Ascorbic Acid Content (ascorbic + acid_content)

Distribution by Scientific Domains


Selected Abstracts


THE COMPOSITION OF TWO SPANISH PEPPER VARIETIES (FRESNO DE LA VEGA AND BENAVENTE-LOS VALLES) IN DIFFERENT RIPENING STAGES

JOURNAL OF FOOD QUALITY, Issue 6 2008
ANA BERNARDO
ABSTRACT The chemical composition of two traditional varieties of Spanish peppers, "Fresno de la Vega" and "Benavente-Los Valles" harvested in the provinces of Len and Zamora, respectively, at different ripening stages (green mature, breaker and red) were evaluated. Herein we report the global composition, mineral and trace element contents, and the most relevant physicochemical parameters of each variety of pepper collected in 2 consecutive years. Both pepper varieties showed a similar chemical composition, except in vitamin C content, which resulted to be about 70% higher in Fresno de la Vega peppers. Red ripe fruits were high in total carbohydrates, fructose, glucose, sucrose, fat (64.5, 29.14, 25.57, 2.94, 1.79/100 g dry weight, respectively) and total soluble solids (6.83Brix). Ascorbic acid content also increased progressively during ripening, reaching a mean value of 1.81 mg/100 g dry weight for Fresno de la Vega peppers. Potassium was the most abundant of the analyzed elements in the all samples, followed by phosphorus, magnesium, calcium and sodium. The order of the levels of the trace elements was iron > manganese > zinc > copper. PRACTICAL APPLICATIONS This report underscores the potential value of two traditional varieties of Spanish peppers and provides information on their composition during ripening to decide the proper harvesting time, which can be useful in the food industry. [source]


Inactivation of Escherichia coli and Shigella in acidic fruit and vegetable juices by peroxidase systems

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2006
I. Van Opstal
Abstract Aims:, To study the bactericidal properties of the lactoperoxidase (LPER)-thiocyanate and soybean peroxidase (SBP)-thiocyanate systems at low pH, their efficiency for inactivation of Escherichia coli and Shigella in acidic fruit and vegetable juices, their effect on colour stability of the juices and interaction with ascorbic acid. Methods and Results:, Three-strain cocktails of E. coli and Shigella spp. in selected juices were supplemented with the LPER or SBP system. Within 24 h at 20C, the LPER system inactivated both cocktails by ,5 log10 units in apple, 2,5 log10 units in orange and ,1 log10 unit in tomato juices. In the presence of SBP, browning was significant in apple juice and white grape juice, slight in pink grape juice and absent in orange or tomato juice. Ascorbic acid protected E. coli and Shigella against inactivation by the LPER system, and peroxidase systems significantly reduced the ascorbic acid content of juices. Conclusions:, Our results suggest a different specificity of LPER and SBP for SCN,, phenolic substrates of browning and ascorbic acid in acidic juices. The LPER system appeared a more appropriate candidate than the SBP system for biopreservation of juices. Significance and Impact of the Study:, This work may open perspectives towards the development of LPER or other peroxidases as biopreservatives in acidic foods. [source]


OPTIMIZING ELECTRON BEAM IRRADIATION OF "TOMMY ATKINS" MANGOES (MANGIFERA INDICA L.)

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2007
MARIA A. MORENO
ABSTRACT We determined the optimum irradiation treatment for decontamination of physiologically mature fresh "Tommy Atkins" mangoes, without detriment to the fruits' sensory and chemical properties. Mangoes were irradiated at 1.0, 1.5 and 3.1 kGy using a 10-MeV linear accelerator (14-kW LINAC, double beam mode). Mangoes were stored for 21 days at 12C and 62.7% relative humidity with nonirradiated fruits as controls. Dose distribution within the fruit was determined using Monte Carlo techniques. Irradiation did not affect the overall sensory quality of mangoes at doses up to 1.5 kGy. Only fruits irradiated at 3.1 kGy were unacceptable by the panelists. Irradiation at 3.1 kGy enhanced the fruit's aroma characteristics. Irradiation at all levels caused a significant (P , 0.05) decrease (,50,70%) in ascorbic acid content by the end of storage. Mangoes irradiated at 1.5 and 3.1 kGy had slightly higher levels of phenolics than the control (27.4 and 18.3%, respectively). E-beam irradiation of Tommy Atkins mangoes up to 3.0 kGy causes no detriment to the fruit's overall sensory and chemical quality. [source]


