fruit from well-watered trees (control). The fresh weight loss of fruit stored at 15 °C was higher than at 10 °C, with no significant effect of drought treatment. In contrast, fruit firmness was reduced by drought treatment compared with the control during storage at both temperatures. Respiration, ethylene production and the endogenous abscisic acid and total sugar concentrations were higher in fruit from the drought-treated trees kept at 15 °C. The total ascorbic acid concentration was higher in fruit from drought-stressed trees kept at 10 °C compared with other treatments. This was concomitant with the DPPH EC50 value, which was lowest in fruit from drought-stressed trees stored at 10 °C. These results implied that pre-harvest drought stress treatment activated antioxidant activity and increased sugar concentration in sugar apple fruit. In addition, pre-harvest drought stress hastened fruit ripening. Thus, based on the results, storage of sugar apple fruit at 10 °C is recommended as this induces antioxidant activity which delays chilling injury for 8 d.

... . (Njoku et al., 2011) . (Shirpour et al., 2016) . ...

  • Mohammad Daneshi Mohammad Daneshi

Lime juice is used to add flavor to foods and to prepare soft drinks. Basically, fresh lime juice is stored at ambient, cold or freezing temperatures immediately after being packed. In this research, the effects of different storage temperatures on physicochemical properties (pH, acidity, total soluble solid, polyphenolic compounds, antioxidant activity, ascorbic acid, and color), microbial features (mold and yeast, total count) and sensory properties of lime juice during the storage period (45 days) were evaluated. The results showed significant changes in pH, acidity and brix of lime juice so that the pH of product decreased, but acidity and brix increased, as the storage temperature of lime juice increased. The range of these changes in the freezer was less than that in other types of storage temperatures. Antioxidant capacity and total phenolic content decreased slightly over time at different temperatures that were higher at ambient storage. The maximum reduction, from 52.66 mg/g in 1st day to 11.16 mg/g in 45th day, was recorded for ascorbic acid at ambient temperature. The storage temperature also had a significant effect on counts of mold, yeast and total bacteria in lime juice during 45 days of storage. The microbial count of lime juice increased as storage duration and temperature increased but it was higher in ambient and cold storage. The results of sensory evaluation indicated a significant decrease in taste, odor, color and overall acceptance of lime juice as duration of storage and temperature increased. These results suggested that freezing of lime juice could have positive effects on preservation method to prolong shelf life with minimum qualitative changes in lime juice.

... Factors that also affect the analysis of vitamin C by 2,6-dichloroindophenol titration method are varieties, temperature, light intensity, metal content, and ascorbate oxidase enzyme. The higher the temperature, the higher the intensity of light, the higher the metal content, and Copyright © 2018, ALCHEMY Jurnal Penelitian Kimia, ISSN 1412-4092, e ISSN 2443-4183 the higher the activity of the ascorbate oxidase enzyme in the analysis process the faster the vitamin C damage due to the rapid oxidation that interferes the determination of vitamin C levels (Lee and Kader, 2000;Njoku et al., 2011;Oyetade et al., 2012;Méndez and Arancibia, 2015;El Ishaq and Obirinakem, 2015). ...

  • Nerdy Nerdy Nerdy Nerdy

Vitamin C is needed by human body to improve the immune system and can be obtained from the bell pepper. Bell pepper has a different color according to the level of maturity, ranging from green, yellow, orange, and red. Differences in color also make possible differences in vitamin C content. The purpose of this study was to determine vitamin C levels in various colors of bell fruit. Measurement of vitamin C was done by titration method with metaphosphoric acid as the solvent and 2,6 dichloroindophenol as the standardized solution. The samples used were green bell pepper, yellow bell pepper, orange bell pepper, and red bell pepper taken from Gundaling, Berastagi, Karo, Sumatera Utara, 22152, Indonesia. The results show that vitamin C level in various colors of bell pepper respectively, for green bell pepper 16.52 mg vitamin C per 100 g green bell pepper; yellow bell pepper 159.61 vitamin C per 100 g yellow bell pepper; orange bell pepper 121.38 vitamin C per 100g orange bell pepper; red bell pepper 81.19 vitamin C per 100 g red bell pepper. These results indicate that different levels of bell pepper maturity have different vitamin C content.

