The characteristics of rice grains cooked with and without monoglyceride (MG) were investigated. The results were as follows: (1) The rice grains cooked with MG were harder and less sticky than the rice cooked without MG. (2) Ninety percent of the MG amount added was remained in an external part of the cooked rice grains. (3) X-ray diffraction and DSC analysis suggested the existence of MG-starch complex in an external part of cooked rice grain but not in an internal part. (4) The density of an external part of the cooked rice grain was lower than that of an internal part. These results indicated that the external part expanded 1.6 times more than the internal part. The addition of MG repressed expansion of cooked rice grain. (5) The amylose content of an internal part of the cooked rice was higher than that of an external part.

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Changes in carbohydrates and related enzyme activities of ginkgo nut (Ginkgo biloba L.)on tree were investigated during growth and development. A tremendous increase in starch contents of the endosperm found at the beginning of pit-hardening. The increasing rate, however, gradually reduced thereafter and starch contents reached to a plateau at full ripening, the level of which was 35%. In contrast, total sugar contents in endosperm stayed relatively low level (approximately 4%) until first appearance of the skin surface yellowing. Thereafter, it rose continuously until full ripening, the level of which was about 7%. Biphasic increases of maltase, sucrase and sucrose synthetase activities during growth and development of ginkgo nut on the tree were noted both in endosperm and episperm. The first peaks were coincident with the stage of completion of pit-hardening and second increases corresponded with yellow color development of skin surface. These biochemical changes in connection to flavor during growth and development of ginkgo nut was discussed.

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The process of preparing physiologically functional water-soluble fraction from rye bran was examined. The water-soluble fraction extracted from rye bran was then separated into a high molecular weight fraction (WEP) and a low molecular weight fraction (WES) by ethanol. Each fraction was then applied to animals in various experiments to estimate its physiological function. (1) The hypocholesterolemic effects of WEP and WES were examined in rats fed on a hypercholesterolemic diet (containing 1% cholesterol, 0.25% sodium cholate). The elevation of serum and liver cholesterol levels in the rats fed on a diet containing 3% WEP were prevented significantly in comparison to those of the controlled rats on a test sample free diet. On the other hand, no such effect was shown in WES. (2) The hypotriglyceridemic effects of WEP and rye bran gum preparation (Gum) were examined in rats fed on a diet containing 20% coconut oil, 17.5% glucose and 17.5% fructose. WEP or Gum was supplemented to the diet at a level of 3%. These samples had a significant effect in preventing the elevation of serum and liver triglyceride levels in rats compared with those on the controlled diet (test sample free). No remarkable changes in these triglyceride levels were observed between WEP and Gum groups. These results indicate that WEP ameliorates hypercholesterolemia and hypertriglyceridemia in rats, the same as Gum does, and suggest that this extraction process is available for the preparation of functional food substances.

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Various test products of canned green tea drinks were subjected to both chemical analysis and sensory evaluation to investigate the effects of sample temperature for tasting and the content of constituents on their palatability. Canned green tea drinks were prepared with six infusion conditions; at 40°C, 50°C, 60°C, 70°C and 80°C for 3min and at 40°C for 10min. When they were tasted at 20°C and 55°C, the sample prepared with moderate infusion condition, at 60°C for 3min, had the best palatability among them. When they were tasted at 10°C, the sample infused at 50°C for 3min had the best palatability among them. As for the sample prepared with high infusion temperature, the higher the temperature for tasting, the better the palatability. On the contrary, as for the sample prepared with low infusion temperature, the lower the temperature for tasting, the better the palatability. These results might be caused by a difference in elution behavior of tea catechins with infusion temperature, and by dependence of threshold value of them in water on temperature for tasting. It was confirmed that acceptability of green tea drinks was not influenced by acidification down to pH5.05 with an addition of L-ascorbic acid to stabilize tea catechins.