PEELING AND THE PHYSICAL AND CHEMICAL PROPERTIES OF KIWI FRUIT

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2003
METIN GULDAS
Hand peeling of kiwi fruit has some disadvantages such as difficulty during peeling, increase of loss in weight and nutritional value. Peeling of kiwi fruits with alkali (NaOH) was investigated. Some chemical (acidity, pectin, and chlorophyll) and physical properties (Hunter color value and weight loss) of the fruits were determined after selected alkali peeling methods were used. Peeling methods at 80, 90 or 100C temperatures; in 13, 18 or 23% of NaOH solutions and for 3, 4 or 5 min durations were tested and compared with hand peeling. Weight (fruit tissue) loss in hand peeling was higher than alkali peeling. Peeling with alkali was easier. Nutritional value (ascorbic acid content) of alkali peeled fruits was higher than hand peeled kiwi fruit. Because of less weight loss, better green color and high pectin content the method including 15% of NaOH solution at 95C for 4 min was selected as most advantageous peeling method. [source]


RING CHARACTERIZATION OF QUALITY INDICES IN BUTTERHEAD LETTUCE CULTIVATED UNDER MULCH AND BARE SOIL

JOURNAL OF FOOD QUALITY, Issue 4 2010
MARA G. GOI
ABSTRACT Butterhead lettuce was characterized by physical, microbiological and nutritional quality indices as a function of plant zoning and soil management (bare soil and mulch). Quality indices were measured in all the rings from the external toward the internal ratio. Assayed indices were: relative water content, water content, free and bound water, and the ratio between free water and total water, leaf area and color, total microbial counts (TMC) and ascorbic acid content (AA). The lettuce characterization by rings showed a remarkable plant zoning as a function of leaf age and development; also, some initial indices were affected by the soil management employed. Plastic mulches affect the microclimate around the plant, resulting in better plant water status. However, the use of black plastic covers could absorb sunlight therefore increasing soil temperature and causing lower AA and higher TMC in lettuce tissue. PRACTICAL APPLICATIONS During lettuce development, each leaf had a different level of exposure to environmental conditions, such as light, humidity, nutrients absorption and temperature affecting the quality indices of the raw material and introducing a source of variability in the physico-chemical, biochemical, nutritional and microbiological indices within the plant. In this way, the location of the leaf within the whole plant is an important factor to be considered. Moreover, during lettuce heads trading, it is a common practice to remove the external leaves as storage advances. These leaves are more perishable than middle and internal ones because of their direct exposure to environmental conditions. Understanding the way in which physical, microbiological and nutritional indices were distributed in the whole lettuce plant could be of interest, to know the value of the losses of regular green grocers' practices, from a nutritional and a safety point of view. [source]


QUALITY OF FRESH-CUT TOMATOES

JOURNAL OF FOOD QUALITY, Issue 3 2004
ABDUL HAKIM
ABSTRACT Tomato fruit at pink or light-red stages of ripening were cut into slices, rinsed with water containing 50 ,L.L,1 sodium hypochlorite and drained. They were stored in perforated polyethylene package at 1C in air or controlled atmosphere for five and ten days. Weight loss, chlorophyll and lycopene contents, seed discoloration, fungal infection, total soluble solids content, titratable acidity, sugar/acid ratio, pH, flavor and taste, firmness, ascorbic acid content, rate of respiration and ethylene production, and electrolyte leakage were evaluated after each storage period. The overall quality of controlled atmosphere-stored slices was better than that of air stored slices. Slices from light-red fruit had lower weight loss, minimum seed discoloration, lower [source]


