On the production of restructured meat using microbial transglutaminase (MTG), there was the report that meat cubes showed acceptable binding in combination with MTG and caseinate. The acceptability of food proteins except of caseinate was studied for binding sausage pieces by MTG, and the mechanism of binding was investigated. By optimizing the volume of water added for food proteins, not only caseinate but also gelatin and soy protein showed effective binding by MTG. The amount of ε-(γ-glutamyl)lysine linkage in binding surface of sausage was contributed to binding strength. The amount of the crosslinkage in bound sausage pieces was just 33∼75 μmol, on the other hand, 320∼846 μmol in glue paste. Tight binding was obtained by binding the adhesive surfaces of sausage. Based on the examination by microscope, it was suggested that glue paste permeated into a narrow space of binding surface of sausage, and gelled by MTG afterwards.

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“Hayadakimai” is a newly developed rice product prepared by steam treatment. It is served after brief cooking without pretreatments such as soaking and washing and also shows the taste similar to regularly cooked rice. Physico-chemical and rheological analyses, such as water absorption, SEM, X-ray diffraction and viscosity analysis, have been carried out to characterize this new product. The rice showed high water absorption, similar viscometric properties, but lack the crystalline starch structure. The remarkable reduction of cooking time in “Hayadakimai” is caused by its high water absorption, which, in turn, resulted from the partial gelatinization of starch on the grain surface of “Hayadakimai” and from the destruction of crystalline structure of starch granules even in the inside depth of the grain. It was suggested that changes in cell wall structure in endosperm cells might also affect the morphological change observed with the “Hayadakimai” grain.

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Effects of transglutaminase derived from microorganisms (MTG) on mechanical properties of sponge cake were evaluated. The specific volume of sponge cake increased by the addition of MTG at 0.5-5.6 u/gp. When MTG was used with other quality-improving agents, its effect was enhanced by the concomitant use of an emulsifier, a viscosity-increasing polysaccharide, and a wheat degradation product. The specific volume was increased to about 1.2 times by the use of 1.4 u MTG and 0.2% emulsifier compared with MTG alone. By the addition of MTG, sponge cake with a better appearance having no depression or creases on the top surface was obtained, and the optimal dosage of MTG was 0.5-1.4 u/gp. When MTG was added at more than 2.8 u/gp, the surface tended to be slightly hardened, but a crumb with a good shape-retaining property was obtained by the simultaneous addition of an emulsifier and a viscosity-increasing polysaccharide, air bubbles were distributed adequately, and a moist and soft feeling on eating was obtained. On testing of mechanical properties by the breaking test, the breaking distance as well as the breaking strength increased by the addition of 1.4 u/gp MTG compared with no MTG, suggesting improvements in both elasticity and softness. On SDS-PAGE, a decrease in low-molecular-weight gliadin was noted, indicating the usefulness of MTG for improving the quality of sponge cake and its primary substrate protein.

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The effect of various types of salt on the properties of emulsions prepared with diacylglycerol (DAG) was measured by comparison with triacylglycerol (TAG) in a simulated-mayonnaise oil-in-water emulsion system. DAG and TAG samples with the same fatty acid composition were used. NaCl, KCl, CaCl₂, MgCl₂ and MgSO₄ were used separately or in combination with NaCl as salt samples, as well as several commercial salt products containing these types of salt in various ratios. O/W emulsions with a 0.7 oil-volume fraction were prepared with either DAG or TAG, fresh egg yolk and a 3.5% aqueous acetic acid solution containing each salt sample at a concentration of 0, 1.65% (low) or 3.30% (high) (w/v), and the flow behavior and oil-particle-size distribution of these prepared emulsions were measured. The addition of any salt at any concentration decreased the mean oil-droplet size in the all emulsions prepared. On the other hand, the viscosity of the emulsions was affected differently according to the type of oil, type of salt and salt concentration. Increasing the amount of salt increased the viscosity of all the TAG emulsions prepared, this effect being stronger with those salts having divalent cations than with those having monovalent cations. A low concentration of salt increased the viscosity of all the DAG emulsions more than the TAG emulsions. It is thought that the incorporation of divalent cations rendered the emulsion structure liable to breakage.

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Qualities of the deodorized soybean were studied on compositions, texture and flavor. The contents of moisture of the deodorized soybean flour was lower about 7% than the control, but there were no differences in other compositions and amino acid analysis between both flours. The flour and SPI from the deoderorized soybean decreased in each peaks of flavors and areas of total flavors. The SPI gel from the odored soybean showed less dark and more bright color than the control. Based on the results of creep test, the SPI gel from the deodored soybean was lower in E₀, and higher in η_N than the control. However, there was no signification between these parameters. The SPI gel from the deodored soybean was decreased in soybean flavors, especially astringent flavor, and was flexible by sensory evaluation.

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