When yeast cells suspended for ten minutes in a solution containing each of four kinds of cationic detergents at a concentration of 0.25mM respectively were washed 3 times with water, 11% to 83% of the adsorbed detergents were removed. However, no significant reversal of the growth-inhibition was observed after such washing, as seen in Fig. 1. On the other hand, effects on the cell of washing with 10^-4M anionic detergents such as sodium lauryl sulfate or sodium laurate were presented in Fig. 3. Cells treated with cetyldimethylbenzylammonium chloride (C-Bz) or lauryl-3-chloro-2-hydroxypropylammonium chloride (L-Ep) showed considerable reversal of the growth-inhibition, while the growth of the cells treated with lauryldimethylbenzylammonium chloride (L-Bz) was more strongly inhibited by repeated washing with anionic detergents. As shown in Fig. 4, among the cationic detergents, C-Bz was the most efficient both in the degree and the rapidity of growth-inhibition, and the effectiveness decreased in the order of L-Ep, L-Bz, and cetyl-3-chloro-2-hydroxypropylammonium chloride (C-Ep). However, a relation between the effectiveness of a cationic detergent and the reversal of growth-inhibition by its elution was not clear.

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Twenty-five samples of spray-dried milk powder obtained from five dairy plants at various districts in Japan in May 1964, and six samples subjected to the previous work (the third report) were examined to clarify the flora of bacteria in them.
The examination of bacterial flora were made by picking all colonies on two or three plates of Plate Count Agar for the colony counts.
The predominating type of bacterial flora in samples from plant A and B was Bacillus. However, the type in samples from plant C as well as E, and in samples subjected to the previous work was enterococcus group, and in some cases it was enterococcus group only.

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Free sterols were prepared from a pure butter supplied from the National Institute of Animal Industry and six ordinary commercial butters. Steryl fraction dissolved in acetone was applied to Shimadzu GC-1B apparatus with hydrogen flame ionization detector. The glass column used was 4mm in diameter and 150cm in length and was packed with 1.5% SE-30 on silanized Chromosorb W 60/80. The column temperature was 235° and the flow rate of nitrogen gas 90ml/min, with the separated sterols being detected at 245°.
From the butter samples which had been confirmed to be negative to the phytosteryl acetate test, no phytosteryl peaks or only that of stigmasterol peaks were detected, on the contrary, three peaks corresponding to campesterol, stigmasterol and β-sitosterol were detected from the butter samples proved to be positive to the phytosteryl acetate test.
It can be concluded that a pure butter sample may contain stigmasterol in minute quantity as the essential component. When either campesterol or β-sitosterol was detected from a sample, the butter will be thought to have been adulted with vegetable fat and oil.

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The degradation mode of sorbic acid, dehydroacetic acid, methyl- and propyl-p-hydroxybenzoate in aqueous solution respectively was studied, using gas chromatographic assay method. It was noted that sorbic acid both in acidic and alkaline region was the most stable of these preservatives, whereas dehydroacetic acid was rapidly decomposed either in acidic or in strong alkaline and, hydrolysis of p-hydroxybenzoate was observed in alkaline region.
The simultaneous detection of 2, 6-dimethyl-4-pyrone, 2, 6-dimethyl-4-pyrone-3-carboxylic acid, triacetic acid lactone and 2, 6-dihydroxy-2, 5-heptadien-4-one (diacetylacetone) as presumable degradation products of dehydroacetic acid could be readily implemented with direct injection gas chromatography.
The degradation mechanisms of dehydroacetic acid and 2, 6-dimethyl-4-pyrone-3-carboxylic acid, both in acidic solution at 60° respectively, were followed by gas chromatography at a given time interval. As degradation products of dehydroacetic acid and 2, 6-dimethyl-4-pyrone-3-carboxylic acid, 2, 6-dihydroxy-2, 5-heptadien-4-one (diacetylacetone) and 2, 6-dimethyl-4-pyrone were identified with direct injection gas chromatography, and 3-carboxy-2, 6-dihydroxy-2, 5-heptadien-4-one was separable newly as the ester.
According to the degradation products, the degradation pathway of dehydroacetic acid in acidic solution was considered to be the fact that of the lactone ring dehydroacetic acid was first broken to produce 3-carboxy-2, 6-dihydroxy-2, 5-heptadien-4-one, and then its decarboxylation immediately following the reaction yielded 2, 6-dihydroxy-2, 5-heptadien-4-one, which was dehydrated finally to 2, 6-dimethyl-4-pyrone.

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A large amount of evidence has been reported to support the view that anions combine with positive groups on the albumin molecule. Therefore, anion-protein interaction in the range of pH 5.2 to 12.0 would involve the imidazolium groups of the histidine residues, the guanidinium groups of the arginine residues and the ∈-ammonium groups of the lysine residues of bovine plasma albumin molecule. In this paper, there is made the comparative study of the interactions of some food azo-dyes (Ponceau R, New Coccine and Orange G) and isoxanthene dyes (Erythrosine, Eosine, Phloxine and Rose Bengale) with native bovine plasma albumin. The study of these interactions after the modification of the protein molecule by the removal of these positive charges by different pH's may give information concerning the identification of the binding sites and in this paper the results, too, are reported.

