In this study, the effects of infrared radiation (IR) on inactivation and injury of two kinds of bacterial spores (B. pumilus, B. subtilis) were investigated.
Inactivation and injury of these spores suspended in sterile distilled water by IR were compared with those by convection heating (HC). The temperature of spore suspension irradiated by infrared ray was a close profile to that heated by convection within the range from room temperature to ca. 97°C. The inactivation of bacterial spores by IR was more intensive than that by HC. It took about 8 and 12min of IR treatment to inactivate 99% of B. subtilis and B. pumilus spores, respectively. These bacterial spores were injured by IR more extensively than by HC in the initial stage of 4min the same bulk temperature of suspension despite.
When bacterial spores air-dried on a stainless petri dish were directly irradiated (direct irradiation) by IR without water, direct irradiation by IR could suppress the bacterial spores in a short time comparing with dry heat sterilization by HC. And, the method by IR could inactivate 90% of both kinds of spores having different heat tolerance for almost same periods (1.0kW: 1min, 0.5kW: 2min), however, B. pumilus spores were more liable to be injured than B. subtilis spores by direct irradiation.

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We studied infrared spectral characteristics derived from disaccharides and the interaction between disaccharides and water. Six kinds of sugar-H₂O solutions (trehalose, kojibiose, nigerose, maltose, isomaltose and sucrose) and three kinds of sugar-D₂O solutions (trehalose, maltose and sucrose) were prepared. Their infrared spectra were collected by use of a FT-IR/ATR method. The different spectral pattern in the fingerprint region was found for each sugar in H₂O solution. Especially, characteristic spectral features were observed for trehalose. We compared the absorption bands of the trehalose, maltose and sucrose spectra in H₂O with those in D₂O based on the absorption intensity and wavenumber. As the results, the solvent affected the absorption intensity rather than wavenumber shift, which was caused by the interaction between disaccharides and solvents. In addition, when plotted against the disaccharide concentration, the absorbance of glycosidic linkage and C-OH vibration bands in H₂O and D₂O, showed good linearity in trehalose, while non-linearity in sucrose. Their bands of trehalose shifted slightly both in the H₂O and D₂O and the shifts of sucrose were significant. Judging from the spectral patterns, trehalose seems to be stable in both H₂O and D₂O.

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By using a HPLC method, the presence of high concentration of vitamin K was confirmed in some seaweeds and sweet potato leaves. Particularly, it was remarkable in the most classical seaweeds of Fudaraku (Pachymeniopsis lanceolata) and Miru (Codium fragile), and sweet potato leaves of Beniazuma and Ayamurasaki.
The highest value (7.4mg vitamin K1/100g dry weight) detected in Benisatsuma was over than that of tea (Macchya) (4.4mg vitamin K1/100g) previously reported by Japanese Food Analysis Organization.
The water-solubility of a Benisatsuma extract (dry powder) was higher than that of the standard vitamin K1. It was also proved that vitamin K1 in this powder is much resistant against light decomposition.

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Fish scales are mainly composed of collagen and hydroxyapatite (HAp). Since HAp is solubilized in a dil. hydrochloric acid aq. soln., crude collagen could be separated from carp (Cyprinus carpio Linnaeus) scales by a HCl treatment. The optimal conditions for the HCl treatment were examined and compared to those applied for sardine (Sardinops melanostictus Temminck et Schlegel) scales, reported previously. The utilization of the separated collagen is discussed on the basis of the contents of heavy metals in the ash obtained by asking of the scales at 1000°C. The determination of hydroxyproline, which is a kind of characteristic amino acid for collagen, and SDS-PAGE analysis show that the crude collagen obtained is Type-I collagen.

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We investigated the effects of Casein, whey protein, soybean protein, wheat gluten and their peptides on the proliferation and immunoglobulin (Ig) production of mouse spleen lymphocytes. Among them, bovine β-Casein remarkably enhanced the production of IgA, IgG and IgM. In addition, some peptides from Casein enhanced IgA production and a peptide from wheat gluten enhanced IgA, IgG and IgM production. On the other hand, whey and soybean proteins exerted no immunoregulatory activity, as well as peptides derived from these proteins. β-Casein elevated Ig producing cell population in mouse spleen lymphocytes, but peptides derived from casein did not increase Ig producing cell population. These data suggest that immunoglobulin production stimulating effect of β-Casein takes part in increasing of Ig Producing cells. Therefore, Casein and wheat gluten peptides may well be available as immunoregulatory food materials.

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Many methods to detect some foreign oligosaccharides (mainly from corn fructose syrup) in a honey have been studied, and a combined method of charcoal treatment and thin layer chromatography (TLC) is recommended to use in Japan. But the method has some weak-points such as being time-consuming and uneven due to charcoal treatment. We have tried to improve an analytical method using the gel chromatography on Sephadex G-15 and high performance liquid chromatography (HPLC) equipped with a post-column reaction system. By this method, the foreign oligosaccharides (relative retention time to glucose, 0.71-0.78) could be detected even in a honey added 5% of syrup. We will, herein, propose a combined method of gel chromatography and high performance liquid chromatography for swift distinction between a real and a syrup-added honeys.

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We had tried to measure antioxidant effect of flavonoids on the oxidation of LDL using capillary electrophoresis. When LDL was oxidized in the presence of Cu²⁺, the mobility time of LDL was rightly shifted on the chromatogram with increased oxidation time. The elongation of the mobility time was inhibited by addition of BHT and ascorbic acid. When inhibitory effect of flavonoids on the LDL oxidation was examined, the oxidation of LDL was prevented in proportion to the number of OH group in the B ring of flavonoids. The capillary electrophoresis method is useful for evaluation of antioxidant effect of flavonoids on Cu²⁺ -induced LDL oxidation.

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The changes in aroma of Awamori during storage after distillation were investigated using sensory evaluation, and chemical and sensory analyses. Three Awamori samples, just after distillation (S0), and then stored for one month (S1) and two months (S2) in Kame (porous earthenware pots), respectively were used. The significant difference (p<0.01) between S0 and S2 samples was revealed in duo-trio test. Accordingly to chemical analysis by GC and GC-MS, 82 volatile compounds were detected in S0 sample but these contents almost decreased during storage. On the other hand, 27 volatile compounds in S0 sample had high flavor dilution (FD) factor (>10⁴) in aroma extract dilution analysis, but the FD factors of 24 volatile compounds also decreased during storage. The results obtained suggest the changes in aroma of Awamori during storage after distillation are different from the ones of Awamori kuusu by aging.

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To examine the effects of inorganic elements on undesirable browning reaction in cooked barley grain, barley pastes were heated with or without salts including inorganic elements 0.3-10 times as much as the intrinsic ones. Effects of additives were evaluated by the differences in paste color (L^*, a^*, b^*) and the Hunter's Whiteness value. The browning reaction was enhanced by iron chloride and copper chloride dose-dependently, and inhibited by zinc chloride and calcium salts (chloride, nitrate, acetate) dose-dependently. Inhibition of browning reaction by three chelators (diethylenetriamine-N, N, N', N", N"-pentaacetic acid, EDTA, phytate) suggested that intrinsic iron and copper could catalyze browning reaction in barley.

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