Vegetal Reduction of Dehydroascorbic Acid

Kohman, E. F.; Sanborn, N. H.

doi:10.1021/ie50334a023

Cited by 9 publications

(6 citation statements)

References 9 publications

(10 reference statements)

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“…Attention is called to the figures for peas and tomatoes, both of which are within the limiting values previously set down for these foods, because of the view put forward by Kohman & Sanborn (1937) that the estimation of vitamin C by the dye method is complicated for these two vegetables by the presence of other reducing bodies. If this view is correct the true vitamin content will be lower than the figures obtained, but throughout this work all samples of peas and tomatoes were examined in an identical manner, so that for purposes of comparison the results may be considered satisfactory.…”

Section: The Results Of Examinations Of Cheap Foodsmentioning

confidence: 99%

The distribution of vitamin C in foods sold on the open market

Chappell

1940

Epidemiol. Infect.

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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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Section: The Results Of Examinations Of Cheap Foodsmentioning

confidence: 99%

The distribution of vitamin C in foods sold on the open market

Chappell

1940

Epidemiol. Infect.

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“…5 These experiments indicate that oxygen may play a distinctly destructive role toward vitamin C. They indicate but do not prove that heating is without effect. This was shown by increasing the normal processing of canned peas from twenty-five minutes to fifty minutes at 250 F.6 without there being any increased destruction of vitamin C. Many foods have reducing effects on oxidized (dehydro) ascorbic acid, as was strikingly demonstrated in peas 7 and as the following unpublished experiment illustrative of a common behavior of many foods shows : Tomato juice was extracted without incorporating air and the ascorbic acid determined with 2,6-dichlorphenolindophenol. The juice was then divided into two portions, to one of which dehydro ascorbic acid was added.…”

Section: Morbidity Reportsmentioning

confidence: 96%

“…7. That workers with gonorrhea should be allowed to work only under special medical observation during the administration of sulfonamide drugs.…”

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confidence: 99%

The Preservation of the Nutritive Value of Foods in Processing

Kohman¹

1942

JAMA

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“…1733 showed no loss in ascorbic acid; these peas were also assayed by the animal-feeding method (Table l), and ascorbic acid values determined by the two methods were the same. A possible explanation of this apparently contradictory information may be found in the work of Kohman and Sanborn (1937). These investigators found that freshly pressed green-pea juice held in the absence of air gradually increased its reducing value to 2,6 dichlorophenolindophenol, and the effect was increased if the juice was first well aerated.…”

Section: °Cmentioning

confidence: 99%

Vitamin Values of Garden‐type Peas Preserved by Frozen‐pack Method. I. Ascorbic Acid (Vitamin C)

Todhunter

Sparling

1938

Journal of Food Science

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Fresh green peas are recognized as a good source of ascorbic acid, but there have been comparatively few studies on the influence of commercial handling and processing on the ascorbic acid content of this vegetable. Eddy, Kohman, and Carlsson (1926) and Fellers and Stepat (1936) have reported on the losses of ascorbic acid due to canning. Mack and Tressler (1936) have found variety and sieve size to be factors which influence the ascorbic acid content of fresh peas, and the cooking losses in fresh peas have been studied by Fenton, Tressler, and King (1936). Fellers and Stepat (1936) have estimated that losses due to canning operations were 66 per cent of the original ascorbic acid and that defrosting f o r several hours resulted in a loss of 70 per cent of the amount present in the frozen peas.Frozen-pack peas are of considerable commercial importance and are produced in large quantities in the Pacific Northwest. Differences in soil and climatic conditions are probably factors which influenee ascorbic acid content; also the method of freezing which is used in the Northwest differs from those generally used in the eastern section of the country. It was therefore considered of importance to investigate the ascorbic acid content of garden-type peas preserved by the frozen-pack method. The investigation here reported covers the following phases of the problem: ( a ) the ascorbic acid content of peas of the same variety scalded at different temperatures and for varying periods of time before freezing; ( b ) distribution of ascorbic acid between the cotyledon and seed coat of the peas, and the effect of thawing the peas under different conditions of time and temperature; and ( c ) varietal differences in ascorbic acid content of frozen peas.This investigation was undertaken at the suggestion of H. C. Diehl of the Frozen Pack Laboratory, U. S. Bureau of Chemistry and Soils, at Seattle, Washington, and was made possible through courtesy of the laboratory which provided the peas. Its personnel undertook the preparation and freezing of all the peas except those used in the 489

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Vegetal Reduction of Dehydroascorbic Acid

Cited by 9 publications

References 9 publications

The distribution of vitamin C in foods sold on the open market

The distribution of vitamin C in foods sold on the open market

The Preservation of the Nutritive Value of Foods in Processing

Vitamin Values of Garden‐type Peas Preserved by Frozen‐pack Method. I. Ascorbic Acid (Vitamin C)

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