... Pepper fruits like most vegetables are low in calories but high in vitamins especially in vitamin C. However, different levels of ascorbic acid could be detected, this may be due to varieties, post-harvest (processing and storage) ,maturity stage and growth conditions such as, soil, temperature and fertilizer (Lee and Kader, 2000;Njoku et al., 2011). It could be seen from table (2) that ascorbic acid content of pepper fruits ranged between 83.3 to 194.44 mg/g fw. ...

This study was conducted to investigate the phytochemical properties of different varieties of pepper fruits, to identify and quantify the phenolic profile of methanolic extracts of the aforementioned plants and to evaluate the antioxidant activity of the crude extracts of the plants under investigation in comparative study. Results revealed that ascorbic acid and total carotenoids contents of pepper fruits ranged between 83.30 to 194.44 (mg/g fw) and 12.19 to 75.72 (µg/g F.W), respectively. Balady green pepper extract contained the highest total polyphenols and total flavonoids contents as 52.65 (mg GAE/g) and 41.69 (mg QE/g), respectively. Hesperidin was the predominant flavonoid in red bell and Balady green peppers extracts with concentrations of 1513.13 and 1065.65 µg/g, respectively. While, pyrogallol was identified as the highest phenolic compound in yellow bell pepper extract as 2175.89 µg/g. This study also confirmed the highest antioxidant activity of Balady green pepper extract using total antioxidant capacity (TAC), DPPH radical scavenging and reducing power assays. This study recommends consumers using the balady green pepper as a rich and inexpensive source of natural antioxidants

... The higher concentration of ascorbic acid than that of anthocyanins is related to intensification of degradation of polyphenolic pigments [40][41][42][43]. Analysis of literature data and of the results obtained in the presented study indicates that, to retain their nutritive value, fruit juices should be stored at a temperature lower than room temperature [44][45][46][47]. ...

The objective of the study was to identify suitable additives stabilizing standard solutions of ascorbic acid (AA) that would not cause interference in the analytical process with the use of voltammetry in the determination of the AA content in food products. In addition, the effect of various conditions of storage of selected fruit juices and drinks on the concentration of vitamin C was studied. The study demonstrated that AA degradation was inhibited the most effectively by tartaric acid and its optimum concentration was set to 200 mg L ⁻¹ . Analysis of selected fruit juices stored in various temperature conditions confirmed that an elevation of temperature and extension of the time of storage caused a decrease in the content of vitamin C in the analyzed samples, while closing the packages caused a limitation of the changes in concentration of this vitamin. On the basis of literature data and of the results obtained in the present study it can be concluded that fruit juices should be stored at a temperature lower than room temperature to retain their nutritive value.

... It can be concluded that the higher the emulsion temperature will be increasingly unstable so that the amount of water is more and more separate [8]. Njoku [10] said that the increase in temperature generally reduces the concentration of vitamin C so as to decrease the acidity level. ...

  • Ranganathan Kapilan Ranganathan Kapilan

Mango fruit (Mangifera indica, L.) is considered as the king of the fruits in the South Asian countries where they are widely grown. If optimum time for harvesting is determined, then it would reduce the post harvest loss by a big margin. Karuthakolumbaan mangoes are very delicious, comparatively large and economically important for the local public. This work was aimed to determine the appropriate maturity indices for Karuthakolumbaan mango to reduce the post harvest loss due to improper harvesting time. Time after the full bloom stage, the colour of the skin, floating / sinking ability, total soluble solids (TTS), titratable acidity (TTA), moisture content, dry matter, TTS/TTA ratio of the fruits harvested at regular time interval were measured from the mango trees grown in Thirunelvely area, Jaffna. TSS, pH, dry matter content increased rapidly, whereas TTA and moisture content percentage decreased rapidly towards maturity. Fruits harvested up to 94 days from full bloom stage, showed significant differences in the values TSS, pH, dry matter content and moisture content than the fruits harvested after 94 days. Based on the testing panel, the fruits harvested after 95 days from full bloom stage were over-ripened with poor edible quality. This study recommends the appearance of dark yellow colour on either side of the green shoulder, as a non-destructive maturity index that appears on the 94 th day from full bloom stage for Karuthakolumbaan mango variety grown in an ideal tropical climate.

Fruits and vegetables play an important role in human nutrition providing vitamins, minerals, fibers and essential nutrients. In order to prolong the marketing of these products and ensure nutrients throughout the year, preservation by different methods of fruit and vegetables is necessary. Dehydration is one of the oldest forms of conservation of fruits and vegetables and is used in order to reduce both the water content of the product and thus the activity of microorganisms and their multiplication, and the mass and volume of products, the costs of packaging, storage and transport. This paper aims analyze a convective drying process of plums, in order to identify opportunities for the energy consumption optimization process through monitoring and controlling essential parameters like: temperature, relative humidity and air velocity, as well as automatic control algorithms of the dehydration process.

