Moisture distribution in rice grains used for sake brewing analyzed by magnetic resonance imaging

Water absorption in individual white-core and non-white-core grains of rice varieties used in sake brewing was observed during soaking by magnetic resonance imaging (MRI). Water was absorbed faster in white-core grains than in non-white-core grains and was pooled in the core. Moisture distributions were compared using the line profiles of nuclear magnetic resonance signal intensities (SI profiles) generated from magnetic resonance images of grains soaked for 2 h. SI profiles of white-core and non-white-core grains overlapped despite slight differences in the central and intermediate regions of the grains. A white-core-like structure with loosely packed starch granules was found to exist in the endosperm of non-white-core grains. SI profiles of grains polished to 70% of the yield weight of brown rice were similar in shape to those of grains polished to 90% of the yield, but their overall moisture content was higher after the removal of the hydrophobic grain periphery. A varietal difference in the thickness of the intermediate region, which may affect fissuring resistance in the polishing process, was detected in SI profiles. Differences in water absorbability between parents and their offspring were also apparent from their SI profiles. MRI enabled the detection of variety-specific water-absorption properties in grains.     

耐酸性清酒酵母A发酵工艺研究

[目的]为生产优质清酒奠定理论基础。[方法]以优质粳米为原料,在单因素试验的基础上。采用正交试验法研究耐酸性清酒酵母A的发酵规律。[结果]水料比为1—2时,清酒酒精度较高。水料比为0．5时,发酵醪的糖浓度和渗透压较高。水料比为3时,发酵醪的淀粉浓度降低,清酒酒精度低。酒母量为20％时,利于清酒双边发酵,清酒的可溶物含量约为11％。米曲量为30％～50％时,清酒色度低,苦涩味轻。乳酸添加量为8‰～12‰时,发酵结束后米曲中糖化酶的活力约为290mg/（g·h）。乳酸量超过12‰时,酶活力下降比较快,清酒有异杂味感。15℃下发酵21d的清酒酒精度达17．1％（V／V）,淀粉利用率为88．1％。[结论]利用耐酸性清酒酵母发酵生产清酒,简化了生产工艺,缩短了发酵时间,提高了原料利用率。     

Temperature during grain ripening affects the ratio of type-II/type-I protein body and starch pasting properties of rice (Oryza sativa L.)

The starch and protein properties of rice grain are important factors for sake brewing and these properties are reported to be influenced by temperatures during grain ripening. Amylose content, nitrogen content, protein composition, pasting properties measured by a Rapid Visco Analyser (RVA), and their relationship to temperatures during ripening were investigated in a rice cultivar, Yamadanishiki, which was grown under various conditions in the same experimental field. The average temperature after heading was significantly correlated with amylose content and RVA properties, but not with nitrogen content. Under high temperatures during ripening, a decrease in prolamin, which accumulated in type I protein body (PB-I), and an increase in glutelin, which deposits in type II PB (PB-II), were recognized. The ratio of PB-II/PB-I and RVA pasting temperatures were distinctly increased as the temperature became higher. High temperatures during grain ripening would lead to difficulties in digesting steamed rice grains by Aspergillus oryzae, together with ease in digesting rice protein. The average temperature of 11–20 days after heading showed a higher correlation coefficient than that of 1–10 or 21–30 days, implying that temperatures during the middle stage of grain development would be important in determining the rice component that relates to brewing properties.     

奶牛微生物培养物BLS的研究

用鉴别培养基从土壤矗、新疆传统奶酪和马奶洒中分离出地衣芽孢杆菌、米酒乳杆菌和酿酒酵母。经鉴定和安全试验，上述三株茵混合后的联合培养物，接种生料发酵制成微生态制剂BLS，饲喂泌乳牛。试验组平均每日奶产量显著高于对照组。