Changes of invertase activity, sugar contents and astringency in Japanese persimmon fruits (Diospyros kaki Thunb.) during maturation, storage and processing were studied by gas chromatoraphy. Results were as follows; (1) Optimum pH of invertase activity was aroud 5.5 and optimum temperature was about 30-40°C. (2) Invertase activity per 1g of fruit was 80-230 nano Katal (4.8-13.8U)at 30°C, pH 5.5. (3) Invertase activity was proved to increase during storage and various methods of deastringency, that is alcohol (25%) spraying, alcohol powder of (prepared with starch and ethanol) spraying and sun-drying with or without sulfur fumigation.

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On the application of animal blood to food, blood plasma has already been put to practical use in food industry, whereas red blood cell cannot be fully utilized mainly because of the color due to heme-pigment. We investigated the possibility of utilization of red blood cell as food materials by enzymatic hydrolysis to peptide and subsequent decolorization. The results obtained are as follows. The recovery in protein of the enzymatic hydrolysate of red blood cell (EHB) was 56% in pilot plant scale. EHB was white hygroscopic powder with saltishness and slight bitterness. Its protein score was 5. EHB was composed of more than forty kinds of low molecular weight peptides of which molecular weight ranged mainly 1000-2000. With respect to food funitional properties, EHB possessed good solubility, but not emulsifying, foaming, whipping and gelling capacities, so that it may be used only as protein supplements. In the application to processed meat products, it was possible to add 0.5% EHB to cooked ham 2.5% to pork sausege and 2.5% to hamburg.

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As a part of studies on the effective utilization of red blood cell, hydrolysate from pork red blood cell (EHB) were prepared by enzymatic hydrolysis and studied on application as media materials for bacteria. In this study, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Micrococcus luteus, Staphylococcus aureus, Streptococcus thermophilus, Lactobacillus bulgaricus and Lactbacillus plantarum were used as tested bacteria. The growth of these bacteria were examined on the medium containing 1.0% of EHB (EHB medium) as a nitrogen source which is to be compared with casein peptone (Trypticase, BBL). The results obtained are as follows: (1) EHB was mainly consisted of lower molecular weight peptides, about 200-1000 M.W., and its amino acid contents were richer in histidine, alanine and glycine and poorer in tryptophan, methionine and isoleucine than Trypticase. (2) S. aureus, L. plantarum and gram-negative bacteria showed good growth on the EHB medium, and no difference in the efficiency as media materials between Trypticase and EHB was recognized. However, the growth of the other bacteria were relatively poor, as compared with Trypticase. (3) The growth of these bacteria which showed less growth on the EHB medium was improved by adding 0.0459% of isoleucine, 0.124% of glutamic acid or 0.5% of yeast extract to the EHB medium. (4) S. aureus, S. thermophilus, L. bulgaricus especially P. fluorescens and L. plantarum were inhibited when the EHB was partially replaced by the enzymatic hydrolysate from pork blood plasma (EHP) in the EHB medium, and it is suggested that some inhibitory substances for growth of bacteria exist in EHP.

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Three pectic polysaccharide preparations (HXSP, from uncooked cotyledons; HWIP, from cooked ones; HWSP, from the cooking soup) were fractionated into neutral (I) and acidic (II, III and IV) fractions by DEAE-cellulose chromatography. II and III, the major components, were analyzed in more detail. The uronic acid contents of II and III from HXSP were about 40 and 45%, respectively, while those of II and III from HWSP and also from HWIP were about 46 and 50%, respectively. The degree of esterification of the pectic polysaccharides was generally low; about 20% for II and III from HXSP, about 10-15% for those from HWSP and HWIP. In each case, II was composed mostly of high molecular weight polysaccharides (MW: above 5×10⁵), whereas the greater part of III was low molecular weight polysaccharides (MW: below 1×10⁴). Analysis of sugars showed that xylose and arabinose amounted together to about 70% of the neutral sugars in each fraction, the xylose: arabinose ratio in II and III being about 1:1 and 4.5:1, respectively. In addition, considerable amounts of galactose and mannose, and small amounts of rhamnose and glucouse were detected. After heating in hot neutral solutions, all the fractions gave a negative thiobarbituric acid test for unsaturated pectic acids, the degradation products of pectin by transelimination. These results indicate that the pectic polysaccharides of Adzuki bean cotyledons are fairly stable during cooking.

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The antioxidant efficiencies of α-, γ- and δ-tocopherols (Toc) were comparatively investigated by the evaluation of oxidative stability of potato chips fried by lard and palm oil based on the change of peroxide value at 60°C. (1) In the case of potato chips fried by lard, the antioxidant efficiency of α-Toc was the weakest, and that of δ-Toc was somewhat stronger than that of γ-Toc. Also, the addition of 0.05% δ-Toc to lard was more effective than that of 0.02%. (2) Each Toc did not show any effect on the oxidation of the potato chips fried by palm oil. (3) In the case of using a mixture of α-, γ- and δ-Toc, the mixture showed better effect on the oxidation of the potato chips fried by lard according to the decrease of the percentage of α-Toc. (4) During the storage of potato chips at 60°C, Toc contained in chips fried by lard was disappeared more rapidly than that of palm oil. The disappearance of Tco was rapid by the order ofα>γ>δ.

