scholarly journals Efecto de la radiación gamma sobre la vitamina C

2019 ◽  
pp. 26-29

Efecto de la radiación gamma sobre la vitamina C Effect of gamma radiation on vitamin C Johnny Vargas R. Instituto Peruano de Energía Nuclear. Av. Canadá 1470 Lima 41 DOI: https://doi.org/10.33017/RevECIPeru2011.0005/ RESUMEN Uno de los compuestos orgánicos más sensibles a la temperatura, almacenamiento y radiaciones es el ácido ascórbico. En una planta de irradiación para el tratamiento cuarentenario, se procesarán frutas y hortalizas frescas; vegetales portadores de vitamina C. Se irradió a una determinada concentración la vitamina C (42,24 mg/100 ml) contenida en 3 diferentes sustratos: en jugo de naranja, en solución de agua y acido ascórbico puro en cristales, diluida posteriormente en agua; se aplicaron diferentes dosis de radiación gamma (0; 0,1; 1,0; y 10 kGy), la tasas de dosis fue 7,433 Gy/min. Los resultados mostraron que los mayores porcentajes de destrucción vitamina C irradiada a las dosis respectivas se presentaron en la solución de vitamina C contenida en agua,(15,62; 64,11 y 84,38 %) debido al efecto indirecto de la radiación gamma, luego en la vitamina C contenida en el jugo de naranja,(5,25; 7,33 y 50,50 %) esto es debido a que los otros constituyentes del jugo de naranja, tienen un efecto protector en la vitamina C contra las radiaciones, la vitamina C en cristales fue la que presentó los menores porcentajes de destrucción (3,13; 4,60 y 6,74%). Las diferentes muestras presentaron un contenido inicial de 42,24 mg de vitamina C por 100 ml del sustrato seleccionado. A la dosis de 0,1 kGy el porcentaje de destrucción en la solución de agua fue de 15,62 % mientras en el jugo de naranja y en cristales fue de 5,25 % y 3,13 % respectivamente; a la dosis de 1 kGy presentaron los siguientes porcentajes de destrucción solución 64,11; jugo 7,33 y cristales 4,60% respectivamente y a la dosis de 10 kGy la destrucción de la vitamina C en solución fue de 84,38; en jugo de naranja 50,50 % y en cristales 6, 79% demostrándose que el tipo de sustrato y la dosis juega un papel importante en los efectos de la radiación sobre la vitamina C. En una planta de irradiación para el tratamiento cuarentenario de frutas y hortalizas frescas se aplicaran dosis alrededor de 0,1 kGy, por lo que las pérdidas en vitamina C serán mínimas. Descriptores: Irradiación, Vitamina C, dosis, tratamiento cuarentenario. ABSTRACT One of the organic compounds more sensitive to temperature, storage and radiation is ascorbic acid. In an irradiation plant quarantine treatment, be processed fruits and vegetables, vegetable carriers of vitamin C. Was irradiated at a given concentration of vitamin C (42.24 mg/100 ml) contained in 3 different media: orange juice in water solution and pure ascorbic acid crystals, then diluted in water, we applied different doses of radiation Gamma (0, 0.1, 1.0, and 10 kGy), the dose rate was 7.433 GY / min.The results showed that higher percentages of vitamin C destruction irradiated to the respective doses were presented in the solution of vitamin C contained in water, (15.62, 64.11 and 84.38%) due to the indirect effect of gamma radiation , then vitamin C contained in orange juice, (5.25, 7.33 and 50.50%) This is because the other constituents of orange juice, have a protective effect of vitamin C against radiation, vitamin C crystals, was the one with the lowest percentages of Destruction (3.13, 4.60 and 6.74%). The different samples showed an initial content of 42.24 mg of vitamin C per 100 ml of the selected substrate. A dose of 0.1 kGy the percentage of destruction in the water solution was 15.62% while in the orange juice and glasses was 5.25% and 3.13% respectively, at a dose of 1 kGy showed the following percentages of destruction solution 64.11; juice crystals and 7.33 respectively 4.60% and the dose of 10 kGy the destruction of vitamin C in solution was 84.38, in orange juice 50.50 % and in crystals 6, 79% demonstrated that the type of substrate and the dose plays an important role in the effects of radiation on vitamin C. In an irradiation facility for quarantine treatment of fruits and vegetables are applied about 0.1 kGy dose, so the vitamin C losses will be minimal. Keywords: Irradiation, Vitamin C, dose, quarantine treatment.