Vitamin C (L-ascorbic acid) has been known as an antioxidant for most people. However, its physiological role is much larger and encompasses very different processes ranging from facilitation of iron absorption through involvement in hormones and carnitine synthesis for important roles in epigenetic processes. Contrarily, high doses act as a pro-oxidant than an anti-oxidant. This may also be the reason why plasma levels are meticulously regulated on the level of absorption and excretion in the kidney. Interestingly, most cells contain vitamin C in millimolar concentrations, which is much higher than its plasma concentrations, and compared to other vitamins. The role of vitamin C is well demonstrated by miscellaneous symptoms of its absence—scurvy. The only clinically well-documented indication for vitamin C is scurvy. The effects of vitamin C administration on cancer, cardiovascular diseases, and infections are rather minor or even debatable in the general population. Vitamin C is relatively safe, but caution should be given to the administration of high doses, which can cause overt side effects in some susceptible patients (e.g., oxalate renal stones). Lastly, analytical methods for its determination with advantages and pitfalls are also discussed in this review.

  • Rose Mboya Rose Mboya

Blackjack (Bidens pilosa L.) grows naturally as a perennial herb across the world, especially in tropical regions, and it is used in many parts of the world for treating illnesses such as diarrhea, indigestion, wounds and respiratory infections. Blackjack's agricultural and pharmaceutical benefits have been well studied by scientists, following which several suggestions for using it as a source of supplements and alternative antibiotics have been made. Moreover, blackjack is edible, but very much underutilized for food purposes. In this article, the author reviews the advantages and disadvantages of blackjack, and argues for the deliberation of promoting its use for food.

Nutritional quality of fruits and vegetables depends on genetic and environmental factors. Soil factors, temperature, light and CO2 are the major factors which determine the quality of horticulture produce. Most of the health-benefiting nutrients including vitamins, minerals and antioxidants are supplied through fruits and vegetables. However, the changed climate has affected the quality of many fruits and vegetables. Elevated CO2 has improved the vitamin C, sugars, acids and carotenoids in oranges, tomatoes and strawberries. Positive effect of CO2 was also observed on total antioxidant capacity, phenols and anthocyanins in fruits and oil palm. However, elevated CO2 may decrease the protein and mineral content of the produce. High-temperature stress is known to decrease vitamin C, starch, sugars and many antioxidants especially anthocyanins and volatile flavour compounds in fruits. Deficit irrigation increases sugars, anthocyanins and even volatiles in strawberries and tomatoes. However, severe stress decreases the quality of fruits and vegetables. A higher temperature coupled with water stress is going to definitely reduce the fruit and vegetable quality in terms of vitamins, antioxidants and minerals.

  • Rose Mujila Mboya

Blackjack (bidens pilosa l.) grows naturally as a perennial herb across the world, especially in tropical regions, and it is used in many parts of the world for treating illnesses such as diarrhea, indigestion, wounds, and respiratory infections. Blackjack's agricultural and pharmaceutical benefits have been well studied by scientists, following which several suggestions for using it as a source of supplements and alternative antibiotics have been made. Moreover, blackjack is edible but very much underutilized for food purposes. In this article, the author reviews the advantages and disadvantages of blackjack and argues for the deliberation of promoting its use for food.

Fruit juices are amongst the most non-alcoholic beverages appreciated and consumed in Libya.These beverages contain minerals, nutrients, trace elements, vitamins and phytochemicals, which are essential for a healthy life. However, fruit juices may also contain high levels of metals, posing a health risk to humans, especially to children, since they consume more fruit juice per body weight unit, and have a less varied diet than adults. Thus, in order to guarantee food safety and to make sound nutritional considerations, fruit juices require careful investigation. he results shows that, the packed fruit juices contains 0.94-2.02 % ash, 13.1- 16.5% total dissolved solids, 9.2-16.25% total sugars, the lowest percentage value of citric acid was 0.15% in a Saudi SunTop juice sample and the highest value was 0.42% for Don Simon juice sample. Vitamin C content was 13.6 - 23.01 mg/100ml, it conforms to Libyan standards. The pH of all samples varied from 2.86 to 4.10 in all samples. The concentrations of Na, Fe, Cu, Zn, Cr, Pb, and Cd were determined by Microwave Plasma - Atomic Emission Spectroscopy (4100 MP-AES) and the results were (53.41 - 107.43), (0.07 -1.2), (0.01 - 0.08), (0.03 - 49.66), (0.02 - 0.17), (0.013 - 0.0510 and (0.00 - 0.02) mg/l, respectively in different types of fruit juices. Results obtained were compared with permissible levels set out by Libyan Standard Specifi-cations, and with similar studies performed in other countries.

