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In this present report, the method to determine sterilization effect by means of counting the number of colonies has been mathematico-statistically analyzed.
This method is generally accepted to result in a wide dispersion of measured effects.
The error factors of this method are discussed by using the variance or standard deviation and relations between these, factors are expressed by using a few equations.
It is found that the dispersion of the estimated value of sterilization effect; mortality, can be expressed as shown in eqntions 11, 12.
Thus, the dispersion of the number of colonies cultured in each petri dish (σX_ij) and the dispersion of the estimated value of the number of survived spores in their suspensions (σX_i) are obtained experimentally. And these dispersions can be expressed as shown in (2) - (5) and (6) (7).
When using improved method proposed herein, the dispersions of sampling errors will equal to those of measuring errors.
It is concluded from the above presentation that the dispersion of mortality measured by means of using the improved method is much smaller than that measured by the conventiOnal method.

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Time and dosage-mortality curves are obtained experimentally, first, of Aspergillus oryzae to which methyl bromide was applied and second, of Penicillium islandicum to which chloropicrin was applied.
It is confirmed through a X²-test that these curves represent a normal distribution on the time and dosage and are expressed as sigmoid curves. These findings give many suggestions which would help determine a practical combination of fumigation conditions applicable to food.
These findings also suggest a means of expressing fumigation effectiveness.

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To investigate the decomposition of margarine during storage, 6 samples of margarine for household use and 7 samples of margarine for bakery use were stored at 5°C and 30°C for twelve months, and AV and POV of these margarines were determined every month.
Samples kept at 5°C were little decomposed, but samples kept at 30°C, particularly margarines for bakery use, extremely decomposed.
Fats were separated from samples after finishing the storage test, and m. p., SV, IV, ThV and colour of these fats were determined respectively.
The fats separated from samples kept at 5°C were little decomposed, but those separated from samples kept at 30°C showed the increase in S V, the decrease in IV and ThV, and decolourization in response to the degree of decomposition.

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Although it is considered that vitamin B₁₂ and its analogues are not contained in vegetable foods as are they often called “Animal Protein Factor”, it was found that vitamin B₁₂ group was contained in such vegetables grown in the mud as arrow head (Sagittaria sagittifolia L. var. sinensis Makino), Lotus-rhizome (Rhizome of Nelumbo nucifera), Brasenia schreberi, and also in bamboo sprout grown in the soil, but these amounts were not so much.

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Phar nacological studies on microbial rennet which was isolated from culture media obtained by fermentation with Mucor pussillus were performed, and the results were as follows:
1) By daily oral administration, microbial rennet does not inhibit the growth of young rats, but promotes their growth by a certain dose.
2) But by parenteral administration, microbial rennet causes some toxic and pharmacological effects.

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Pharmacological studies on microbial lipase which was isolated from culture media obtained by fermentation with Candida paralipolytica or Candida cylindracea were performed.
1) By daily oral administration, microbial lipase had no influence upon the growth of young rats during the period of 10 weeks.
2) But by parenteral administration microbial lipase caused some toxic and pharmacological effects.

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The color reaction with a 0.5% alcoholic solution of aromatic amine and the irradiation of ultraviolet light resulted in the feasibility of detecting a few μg of chlorinated pesticides on the thin-layer chromatogram. Sensitivities by the various chromogenic agents used in this method are given in Table 2.
Obtained Rf values of the chlorinated pesticides and photocopy of their chromatogram are given in Table 3 and Figure 1
Stahl has indicated that more precise Rf values could be acquired by considering the correlation between each Rf value of chemical compounds and that of a standard dye. Then we used a 0.5% benzene solution of anthracene in substitute for the standard dye he described. According to our experiments, the spots of both DDT and anthracene always show the same Rf values so that we are able to presumably identify not only DDT but other pesticides in comparison with a spot of anthracene, even if in the absence of standard pesticides.

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Construction and efficiency of “Gasu-netsuzoko”, a preservation-box with gas heating type were studied from a food-hygienic view-point. As a result of our research, several parts of the instrument were pointed out to be improved in view of its construction.

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Changes of food quality stored in a preservation-box with gas heating type were compared with those in the case of cold storage and keeping at room temperature. Foods stored in the preservation-box with gas heating type somewhat degraded in their appearance, colour and taste, but they were still good to eat.

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Under practical uses conditions of a preservation-box with gas heating type heat resistance test on several microorganisms, e. g. E. coli, Sh. flexineri, St. aureus, Vib. parahaemolyticus, Sac. carlsbergensis, Lact. casei, Asp. niger and B. subtilis, which are deeply in connection with our daily life, was carried out.
As a result, the preservation-box with gas heating type was found to be effective in bacteriocidal and bacteriostatic actions.

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[in Japanese]

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[in Japanese]

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