重离子辐照对红酵母的诱变作用

应用重离子加速器的 5 0MeV/u12 C6+ 重离子对胡萝卜素生产菌 -红酵母(RhodotorulaRYStrain )进行辐照处理 ,经酵母发酵实验 ,发现 5 0MeV/u12 C6+ 重离子对胡萝卜素生产菌———红酵母具有诱变作用 ,并初步筛选到产胡萝卜素有较大变化的辐照变异菌株 ,为工业上利用重离子对胡萝卜素生产菌进行诱变育种展现新的前景     

贵州黄花梨蜂蜜的品质分析

首次对贵州中华蜜蜂黄花梨蜂蜜的感官指标、理化指标、卫生指标、营养成分、活性成分和安全性指标等进行检测分析,探讨其品质特性和安全性。根据相关标准规定的方法对上述各项指标进行测定,结果显示贵州黄花梨蜂蜜呈浅琥珀色,口感甘甜,有黄花梨花香味,常温下呈粘稠状,低温易结晶;水分含量19.43%,果糖和葡萄糖含量66.47%,蔗糖含量0.25%,酸度37.44 mL/kg,羟甲基糠醛含量0.91 mg/kg,淀粉酶活性28.20 mL·g-1·h-1;微生物含量符合标准规定;铁元素含量3.1767 mg/kg,锌元素含量1.6870 mg/kg,蛋白质含量0.36 g/100g,维生素C含量1.38 mg/100g,在检测的16种氨基酸中,天冬氨酸的含量最高（0.0400 g/100g）,谷氨酸（0.0373 g/100g）、异亮氨酸（0.0303 g/100g）、脯氨酸（0.0280 g/100g）和苯丙氨酸（0.0277 g/100g）次之,酪氨酸和蛋氨酸则未检出;超氧化物歧化酶活性4.29 U/g,总三萜含量65.97 mg/100g,总黄酮含量和兽药残留量未检出,重金属含量极低。本研究结果表明了产自贵州的黄花梨蜂蜜为健康安全的蜂蜜食品,并达到了蜂蜜标准的一级品水平要求。     

基于向量场正规形理论的电力系统低频振荡分析

正规形分析方法在传统的线性模式分析法中计入了非线性的影响,能够从系统内部结构入手分析系统的动态特性,因而可将小信号稳定方法与时域仿真方法有效结合起来.基于非线性向量场的正规形变换推导了电力系统状态方程的二阶近似解析解,提出了度量电力系统非线性程度大小的非线性指标,并揭示了低频振荡模式间的非线性相关作用以及对电力系统动态特性的影响.仿真分析的结果验证了该方法的正确性和有效性,表明该方法是电力系统低频振荡分析的有效工具.     

纯棉织物KN型活性染料冷轧堆染色工艺探讨

进行活性染料冷轧堆染色工艺实验,探讨了染料和碱剂的选择、碱剂用量、尿素及硫酸钠用量、堆置时间、水质等诸因素对冷轧堆工艺的影响.通过测量试样的表观深度和色牢度发现,当KN型活性红HF-6BN染料浓度为10 g/L时,Na2SiO3用量为10～15 g/L,尿素浓度低于5g/L,硫酸钠浓度10g/L为宜;在室温下堆置16 h.固色达到平衡;且冷轧堆染色以使用软水为佳.     

三相不平衡运行对电网的影响及无功补偿方法研究

在低压配电网中由于存在的大量电感性负荷及三相负荷用电的不同时性,尤其是单相大容量负荷的使用,造成配电网处在不平衡状态下运行,这将给配电网带来很大危害,如造成电网功率因数低、增加配电网线路和设备的损耗,影响电网电能质量等。因此,研究三相不平衡电网运行的补偿理论和算法,实现配电网三相负荷平衡化。降低线路损耗和提高电能质量,都具有相当重要的经济意义和社会效益。     

