Wistar rats were fed diets containing 13 food additives at dose levels of 1, 10 and 100 times the estimated daily intake by Japanese people for 1, 3 and 12 months. An increase of liver weight was observed at the medium dose level. The group that received the highest dose showed decreases in hematocrit value and body weight gain (female), and an increase in liver weight, mainly due to hyperplasia. After 12 months fatty degeneration of the liver occurred in females given the highest dose. It is likely that these pathological changes were caused by the synergistic effects of the food additives tested.

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A high performance liquid chromatographic method was established for the simultaneous quantitative determination of diphenyl (DP), o-phenylphenol (OPP) and thiabendazole (TBZ) in citrus fruits and banana. Dibasic sodium phosphate and anhydrous sodium sulfate were added to homogenized samples. The three food additives were extracted with ethyl acetate. They were separated within 20min on a 15cm reverse phase “Zorbax ODS” column with methanol-0.1N ammonia water as the mobile phase. DP was detected spectrophotometrically at 254nm. OPP and TBZ were detected spectrofluorometrically at an excitation wavelength of 285 or 305nm, with emission at 350nm. Recoveries of DP, OPP and TBZ from orange were 92.2%, 96.4% and 91.4%, respectively.

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The effects of two commercial emulsifiers (sucrose esters of fatty acids with C₁₆ and C₁₈ fatty acid moieties) on the growth, germination and/or outgrowth of six strains of the causative bacteria of O. A. flat sour spoilage were studied.
In the TSiF medium, both emulsifiers at concentrations higher than 100ppm inhibited the growth of all six strains. For germination and/or outgrowth, the minimal inhibitory concentration (MIC) of one of the emulsifiers was 10ppm and that of the other was 10 to 100ppm depending on the strain.
In the coffee medium, the highest MIC of both emulsifiers for growth, germination and/or outgrowth was 300ppm. In the shiruko medium, the highest MIC of one of the emulsifiers for growth was 5000ppm and that of the other was 6000ppm. The highest MIC of both emulsifiers for germination and/or outgrowth was 5000ppm.
It is concluded that the sucrose esters can prevent O. A. flat sour spoilage at 300ppm in canned coffee and at 5000ppm in canned shiruko. It is suggested that the addition of the sucrose esters would effectively prevent the spoilage of canned drinks kept hot in vending machines in Japan.

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The percentage contents of styrene (St) and α-methylstyrene (α-MSt) in St-based polymers such as polystyrene (PS), acrylonitrile-St (SAN) and acrylonitrile-butadiene-St (ABS) products were determined by pyrolysis-gas chromatography.
St-based polymers were dissolved in dichloromethane and 4μl of 5% polymer solution was used for the determination. The calibration curves from 40 to 200μg of PS and poly α-methylstyrene (Pα-MS) were linear.
Suitable pyrolysis temperatures for PS and Pα-MS for the formation of St and α-MSt were 500-640°C and 420-600°C, respectively. Moreover, the repeatability was found to be 1.61 and 2.22% for 0.2mg of the polymers, respectively.
Commercial St-based polymer materials such as containers, trays, lids, cups, sheets, ladles and graters were analyzed, and most of the samples were found to contain more than 50% St and/or α-MSt.

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A culture method was developed suitable for selective cell counting of bifidobacteria in Japanese commercial dairy and pharmaceutical bacteria products.
1) A dissolved agar medium was added at 45°C to the bacterial suspension in the bottom of a test tube to achieve a deep culture medium, then the culture was incubated. The present culture method in the agar column, tentatively called the test tube method by the authors, was suitable for carrying out anaerobic incubation for viable cell counting of bifidobacteria.
2) Modified Garche's agar with lithium chloride (MGL agar) or with lithium chloride and penicillin G potassium (MGLP agar) was demonstrated to be a suitable medium for the selective cell counting of bifidobacteria by the test tube method described, above since it discriminated the growth of lactobacilli and streptococci.
3) Bifidobacteria in commercial dairy and pharmaceutical bacteria products were determined satisfactorily by the present test tube method with MGL agar or with MGLP agar, except for products which contained enterococci.