RIPENING AND QUALITY CHANGES IN MANGO FRUIT AS AFFECTED BY COATING WITH AN EDIBLE FILM

JOURNAL OF FOOD QUALITY, Issue 5 2000
A. CARRILLO-LOPEZ
ABSTRACT Mango fruit has a relatively short storage life of about 2 to 3 weeks at 13C. In order to prolong the storage life of ,Haden' mangoes, fruit were coated with 3 concentrations (8,16 and 24 g.L,1) of the edible coating film "Semperfresh" and then stored at 13C and 85% RH. Fruit were then evaluated every 4 days for up to 32 days for total soluble solids (TSS), titratable acidity (TA), pH, firmness, weight loss, color of the skin, and ascorbic acid content. All 3 concentrations applied to the fruit affected fruit ripening. TA, firmness, and green color were higher in coated fruit, and weight loss, SST, and pH were lower compared with the noncoated fruit. "Semperfresh" had no effect on decay development. Ascorbic acid decreased in all stored fruit, but this decrease was slower in coated fruit, and there were no significant differences between the different "Semperfresh" concentrations. [source]


Changes in the Radical-Scavenging Activity of Bitter Gourd (Momordica charantia L.) during Freezing and Frozen Storage with or without Blanching

JOURNAL OF FOOD SCIENCE, Issue 7 2008
C. Myojin
ABSTRACT:, The effects of blanching, freezing, and frozen storage on the retention of radical-scavenging activity (RSA), total phenolics, and ascorbic acid in bitter gourd were investigated. Blanching of sliced bitter gourd resulted in considerable losses of RSA and total phenolics, and most extensively, of ascorbic acid. In the subsequent frozen storage at ,18 C, RSA and total phenolic content of unblanched and blanched bitter gourd underwent little change for 90 d then gradually declined, but at ,40 C, they practically remained unchanged throughout the entire storage period. On the contrary, ascorbic acid content of both unblanched and blanched bitter gourd decreased abruptly at the early stage in frozen storage. The results show that blanching of bitter gourd improves the retention of RSA and total phenolics during subsequent frozen storage but markedly aggravated loss of ascorbic acid. Finally, it is to be noted that RSA, total phenolics, and ascorbic acid originally contained in the raw bitter gourd were overall best retained by quick freezing followed by frozen storage at ,40 C without preceding blanching. [source]


Effect of Hot Water Surface Pasteurization of Whole Fruit on Shelf Life and Quality of Fresh-Cut Cantaloupe

JOURNAL OF FOOD SCIENCE, Issue 3 2008
X. Fan
ABSTRACT:, Cantaloupes are associated with recent outbreaks of foodborne illnesses and recalls. Therefore, new approaches are needed for sanitization of whole and cut fruit. In the present study, whole cantaloupes were submerged into water in the following 3 conditions: 10 C water for 20 min (control), 20 ppm chlorine at 10 C for 20 min, and 76 C water for 3 min. Populations of microflora were measured on the rinds of the whole cantaloupes. Quality and microbial populations of fresh-cut cantaloupes prepared from whole fruit were analyzed after 1, 6, 8, 10, 13, 16, and 20 d of storage at 4 C. The hot water significantly reduced both total plate count (TPC) and yeast and mold count on rind of whole fruits while chlorine or cold water wash did not result in a significant reduction of microbial population. Fresh-cut pieces prepared from hot water-treated cantaloupes had lower TPC than the other 2 treatments in the later storage periods (days 13 to 20) in 2 of 3 trials. The hot water treatment of whole fruits was inconsistent in reducing yeast and mold count of fresh-cut pieces. Soluble solids content, ascorbic acid content, fluid loss, and aroma and appearance scores were not consistently affected by either hot water or chlorine treatment. Our results suggested that hot water pasteurization of whole cantaloupes frequently resulted in lower TPCs of fresh-cut fruit during storage and did not negatively affect quality of fresh-cut cantaloupes. [source]


