淀粉与油脂对妊娠母猪糖脂代谢及其繁殖性能影响的研究进展

妊娠后期随着胎儿生长速度和乳腺发育加快,母猪机体代谢强度逐渐增加,机体糖脂代谢失衡,出现代谢紊乱。能量占整个日粮成分的70%以上,选择适当的日粮能量来源以调节糖脂代谢的平衡是提高母猪繁殖效率的有效方法。淀粉与油脂作为母猪日粮主要能量来源,均可显著影响后备母猪的初情期启动或经产母猪的繁殖性能,但以母猪本身的糖脂代谢特征为出发点,评述不同来源与水平的淀粉或油脂对母猪繁殖性能的影响鲜有总结报道。文章首先综述了母猪妊娠期糖脂代谢特点和代谢机制,简述了妊娠期代谢紊乱对母猪繁殖性能的不良影响,介绍了淀粉与油脂在母体的吸收及代谢特点,对比分析了不同水平与来源的淀粉和油脂对母猪产仔性能和泌乳性能的影响。最后,为最大化提高猪场经济效益,根据实际生产目的,总结了选择合适能量来源的依据。该综述旨在选择日粮适宜水平和来源的淀粉和油脂以期为提高母猪繁殖效率提供数据支持和理论指导。     

Gelation characteristics of Mesona chinensis polysaccharide-maize starches gels: Influences of KCl and NaCl

An investigation was conducted into the effects of potassium chloride (KCl) and sodium chloride (NaCl) on the gelation properties of maize starch-Mesona chinensis polysaccharide (MCP) gels. Waxy maize starch (WS), normal maize starch (NS), and high amylose maize starch (HS) were used to compare the effects of different amylose contents on the gel properties of maize starch-MCP gels. The results showed that KCl and NaCl have similar effects on the gelation, rheological, and structural properties of maize starch-MCP gels. The addition of KCl and NaCl increased the pasting viscosity, breakdown values, setback values, dynamic modulus, and apparent viscosity of maize starch-MCP gels, especially for HS-MCP gels. LF-NMR (Low-field nuclear magnetic resonance) showed that salts reduced bound water content while increasing the free water content of maize starch-MCP gels. CLSM (Confocal laser scanning microscopy) results also indicated that salt can restrict the expansion and maintain the integrity of starch granules, especially for WS-MCP gels.     

Developing gene-tagged molecular markers for functional analysis of starch-synthesizing genes in rice (Oryza sativa L.)

The granule-bound starch synthase(GBSS), starch branching enzymes 1 (SBE1)and 3 (SBE3) are major enzymes involved in starch biosynthesis in rice endosperm. Available sequences of Sbe1 and Sbe3 genes encoding corresponding SBE1 and SBE3 have been used to identify homologous regions from genome databases of both the indica rice 93-11 and the japonica rice Nipponbare. Sequence diversities were exploited to develop gene-tagged markers to distinguish an indica allele from a japonica allele for both Sbe1 and Sbe3 loci. With these newly developed gene-tagged markers and available Wx gene markers, the roles of these starch-synthesizing genes (Sbe1, Sbe3, and Wx) in determining amylose content (AC) in the rice endosperm were evaluated using a double-haploid (DH)population derived from a cross between the indica rice cv. Nanjing11 and the japonica rice cv. Balilla. Only the Wx and Sbe3 loci had significant effects on the AC variation. On average, indica Wx ^a genotypes showed ∼9.1% higher AC than japonica Wx ^b genotypes, while indica Sbe3 ^a genotypes showed ∼1.0% lower AC than japonica Sbe3 ^b genotypes. A significant interaction was also observed between Wx and Sbe3 loci whereby the amylose content was 0.3% higher in Sbe3 ^a than Sbe3 ^b genotypes in the presence of the Wx ^a allele, but it was lower by 2.3% in the presence of the Wx ^b allele. Overall, polymorphisms at the Wx and Sbe3 loci together could account for 79.1% of the observed AC variation in the DH population. The use of gene-tagged markers in marker-assisted selection and gene functional analysis was also discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

烤烟烘烤中烟叶淀粉降解的研究进展

综述了烤烟烘烤中烟叶淀粉降解对烟叶品质的影响、降解的生化过程及影响降解程度与速率的因素。烘烤中,烟叶淀粉的降解程度和产物均影响烟叶品质,降解是在多种酶的催化下以水解和磷酸解2种方式实现的。影响烟叶淀粉降解的内部因素为烟叶淀粉粒属性、烟叶成熟度、烟叶微生物等,外部因素为烘烤设备及其参数、人工添加酶和微生物制剂等。可为烤烟烘烤工艺的优化、烘烤中促进烟叶淀粉降解措施的制定提供参考。     

豆制品加工中黄浆水无害化处理技术研究

对豆制品中黄浆水进行超滤处理的工艺参数进行研究。用外加压管式膜组件对黄浆水进行了超滤试验,分析了液体分别在不同的温度、压力、流速、pH值等因素下对渗透流量和截留率的影响。通过正交试验,得到了处理黄浆水废液的最佳工况。实验结果表明,超滤处理黄浆水的最佳工况是:在压力0.15MPa下,用泵的最大流量对刚排放的黄浆水(温度55℃左右)进行超滤处理,可回收全部脂肪、75%以上的蛋白质和70%以上的总糖。回收后的浓缩物(或干燥物)可以作为饲料或经纯化后食用。     

GA_3处理对天女木兰种子解除休眠过程中碳水化合物含量的影响

研究了GA3对天女木兰种子在变温层积条件下解除休眠过程中碳水化合物的影响,以此探讨外源赤霉素(GA3)对层积过程中天女木兰种子解除休眠的作用机理。结果表明,1000mg/LGA3水溶液处理极显著促进天女木兰种子萌发,在整个层积过程中,GA3水溶液处理诱导淀粉含量下降;蔗糖含量变化剧烈,在层积90d降至最低,果糖和葡萄糖含量显著增加;在层积后期(90～120d)果糖和葡萄糖含量下降,蔗糖含量上升,从而说明了碳水化合物参与并调节了天女木兰种子休眠解除这一过程。     

小麦蛋白质和淀粉性状与面包品质关系研究进展

蛋白质和淀粉是影响面包品质的主要因素。蛋白质的含量和质量,直链淀粉、支链淀粉比例以及破损淀粉含量都对面粉烘培品质有重要影响。本文综述了国内外对蛋白质和淀粉特性与面包品质关系的研究进展,并指出了下一步研究的重点。     

湿热处理制备马铃薯抗性淀粉工艺优化

为获得湿热处理制备马铃薯抗性淀粉的最适工艺参数,以抗性淀粉得率为考察指标,研究淀粉含水量、湿热处理温度和湿热处理时间对抗性淀粉得率的影响。在单因素试验的基础上进行正交优化,确定了制备马铃薯抗性淀粉的最佳工艺条件为：淀粉含水量30%,湿热处理温度90 ℃,热处理时间90 min。在此条件下制得的抗性淀粉得率为26.63%。淀粉经过湿热处理后仍然保持偏光十字,为颗粒型抗性淀粉。     

淀粉和面筋蛋白对面制品流变特性的影响

面粉的两种主要成分淀粉和蛋白质对面制品的流变特性有显著的影响。概括了影响淀粉糊流变特性的几个主要因素:蒸煮温度、搅拌时间、搅拌速度、pH值以及淀粉糊浓度、盐和蔗糖的作用,同时讨论了面筋蛋白对面制品流变特性的影响机理。