In order to study conditions to retain the effect of vitamin or antioxidant action, substances mentioned in the heading were examined as to how their stabilities were affected by sodium hexametaphosphate coexisting with other food additives and food components in water containig 32μg% Cu2+. 1. Sodium hexametaphosphate had remarkable stabilizing effect on ascorbic acid and its sodium salt, and had the maximum effect within a range of 8 to 30mg%concentration. 2. The effect of coexisting other food additives and food components with sodium hexametaphosphate on the stabilities of the vitamin and its sodium salt could be grouped into four types as follows: a) Residual rates of ascorbic acid and its sodium salt went on decreasingly and their differences were remarkable when certain food additives (below mentioned) coexisted with sodium hexametaphosphate. Name of the food additives: saccharin sodium, sodium cyclamate. b) Residual rates of ascorbic acid and its sodium salt went on decreasingly and their differences were slight when food additives described later coexisted sodium hexametaphosphate. Name of the food additives: sodium benzoate, sodium alginate, sodium carboxymethyl-cellulose. c) Residual rates of ascorbic acid and its sodium salt were at the the lowest level at a certain concentration of food additives which were added to the vitamin solution with sodium hexametaphosphate. Name of the food additives: sodium tripolyphosphate, sodium dehydroacetate, glycine, sodium glutamate, soluble starch, sodium chloride. d) Good effect of sodium hexametaphosphate on the vitamin-stabilizing ability was found by the coexistence of below described food additives. Name of the food additives: citric acid, sucrose, sorbitol, propylene glycol. As observed above, although sodium hexametaphosphate alone had a good stabilizing abilizing ability, the coexistence of other food additives and food components reduced its protective effect against the decomposition of ascorbic acid and its sodium salt. The mixture of citric acid and sodium hexametaphosphate showed a extremely good effect on stabilizing ascorbic acid and its sodium salt.
Since the authors have confirmed that some vegetable oils contain detectable amounts of cholesterol, it would not be appropriate to determine the presence of animal oil in margarine only with the existence of cholesterol, unless extremely a large portion of animal fats were occluded. Secondly, the authors found that the composition of fatty acids in margarine is highly characteristic in respect to its constituent. That is, the vegetable oils hardly contain fatty acids having over 20 carbons, carbon odd-nnumbered acids and C16: 1 acids, on the other hand, beef tallow contains considerable amounts of carbon odd-numbered acids and C16: 1 acids. Besides, oils of fish or whale origins are rich in fatty acids with over 20 carbons, Furthermore, hydrogenated vegetable oils contain fair amounts of C18: 1 trans acids. In conclusion, with consideration on the pattenn of these components, it would be possible to judge the animal or vegetable nature of margarine, as well as sorts of oils as components in margarine to some extent.
The oxidation of methyl linolenate in diffused daylight, and under UV ray γ ray was studied by pursuing changes of its thiobarbituric acid (TBA) value, peroxide value, quantity of conjugated diene, carbonyl value, and rate of weight increase. As a result, it was found that the tendency of changes in TBA value and cardonyi value were similar, and that UV ray did not only accelerate to produce the first oxidative product[s]of methyl linolenate, but did more intensely to decompose this product[s], which influenced TBA value and carbonyl value after UV treatment. Three pigments were always identified from the reaction products of oxidized methyl linolenate and TBA by chromatography without regard to the methods and various stages of oxidation. The pigment 1, λ max. 454mμ, seemed to be similar to n-vaieraldehyde-TBA condensation product from the viewpoint of chromatographic behaviours and spectro-photometric character, which was presumed as one of substances disturbing TBA value. The pigment 2, λmax. 510mμ, was found to be very small in quantity amoag the reaction mixtures. The pigment 3, λmax. 532mμ, was identified as the object of TBA value and a malonaldehyde-TBA condensation product.
Nitrate, when contained in canned acid products, is known to cause severe corrosion on the internal tin surface of container, accompanied by rapid dissolving of tin which migrates into the contents. The present paper dealt with results obtained by a test pack experiment and a model experiment, and mechanism of nitrate action to dissolve tin was discussed. (1) Apositive logarithmic relationships were observed between initial nitrate amounts in the can and formation of ammonia. The tin-dissolving rate was found to be proportional to the former. (2) Mechanism of the nitrate action was studied with a model pack experiment, in the event of which a model canned drink containing nitrite or nitrate was kept in the absence of oxygen. It was found that detinning by nitrite was rapid with the rapid decrease of nitrite, whereas, in the case of nitrate, both detimling and nitrate reduction were very slow. From these results, it was concluded that the nitrate reduction to nitrite was a ratelimiting step in the over-all reaction, and nitrite acted in the canned acid products as a strong oxidizing agent against tin, while itself rapidly being further reduced to ammonia. It was assumed that when bivalent tin, Sn (II), a strong reducing agent, was formed by the action of oxygen, nitrate present was reduced to nitrite which readily attacks metallic tin to form bivalent tin, and, thus, the reaction proceeded in such a manner as a chain reaction. Oxygen must, therefore, be playing such a role as a “trigger” in the over-all reaction.
A method for recovering preservatives in foods by the steam distillation under reduced pressure was studied. The outline of procedure is as follows. 1) In the case of samples containing dehydroacetic acid (DHA), sorbic acid (SOA), benzoic acid (BA) and salicylic acid (SA), the distillation was conducted under 90mmHg of pressure and at 50°C (water bath temperature: about 70°C), after addition of a 10ml of portion of 10% citric acid, suitable amouts of water, 20g of NaCl and 50g of MgSO4·7H2O, and adjusting pH to 2.0-2.5. 240ml of distillate was retained. 2) In the case of samples containing butyl p-hydroxy-hydroxy benzoate (POBA-Bu), the distillation was carried out at about 80°C (water bath temperature: about 95°C), and under the same low pressure, after addition of suitable amouts of water, 20g of NaCl, and adjusting pH to 3.0, and then 490ml of distillate was obtained. By the application of this method, the preservatives in foods could be recovered rapidly, and sucrose, in particular, among other ingredients in foods were almost never decomposed during the process.
There have been few reports in which Japanese cakes were examined for microbiological contamination from the standpoint of food hygiene. The present study was aimed at standardizing microbiological sanitary indices for Japanese cakes based on survey in which these cakes were bacteriologically examined. The frequency of coliform-group-positive samples was 44.0%, while that of samples in which more than 100 colonies per gram could be detected was 84.0% for viable counts, 50.0% for Staphylococci, 46.0% for yeasts or 62.0% for molds. There was a tendency that the more the viable counts, the more Staphylococci and yeasts counts as well as the detection ratio of coliform group. No coliform group organisms could be detected in samples with viable counts of less than 100 colonies per gram. From these results, it will be proposed that the existence of coliform group organisms and viable counts of more than 100 colonies per gram of samples are regarded as two most critical sanitary indices for Japanese cakes.