Comparison of the Stability of Pelargonidin-based Anthocyanins in Strawberry Juice and Concentrate

JOURNAL OF FOOD SCIENCE, Issue 4 2002
G.A. Garzn
ABSTRACT Strawberries were processed into juice (8 Brix) and concentrate (65 Brix) and different lots were fortified with pelargonidin 3-glucoside, pelargonidin 3-sophoroside, and acylated pelargonidin 3-sophoroside 5-glucoside. Changes in pigment concentration, color (CIE L*a*b*) and ascorbic acid content were monitored during storage at 25 C. Anthocyanin and ascorbic acid degradations followed 1st order reaction kinetics. Fortification increased the half-life of the pigments from 3.5 to 5 d in concentrate and from 5 to 12 d in juice. The half-life of ascorbic acid was 2 d in juice samples and ranged from 3 to 10 d in concentrate samples. Both systems showed changes in chroma and hue angle, but maintained L* values. [source]


Influence of growth stage and postharvest storage on ascorbic acid and carotenoid content and visual quality of baby spinach (Spinacia oleracea L.)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2006
Sara M Bergquist
Abstract To investigate the variations in quality with growth stage and postharvest storage, spinach was sown on three occasions. For each occasion, the spinach was harvested at three growth stages at 6-day intervals. The second stage corresponded to a growth period used for baby spinach by commercial growers. After harvest, the leaves were stored in polypropylene bags at 2 C or 10 C. The highest ascorbic acid content in fresh material was found at stage I. During storage, the ascorbic acid content decreased considerably and the dehydroascorbic acid/vitamin C ratio increased. Storage at 2 C gave a smaller reduction in ascorbic acid content than storage at 10 C. Total carotenoid content increased or remained stable during storage. Lutein was the major carotenoid, making up about 39% of the total carotenoid content, followed by violaxanthin, ,-carotene and neoxanthin. Visual quality decreased during storage in most cases, and was correlated to initial ascorbic acid and dry matter contents. The initial AA content might therefore be used as a parameter for predicting the shelf-life of baby spinach. The results also indicate that by harvesting baby spinach a few days earlier than the current commercial stage of harvest the postharvest visual quality and nutritional quality may be improved. Copyright 2005 Society of Chemical Industry [source]


Evaluation of heat and oxidative damage during storage of processed tomato products.

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2003

Abstract Tomato products (pulp, puree and paste) submitted to accelerated aging (30, 40 and 50 C for 3 months) were studied to evaluate variations in the kinetics of the degradation of antioxidants and antioxidant activity. The carotenoids lycopene and ,-carotene, ascorbic acid, rutin and total phenolics were analysed. The antioxidant activity was measured using (a) the xanthine oxidase (XOD)/xanthine system, which generates superoxide radicals and hydrogen peroxide, and (b) the linoleic acid/CuSO4 system, which promotes lipid peroxidation. The ascorbic acid content decreased even at 30 C, following pseudo-first-order kinetics, with an activation energy of 105 200 J mol,1 for tomato pulp and 23 600 J mol,1 for tomato paste. The lower the initial ascorbic acid content, the higher was the degradation rate. Variations in phenolic compounds occurred at 40 C and higher, following pseudo-zero order kinetics. The antioxidant activity of the hydrophilic fraction of the tomato products depended on both antioxidant degradation and the Maillard reaction and could not be described by a kinetic model. The ,-carotene content decreased even at 30 C, whereas the lycopene content was stable in all samples. The antioxidant activity of the lipophilic fraction of the tomato products decreased following pseudo-first order kinetics, with an activation energy of 22 200 J mol,1 for tomato pulp and 20 200 J mol,1 for tomato paste. It is concluded that significant ,oxidative damage' can occur in tomato products during their commercial shelf-life. Copyright 2003 Society of Chemical Industry [source]


Hypocholesterolaemic and antioxidant effects of Glycyrrhiza glabra (Linn) in rats