Food can be a rich source of nutrients that are required for optimal health. Vitamin C is an antioxidant that protects cells and bodily fluids against oxidative stress. Cornelian cherry (Cornus mas L.) is widely recognized for its health benefits, taste and qualitative attributes. It is a source of biologically active compounds, including vitamin C. The determination of the vitamin C content of new ecotypes of cornelian cherry supported the identification of the most cost-efficient and accurate analytical method. The results of this study revealed that new ecotypes of cornelian cherry differed significantly with respect to their vitamin C content. Ecotypes 5, 10, 12 and 14 had the highest concentrations of vitamin C, which were determined at 201.61– 210.75 mg·100 g–1 by the titration (Tillmans) method and 70.90–82.30 mg·100 g–1 by the spectrophotometric method. Ecotype 6 had the lowest vitamin C content which ranged from 177.19 mg·100 g–1 (titration method) to 54.68 mg·100 g–1 (spectrophotometric method). The vitamin C content of cornelian cherry fruit, measured by HPLC, reached 63.1 mg·100 g–1 and it was 4-fold higher than in other analyzed fruits.

Limbah pulp merah kopi (Coffea sp.) mengandung kafein, senyawa fenolik dan antioksidan alami seperti antosianin, betakaroten, polifenol, dan vitamin C. Penelitian ini bertujuan untuk mempelajari pengaruh jenis jeruk, konsentrasi jeruk nipis (Citrus aurantifolia) dan lemon (Citrus limon) serta penambahan gula terhadap mutu minuman sari pulp kopi arabika (Coffea arabika L.). Rancangan Acak Kelompok (RAK) faktorial digunakan dalam penelitian ini. Faktor 1 jenis jeruk yaitu (J) yaitu J1 = jeruk nipis dan J2 = lemon. Faktor 2, konsentrasi sari jeruk (S) yaitu S1 = 20%, S2 = 30% dan S3 = 40%, serta faktor 3, konsentrasi gula (K) yaitu K1 = 20% dan K2 = 30% dari berat sari pulp kopi. Proses pengolahan dan pemanasan sari pulp kopi dengan penambahan jeruk nipis atau lemon menjadi minuman sari pulp kopi menyebabkan penurunan kandungan vitamin C dan pH. Perlakuan terbaik dalam pembuatan minuman sari pulp kopi yaitu menggunakan jeruk nipis dengan konsentrasi 20% dan gula 30% yang menghasilkan minuman sari pulp kopi dengan nilai sensori hedonik yang lebih baik, dan aktivitas antioksidan (DPPH) 74,9 %, vitamin C 17,6 mg/100g, gula reduksi 19,4 mg/ml, pH 3,40.

Performance of aonla (Emblica Officinalis Gaerten.) varieties was evaluated with respect to their flowering behaviour, yield and fruit quality at Central Horticultural Experiment Station (ICAR-IIHR), Bhubaneswar during 2011-14. Flower initiated in November and continued till February with the perceptibly long flowering duration (51- 85 days). December-January was considered as a critical period for bloom. Post-fertilization fruit dormancy was relatively short (45 days) and fruits took about six months to get matured. Aonla genotypes showed low alternate bearing index (ABI) by exhibiting minimal temporal variation in yield. NA 7 exhibited maximum flowering intensity (82.5%), number of productive branchlets (80.93) and pistillate flowers/branchlet (6.15). It was the most promising variety in eastern tropics due to high yield (42.34 kg/tree), yield efficiency (0.86 kg/m3) and crop density (6.37 fruits/ cm2), whereas, Krishna was found to the second most productive variety in the region. It was observed that fruit yield was not significantly related with flowering intensity, number of productive branchlets and sex ratio. NA 7 had maximum TSS (10.38 °B), whereas NA-10 had maximum vitamin C content (365.67 mg/100g). In comparison to subtropical regions, aonla genotypes had low TSS and vitamin C content.

Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage.

  • M Antonia Murcia
  • Beatriz López-Ayerra
  • Maria José Martínez-Tomé Maria José Martínez-Tomé
  • Francisco García-Carmona

The ascorbic acid content and peroxidase activity of raw, canned and frozen (after blanching times of 60, 90, 120 and 150 s) broccoli florets and stems were determined. The ascorbic acid content represented 1.12 and 0.78 g kg−1 fresh weight in raw florets and stems respectively. After blanching (for different times) and freezing, the ascorbic acid content decreased to values of 0.55–0.56 g kg−1 fresh weight in florets and 0.35–0.36 g kg−1 fresh weight in stems. The industrial processing involved in canning decreased the ascorbic acid content to 0.18 g kg−1 fresh weight in florets. The peroxidase activity observed in the florets and stems of raw broccoli was 308.8 and 278.6 µmol min−1 per 100 g fresh weight respectively. The peroxidase activity remaining in frozen florets varied from 0.9 to 0.2%, while that in stems showed values of between 7.5 and 8.4%. These values for stems were within the range recommended for residual activity after blanching and freezing. The peroxidase activity of canned broccoli florets was practically undetectable.© 2000 Society of Chemical Industry

  • Morris Goodman
  • Calvin A. Porter Calvin A. Porter
  • John Czelusniak
  • Colin P. Groves

A highly resolved primate cladogram based on DNA evidence is congruent with extant and fossil osteological evidence. A provisional primate classification based on this cladogram and the time scale provided by fossils and the model of local molecular clocks has all named taxa represent clades and assigns the same taxonomic rank to those clades of roughly equivalent age. Order Primates divides into Strepsirhini and Haplorhini. Strepsirhines divide into Lemuriformes and Loriformes, whereas haplorhines divide into Tarsiiformes and Anthropoidea. Within Anthropoidea when equivalent ranks are used for divisions within Platyrrhini and Catarrhini, Homininae divides into Hylobatini (common and siamang gibbon) and Hominini, and the latter divides into Pongina forPongo(orangutans) and Hominina forGorillaandHomo. Homoitself divides into the subgeneraH.(Homo) for humans andH.(Pan) for chimpanzees and bonobos. The differences between this provisional age related phylogenetic classification and current primate taxonomies are discussed.

  • C J Schorah
  • C Downing
  • A Piripitsi
  • A Bodenham

Plasma concentrations of the antioxidant vitamin ascorbic acid were measured by high-performance liquid chromatography in critically ill patients in whom the excessive generation of reactive oxygen species could compromise antioxidant defense mechanisms. Median concentrations of both total vitamin C (ascorbic acid and dehydroascorbic acid) and ascorbic acid in these patients were < 25% (P < 0.001) of the values found in healthy control subjects and in subjects in two other disease groups (diabetes, gastritis) in which reactive oxygen species are reported to be increased. The low values could not be explained by age, sex, intake, or treatment differences, but were associated with the severity of the illness and were not prevented by the use of parenteral nutrition containing ascorbic acid. In addition, the vitamin was less stable in blood samples taken from critically ill patients than in similar samples from subjects in the other groups. The findings indicate that antioxidant defenses could be considerably compromised in these very sick patients. If this reduces the patient's capacity to scavenge reactive species, then the potential of these species to damage DNA and lipid membranes could be increased and compromise recovery.

Review: Nutritional comparison of fresh and frozen fruits

  • J C Rickman
  • D M Barret
  • C M Bruhn

Rickman, J.C., D.M. Barret and C.M. Bruhn, 2007. Review: Nutritional comparison of fresh and frozen fruits. J. Sci. Food. Agric., 87: 930-944.

Oxidation and reduction method of determining Vitamin C in fruits juice

  • Helmenstine

Helmenstine, 2008. Oxidation and reduction method of determining Vitamin C in fruits juice, 5: 25-29.

Industrial processing of broccoli in fruits

  • M A Murcia
  • B L A Opez-Ayerra
  • M Martinez-Toma
  • A M Vera

Murcia, M.A., B.L.A. Opez-Ayerra, M. Martinez-TomA and A.M. Vera, 2000. Industrial processing of broccoli in fruits. Sci. Food Agric., 80: 1882-1886.

Vitamin C contents of citrus fruits and their product: A review

  • S Naggy

Naggy, S., 1980. Vitamin C contents of citrus fruits and their product: A review. J. Agric. Food Chem., 15: 632-640.