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Near-infrared (NIR) spectroscopy scanning from 1100nm to 2500nm was applied for peroxide value (POV) determination of edible oil. Hundred and five samples were allowed to stand at 60°C in air for 0-4 days (0 day: not treated), and their POV were analyzed by iodometry. The samples were divided in two sets: 75 as a calibration set and 30 as an analytical (prediction) set. The multiple regression equation (MRE) established between POV analyzed by iodometry and by NIR for the calibration set gave the multiple correlation coefficient of 0.980 and a standard error of estimation of 1.501meq/kg. Absorbances at 2076 and 2052nm and at other three wavelengths were used in this MRE. Selection of the first two wavelengths can be attributed to an increase in hydroxy group by the formation of hydroperoxides and a decrease in ester bond by the breakdown of triacylglycerol. This MRE gave a standard error of prediction of 1.098meq/kg for the sample of prediction set. The obtained results indicate that NIR procedure can be used as a method for the rapid and simple POV determination for the purposes of inspection of edible oil and fat and quality controls in the irindustries.

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A selective medium for counting spores of Bacillus coagulans, one of the principal causative organisms for flat sour-type spoilage of thermally processed foods packaged in a sealed container, was developed and named m-TAA medium. To prepare the medium, phytone, 10g; yeast extract, 5g; dextrin, 5g; and dipotassium phosphate, 4g were dissolved in 500ml of distilled water followed by adjusting the pH to 4.6, and 20g of agar was dissolved in 500ml of distilled water. The two solutions were autoclaved at 121°C for 15min. A time of use, they were mixed after melting. In a pour plate of the medium incubated at 55°C for 5 days, B. coagulans spores, heated at 100°C for 30min, produced an average equivalent number of visible colonies to dextrose tryptone agar (pH 7.0), while spores heated as above for B. stearothermophilus, B. circulars, B. licheniformis, B. subtilis, B. cereus, B. macerans, B. brevis and B. pumilus produced no colonies. This selective counting method was applied to food ingredients. All of 14 isolates from the colonies formed in the plated medium were identified with B. coagulans.

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YAMAGAWA MURASAKI (Ipomoea batatas POIR.), a traditional variety of purple sweet potato cultivated in the southern Kyushu district, is richer in anthocyanin pigments than other varieties. However, it is unsatisfactory both in pigment content and crop yield for use as a starting material for industrial production of food colorants. From this variety, we bred a new variety characterized by 4-fold pigment content and 2-fold crop yield. In this breeding, changes in pigment composition and content, determined from HPLC peak patterns, were monitored at each step of hybridization, cultivation, pigment extraction and tuber storage. Although no new pigment peaks were seen in the new variety, a pigment content change was observed at every steps. In the tuber dried and deteriorated during storage purplish red pigments of long HPLC retention time decreased in quantity, while yellowish red pigments of short HPLC retention time increased. In assessing the characteristics of the new variety and methods of processing it, plants with minor peak pattern changes were selectively sampled.

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Irreversible temperature indicators were produced to keep the quality of food and raw material. Two types of indicators were developed to use at 7 and 13°C. Length of color-zone expansion against time was measured at 7 or 13°C. Their coefficients of variation were less than 10% (n=100). Color-zone expansion started from 7 or 13°C and its speed was accelerated with temperature rising. Expansion stopped under 7 or 13°C. Relationship between the color-zone expansion of indicator and the bacterial growth in food was investigated. Both the expansion of color-zone and bacterial growth increased with temperature rising. Bacterial cell number was increased even if food was placed only for a few hours at 30°C. Color of indicators developed before the bacterial growth, so that it was useful to apply the temperature indicators for keeping the quality of food and its raw material.

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Reimen is an unique noodle made of wheat flour (70%) and potato starch (30%). Extruding dough at 100°C followed by immediate cooling of the formed noodle by blow-drying yield a final product with a water content of 35%. Ethanol added to the dough was found to remain with a high yield in the final product, in spite of the above conditions that would stimulate the evaporation of ethanol. In the comparison of drying methods, stand-drying decreased both water and ethanol contents in the noodle rapidly and in parallel. On the contrary, blow-drying did not decrease the ethanol content in the noodle, but increased it slightly, whereas it decreased the water content more rapidly than stand-drying. In reimen containing 1.94% alcohol, microbial growth was negligible during storage at 30°C for 14 days. With a lower ethanol content of 1.26%, nomicrobial growth was observed when reimen was stored at 15°C. Thus, it was found that blow-drying of then noodle is quite effective for preventing evaporation of added ethanol, and that the final ethanol content of 1.94% is much enough to keep the shelf-life of the reimen product.

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