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Since Salmonella or S. aureus was often detected in unpasteurized whole eggs when the quality control was inadequate, the behavior of these bacteria during the storing and processing of liquid whole eggs was examined under conditions similar to those in the plant.
1) Salmonella in whole eggs decreased at 5°C, but increased at 10°C. The count of S. aureus in whole eggs hardly changed at these temperatures.
2) At 25°C, the counts of these bacteria increased rapidly.
3) Storage at -20°C (frozen) resulted in only a slight change in the counts of these bacteria in whole eggs.
4) Though S. aureus showed greater resistance to the pasteurization of whole eggs than Salmonella, it should be possible to eliminate S. aureus under normal pasteurization conditions (at 60°C for 3.5min) in view of the low counts in usual unpasteurized whole eggs.
5) These bacteria, specially S. aureus, were not eliminated by spray-drying at 150-170°C, but were eliminated by heat-treatment of whole egg powder at 70°C.
6) It was observed that when “Atsuyaki” egg or custard cream was prepared, S. aureus in raw liquid whole eggs could be eliminated by heating to 80°C in the former case, and 90°C in the latter.
7) Though Salmonella and S. aureus hardly decreased during the preparation of mayonnaise with low acidity, they were eliminated on storing the mayonnaise for 2 to 6 days at room temperature.

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The water-soluble fraction of soybeans was extracted with 0.01M Tris-HCl buffer (pH 7.4). The low molecular weight fraction (F-II, MW.<10, 000) was separated from the soluble fraction by gel filtration on Sephadex G-50. The chemical forms of copper (Cu) in F-II were studied.
F-II was chromatographed over Sephadex G-25 (1.5×90cm) and Sephadex G-10 (2.0×80cm). Cu in F-II showed only one peak on the chromatogram. The elution volume of Cu in F-II was approximately one-half of that of inorganic copper (CuSO₄). The molecular weight of Cu in F-II was approximately 500-1, 500.
Upon addition of Cu to F-II, two new peaks appeared. One (F-IIA) was eluted before the native peak (F-IIB) and the other (F-IIC) after. The molecular weights of F-IIA and F-IIC were 1, 500-5, 000 and less than 500, respectively. These three components in F-II had different binding affinities for Cu (F-IIB>F-IIC>F-IIA).
All three Cu complexes in F-II were eluted together with nitrogen-containing materials, which were all ninhydrin-positive, but they were not eluted with sugars or phosphorus compounds.
Amino acid analyses of the three Cu complexes in F-II were carried out. The amino acid composition of F-IIA was similar to that of F-IIB, but differed from that of F-IIC. Approximately 35% of the amino acid residues in F-IIC were found to be arginine.
Both F-IIA and F-IIB showed ninhydrin-positive spots on a paper chromatogram. The Rf values of the spots from F-IIA and. F-IIB were different, and both were less than those of free amino acids. F-IIC showed several ninhydrin-positive peaks on a Sephadex G-10 chromatogram. Cu in F-IIC was eluted with ninhydrin-positive materials having an Rf value similar to that of arginine.

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A survey of mycotoxin contamination was carried out on a total of 94 samples of cereal grains and products. All samples were collected from commercial sources in Tokyo.
Aflatoxin B₁, B₂ and citrinin were detected together in 11 samples of corn flour in the range of 3.7-37, 2.3-9.9 and 10-98ppb, respectively. In addition, these mycotoxins were detected in 2 samples of corn grains imported from Thailand as raw material for corn flour.
This is the first report on the natural occurrence of this mixture of mycotoxins in commercial foods in Japan.
It is noteworthy that the samples from Thailand were also contaminated with Aspergillus flavus and Penicillium citrinum.

