Vitamin methods

Harris, Leslie J.; Olliver, Mamie

doi:10.1042/bj0360155

Cited by 95 publications

(24 citation statements)

References 21 publications

(10 reference statements)

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“…Ascorbic acid was determined by the 2 : 6-dichlorophenolindophenol method (Harris & Olliver, 1942) in extracts of the plant tissues.…”

Section: Methodsmentioning

confidence: 99%

Ascorbic acid in some oleiferous brassicas cultivated in Pakistan

Tremazi¹

1957

Br J Nutr

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Certain forms of oleiferous brassicas (brown-seeded sarson, Japan rapes and toria) are grown in Pakistan as oilseeds and fodder crops, and some varieties of these have been introduced recently as new crops in consequence of work done at the Agricultural Research Institute, Lyallpur. In the young stage the plants are eaten as vegetables; the non-fibrous stem known as gandal mixed with the young branches and leaves is cooked as sag by the villagers in winter. It is well known that leafy vegetables, particularly if eaten raw, form a valuable source of ascorbic acid in the diet, so the ascorbic-acid content of the oleiferous brassicas mentioned above has been investigated.The results of the work over a period of 2 years (1950-1) are now described. EXPERIMENTALTwo forms of Japan rape (light-and dark-green leaved), brown-seeded sarson and toria were grown in plots. Five plants were removed from each plot on each day of sampling; the plants of each variety were pooled in one sample and were divided into stems, branches, leaves and buds for analysis. The samples were thus representative of the whole plot. Analyses for ascorbic acid were carried out in duplicate on each sample and the results were averaged.Samples of each variety were taken at two stages of development, one before, and the other immediately after, blooming, that is while the plants were quite fit for culinary purposes. Beyond the blooming stage the stems become too fibrous for use. The effects of cooking and storage were studied.A large number of undeveloped, fully grown immature and mature seeds was collected from the pods of each crop so as to make a composite and representative sample, a portion of which was analysed for ascorbic-acid content. Seeds of the four crops were germinated and the ascorbic-acid content was determined at different stages.Ascorbic acid was determined by the 2 : 6-dichlorophenolindophenol method (Harris & Olliver, 1942) in extracts of the plant tissues.In preparing the extracts 5 g of the sample were ground with about 10 g fine sand and a few ml. 3 yo (w/v) metaphosphoric-acid solution; the mixture was immediately filtered and the residue well washed with metaphosphoric-acid solution ; portions of the extract were immediately titrated with the dye solution.

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“…Ascorbic acid was determined by the 2 : 6-dichlorophenolindophenol method (Harris & Olliver, 1942) in extracts of the plant tissues.…”

Section: Methodsmentioning

confidence: 99%

Ascorbic acid in some oleiferous brassicas cultivated in Pakistan

Tremazi¹

1957

Br J Nutr

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“…For determining the degree of protection against scorbutic changes afforded by various graded doses of ascorbic acid, either with or without the concurrent daily administration of cortisone, the assay procedure described by Harris & Olliver (1942), based on the method of Key & Elphick (1931), was rigidly followed.…”

Section: ' Experimentalmentioning

confidence: 99%

“…Each section was awarded a score of from o to 4 points, the criteria being essentially the same as those previously accepted by Key & Elphick (1931) and by Harris & Olliver (1942). The assessors were asked to pay special attention to three factors, namely (I) the degree of degeneration of the odontoblasts, (2) the length of the odontoblasts and (3) the width of the layer of inner dentine.…”

Section: ' Experimentalmentioning

confidence: 99%

Influence of Cortisone on Ascorbic-acid Requirements of Guinea-pigs: an Assessment by the Tooth-structure Method

et al. 1955

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“…Bracewell, Hoyle and Zilva (1930) used the weight increase of guinea-pigs as one criterion in an assessment, by bioassay, of the vitamin C in apples. The methods of measurement which have been elaborated by Coward and Kassner (1936) and Coward (1938) and by Harris and Olliver (1942) depend solely on the growth response of young guinea-pigs to graded intakes of vitamin C. The former used a preventive method in which antiscorbutic supplements were fed from the beginning of the experiment. In the curative method of Harris and Olliver there was an initial period of about ten days when the experimental animals received only the scorbutic diet.…”

mentioning

confidence: 99%

“…Diet 4 was based on that of Harris and Olliver (1942) though not identical with it. It had the following composition:…”

mentioning

confidence: 99%

The Determination of Vitamin C by the Growth of Guinea‐pigs

Dawbarn

1945

Aust J Exp Biol Med

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The administration of antiscorbutic foodstuffs to young guinea-pigs living on a scorbutic diet, has been observed to evoke growtli responses which are dependent on the amount of vitamin C in the supplements fed. Bracewell, Hoyle and Zilva (1930) used the weight increase of guinea-pigs as one criterion in an assessment, by bioassay, of the vitamin C in apples. The methods of measurement which have been elaborated by Coward and Kassner (1936) and Coward (1938) and by Harris and Olliver (1942) depend solely on the growth response of young guinea-pigs to graded intakes of vitamin C. The former used a preventive method in which antiscorbutic supplements were fed from the beginning of the experiment. In the curative method of Harris and Olliver there was an initial period of about ten days when the experimental animals received only the scorbutic diet. These methods, with modifications of the basal diet and of the duration of the experiment have been used by numerous investigators (Gould, Tressler and King, 1936;Mack, Tressler and King, 1936;Harris and Poland, 1937;Tressler, Mack, Jenkins and King, 1937; Fenton, Tressler, Camp and King, 1938;Mack, Tapley and King, 1939;Wheeler, Tressler and King, 1939;Kirk and Tressler, 1941; Dunker, Fellers and Esselen, 1942;Cruickshank, 1943).The procedure followed in preliminary experiments carried out by the growth method in this laboratory was based on conclusions which were drawn from published data. Only two levels of intake of the vitamin were employed, namely 0-4 mg. and 0-8 mg. ascorbic acid per day. From the experience of others it was expected that a significant difference in the growth response of guinea-pigs to these amounts of vitamin C would result, without entailing a degree of depletion on the lower level of intake so severe as to cause actual loss in weight.Groups of five guinea-pigs, subsisting on a basal diet supposedly devoid of vitaniin C, were given each day supplements containing, on the basis of chemical analyses, the equivalents of 0-4 mg. and 0-8 mg. ascorbic acid. These were administered for 6 weeks. The response was estimated by the curative and by the preventive methods.In each case the difference between the mean weight increments of groups of guinea-pigs ingesting respectively 0 • 4 mg. and 0 • 8 mg. of pure ascorbic acid per day, was so sm^all as to be statistically insignificant. The five negative control animals on the basal diet all developed scurvy and died in 23, 24, 24, 25 and 31 days respectively. (The negative control guinea-pigs weighed from 200 to 280 gm. at the beginning of the experiments).The response to the supplements was variable and the failure to secure a significant difference between the mean weight increments of the groups of guinea-pigs on the two levels of ascorbic acid intake was probably due to the small number of animals employed. Nevertheless, the good growth of those which received only 0-4 mg. ascorbic acid daily, roused the suspicion that the

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Vitamin methods

Cited by 95 publications

References 21 publications

Ascorbic acid in some oleiferous brassicas cultivated in Pakistan

Ascorbic acid in some oleiferous brassicas cultivated in Pakistan

Influence of Cortisone on Ascorbic-acid Requirements of Guinea-pigs: an Assessment by the Tooth-structure Method

The Determination of Vitamin C by the Growth of Guinea‐pigs

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