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 55
Author(s):  
Alina Soceanu ◽  
Nicoleta Matei ◽  
Simona Dobrinas ◽  
Viorica Popescu

Vitamin C or ascorbic acid is a basic nutrient, a highly effective antioxidant, widely used as food additive. Therefore, quality control in food industry demands ascorbic acid determination methods. The purpose of this study was to determine vitamin C in natural orange juices by spectrometric and voltammetric methods. Another goal was to determine the kinetic and thermodynamics activation parameters for ascorbic acid degradation in orange juices over time and at different temperatures. It was observed that during storage, ascorbic acid concentrations in orange juices were gradually decreased with time at a rate depending on storage temperature and type of orange juice. The reaction order was determined through integrated graphical analysis where the dependences of ln ct/c0 as a function of time reveals the high values for R2, indicating that the kinetics of the degradation of AA follows first order reaction at both studied temperatures. For studied samples the loss of ascorbic acid was varied between 4.33% and 9.13%. Enthalpy variation (ΔH) and entropy variation (ΔS) of activation process were obtained from the Eyring–Polany model based on transition state theory. The values of activation energy ranged between 7289.24 kJmol−1 and 15689.54 kJmol−1.


2006 ◽  
pp. 80-84
Author(s):  
Zsuzsanna Veres ◽  
Miklós Gábor Fári

There is a lot of evidence that the pepper is one of the most important sources of vitamin C. Albert Szent-Györgyi was the first to extract ascorbic acid from a red bell pepper in the 1930s. Previously people had eaten vitamin C on the long voyage to protect against scurvy. Vitamin C is an important antioxidant, and it is a cell protector today. Vitamin C protects the cardiovascular system against infection. This vitamin decrease blood-pressure, a raises the HDL cholesterol level (good), and inhibits gout.„Antioxidant density” is a biological value indicator obtained in synthetic way. „Antioxidant density” indicates the antioxidant capacity of a particular food, e. g. fruits and vegetables, related to 1 Calorie. In our study, we measured the total antioxidant capacity, vitamin C content and „antioxidant density” of Hungarian paprika varieties.


2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Ana Carolina Loro ◽  
Victor Wilson Botteon ◽  
Marta Helena Fillet Spoto

Abstract Ionizing radiation can be used for different purposes in the food industry. In this study, the effect of irradiation doses (0, 0.5, 1.0 and 1.5 kGy) on the quality parameters of long life tomatoes (Lycopersicon esculentum Mill.), was evaluated during 4 storage periods (1, 7, 14 and 21 days). The different treatments were evaluated by analysing for colour, pH, total soluble solids (TSS), total titratable acidity (TTA), ratio (TSS/TTA), hardness, total lycopene and ascorbic acid contents, weight loss and maturation stage (O2 /CO2 ratio) for all the storage periods. The tomato samples were irradiated in a Co60 irradiator and maintained at 22 °C ± 1 °C. The quality of the tomato fruits was influenced by the gamma radiation basically by making the fruits softer and not degrading the ascorbic acid and lycopene contents at the doses evaluated. The irradiation process used in the doses evaluated was promising with respect to maintaining the quality parameters of long life tomatoes.


