Effect of steaming,freezing, and re-steaming on the texture properties of non-glutinous rice cakes

The effects of steaming time (6, 8, and 10 min), freezing storage period, and re-steaming for thawing on the textural properties of non-glutinous rice cakes (baekseolgi) were investigated. As the steaming time increased, the rice cakes softened. In particular, the sample that was steamed for 10 min showed lower hardness than those steamed for shorter periods. A short period of steaming was insufficient for water bound to the surface of the starch granules to penetrate the granules in the dough. During the re-steaming process of the frozen non-glutinous rice cake samples, the retrogradation of starch and water syneresis contributed to the increased hardness of non-glutinous rice cakes.     

采后热处理对红富士苹果青霉病和灰霉病的控制

热空气处理能有效抑制灰葡萄孢(Botrytiscinerea)和扩展青霉(Penicilliumexpansum)的毒性。灰葡萄孢比扩展青霉的热敏感度高,Bcinerea孢子38℃热处理48h即能完全抑制孢子萌发。热处理72h的Bcinerea平板均无菌丝生长。Pexpansum的孢子活性和菌丝生长随热处理时间的延长而明显减缓。热处理后的霉菌孢子在苹果果实内生长缓慢,Bcinerea孢子在热处理72h后在苹果中的生长完全受抑制,腐烂发生率为零。Pexpansum热处理72h后才能显著抑制苹果的腐烂发生。苹果接种霉菌后再进行热处理(38℃,96h),无论是0℃还是20℃下放置,均未发现腐烂,大大减少贮期灰霉病、青霉病的发生。研究还发现,经过2个月冷藏后,与对照组相比,热处理过的红富士苹果果皮色泽更黄,糖酸比上升,呼吸强度较低,硬度保持较好,说明热处理能够正面影响苹果的贮藏品质。     

紫外分光光度法测定卵磷脂保健食品中磷脂酰胆碱含量

建立简便、快速、准确测定卵磷脂保健食品中磷脂酰胆碱含量的方法。采用丙酮、乙醇将卵磷脂分离出来,以卵磷脂正己烷溶液与0.5%碘-正己烷溶液反应,用紫外分光光度计在292nm处测定反应液的吸光度,磷脂酰胆碱的含量与吸光度成正比,磷脂酰胆碱在0.0100～0.0500mg/mL浓度范围内线性关系良好,相关系数为0.99994。本法可作为卵磷脂保健食品中磷脂酰胆碱的质量控制监测。      

分子蒸馏及其在多不饱和脂肪酸中的应用

阐述了分子蒸馏的基本原理及其主要特点。介绍了分子蒸馏在不饱和脂肪酸方面的应用研究成果。     

Distribution of organochlorine pesticides in the northern South China Sea: implications for land outflow and air-sea exchange

The South China Sea (SCS) is surrounded by developing countries in Southeast Asia, where persistent organic pollutants (POPs), such as organochlorine pesticides (OCPs), are still used legally or illegally, and are of concern. Yet little is known about the distribution of OCPs in the water and atmosphere over SCS, as well as their air-sea equilibrium status and time trends. In this study, ship-board air samples and surface seawater collected in the northern SCS between September 6 and 22, 2005 were analyzed for selected OCPs. The measured OCP concentrations in the atmosphere over the northern SCS were influenced by proximity to source regions and air mass origins. The highest atmospheric OCP concentrations were found at sampling sites adjacent to continental South China. OCPs in surface seawater showed significant spatial variations, with the highest concentration observed in a water sample from off Vietnam. The coastal currents were suggested to play a key role in the delivery of waterborne OCPs in the northern SCS. Time trend, land outflow, and air-sea exchange of selected OCPs in the SCS were investigated, by comparison of this dataset with historical data.     

丝用槽筒及倒筒机的成形原理与技术突破

阐述了丝用槽筒的卷绕特性及丝层防叠原理,分析了纱用槽筒及络筒机用于长丝卷绕的失败原因,提出了丝用槽筒及倒筒机的设计措施。