Ascorbic Acid and 5‐Methyltetrahyclrofolate Losses in Vegetables with Cook/Chill or Cook/Hot‐Hold Foodservice Systems

Williams, Peter; Ross, Helena; Miller, Jennie C. Brand

doi:10.1111/j.1365-2621.1995.tb09822.x

Cited by 31 publications

(23 citation statements)

References 26 publications

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“…After 12 weeks, the ascorbic acid contents of all samples were reduced to values less than 20 mg·100 mL -1 . This is well below the minimum values recommended for processed orange juice (40 mg·100 mL -1 ) [4]. Choi et al [16], studying the retention of ascorbic acid with storage in blood orange juice, observed a linear reduction in concentration with time.…”

Section: Ascorbic Acid Contentmentioning

confidence: 93%

“…Because of the instability of vitamin C and its nutritional importance, its content guarantees the presence of other nutrients and is considered an indicator of the nutritional quality of foods [4]. The main source of vitamin C for consumers is usually citrus fruits.…”

Section: Introductionmentioning

confidence: 99%

“…The nutritional quality of sour orange juice is largely related to its vitamin C content and its antioxidant capacity [3]. The juice is used as a food additive, ingredient in salad dressing and as a popular drink because of its rich flavor and aroma [4].…”

Section: Introductionmentioning

confidence: 99%

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Shelf life of unpasteurized sour orange juice in Iran

Amiri¹,

Niakousari²

2008

Fruits

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-squeezing fresh fruit; it was filtered, and then poured into clear or dark green glass bottles. Bottles were stored at room temperature [(28 ± 2)°C], in the refrigerator [(4 ± 1)°C] and in the freezer [(-12 ± 1)°C] for 12 weeks. Additional samples were prepared by supplementing juice with 2% (w/w) citric acid and they were stored in the refrigerator. Total soluble solids and pH values were measured every 2 weeks and analysis was carried out on ascorbic acid content by means of the titration method in the presence of 2,6-dichlorophenol indophenol. The study was performed for 12 weeks. Results and discussion. Total soluble solids content and pH value of the initial juice were 11.5°Brix and 3.18, respectively. pH appeared not to be significantly influenced by storage time or conditions; however, total soluble solids content in a few samples was reduced to about 9.5°Brix. The initial ascorbic acid content was 130 mg·100 mL -1 ; after 2 weeks, it was reduced by nearly 50% for all unfrozen samples. The final concentration of ascorbic acid in the juice was approximately 20 mg·100 mL -1 , regardless of storage conditions. The deteriorative reaction of ascorbic acid in the juice at each temperature experienced followed a first-order kinetic model with activation energy of 2.67 kJ·mol -1 .Iran Islamic Republic / Citrus aurantium / fruit juices / packaging / storage / keeping quality / ascorbic acid Durée de conservation du jus d'orange amère non pasteurisé en Iran.Résumé --introduction. En Iran, l'orange amère est disponible de mi-octobre à mars. Les consommateurs stockent fréquemment de gros volumes de jus non pasteurisé, à basse température ou à température ambiante, en prévision des périodes où le fruit frais ne sera pas disponible. L'objectif de nos recherches a été de déterminer la durée de conservation du jus non pasteurisé de ces oranges amères, stocké dans des conditions semblables à celles utilisées, chez eux, par les consommateurs. Matériel et méthodes. Du jus d'orange amère a été préparé en pressant à la main le fruit frais ; il a été ensuite filtré, puis versé dans des bouteilles en verre clair ou en verre vert-foncé. Les bouteilles ont été stockées à la température ambiante [(28 ± 2°C)], au réfri-gérateur [(4 ± 1)°C], et au congélateur [(-12 ± 1)°C] pendant 12 semaines. D'autres échantillons ont été préparés en ajoutant au jus 2 % (poids / poids) d'acide citrique ; ils ont été stockés au réfrigérateur. La matière sèche soluble et les valeurs du pH ont été mesurées toutes les 2 semaines et la teneur en acide ascorbique a été analysée par titration en présence d'indophénol 2,6 dichlorophénol. L'étude a été réalisée pendant 12 semaines. Résultats et discussion. La teneur en matière sèche soluble et la valeur du pH du jus initial ont été de 11,5°Brix et 3,18, respectivement. Le pH a semblé ne pas être significativement influencé par le temps ou les conditions de stockage, toutefois la teneur en matière sèche soluble dans quelques échantillons a été réduite à environ 9.5°Brix. La teneur en acide ascorbique initia...

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Section: Ascorbic Acid Contentmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

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Shelf life of unpasteurized sour orange juice in Iran

Amiri¹,

Niakousari²

2008

Fruits

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“…Vegetables prepared by microwave-steaming and stir-frying with oil had significantly higher (1.3-1.8-fold) vitamin C retention values than those that were boiled (Masrizal et al, 1997). Vegetables reheated after 1 day of chilled storage had greater losses of vitamin C compared to those held at 72°C for 30 min, but better vitamin C retention than vegetables held hot for 2 h. If warm-holding is restricted to less than 90 min vitamin retention in vegetables is likely to be higher in a cook/hot-hold foodservice than with a cook/chill system (Williams et al, 1995). Howard et al (1999) reported that steam blanching of broccoli, carrot, and green beans resulted in slight losses in carrot and green beans but up to 30% loss of total AA in broccoli; microwave cooking had minimal effects on AA content.…”

Section: Storagementioning

confidence: 96%

Preharvest and postharvest factors influencing vitamin C content of horticultural crops

Lee

Kader

2000

Postharvest Biology and Technology

1,891

117

1,088

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Vitamin C, including ascorbic acid and dehydroascorbic acid, is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. The content of vitamin C in fruits and vegetables can be influenced by various factors such as genotypic differences, preharvest climatic conditions and cultural practices, maturity and harvesting methods, and postharvest handling procedures. The higher the intensity of light during the growing season, the greater is vitamin C content in plant tissues. Nitrogen fertilizers at high rates tend to decrease the vitamin C content in many fruits and vegetables. Vitamin C content of many crops can be increased with less frequent irrigation. Temperature management after harvest is the most important factor to maintain vitamin C of fruits and vegetables; losses are accelerated at higher temperatures and with longer storage durations. However, some chilling sensitive crops show more losses in vitamin C at lower temperatures. Conditions favorable to water loss after harvest result in a rapid loss of vitamin C especially in leafy vegetables. The retention of vitamin C is lowered by bruising, and other mechanical injuries, and by excessive trimming. Irradiation at low doses (1 kGy or lower) has no significant effects on vitamin C content of fruits and vegetables. The loss of vitamin C after harvest can be reduced by storing fruits and vegetables in reduced O 2 and/or up to 10% CO 2 atmospheres; higher CO 2 levels can accelerate vitamin C loss. Vitamin C of produce is also subject to degradation during processing and cooking. Electromagnetic energy seems to have advantages over conventional heating by reduction of process times, energy, and water usage. Blanching reduces the vitamin C content during processing, but limits further decreases during the frozen-storage of horticultural products.

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“…Other effects from the matrix may also be of importance; the protective effects of plasma proteins on tetrahydrofolate (H 4 folate) stability in pig plasma (4) are an example. Williams et al (5) compared cook/chill vs. cook/hot-hold treatments to the retention of 5-methyltetrahydrofolate (5-CH 3 -H 4 folate) in vegetables. However, these results were not compared with total folate retention or with the retention of other vitamers of folic acid, maybe because 5-CH 3 -H 4 folate was likely to be the predominant folate form in these foods.…”

Section: Introductionmentioning

confidence: 99%