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 11 2006
Nishant P. Visavadiya
Abstract The hypocholesterolaemic and antioxidant effects of Glycyrrhiza glabra (GG) root powder were examined in hypercholesterolaemic male albino rats. A 4-week administration of GG root powder (5 and 10 gm% in diet) to hypercholesterolaemic rats resulted in significant reduction in plasma, hepatic total lipids, cholesterol, triglycerides and plasma low-density lipoprotein and VLDL-cholesterol accompanied by significant increases in HDL-cholesterol levels. Furthermore, significant increases in fecal cholesterol, neutral sterols and bile acid excretion along with an increase in hepatic HMG-CoA reductase activity and bile acid production were observed in these animals. The root powder administration to hypercholesterolaemic rats also decreased hepatic lipid peroxidation with a concomitant increase in superoxide dismutase (SOD) and catalase activities and total ascorbic acid content. Thus, the hypocholesterolaemic and antioxidant effects of GG root appeared to be mediated via (i) accelerated cholesterol, neutral sterol and bile acid elimination through fecal matter with an increased hepatic bile acid production and (ii) improving the activities of hepatic SOD, catalase and increasing the ascorbic acid content. The normo-cholesterolaemic animals when fed with GG root powder at 10 gm% level, registered a significant decline in plasma lipid profiles and an increase in HDL-cholesterol content. The antioxidant status of these animals also was improved upon treatment. [source]


Diphenyl Diselenide and Ascorbic Acid Changes Deposition of Selenium and Ascorbic Acid in Liver and Brain of Mice

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2001
Maria Caroline Jacques-Silva
These compounds have been reported to inhibit the cerebral and hepatic aminolevulinic acid dehydratase (ALA-D) in vitro, and now we show that ascorbic acid can reverse some alterations caused by in vivo selenium exposure, but not ALA-D inhibition. The effect of Na2SeO3 or (PhSe)2 and ascorbic acid on selenium distribution, total non-protein thiol, ascorbic acid content (liver and brain) and haemoglobin was also examined. Mice were exposed to 250 ,mol/kg (PhSe)2, or 18.75 ,mol/kg Na2SeO3 subcutaneously, and to ascorbic acid, twice a day, 1 mmol/kg intraperitonially, for 10 days. Hepatic ALA-D of mice treated with (PhSe)2 was inhibited about 58% and similar results were observed in the animals that received ascorbic acid supplementation (P<0.01, for (PhSe)2 -treated and (PhSe)2+ascorbic acid-treated mice). The haemoglobin content decreased after treatment with (PhSe)2 (P<0.01). However, the haemoglobin content of the (PhSe)2+ascorbic acid group was significantly higher than in the (PhSe)2 -treated mice (P<0.05), and similar to control (P>0.10). Ascorbic acid treatment decreased significantly the hepatic and cerebral deposition of Se in (PhSe)2 -exposed mice (P<0.01). Hepatic non-protein thiol content was not changed by treatment with (PhSe)2, ascorbic acid or (PhSe)2+ascorbic acid. Hepatic content of ascorbic acid was twice that in mice that received (PhSe)2, independent of ascorbic acid treatment (P<0.001). The results of this study suggest that vitamin C may have a protective role in organodiselenide intoxication. [source]


Capillary Zone Electrophoresis and Micellar Electrokinetic Capillary Chromatography for Determining Water-Soluble Vitamins in Commercial Capsules and Tablets

JOURNAL OF FOOD SCIENCE, Issue 1 2001
S-C. Su
ABSTRACT: A rapid method was developed for simultaneously determining thiamine, riboflavin, pyridoxine, nicotinamide, nicotinic acid, and ascorbic acid. It was tested on 15 samples. The peaks of all components were cleanly separated with good resolution by capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MECC). CZE was performed with 0.02 M borate buffer, and MECC was performed with 4% acetonitrile in 0.02 M borate/phosphate buffer containing 0.1 M sodium dodecyl sulfate. Average recoveries for all components were 80.3% to 103.7% with coefficients of variation being less than 5%. Thiamine, nicotinic acid, and pyridoxine contents were consistent with those labeled on the packages, but nicotinamide, riboflavin, and ascorbic acid contents of some samples were less. [source]


