Effects of heat-dry or heat-moisture treatment on physicochemical properties of rice flour were investigated. The particle size and the degree of damaged starch of heat-dry treated (HDT) rice flour were smaller than the untreated and heat-moisture treated (HMT) rice flours. To α-amylase hydrolysis HMT rice flour was less resistant than those of untreated and HDT rice flours. Swelling-power and solubility of HDT and HMT rice ftours were considerably suppressed. The peak viscosity in the RVA viscograms decreased with increasing temperature of heat-dry and heat-moisture treatments. The onset temperature of gelatinization in heating DSC curves shifted to higher temperatures with increasing temperature of heat-moisture treatment. The alteration of the thermal properties of HMT rice flour was attributed to the changes in rigidity of starch granules and their surroundings during the treatment. The X-ray diffraction patterns of HMT rice flour indicated that amylose-lipid complexes were formed during the heat-moisture treatment.

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In this study, we aim to verify the freshness-preserving effects of contact dehydration sheets (CDS) on pacific mackerel and Japanese sardine using K value, total volatile base nitrogen (T-VBN), and viable cell count as freshness indicators. The amounts of drip and moisture contents of two fish, one wrapped with CDS and the other with poly (vinylidene chloride) film (control), were also measured to compare the freshness-preserving effects of CDS. After two days of storage, K values for pacific mackerel wrapped with poly (vinylidene chloride) film reached 30%, indicating that they are unsuitable for raw consumption, while K values for pacific mackerel wrapped with CDS were less than 20%, indicating that they are suitable for raw consumption. Similar differences in T-VBN were also observed after two days of storage. The treatment effects were more pronounced for pacific mackerel than for Japanese sardine. No significant differences in viable cell count between the two treatments throughout the storage period for either fish were observed. Judging from the results of drip loss and moisture content, CDS appears capable of absorbing the majority of the excess moisture. The differences in moisture content between the two treatments were 10% for pacific mackerel and 4% for Japanese sardine after one day of storage. The distinct freshness-preserving effects of CDS on the K value and T-VBN seem to be due to a decline in the catalytic reaction speed of enzymes, which is a result of reduced drip.

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The effects of absorbed moisture on textural properties were studied with twenty-seven kinds of commercial confections made from different starch ingredients (i.e., wheat, corn, potato and rice) and natural fried chips made of potato, fruits and vegetables.
(1) On moisture absorption at R.H. 43-97%, the initial elastic modulus of all the test samples decreased with increasing absorbed moisture.
(2) Changes in the maximum breaking force and breaking energy began to occur at R.H. 43-56%, and these characteristic breaking properties could be observed within R.H. 68-88%; some samples became softer and a lot of the other samples became harder at approximately 9-16g of water/100g of dry matter.
(3) A high positive correlation between the breaking properties of samples under high moisture surroundings and their gelatinization characteristics was obtained.

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Soluble (SDF), insoluble (IDF), and total dietary fiber (TDF) contents were determined in soybeans cultivated in different countries, i.e. Japan, U.S.A., China, Brazil, Paraguay and Argentina in 1992 to1994, and further their variation in five apanese cultivars in 1993 was evaluated. On the average value on dry matter basis of soybeans, SDF was observed significantly high in soybeans from Japan (1.88%), U.S.A. (1.50%) and China (1.61%), and IDF and TDF were comparable in all the samples sted. The ratio of IDF to SDF was ranged from 9 (Japan) to 15 (Brazil). Coefficient of variation (CV) was large in SDF and small in IDF and TDF in the samples of all countries. Among the Japanese cultivars, the CV values of SDF differed distinctly, i. e. mall in Akishirome and Tamahomare, and large in Enrei and Fukuyutaka. On SDF measurement, protein contents of heresidue were high in Enrei andFukuyutaka, and low in Akishirome and Tamahomare. The CV value of SDF in the cultivars correlated positively with the protein content of the residue which also correlated positively with the protein content of soybeans. From these results, the variation of SDF content was proved to be influenced by the protein content of soybeans. The same tendency was observed on the residue of IDF, but the CV values were small. Accordingly, it is considered that the differences between SDF and IDF in the CV value were attributable to the protein content ratio in the residue, namely, the ratio in IDF was small. On the correlation between dietary fiber contents and other measured values, following negative correlations were observed; SDF with oil value of soybeans, IDF and TDF withprotein value of soybeans, and IDF with 100-seed-weight. Negative correlations were also observed on IDF and TDF with the protein content of each residue. In conclusion, the protein content of soybeans influenced on IDF and TDF values, but not on SDF value. Ash content of each residue is not correlated to SDF, IDF, and TDF values.