小麦交联-羧甲基双重变性淀粉的制备及性质研究

以小麦淀粉为原料，采用一氯乙酸为醚化剂，环氧氯丙烷为交联剂．利用Design—expert6．0．3软件，通过响应面实验制备交联-羧甲基双重变性淀粉并得到其制备优化条件。对羧甲基淀粉、交联淀粉，交联-羧甲基双重变性淀粉的透明度、溶解度和溶胀力、冻融稳定性进行研究。结果表明：小麦交联-羧甲基双重变性淀粉兼有羧甲基淀粉和交联淀粉两种单一变性淀粉的优良特性。     

Aroma components at various stages of litchi juice processing

BACKGROUND: Considering the importance of flavour on the quality of litchi juice, a study was conducted on how processing and operating stages influence the aroma components of clear litchi juice during processing. RESULTS: The aroma fractions isolated by solid‐phase micro‐extraction were analysed by capillary gas chromatography–mass spectrometry. According to statistical analyses, the amount of total and seven characteristic aroma compounds (geraniol, citronellol, phenylethyl alcohol, D ‐limonene, nonanal, geranial and linalool) increased significantly after enzyme hydrolysis, but decreased significantly during the process of enzyme inactivation, ultra‐filtration and sterilisation. CONCLUSION: The aromatic fraction of litchi juice decreased greatly during processing. The major losses in aromatic composition of clear litchi juice were related to the ultra‐filtration and sterilisation processes. With regard to the retention of aroma, an ultra‐filtration membrane with a larger pore size is better than a membrane with a smaller pore size, and a high‐voltage pulsed electric field was better than thermal sterilisation. Copyright © 2009 Society of Chemical Industry     

酶解蚕豆蛋白制备多肽酒及其抗氧化性研究

以蚕豆蛋白为原料,采用碱性蛋白酶酶解、酒精发酵制备蚕豆多肽酒,并对其抗氧化性进行了研究.结果表明:蚕豆蛋白酶解优化工艺为底物浓度32 g/L,水解温度43.2℃,酶用量9 821.12 U/g,pH 9.50,在此条件下酶解2h,蚕豆蛋白的水解度达到19.64％.以蚕豆酶解液为原料制备多肽酒的发酵工艺为加糖量20％,酵母接种量0.22％,发酵温度28℃,发酵时间6d,在此条件下制得的蚕豆多肽酒的酒精含量为9.6％,呈透明的棕黄色,口感醇正、鲜爽、具有发酵酒的醇香.本试验条件下制备的蚕豆多肽酒具有较强的抗氧化性.     

盒装羊血豆腐的研制

以新鲜的藏羊血为原料,通过单因素和正交试验对羊血豆腐的生产工艺进行了优化。结果表明:羊血与抗凝剂比例1∶2,凝固剂浓度为0.8%,凝固剂与羊血的比例为1∶4,灭菌温度80℃时,产品质地细嫩,气孔细小均匀,无大量水析出,富有弹性,颜色鲜艳,风味较好。     

Mutations in calpastatin and μ-calpain are associated with meat tenderness,flavor and juiciness in Hanwoo (Korean cattle): Molecular modeling of the effects of substitutions in the calpastatin/μ-calpain complex

The objective of this study was to evaluate the effects of seven single nucleotide polymorphisms (SNPs) in Calpain 1 and Calpastatin genes previously associated with meat tenderness attributes in other cattle breeds in Korean Hanwoo cattle. The Hanwoo resource population was used to study association of 7 SNPs with beef tenderness, flavor, juiciness, intramuscular fat and shear force. In this association study, CAST:c.182A > G (+ 0.14, P = 0.04) and CAST:c.1985G > C (− 0.12, P = 0.02) had significant effects on juiciness, but no effects on other traits. In contrast, CAPN1:c.1589G > A was associated with meat tenderness (P = 0.01) and juiciness (P = 0.04). The CAPN1:c.1589G > A (Val530Ile) SNP marker displayed significant effect on the meat tenderness score which is strongly supported by molecular modeling of the CAPN1:c.1589G > A (Val530Ile) variant that inhibits CAST protein from binding more strongly than the wild-type protein, which may explain its effect on meat tenderness.