A major use of rice is as cooked rice, which is a staple food in Japan. Furthermore, rice is also used as a raw material for various food items such as rice crackers, rice flour and sake by making use of its characteristics. However, the recent decrease in rice consumption has led to strong demands for the expanded use of rice. Therefore, research has been undertaken into various developments in the use of rice flour in Niigata Prefecture over the past 30 years. Two milling methods to make rice into fine rice flour have been established, the ‘two-step milling method” and the ‘enzyme-treated milling method”. These two methods have resulted in the use of rice flours in place of wheat flour in the production of foods such as breads and noodles. Rice flours produced by the two-step milling method and the enzyme-treated milling method have been used in western-style confectionery, as well as the production of breads and noodles, respectively. Niigata Prefecture holds the patents to these methods, which are used by 8 companies in Niigata and other prefectures. As for the processed food items from rice flour, two types of noodles have come into the market. Rice noodles are made only from rice flour, and therefore contain no wheat flour or gluten. The other type of noodle is made with koshinomenjiman, a high-amylose rice variety bred in Niigata Prefecture. This has the characteristic quality of an elastic texture, and has therefore been brought to market. These technologies are used as the basis for the Rice flour 10% Project (‘R10 Project’), which is a policy of Niigata Prefecture. This project aims to replace the use of wheat flour with rice flour by more than 10%.

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The effect of the addition of gelatinized rice porridge was investigated on the following bread qualities : loaf volume, viscoelastic properties and air-bubble structure. Four kinds of bread were prepared : bread containing rice porridge (rice porridge bread), bread containing gelatinized rice flour (gelatinized rice flour bread), wheat flour bread and rice flour bread. Evaluation of qualities of the breads was carried out by volume measurement of loaf samples, creep test and digital image analysis on the air-bubble structure of crumb specimens. Rice porridge bread showed a maximum specific volume of 4.51cm³/g, and gelatinized rice flour bread also showed 4.30cm³/g, which was larger than rice flour bread. The viscoelastic moduli values of gelatinized rice flour bread and rice porridge bread were significantly smaller (p<0.05) than those of wheat flour and rice flour breads, which indicates that the addition of gelatinized rice flour or rice porridge to bread dough made breads softer. Bubble parameters such as mean air-bubble area, number of air-bubbles, and air-bubble area ratio (ratio of bubble area to whole area) were not significantly different among the bread crumb specimens. Therefore, the bubble structures of the bread samples seemed similar, which implied that differences in viscoelasticity resulted from the air-bubble wall (solid phase of bread crumb) rather than the air-bubble. This study showed that a 15% addition of gelatinized rice to bread dough produces bread with larger loaf volume and soft texture without improving agents such as gluten.

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We compared the effects of Japanese quail trypsin inhibitor ovomucoid (OM) and Japanese quail egg white (EW) on lipid metabolism in rat. SD rats were divided into 3 groups and each group was given one of the following diets for 3 weeks : 20% casein control diet, OM diet containing 1% OM, and EW diet containing 7% EW with an equivalent trypsin inhibitor activity to the OM diet. After the feeding trial, body fat content of each rat was determined by X-ray computed tomography (CT). The rats were then dissected for measurements of their liver and plasma lipids, and enzyme activities in liver and pancreas. No significant differences were seen in liver lipids and enzyme activities. The OM- and EW-diet groups had nearly the same levels in final body weight, feed intake, pancreas weight and pancreatic trypsin activity, which were significantly different from those of the control diet group. Moreover, X-ray CT analysis showed a significant decrease in subcutaneous fat mass in the OM- and EW-diet groups compared to the control group. The percentage of rat body fat and visceral fat mass in the OM- and EW-diet groups showed a lowered tendency compared to the control. On the other hand, plasma triglyceride and HDL-cholesterol levels of the EW-diet group were different from those of the OM-diet group. These results suggest that favorable effects of egg white protein on rat lipid metabolism cannot be ascribed only to the presence of OM in the protein.

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A previous study reported an effective method to determine the inhibitory activities of naturally occurring antioxidants on the degradation of target proteins by ROS. However, determination of the important ROS, hydrogen peroxide, among four ROS types, including H₂O₂, ClO·, OH· and ONOO·, was earlier omitted in view of its low ability to destroy protein. In this report, H₂O₂ is employed as the fourth ROS for novel examination of the antioxidant activities of various naturally occurring substances from foods on DNA degradation. The target DNA was decomposed by each ROS type (H₂O₂, ClO·, OH· and ONOO·) in a dose-dependent manner, similar to that observed in the protein degradation system. The reactive potency of antioxidants was assessed as reaction-dependent specificity against ROS, resembling that observed in the inhibition of protein degradation. A mixture of anserine-carnosine, imidazole dipeptides isolated from chicken extract, displayed antioxidant activity against the ClO· radical, ferulic acid against the OH· radical, and vitamin C and the imidazole dipeptides against the ONOO· radical. Against hydrogen peroxide, the imidazole dipeptides exerted the strongest antioxidative effect examined. From this, it is indicated that the imidazole dipeptides, especially anserine, can prevent DNA degradation by all four of the ROS. On the other hand, vitamin C significantly stimulated DNA degradation by hydrogen peroxide.

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Influence of culture medium on the composition of water-soluble polysaccharides in the Ganoderma lucidum fruit body was investigated using various kinds of pruned off branches as the medium. Total carbohydrate content of water-soluble polysaccharides obtained from the fruit body differed among them : persimmon (90.2mg/10g dry weight of fruit body), mulberry (49.8mg), Japanese cherry (33.1mg), Japanese plum (34.1mg), apple (52.1mg), Japanese oak (28.3mg), and grape (28.4mg). Neutral sugar composition and neutral-sugar linkage analyses indicated that galactan-like polysaccharide and xylan-like polysaccharide, in addition to β-glucan, were present at different ratios in the water-soluble polysaccharide fractions. This means that the content of these polysaccharides in the fruit bodies is influenced by the culture medium, i.e., the kind of pruned off branch.

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A quality evaluation method for dried herbs was studied with sweet basil leaves (fresh, air-dried, freeze-dried and vacuum-dried sweet basil leaves) as herbal teas, involving hot-water extraction. Sensory evaluation revealed that the flavor of herbal tea with vacuum-dried sweet basil leaves was similar to that with fresh leaves. Seven odor-active compounds (cineole, linalool, eugenol, octanal, 1-octanol, (E)-2-hexenal and (Z)-3-hexenol) from herbal teas were identified by capillary gas chromatographic-mass spectrometry and olfactometry analysis, and it was considered that three compounds (octanal, (E)-2-hexenal and (Z)-3-hexenol) were key compounds for describing the results of sensory evaluation. The structure of dried sweet basil leaves with water-absorption and fresh leaves was observed by differential interference contact microscopy, and their rheological characteristics were measured for storage modulus. As a result, the characteristics of vacuum-dried sweet basil were similar to those of fresh basil. These results suggest that investigation of the aroma using hot-water extraction, tissue structure and rheological characteristics could be effective approaches to qualitatively evaluate dried herbs.

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