Lactobionic acid is produced by the oxidation of lactose and has been reported to promote calcium absorption in the intestine. Lactobionic acid also promotes the intestinal production of equol, which has been reported to prevent menopause. Thus, an efficient and safe production method of lactobionic acid was required for its application to food products. Although a wide variety of lactose oxidation methods have been reported, no suitable production method had been developed for lactobionic acid. We found lactobionic acid in a Caspian Sea yogurt and estimated the annual intake of lactobionic acid based on daily yogurt consumption. The lactobionic acid-producing bacterium was identified as an acetic acid bacterium. This bacterium is one of the main fermentation bacteria in this yogurt. In collaboration with a company, we developed a method for the commercial production of lactobionic acid using an acetic acid bacterium. Consequently, a number of food products containing lactobionic acid are now commercially available on the Japanese market. Acetic acid bacteria were previously reported to be unable to oxidize lactose because their sugar-oxidizing enzyme—a membrane-bound glucose dehydrogenase−does not show lactose-oxidizing activity. In contrast, we demonstrated that the glucose dehydrogenase of the acetic acid bacterium could oxidize lactose.

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We focused on the colloidal contribution of lipid and protein in soymilk, and investigated the influence of pH on the stability of soymilk. The particle size distribution and viscosity were evaluated in relation to decreases in the pH of soymilk. By the addition of ascorbic acid, the average size of particles in soymilk was slightly increased at pH 6.0-5.8 and remarkably increased at pH 5.6. Moreover, the fluidity index was severely reduced from 1 at pH 5.8 or less. These results show that the viscosity of soymilk increased as a result of lipid and protein aggregation depending on the pH decrease. Then, soymilk colloidal stability was assessed using the centrifugal method. The state of soymilk changed in three steps as a function of decreasing pH. With respect to the viscosity and stability changes of soymilk, it was suggested that lipid-protein aggregates were generated, and the soymilk constituent content influenced the generation of lipid-protein aggregates. These results show that the pH-dependent stability of soymilk could be predicted from the constituent composition of soymilk.

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The quality of surimi products such as kamaboko can be evaluated according to the following four textural characteristics: elasticity, hardness, pliability, and “hagire”. In this study, electromyography (EMG) examination of masticatory muscles was conducted to determine whether EMGs can be used to evaluate these textures objectively. Twelve model gels made from surimi, corresponding to four textural characteristics with three different strengths, were prepared as samples. From the EMG analyses, characteristic parameters were determined for the masseter muscle (Mass) and the suprahyoid muscles on the first cycle (the 1st) and the third to seventh cycles (the 3rd-7th). The following results were obtained.
(1) Elasticity was correlated with integrated EMG (iEMG) and pre-peak iEMG on Mass in the 1st and the 3rd-7th.
(2)Hardness was correlated with peak value and root mean square value (RMS) on Mass in the 1st and the 3rd-7th.
(3) Pliability was correlated with post-peak duration on Mass in the 3rd-7th. That is, pliability plays the most important role in the lasting, unique texture of surimi products.
(4) “Hagire” from the viewpoint of chewiness was correlated with iEMG and pre-peak iEMG on Mass in the 3rd-7th.
(5)We propose that the EMG method is applicable to evaluate the texture of surimi products at the early stage of mastication, and the four important textural characteristics can be evaluated using specific EMG parameters.

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We collected 16 sample of red rice, 38 sample of black rice, 21 sample of Koshihikari cultivated by only organic fertilizer and 43 samples Koshihikari cultured by conventional farming system between 2004 and 2005 via mail order. Then, we measured 7 mineral contents in these samples, and compared with mineral contents. In the results, it was shown that calcium and potassium content of pigmented rice were higher than those of Koshihikari cultivar. It was shown that Koshihikari cultivated by only organic fertilizer was not significantly difference from those cultured by conventional farming system.

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The aim of this study was to produce a healthful rice ball showing a reduction in postprandial glycemia, and to investigate its contents of isoflavones and anthocyanins, in vivo hypoglycemic effect, inhibition of insulin secretion, and sensory characteristics. Kurosengoku soybean from Japan is rich in isoflavones and anthocyanins. Cooked rice was prepared with either broth generated from boiled bean production or water. Kurosengoku rice ball (KRB) was prepared by mixing 20% boiled bean with the cooked rice. On the other hand, rice ball wound with dried laver was prepared with pickled ume, sesame and salt, and cooked rice with only water. The rice ball wound with dried laver was used as a control. Results indicated that the glycemic index was lower in KRB than in the control. Blood glucose and immunoreactive insulin levels were also both lower in the former than in the latter after the intake of a substantial amount of lunch. Preference test revealed that the overall acceptability was significantly lower (p<0.01) in KRB than in the control.

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Generally, baking powder contains aluminum compounds (alum) as the acidic agent. However, because ingredients such as potassium aluminum sulfate (PAS) may affect the nervous system, the Codex Alimentarius Commission has recommended restricting its use in infants. Instead of alum, therefore, glucono-δ-lactone (GDL) has been developed for use as a substitute. The addition of PAS or GDL to batter increased the pancake volume as well as the ratio of insoluble proteins, as fractionated by Osborne’s method. The addition of hydrogen peroxide (HP) also resulted in similar effects in pancakes.

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