Thermophilic, obligate anaerobes were isolated from flat sour spoiled canned “Shiruko” which had been retailed in an automatic hot vending machine. The spoiled canned “Shiruko” showed significantly reduced pH of the contents without swelling of the cans, resulting from the production of acetic acid.
The isolated bacteria were spore-forming, Gram-positive rods. The spores were round and terminal or subterminal. The vegetative cells appeared to swell at the time of sporulation. The optimum temperature for growth ranged from 58°C to 60°C, and no growth was seen above 70°C or below 40°C. The organisms fermented fructose, glucose, inositol, ribose and pyruvate to acetate without gas production. Gelatin not hydrolyzed. Nitrate was reduced to nitrite, but sulfate was not reduced to sulfite. The G+C contents of the DNA of these isolates were estimated to be 53.2mol% (Tm). From these taxonomical characteristics, the isolates were presumed to be similar to Clostridium thermoaceticum, although the growth did not depend on Carbon dioxide/bicarbonate and the organisms did not ferment xylose.
The cellular fatty acid compositions of the isolates were determined: iso-C_15:0 and iso-C_17:0 were predominant species, while hydroxy- and cyclopropane-fatty acids were not detected.

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Aflatoxins and aflatoxicols were analyzed as contaminants in nuts, cereals and their products. Aflatoxin (AF) B group and G group were detected in 7 pistachio nuts, 5 corn flours and 2 corns for feed, and among them AF-M group and aflatoxicols were simultaneously detected in 6 pistachio nuts and 2 corns for feed. The contents of AF B group, G group, M group and aflatoxicols were compared.
AF-M₁, AF-M₂ and aflatoxicols (AFL) I and II were not detected in 2 pistachio nuts in which other aflatoxins were detected (B₁ 2.0, 4.7ppb; B₂ 0.4, 1.3ppb; G₁ 0.6ppb; and G₂ 0.2ppb) or in 5 corn flours in which other aflatoxins were detected (B₁ 11.1-33.6ppb; and B₂ 5.3-9.9ppb).
However, AF-M₁ was detected at the level of 1.8-39.3ppb and AFL-I was detected at the level of 3.2-26.3ppb in 5 pistachio nuts in which other aflatoxins were detected (B₁ 47.1-800ppb; B₂ 6.3-180ppb; G₁ Tr-51.4ppb; and G₂ Tr-16.3ppb). AF-M₁ was detected at 13.5, 25.0ppb, AFL-I was detected at 12.9, 25.4ppb and AFL-II was detected at 7.9, 15.7ppb in 2 corns for feed in which other aflatoxins were detected (B₁ 131, 340ppb; and B₂ 17.1, 46.9ppb).
Aflatoxicols I and II from pistachio nuts and corns for feed were identified as follows.
1) They were developed by several solvent systems.
2) Their fluorescence excitation and emission spectra were measured on a silica gel 60 plate after development with ethyl ether. The spots were scraped from the plate and eluted with chloroform, then the fluorescence excitation and emission spectra were measured again in chloroform.
3) Their acetate derivatives were prepared.

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The stability of sorbic acid to light and the interaction of sorbic acid with sulfur-containing amino acids were studied. It was found that the trans-trans form of sorbic acid was markedly isomerized by ultraviolet irradiation. The stability of sorbic acid fell markedly and the formation of TBA-active substances increased remarkably in the presence of cysteine and cystine under all conditions of irradiation with ultraviolet and fluorescent light, and even on standing in the dark. These reactions were inhibited by ascorbic acid, propyl gallate and dibutyl hydroxy toluene, but were stimulated by ferric salts and histidine. The main reaction product was identified as 5-(S-cysteinyl)-3-hexanoic acid, which was formed from sorbic acid and cysteine under all the conditions tested.

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In order to elucidate the mechanism involved in the toxification of trumpet shell, Charonia sauliae, with tetrodotoxin (TTX), nontoxic trumpet shells were fed with toxic specimens of a starfish, Astropecten polyacanthus, for one to four weeks. All the digestive glands of the trumpet shells became toxic after one week of feeding. The accumulation/administration value (percent) of TTX was 33% on average, and the total amount of accumulated toxin tended to increase with the amount administered.
It was found by feeding of the toxified trumpet shells with nontoxic mackerel meat that the accumulated toxin is not readily metabolized in and/or excreted from the trumpet shell.

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A method was developed for the determination of solanine in potato by high performance liquid chromatography (HPLC). Solanine was extracted from potato with methanol, and 20μl of the filtrate was injected into a high performance liquid chromatograph. HPLC was performed on a stainless steel column packed with Patisil 10 ODS, with methanol (pH 3 with phosphoric acid) as the mobile phase. The retention time of solanine was about 7min. The average recovery of solanine was 91.6% and the lower limit of detection was 5ppm.
This method was applied for the determination of solanine in potatoes stored for 3-6 months in a dark room and in commercial potato products. Solanine was detected only in sprouts and green potato tubers. The contents were 0.86-2.21mg% in the periderm and 0.85-1.23mg% in the cortex of green potato tuber, and 1.22-7.43mg% in sprouts. No solanine was detected in other foods tested.

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The effects of washing and boiling on pyrethroid insecticides (Allethrin, Resmethrin, Phthalthrin, Permethrin and Pyrethrin) applied to the surfaces of agricultural products were studied. Pyrethroid insecticides were removed most effectively by using liquid detergent for kitchen use, but were scarcely removed by washing with water alone. Pyrethroid insecticides decreased by 80 to 90% after boiling of spinach treated with them. Pyrethrin II was most stable to boiling among the isomers of Pyrethrin.

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A method was developed for the determination of residual gossypol in edible cottonseed oil by high performance liquid chromatography. Gossypol in cottonseed oil was dissolved in n-hexane containing a little tetrahydrofuran, and then extracted with acetonitrile. The acetonitrile layer was concentrated and made up to volume with tetrahydrofuran. The test solution was injected into a high performance liquid chromatograph.
Recoveries of gossypol added to cottonseed oil at levels of 50 and 200μg/10g were 87.4 and 93.7%, respectively. In heating experiments (180°C for 5, 15 and 30 minutes), it was found that the amount of gossypol added to cottonseed oil decreased with heating time. By this method, no gossypol (less than 1μg/g) was detectable in commercial edible cottonseed oil.

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[in Japanese]

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