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Thirty-six kinds of water-soluble food dyes permitted in Japan, U.S.A., U.K., and West Germany were classified into three groups in accordance with those positions of flow when they were chromatographed on paper with a mixture, as developing solvent, of 6 volumes of aceton, 5 volumes of iso-amylalcohol, and 5 volumes of water, by using Naphthol Yellow S and New Coccine as the standards.
Dyes of each group were then divisible according to the homogeneity of color.
Samples thus divided were submitted to high-voltage paper electrophoresis in the same manner reported in the previous paper (This Journal, 2, No. 2, 44 (1961)) by use of Sørensen buffer of pH 4, 6, 8, and 10, besides 5N HAcO and 0.1N NaOH as electrolytes.
The results obtained were compared with those of paper chromatography with the following three solvent systems.
Sol. 1 Butanol·Alcohol·0.5N NH₄OH (6: 2: 3)
Sol. 2 Butanol·Alcohol·0.5N HAcO (6: 2: 3)
Sol. 3 25% Alcohol·5% NH₄OH (1: 1)
Some similarity was found between paper electrophoresis and non-partition paper chromatography (e. g. Sol. 3), but (in the case of electrophoresis), electrophoretic zones were less diffused and the better separation of dyes having similar chemical structure was attained in general, as compared with that of paper chromatography.
A Table attached shows the systematic separation method for all dyes by means of paper electrophoresis and paper chromatography respectively.

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The yeast flora isolated from frozen food comprised mainly asporogenous species. They were represented by Candida (42%), Torulopsis (16%), Trichosporon (13%), Cryptococcus (11%), Rhodotorula (7%), Debaryomyces (7%), Sporobolomyces (2%) and Aureobasidium (2%). Most strains grew well at relatively low temperatures. More than half of the isolates started to grow within a week at -2°C. Strains belonged to the same species had nearly the same maximum growth temperature in spite of their different origins, either frozen food or non-frozen, except for Trich. cutaneum. So-called “obligately psychrophilic yeasts” had some common characters such as alcoholic fermentation, starch synthesis and nitrate assimilation, and supposed to be related taxonomically to each other.

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Of the microorganisms isolated from frozen foods, the following 50 strains of yeasts were identified: Sporobolomyces roseus Kluyver et van Niel (1 strain), Debaryomyces hansenii (Zopf) Lodder et van Rij (4 strains), Cryptococcus laurentii (Kufferath) Skinner (3 strains), Cr. albidus (Saito) Skinner (2 strains), Cr. luteolus (Saito) Skinner (1 strain), Torulopsis candida (Saito) Lodder (9 strains), Candida lipolytica (Harrison) Diddens et Lodder (1 strain), C. curvata (Diddens et Lodder) Lodder et van Rij (7 strains), C. zeylanoides (Cast.) Langeron et Guerra (4 strains), C. guilliermondii (Cast.) Langeron et Guerra (4 strains), Candida sp. (2 strains), Trichosporon cutaneum (De Beurm, Gougerot et Vaucher) Ota (6 strains), Trich. pullulans (Lindner) Diddens et Lodder (1 strain), Rhodotorula infirmo-miniata (Okunuki) Hasegawa et Banno (3 strains), R. glutinis (Fres.) Harrison (1 strain), and Aureobasidium pullulans (De Bary) Arnaud (1 strain).

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Hydrogen peroxide (H₂O₂) has been used for Japanese noodle for the purpose of bleaching, but in the case of packaged noodle, soaking in H₂O₂ solution and heating were expected considarable sterilizing effects, too.
Repeating the soakness of noodle, the concentration of the H₂O₂ solution was reduced. Therefore, it was necessary to keep the constant concentration of H₂O₂ in the solution. A new type of the test paper by which H₂O₂ concentration was checked, was developed. The white color of the paper in which Ti (SO₄) ₂ permeated, was changed yellow to orange according to the H₂O₂ concentration, when it was soaked in H₂O₂ solution. The effect of other substances against colorization was not observed.
The consumption of H₂O₂ by the treatment of soaking Japanese noodle in the period of process, consisted of one third of decomposition and the rest which was absorbed in noodle. Absorbed H₂O₂ to noodle was almost easily extracted with water, washing several times. Absorbed quantity of H₂O₂ was varied by the length of soaking period, H₂O₂ concentration, ratio of amounts of noodles and H₂O₂ solution and so on.
H₂O₂ was observed not only the surface absorption but also inner parts of noodle. Permeable velocity of H₂O₂ into noodle and the decomposed quantity of H₂O₂ in heating process were to do with the sterilization of it.
From the commercial products, just after the production, H₂O₂ was determined 300-500ppm (in the case of Japanese noodle), and 50-150ppm (spaghetti). This H₂O₂ decreased gradually, and almost vanished for one to three monthes under the ordinal storage conditions.

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Possible metabolites of Disyston were studied by means of thin-layer chromatography, IR spectrum and electron capture gas chromatography.
Ten ng of Disyston, 1-2ng of Disyston sulfoxide, 5ng of Disyston sulfone, 500ng of Systox, 5ng of Systox sulfoxide and 100ng of Systox sulfone were detectable on gas chromatograms, utilizing 2% Apiezon L and 1% 1, 4-Butandiolsuccinate as the stationary phase. And actually as the metabolic residues, Disyston sulfoxide and Systox sulfoxide were detected at the very low level in extracts of strawberries and edible roots of lilies.

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