For the utilization of protein in the surplus activated sludge, the conditions to liberate the amino acids from the sludge protein were investigated employing pronase (proteinase from Str. griceus) to digest for 72 hours at 50°C after mild hydrolysis with dilute hydrochloric acid or sulfuric acid.
For the liquefaction over 80% of total nitrogen of the sludge, the following conditions of preheating with acids are necessary: 1) 10ml/g of acid over 0.5N for 60 minutes or 1N for 30 minutes at 120°C and 0.25N for 60 minutes or 0.5N for 30 minutes at 140°C. 2) 60ml/g of acid over 0.1N for 60 minutes or 0.5N for 30 minutes at 120°C and 0.01N for 60 minutes or 0.05N for 30 minutes at 140°C. The residual rates of tryptophan in the sludge on the pretreatment at 140°C for 60 minutes under 1N of acids in the above conditions were over 30% of the total amount in the sludge. (Received Dec. 9, 1971)

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To evaluate single cell proteins as food resources, both the baker's yeast (Saccharomyces) and the yeast of Candida family grown on n-paraffin were comparably subjected to the study. Extraction with heated alkali and successive precipitation at about pH 4.5 were tested to isolate protein from the cells of the above stated yeast. From the evidences experimentally obtained here, conditions in question in the present study, regarding the strength of applied alkali and its tempeature to obtain the hignest recovery of protein from the cell, were found to be as follows; extraction at 80° to 90°C for 30 to 60 minutes with 0.1 to 0.25N sodium hydroxide (approximately 100mg per g of the dried cell) was found to be the most favorable when the resulted liquid was examined in the soluble nitrogen, liberated amino acid potency, ammoniacal nitrogen level, and the total nitrogen of trichloracetic acid precipitates, of tungstate precipitates or of isoionic precipitates as the criteria. Conditions for extraction from Candida yeast were slightly milder than those conditions required for baker's yeast. Inferior extraction yield was observed in harder dehydrating conditions at 130°C of cell. Over 80% crude protein and crude ash less than 0.1% were recorded with the pH 4.5 isoionic precipitates from the supernatant liquid treated at 80°C for 60 minutes with 20 folds of 0.125N sodium hydroxide solution.

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To investigate the conditions to isolate proteins from Candida cultivated on n-paraffin and partly from a baker's yeast, the quality and quantity of their protein on the total soluble nitrogen and nucleic acid fractionated by gel filtration with Sephadex G-50 were examined to compare the adaptability of the following condition; with the solution of varied strength of alkali or at varied temperature, extraction with deionized water, with 5% trichloracetic acid and with 0.5% saline. As the results, the condition of extraction by 20ml of 0.125N sodium hydroxide solution per g of dried yeast, at 80°C for 60 minutes was the favorable condition to isolate the proteins from yeast cells. A major protein precipitated at pH 4.5 isoionic point, whose molecular weight approximately over 35, 000, was recovered at 35% of the crude protein of the yeast. It was found that little amount of nucleic acid moiety was contained in the isoionic precipitate. The elution patterns of gel filtration of the extracts of yeast by deionized water at a higher temperature, of 5% trichloracetic acid extraction and of 0.5% sodium chloride showed that they also include the protein of over ca 35, 000 of the molecular weight.

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It has been known that carotenoids in tomato pulp are very stable as compared with carotenoid in a free state. Flavonoids with antioxidant activity have been found in some vegetables and fruits. As one of the reasons why carotenoids in tomato pulp are stable, the antioxidant activity of tomato extracts was focused in this study. Antioxidant activity of raw tomato extracts, tomato juice and several flavonoids was examined by the cup-plate assay method described by Blain.
Tomato extracts showed both carotene bleaching activity and antioxidant activity. Antioxidant activity was the highest in quercitrin, followed by rutin and quercetin in this order and scarcely in naringin and narigenin. When carotene bleaching activity was extremely stronger than antioxidant activity, double bleaching zones appeared in the cup-plate assay. Antioxidant activity was also found in the product of tomato juice, and varied among them probably due to the difference in variety, maturity and growing place of the tomatoes.

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Conditions described here were air (room temperature), air (0°C), 9%CO₂-3%O₂ (0°C), 6%CO₂-3%O₂ (0°C), and 3%CO₂-3%O₂ (0°C). Relative humidity of CA-chambers was 85-90% and a CAchamber with lower humidity was also equipped.
There was no difference between the moisture losses (4-8%) of the nuts in air (at 0°C) and in CA condition after the storage period of 200 days, while the loss of moisture of the nuts in air (at room temperature) was 40%. Sprouting and rooting of the nuts was completely inhibited during the storage at 0°C. The nuts (cotyledon) stored for 3 months in air at 0°C began to brown when they were boiled for processing. The higher levels of CO₂ concentration (9% and 6%) delayed the ocurrence of the browning to 7 month after the nuts were stored.
Polyphenol content of the nuts increased gradually during the storage at 0°C and the increasing rate was depressed with higher concentration of CO₂ in the storage atmosphere. Immediately after being removed from cold storage room to a warm, especially from the CA-storage of 6%CO₂-3%O₂, polyphenol content in nuts increased sharply. Mold development was first observed at 6 months after stored at 0°C and 10% of the nuts were infected with mold after 10 month storage. The low humidity (70%) in a chamber reduced the development of mold growth.
From above observation, it was suggested that the optimum condition of CA-storage (at 0°C) for chestnuts was 6%CO₂-3%O₂ of atmosphere and 85-90% of relative humidity and that the storage life of chestnuts in CA storage was 8 months for the use of processing and 10 months for fresh fruits.

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The brine consisting 5% of NaOH, 10% of NaCl and 2% of black teal is the most suitable for making Pidan from quail's egg.
After immersing eggs in the brine for 12 days, the ripening period more than 15 days is essential to obtain mild flavor product.
The amounts of volatile basic nitrogen in egg white and yolk increased slightly during the immersing period. They were relatively high after the ripening.
During the immersing period, the amounts of hydrogen sulfide increased greatly both in egg white and yolk. While the hydrogen sulfide contents in egg white decreased gradually during the ripening.

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