Author(s):  
Tariza Humaira Tembusai ◽  
Annisa Tri Banoeari ◽  
Riris Mandaoni Siahaan

This study aims to find out whether or not there is a content of vitamin C in tomatoes, cucumbers, chayote, spinach, lime and bilimbi by reacting with betadine containing povidone iodine 10% w/v, which is equivalent to 1% iodine. If iodine reacts with vitamin C, then the color of iodine will disappear. Each extract of fruits and vegetables is added to a glass containing aqua that has been added 25 drops of betadine with a solution color that is reddish brown. Obtained discoloration from each addition of fruit and vegetable extract: a) Cucumbers change color to solid bright yellow, b) Tomatoes change color to clear bright yellow, c) Chayote change color to white, d) Spinach changes color to dark green, e) Lime changes color to brownish orange and f) Bilimbi changes color to orange. The discoloration that occurs indicates that tomatoes, cucumbers, chayote, spinach, lime and bilimbi contain vitamin C.


Author(s):  
Hoda Ashari ◽  
Naficeh Sadeghi ◽  
Mohammad Reza Oveisi ◽  
Mannan Hajimahmoodi

This study was designed to measure and compare the total phenols, flavonoids and vitamin C contents in four orange juice brands which are commercially available in Iran. Total phenols, flavonoids and ascorbic acid content of 100 samples from four different commercial brands were evaluated by the spectrometric method. The concentration of total phenol in commercial orange juice samples was between 28.39 and 114.20 mg gallic acid equivalent per liter (mg GAE/L). The measured range of total flavonoids was from 12.53 to 32.62 mg quercetin equivalent per liter (mg QE/L) and the content of ascorbic acid in the samples was between 29.95 and 93.08 mg/L. The results showed a significant difference between the four brand`s total phenols, flavonoids and vitamin C level (P< 0.05). According to the found variation among different studied brands, setting a determined amount for the measured parameters is suggested.


2020 ◽  
Author(s):  
Raghu Krishna Moorthy

Fruits and vegetables have long been considered as good sources of Vitamin C. But there is considerable decay in their Vitamin C content with time in proportion to the temperature they are stored at, which largely reduces their nutritional value. The objective of this study was to determine the effect of temperature on the decay of vitamin C content with passage of time. The samples considered for this study were orange juice, tomato juice and grapes juice. The content of vitamin C in these samples was determined by titration method with iodine solution. These samples were tested for vitamin C content individually in three temperature environments (hot, cold and room temperature). The results show that, initially, the vitamin C content was highest for tomato juice at 87.96 mg/100 ml and lowest for grape juice at 69.975 mg/100 ml with the intermediate being orange juice at 76.47 mg/100 ml. Finally, after four days of storage in certain temperature environments such as hot, cold and room temperature, the highest vitamin C content retained was found in orange juice at 49.48 mg/100 ml, 62.979 mg/100 ml and 62.97 mg/100 ml respectively. Therefore, from the evaluation of average percentage of decay of vitamin C per day for the individual samples, it has been found out that the hot environment provides the conditions for fast decay of vitamin C content and cold environment provides the conditions for slow decay of vitamin C content.. This analysis verifies the fact that vitamin C is an easily oxidizable and unstable compound at higher temperature conditions.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Lydia A Adepoju ◽  
Zinash D Osunde ◽  
Kehinde J Falua

A common way of maintaining essential nutrients in fruits and vegetables is through novel food processing techniques such as pretreatment. This study investigated the influence of pretreatment methods on the proximate composition, vitamin C and β-carotene contents of oven dried pawpaw. Fresh, ripe pawpaw fruit were peeled, sliced and pretreated with three pretreatments – ascorbic acid dip (0.45% w/v), honey dip (0.25% v/v) and steam blanching (100 °C). The fruit slices were soaked in ascorbic acid and honey solutions for 4 min while steam blanching was done for 2 min. Untreated pawpaw sample served as the control. The treated and control samples were dried at an average temperature of 65 °C. Results showed that vitamin C of dried pawpaw samples pretreated with honey dip had the highest retention of vitamin C (116.05 mg/100g) compared to ascorbic acid treated (98.90 mg/100g), steam blanched (109.02 mg/100g), and control samples (77.02 mg/100g). In terms of β-carotene, pawpaw sample treated with ascorbic acid solution had the highest value of 12.68 mg/100g. The use of honey and ascorbic acid solutions as treatments prior to drying can improve the retention of nutrients such as vitamin C and β-carotene in dried fruits.Keywords—Pretreatments, proximate properties, vitamin C, β-carotene