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To apply controlled atmosphere (CA) storage to leafy vegetables, this experiment was examined the effect of composition of CO₂ and O₂ on the respiration and quality preservation of spinach (Spinacia oleracea L.). The CO₂ output rate of spinach was reduced from 0% to 5% of CO₂ due to elevated CO₂ and/or reduced O₂ level in the atmosphere. For over 5% of CO₂, regardless of the CO₂ level, the CO₂ output rate was reduced with reducing O₂ level. The respiration quotient that is qualitative indicator of respiration was unity for the CO₂ range between 0% to 5%. This fact showed that the aerobic respiration continued in those conditions. High preservation of ascorbic acid was also observed when CA of 3% and 5% CO₂ with reducing O₂ levels. This implies the CA-storage provides extended storage term of spinach over 20 days.

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For the purpose of estimating the removal efficiency of flavor using a continuous distillatiod column system (CFD; Continuous Flavor Distillation System) that was composed of newly developed 21 rotating disc sets and a fixing tray in a column, aroma components of raw materials of milk (skim milk, skim milk condensed by ultrafiltration (UF), peptide solution) or soymilk that were distilled under reduced pressure with steam injection, were evaluated using gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS).
Undesirable flavor components of raw materials of milk and soymilk were efficiently removed under the appropriate conditions in the distillation column. Aroma components of skim milkcondensed by UF were removed at an efficiency of more than 70%. Especially undesirable aldehydic and ketonic flavor were preferentially removed. As a result, the raw materials of milk and soymilk after removing undesirable flavor bad a pleasant aftertaste clearly.

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The botulinum neurotoxin produced by Clostridium botulinum exhibits the highest neurotoxicity and has caused botulism in mammals. We have continued our efforts to find an inactivator for clostridial neurotoxins from natural foodstuffs, and have finally found a thearubigin fraction in black tea extract. In this study, we confirmed botulinum toxicity when added to rawtype ham extract and the inhibition of its toxicity when the thearubigin fraction and the neurotoxin were mixed. We then conducted a tasting test with the raw-type ham mixed with the thearubigin fraction. BoNT/B mixed with a supernatant fraction prepared from the rawtype ham was examined for oral toxicity in mice. BoNT/B by itself elicited a paralytic effect depending on the dosage (0.1-10μg/head). The the arubigin fraction was examined for its neutralizing action on the oral paralytic effect of BoNT/B in the supernatant fraction of the rawtype ham. It was quite effective to detoxify the BoNT/B action depending on the dosage (10-40mg/head). A tasting test was performed for the thearubigin fraction when mixed for 1 week with a sample of raw ham available on the market. The thearubigin fraction ruined the taste of the ham.

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Enzymatic synthesis of aspartame precursor, N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester (ZAPM) was successfully performed using molten N-(benzyloxycarbonyl)-Laspartic acid (ZA) and L-phenylalanine methyl ester (PM) mixtures in the presence of salt hydrate (Na₂HPO₄·12H₂O, NaCO₃·10H₂O) without any liquid addition. The mixture composed of ZA, PM, salt hydrate and enzyme could be preserved under the dehydrate temperature of salt without ZAPM synthesis during one year, and available for ZAPM synthesis by control the temperature up to the dehydrate temperature on occasion. This storable mixture is considerable as a useful master powder for ZAPM synthesis.

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After the fermentation of bovine milk by lactic acid bacteria, rennet was added, and then the curd was formed by incubating at 30°C for 12 hours in the presence of soy protein isolate (SI) or 7S globulin (7S). Cheese was produced from the cooked curd. The texture of the curd and the cheese was studied by break down and cutting tests, respectively. In the break down test of the curd, the order of softness was control<SI<7S, and the order of the other analytical items were control>SI>7S. In the cutting test of the cheese, the order of all analytical items were control>SI>7S. The curd and the cheese containing 7S were softer than those containing SI. These results indicate that the texture of the curd and the cheese containing SI and 7S was significantly affected by gel forming abilities of added SI and 7S.

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[in Japanese]

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