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Methods for the determination of ethoxyquin in spices were studied. Ethoxyquin was extracted from spice with iso-octane and re-extracted from the organic phase with 0.3N sulfuric acid containing 2% sodium sulfate. The acidic extract was made alkaline and extracted with iso-octane. Ethoxyquin in iso-octane was measured by spectrofluorimetry.
When its concentration was less than 1μg/g, the basic aqueous solution above was extracted with hexane. The hexane was evaporated off under a nitrogen atmosphere, and the residue was dissolved in acetonitrile. The prepared solution was measured by high-performance liquid chromatography on an RP-18 column with a fluorimetric detector. Butylated hydroxytoluene was included in the mobile phase to avoid on-column loss of ethoxyquin.
In a survey of commercial spices (chili powder, paprika, chili con carne, cayenne pepper, red pepper and chili pepper), ethoxyquin was detected at levels from 0.07 to 34μg/g in 26 out of 57 samples.
The present methods were found to be satisfactory for the quantitative determination of ethoxyquin in spices.

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In March 1980, mycotoxin-contaminated corn flour for sale in Tokyo was found for the first time by the mycotoxin examiner group of the Tokyo Metropolitan Research Laboratory of Public Health. After extensive investigation, it was ascertained that the corn flour was contaminated with a mixture of aflatoxins and citrinin. This flour was processed from imported corn by a corn mill company located in Kanagawa Prefecture. The Kanagawa Prefectural Public Health Laboratory therefore undertook an official mycotoxin survey of raw materials and finished products of corn which had been stocked at the corn mill company, checked for the presence of mycotoxins-producing molds in the milling process and finally carried out the sterilization of all equipment at the mill company. The results of a follow-up survey and the effect of the sterilization are reported in this paper.
All 3 samples of marketed corn flour, produced on various dates by U Company, were contaminated with aflatoxins (6.75-50.0ppb of B₁) and citrinin (13-22ppb).
All samples of raw-material corn obtained from U Company were contaminated with aflatoxins (3.50-41.5ppb of B₁), and 2 out of 3 samples tested were contaminated with citrinin (1.3-14ppb).
All 3 samples of finished-product corn flour from the same source were contaminated with aflatoxins (40.8-76.5ppb of B₁) and citrinin (9-56ppb).
On the other hand, no aflatoxins or citrinin were detected in any marketed corn flour, raw-material corn or finished-product corn flour derived from N Company.
Waste flour, “flour meal”, from U Company was found to be highly contaminated with aflatoxins (410ppb of B₁) and citrinin (133ppb). From this waste flour, large numbers of Aspergillus flavus and Penicillium citrinum were isolated and the production of aflatoxins (0.283-37.0μg/g of B₁), and citrinin (1, 300-4, 850μg/g) was chemically detected in 50% of the A. flavus strains and 100% of the P. citrinum strains examined, respectively.
Since contamination of the millhouse equipment with A. flavus was discovered, all equipment was cleaned mechanically and sterilized by washing with a 1% solution of sodium hypochlorite.
Even after the sterilization, A. flavus contamination in the impact mill system was still observed, so the impact mill was disassembled and re-sterilized by burning in addition to washing with the sodium hypochlorite solution.
After the re-sterilization, no molds were isolated from any part of the impact mill.

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An analytical method for multiresidues of organochlorine and organophosphorus pesticides, including ethoprop (O-ethyl S, S-dipropylphosphorodithioate, prophos, Mocap^®), a nematocide, in crops was developed.
The method consisted of extraction with a mixture of acetone and n-hexane, clean-up by florisil column chromatography and determination by gas chromatography (GC). The pesticides on the column were eluted with 200ml each of 15% ether in n-hexane and ether. Ethoprop was eluted in the second fraction and determined by FPD-GC, organochlorine pesticides were eluted in the first fraction and determined by ECD-GC, and organophosphorus pesticides were eluted in both fractions and determined by FPD-GC.
A recovery test was carried out by fortification of 5 crops, and the recoveries of ethoprop were in the range of 81% to 95%. The recoveries of organophosphorus pesticides from banana and corn were in the range of 71% to 96%. Furthermore, ethoprop in banana could be identified by GC-MS.

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