10.5219/1347 ◽  
2020 ◽  
Vol 14 ◽  
pp. 1124-1130
Author(s):  
Monika Sabolová ◽  
Lenka Kouřimská

Fruits and vegetables are the best food sources of vitamin C. However, fruits and vegetables can be also sources of potentially harmful substances to the human body, nitrates being one of these. The aim of this study was to compare vitamin C and nitrates contents in selected fruits and vegetables from supermarkets and local farmers' markets. Samples of plums, strawberries, apples, spinach, red peppers and tomatoes were chosen for analysis. Content of vitamin C and nitrates was analyzed by HPLC/DAD. The hypothesis was that local market fruits and vegetables contain more vitamin C and fewer nitrates than samples bought in supermarkets. Laboratory analyses showed that there were differences in vitamin C in the case of strawberries, tomatoes and red peppers. The highest level of ascorbic acid was in red pepper samples (141 mg.100g-1). In the case of fruit, the highest content was in strawberries (70 mg.100g-1). As far as nitrates content is concerned, in three cases out of six, the fruit and vegetables we tested from farmers' markets contained lower concentrations of nitrates than those purchased at supermarkets and the hypothesis was accepted in these cases. There was no significant difference between the nitrate content of the local market and supermarket strawberries and red peppers. Tomatoes had significantly higher nitrate content when purchased at farmers' markets than at supermarkets. Leafy vegetables are considered to be the major source of nitrates, and this was confirmed by this study. The highest content of nitrates was in the spinach sample (2969 mg.kg-1). Among all fruit samples, strawberries had the highest nitrates levels (maximum 131 mg.kg-1). The results of this work showed that the content of ascorbic acid and nitrates differs significantly depending on the type of fruit or vegetables.


1940 ◽  
Vol 40 (6) ◽  
pp. 699-732 ◽  
Author(s):  
Gweneth Chappell

Values for the ascorbic acid content of a number of foods sold in diverse markets were determined by titration against 2: 6 dichlorophenolindophenol in acid solution. The results showed that the least expensive material was not necessarily the poorest source of vitamin C and might be more valuable than expensive foods. Samples of cabbage from the cheap market contained 329% as much vitamin C as samples from expensive sources. These results on comparison with figures recorded for fresh garden produce showed that market foods have lost some of their vitamin C content on exposure for sale, but still contain satisfactory amounts of ascorbic acid when purchased.Results from different samples of fruits and vegetables showed wide variation. No data relating to storage before purchase were available, so limiting figures were used for each food. Mean values were calculated for purposes of comparative tabulation.The effect of household storage after purchase was noted for foods from inexpensive and fashionable markets. The values obtained showed that the loss of ascorbic acid in foods stored in the home after a period of exposure for sale, though marked, was not as serious as has previously been indicated.An irregular fall in the ascorbic acid content of some of the material examined was noted and investigated. Wide variations in the amount of ascorbic acid present in different parts of individual fruits and vegetables were observed. In view of experimental results it is recommended that foods be purchased and prepared for consumption immediately before use.Canned foods from diverse markets were examined to determine their ascorbic acid content, and it was shown that the vitamin is distributed throughout solid and liquid. Although a percentage of vitamin is destroyed on heating, those fruits and vegetables initially high in ascorbic acid retained sufficient vitamin to afford a better, and frequently cheaper, source of vitamin than unheated samples with a low ascorbic acid content. Considerable quantities of vitamin C are lost when the liquid from canned vegetables is discarded. When the syrup from cans is used as well as the fruit the vitamin available to the consumer is frequently greater than the amount yielded by the same weight of raw fruit from market sources.Raw and canned plant tissues from cheap and expensive sources were compared for their antiscorbutic value in the human diet, and for the cost of the daily requirement at ruling market prices. It was found that a day's ration of ascorbic acid could be purchased at a cost as low as a farthing to as high as a pound.


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