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Changes in the contents of low molecular weight carbohydrates, polysaccharides and organic acids in pilei and stipes of fruit-bodies of Shiitake mushroom [Lentinus edodes (Berk.) Sing.] during development and post-harvest storage at 20°C were investigated. (1) The total free sugar content in pilei during development was found in the range of 2.3-7.0% in dry materials, and 2.9-4.5% in stipes, respectively, while the total sugaralcohol content 8.8-12.8% in pilei, and 12-5-23.3% in stipes, respectively. In this mushroom, trehalose, mannitol, arabitol, glucose and fructose were identified, and trehalose, arabitol and mannitol were found to be major among them. The contents of each element varied individually during the development, and there was remarkable difference between pilei and stipes. Especially the accumulation of trehalose was found in pilei, and that of arabitol in stipes during the last development. During post-havest storage, the contents of each element decreased without any exception. Especially the decrease in arabitol was marked. (2) The polysaccharide content in pilei during development was in the range of 38.8-40.2%, and 50.4-51.5% in stipes, respectively. The polysaccharide contents in stipes were 1.25-1.32 times as much as those in pilei. The five polysacchride fraction contents: formic acid-soluble fraction (R-glucan), alkali-soluble, acid-soluble fraction, hot alkli-soluble fraction, alkali-soluble, acid-insoluble fraction (S-glucan) and chitin had no change during development and post-harvest storage, but the content of acetic acid-solule fraction decreased during storage. (3) The contents of organic acids in pilei during development was found in the range of 1.8-3.0%, and in stipes 1.3-1.9%. The changing pattern of organic acid contents in pilei was different from that in stipes. The content of organic acid during post-harvest storage increased for the first three days, but it decreased from then on. In this mushrom, ten kinds of organic acids were identified. Malic, pyroglutamic, fumaric and citric acids were found to be major among them. The contents of each element varied individually during development, and the changing patterns of pilei and stipes were different. The contents of fumaric, pyroglutamic and citric acids during post-harvest storage increased for the first three days, but from then on they decreased. The contents of the rest decreased.

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Free sugars, free sugaralcohols and organic acids in the ethanolic extracts of forty-one species of wild mushrooms were investigated by gas-liquid chromatography. The results obtained were as follows: The amounts of total free sugars and total free sugaralcohols obtained from these wild mushrooms were found in the range of 0.1-29.3% (the mean value; 9.95%) and 0.7-29.3% (the mean value: 11.05%) in dry materials, respectively. In these mushrooms, four kinds of free sugars (trehalose, glucose, fructose and galactose) and four kinds of free sugaralcohols (mannitol, arabitol, mesoerythritol and glycerol) were identified. Trehalose and mannitol were found to be predominant in samples, and glycerol, fructose were also found in all the samples, and meso-erythritol was found in Shirohatsu mushroom (Russula chloroides). The distribution patterns and contents of free sugaralcohols had low similarities among different species of mushroom. Organic acid contents were found in the range of 0.1-4.5% (the mean value: 1.56%) in dry materials and eleven kinds of organic acids (malic, citric, fumaric, succinic, pyroglutamic, oxalic, α-ketoglutaric, lactic, tartaric, acetic and formic acids) were identified. Malic, citric, fumaric, succinic, pyroglutamic and oxalic acids were found to be predominant in samples, and acetic and formic acid were also found in all the samples. There were remarkable differences in the distribution patterns of organic acid compositions among the different species of mushroom.

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The actual state of sorbic acid and benzoic acid contents in meat products without preservatives, and their origins were studied. Samples were purified by steam distillation and extraction with ethyl ether. Sorbic acid and benzoic acid in the extract were determined by gas chromatography and identified by gas chromatographic mass spectrometry. Forty-seven of commerecial meat products without preservatives were analyzed. Sorbic acid was found in 17 samples in the range of 0.1-2.4ppm. Benzoic acid was found in all samples in the range of 0.1-8.6ppm. Therefore, the changes in sorbic acid and benzoic acid in wiener sausage without preservatives during manufacturing process were examined. Sorbic acid was detected in the manufactures where the sorbic acid was used to the other meat products, and most of them were found in cooking process. A trace amount of sobic acid was found in a wiener sausage without sorbic acid when the wiener sausages with or without it were dried, smoked and cooked in same smoking room at the same time. These results suggested that a part of sorbic acid added to meat products transferred to those without preservatives in smoking room. Benzoic acid was detected in all manufactures, and all of them were found in stuffing process. Benzoic acid originated from the additives such as spices and aqueous smoke condensate and the smoke.

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The effect of storage and heat treatments on the sugar constituents of cassava and yambean roots were investigated using a high performance liquid chromatography (HPLC). Essentially, the total sugar content increased during the first one or two weeks of any 18-28 days storage period. Also, the ratios of fructose and glucose to total sugar content increased, while the ratios of sucrose and inositol decreased. The linamarin content increased markedly in the first 7 days, and continued to increase for several additional days; then it gradually declined and almost disappeared before decay. In yambean root, the three sugars of glucose, fructose and sucrose were found. Although heat treatments by boiling, roasting, and drying all tended to increase the total sugar content of these roots, the linamarin content of cassava roots and of finely-chopped cassava leaves significantly showed a tendency to decrease by such treatments. Investigated at the same time were changes in the constituent pectic substances of these roots. Finally, the changes in appearance occurring in cassave root tissue during storage and heat treatment were observed by a scanning electron microscope (SEM).

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The conductometric flow injection method was applied to measuring the salt contents in soy sauce and worcester sauce. When the dilution ratio of the system was 1 part of soy sauce to 885 parts of water (1:885), the regression line between salt content in soy sauce and peak conductivity showed the straight line with a correlation coefficient of 0.994. The coexistent electolyte such as amino acids and sodium benzoate did not interfere in the measurement. For worcester sauce measurement, the dilution ratio was set to be 1:354. The regression line between salt content in worcester sauce and peak conductivity showed the straight line with a correlation coefficient of 0.997. The coexistent acetic acid did not interfer in the measurement. The salt contents measured by the proposed method were also compared with those measured by argentometry, ion selective electrodes methods and flame photometry.

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