Influence of postharvest UV-C treatment on refrigerated storage of minimally processed broccoli (Brassica oleracea var. Italica)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2007
Maria L Lemoine
Abstract Minimally processed broccoli was treated with UV-C light (8 kJ m,2) and subsequently stored for 21 days at 4 C. The UV-C treatment delayed yellowing and chlorophyll degradation during storage. Treated broccoli florets displayed lower electrolyte leakage and respiratory activity, indicating higher tissue integrity. Treated samples showed higher phenolic and ascorbic acid contents as well as higher antioxidant activity than controls. Treated samples also had a higher content of soluble sugars, but no differences in the content of soluble proteins between control and treated samples were detected. The UV-C treatment also affected bacterial and mould populations. After 21 days at 4 C the number of colony-forming units of both populations was lower in treated than in control broccoli florets. The results suggest that UV-C treatment reduces tissue damage of minimally processed broccoli during storage at 4 C, thus maintaining nutritional quality and reducing microbial growth. Copyright 2007 Society of Chemical Industry [source]


Optimization of hot water extraction of roselle juice using response surface methodology: a comparative study with other extraction methods

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2003
Peng-Kong Wong
Abstract Roselle has regained the attention of many fruit juice manufacturers in Malaysia as a product that contains high ascorbic acid and anthocyanins. However, ascorbic acid and anthocyanin pigments can be easily destroyed during processing of fruit juice. Therefore, in the present study, the effects of different processing methods, namely hot water extraction (HWE), hot water blending, cold water blending and screw press, on the changes in anthocyanins and ascorbic acid contents of roselle juice were evaluated. The anthocyanins and ascorbic acid contents of roselle were determined using the pH differential method and high-performance liquid chromatography respectively. The physico-chemical characteristics and sensory properties of roselle juice were also evaluated. The results of the study indicate that the HWE method is the most effective extraction method, resulting in high anthocyanins and ascorbic acid contents of 43 g l,1 (as delphinidin-3-glucoside) and 2.34 g kg,1 respectively. The optimum juice extraction conditions were 3.5 h at 60 C. Copyright 2003 Society of Chemical Industry [source]


Preventive effect of Shigyaku-san on progression of acute gastric mucosal lesions induced by compound 48/80, a mast cell degranulator, in rats

PHYTOTHERAPY RESEARCH, Issue 4 2006
Yoshiji Ohta
Abstract The study examined whether Shigyaku-san (Si-Ni-San) extract (TJ-35), a traditional Kampo medicine, prevents acute gastric mucosal lesion progression in rats treated once with compound 48/80 (C48/80). Rats treated with C48/80 (0.75 mg/kg body weight, i.p.) received TJ-35 (0.15, 0.35 or 0.75 g/kg body weight, p.o.) 0.5 h after the treatment at which time gastric mucosal lesions appeared. At 0.5 h after C48/80 treatment, the gastric mucosa of the treated rats had increased myeloperoxidase (an index of neutrophil infiltration) and xanthine oxidase activities and thiobarbituric acid reactive substances (an index of lipid peroxidation) content. At 3 h after C48/80 treatment, the gastric mucosa of the treated rats showed progressive lesions and further increases in myeloperoxidase and xanthine oxidase activities and thiobarbituric acid reactive substances content and decreases in vitamin E, ascorbic acid and adherent mucus contents and Se-glutathione peroxidase activity. Post-administered TJ-35 attenuated all these changes found at 3 h after C48/80 treatment dose-dependently. These results indicate that TJ-35 prevents the progression of C48/80-induced acute gastric mucosal lesions in rats possibly by attenuating enhanced neutrophil infiltration, enhanced lipid peroxidation associated with decreased vitamin E and ascorbic acid contents and Se-glutathione peroxidase activity, and destruction of the defensive barrier in the gastric mucosa. Copyright 2006 John Wiley & Sons, Ltd. [source]