Using a polyclonal antibody raised against lipid transfer protein (LTP) purified from barley flour, a new sandwich-type enzyme-linked immunosorbent assay method was developed to detect barley LTP at concentrations of 0.1-10ng/mL. This method showed 0.003% cross reactivity against LTP of wheat and no cross reactivity against that of oats, adlay, and rye. LTP was detected in several foods containing barley, including fermented foods such as vinegar, soybean paste and beer. The LTP content was approximately the same for similar kinds of beer, even for those manufactured at different facilities or on different production days. Controlling and monitoring the LTP content in beer is important, as LTP is not only known as a factor of foam formation and stability, but also as an allergen. Therefore, this detection method of the LTP content may be a useful tool for quality control of beer.

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Water absorption characteristics of three kinds of dried vegetables (eggplant, radish and carrot) were investigated during soaking. Changes in moisture content of these samples were measured at four temperatures ranging from 20 to 70°C. The infinite plane sheet diffusion model was used to describe the water absorption process for these samples ; the measured results agreed well with the calculated results. The diffusion coefficients were 2.8×10^-9 to 1.0×10^-8m²·s^-1 for eggplant, 1.5×10^-9 to 9.1×10^-9m²·s^-1 for radish and 1.2×10^-9 to 8.9×10^-9m²·s^-1 for carrot. Using an Arrhenius-type equation the relationship between the diffusion coefficients and temperature was determined to estimate the activation energy for each sample. In addition, changes in volume during soaking were determined by measuring the apparent density, true density, and specific volume on a dry basis for the dried vegetable samples at various moisture contents. From the apparent density and true density, internal porosity was determined and its effect on water absorption and volume of the three kinds of dried vegetables was evaluated.

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The regulative effects of lipid metabolism by the dietary antlered form of Ganoderma lucidum (AAFGL) using sawdust of an apple branch as a medium were studied in rats fed 0.5% cholesterol. Male Sprague-Dawly (SD) rats (5 weeks old, n=6-7 per group) were divided into control and 1% AAFGL groups. Rats were given test diets for 14 days. In the AAFGL group, the weight of white adipose tissue tended to be lower, blood pressure was decreased and blood flow velocity tended to be faster. Moreover, the levels of liver and serum cholesterol tended to be lower in the AAFGL group, but the level of serum HDL-cholesterol was significantly higher, indicating that the atherosclerotic index in the AAFGL group was significantly decreased compared with the control. In addition, dietary AAFGL lowered the liver triglyceride level and there was a slight increase in the excretion of neutral and acidic steroids in the feces of the AAFGL group. Thus, dietary AAFGL may exert a preventive function against obesity and a regulative function of lipid metabolism.

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Shao-mai (steamed Chinese-style meat dumplings) is a familiar food consumed in Japan. Here, the characteristics of several types of shao-mai manufactured in Japan were investigated by descriptive sensory evaluation. A panel of 18 judges who were selected and trained in accordance with the ISO 8586-1 evaluated 8 shao-mai samples. First, 135 sensory descriptive terms of shao-mai were collected through an open-ended sensory evaluation by the trained panel, and then a list of 61 terms were developed from a roundtable discussion by a select number of the judges who had previous experience in evaluating shao-mai. A preliminary sensory test was conducted on a 5-point category scale using the 61 terms as descriptors. After cluster analysis, 19 terms (4 on appearance, 8 on flavor, and 7 on texture) were selected and defined as sensory descriptors for shao-mai. Judges indicated their perception of the intensity of each quality on a 100-mm unstructured line, with anchored terms located 10mm from each end. The principal component analysis determined the first principal component to be “flavor and texture derived from meat products”, the second to be “flavor intensity by seasoning” and the third to be “juiciness”. A sensory characteristic map of each shao-mai sample was drawn by a scatter plot composed of the factor loadings and sample scores to clearly show the sensory characteristics of each sample. Similar results from the different manufactured shao-mai samples confirmed the wide application of the 19 descriptors, thus providing a useful method for designing and developing products for consumer acceptability.

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Polyphenolic compounds were extracted with hot water from the seed shells of Japanese horse chestnut (Aesculus turbinata Blume) and then fractionated and separated into three fractions, F1, F2 and F3 by a multi-step column chromatography procedure. The structures of the isolated fractions were analyzed by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry. F1 contained mainly low-molecular weight phenolic substances, whereas F2 and F3 consisted of polymeric proanthocyanidins (tannins) with the polymerization degrees of 19 and 23, respectively. To determine the type of interflavan linkage of polymeric tannins, F2 and F3 were subjected to thiolytic degradation with 1-dodecanethiol to give their dodecylsulfide derivatives. The resulting derivatives were analyzed by high-performance liquid chromatography followed by electrospray-ionization mass spectrometry. The tannins had doubly linked A-type interflavan linkages in addition to single B-type bonds. The isolated polyphenolic compounds inhibited α-glucosidases including maltase and sucrase, as well as α-amylase, in a dose-dependent manner. In particular, compared to the low-molecular weight F1 substances, the highly polymerized F2 and F3 were more potent inhibitors of α-amylase. Taken together, polyphenolic compounds from seed shells of Japanese horse chestnut are potentially useful as constituents for developing functional foods that suppress an abrupt increase in blood glucose level after eating due to the appreciable ability of these compounds to inhibit digestive enzymes of carbohydrates.

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Matcha, powdered green tea, is difficult to handle in the factory or manufacturing facilities due to its small particle size and low density. In the present study, the powder flowability properties of various matcha samples were investigated using a dynamic powder flow tester with high detection sensitivity to facilitate machine handling during matcha manufacturing. The sample powders were prepared from tea leaves picked during different seasons (i.e. the first, second, third, and fourth crops) using a stone mill or ball mill. Matcha ground with the electrostatically charged stone mill showed poor flowability, whereas that ground with the ball mill showed fairly good flowability. The fine and coarse powders classified after ball-milling had different characteristics. Furthermore, it was found that the electrostatic discharge of matcha can improve flowability, depending on humidity.

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A technique to determine the geographic origin of asparagus was examined using 64 samples from Japan and other countries. A total of 13 elements contained in asparagus were determined by inductively coupled plasma mass spectroscopy. The principal component analysis of the analytical results showed that the geographic origin of asparagus can be discriminated between Japan and other countries. We developed a linear discriminant analysis (LDA) model calibrated with analytical results of 6 elements (Co, Sr, Ca, Rb, Mo and Cu) chosen by a backward stepwise procedure. This LDA model identified the origin of asparagus from Japan with 97% certainty and those from abroad with 90% certainty.

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The optimal conditions for the production of γ- aminobutyric acid (GABA) from sodium glutamate and pyridoxal 5-phosphate were investigated using three agricultural products as sources of the GABA synthesis enzyme. In addition, the effect of a high concentration of glutamate on GABA production was examined using wheat germ. The results showed that GABA production increased with an increase in the glutamate concentration from 60 to 100 g/l, with optimal conditions at a pH range of 5.6-5.8, temperature of 40°C and enzyme reaction time of 4h.

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[in Japanese]

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