粳稻品种的粒厚特征及其对食味品质的影响

 以2006年收获的71份北方粳稻主栽品种为试材,研究了糙米粒厚的分布及粒厚与食味品质的相关性。结果表明,品种间糙米粒厚差异较大,变异系数为6.57%,粒厚在1.81~2.10 mm的品种占参试品种总数的78.88％。糙米粒厚与米饭食味评分呈极显著正相关。用粒厚分级机对其中5个粳稻品种进行粒厚分级,测定同一品种不同粒厚样品的米饭食味评分值、蛋白质含量、直链淀粉含量和RVA谱特征值。结果表明,粒厚对稻米蛋白质含量、RVA特征值、米饭食味评分等指标有显著影响,同一品种随着粒厚的增加,食味品质得到改善。讨论了粒厚作为品种选育指标的必要性。     

不同木薯品种（系）块根淀粉特性研究

对79个木薯品种(系)块根淀粉的鲜薯含粉率、原淀粉水分、直链淀粉和支链淀粉含量、峰值粘度、糊化温度、透明度、恩氏粘度、淀粉粒直径和表面积等淀粉特性指标进行研究.结果表明,不同木薯品种(系)各淀粉特性指标存在很大的差异,不同指标间也有一定的相关性,利用主成分分析对各品种(系)各指标进行综合分析,认为E169、C766、E1424、E339、R72、E217、E344、E232、E316和桂热3号木薯淀粉的加工特性最好,更适合木薯淀粉的深加工.     

高直链淀粉突变体Goamy2的淀粉糊化特性及淀粉结构分析

以高直链淀粉及突变体材料Goamy2及其野生型亲本Ilpumbyeo米粉为材料,比较了它们在理化性质和糊化特性上的差别,并通过体积排阻色谱(Size Exclusion Chromatography,SEC)分析其水溶性和不溶性淀粉组成结构差别。从冷水溶性成分来看,Goamy2主要以小分子DP141～DP2(DP为聚合度)为主,而Ilpumbyeo中带分支的链DP4100～DP64也就是相对大分子所占的比例较高,达到33.3%。从热水溶性淀粉成分来看,突变体Goamy2直链淀粉和支链淀粉的比例大致为4∶1,而Ilpumbyeo直链淀粉和支链淀粉比例大致为1∶1。至于两个材料的热水溶性支链淀粉链长分布,长短链比例差别较大,Goamy2长短链比率为0.67,而Ilpumbyeo为0.32。从热水不溶性成分来看,两个材料均以支链淀粉为主,直链淀粉所占的比例很低,均不到5%。热水不溶性支链成分的链长分布中,野生型亲本Ilpumbyeo以短链为主,短链所占的比例高达72.5%,而突变体Goamy2短链和长链几乎各占一半。     

Endosperm Texture in Wheat

One of the fundamental means of classifying wheat is through its endosperm texture. It impacts significantly on the milling process affecting among other things flour particle size and milling yield. Hardness in wheat is largely controlled by genetic factors but it can be affected by the environment and factors such as moisture, lipid, and pentosan content. The principal genetic locus controlling endosperm texture in wheat, Ha, is located on the chromosome 5D. At this locus several genes, notably the puroindolines, have been identified. Puroindolines are the major components of the 15 kDa protein band associated with starch granules that is more abundant in soft wheats than in hard. Recently the puroindolines have been shown to enhance grain hardness in rice. In this review we discuss the structure of hard and soft wheat endosperm with particular emphasis on when differences in endosperm texture can be detected in the developing seed. The role of the environment and other factors that may affect the endosperm texture is also examined together with the role of the puroindoline genes at theHa locus. Finally, we compare endosperm hardness in wheat and in barley.     

长期施肥对木薯农艺性状、鲜薯产量和淀粉质量分数的影响

1992—2003年12a间，对2个木薯品种(华南205和华南124)，进行氮、磷、钾和火烧土等4种肥料各4个不同施肥水平组成共16个施肥配方的试验，研究了长期施肥对木薯农艺性状、鲜薯产量和淀粉质量分数的影响。结果表明：淀粉质量分数与收获指数呈显著正相关，鲜薯产量与株高、茎径及单株结薯数呈极显著正相关，单株结薯数与株高、茎径呈极显著正相关，株高与茎径呈极显著正相关。并列出它们的相关回归方程。推荐木薯最佳N，P2O5，K2O的施肥质量配比为2～4：1：2～4，其中，N，P2O5，K2O的施肥质量配比在连作初期以2：1：2为佳，而连作后期则以逐渐过度为4：1：4为佳。     

OsESV1基因对水稻淀粉合成的影响

【目的】 研究水稻EARLY STARVATION1 (OsESV1)基因对水稻淀粉代谢的影响。【方法】 通过CRISPR-Cas9技术获得osesv1突变体,考查osesv1的表型及胚乳淀粉的理化特性,分析OsESV1的表达特性及相关功能。【结果】 OsESV1蛋白在植物界中十分保守。osesv1突变体株高、穗长、每穗粒数低于野生型,分蘖数显著多于野生型,叶片中淀粉含量显著下降,籽粒中的直链淀粉含量上升,而总淀粉含量无明显变化。OsESV1呈组成型表达,并且具有昼夜节律表达的特征。OsESV1蛋白定位在叶绿体内且呈点状分布。酵母双杂交和双分子荧光互补实验结果表明OsESV1蛋白可以与ADP-葡萄糖焦磷酸化酶小亚基(OsAGPS) 2a和OsAGPS1互作。【结论】 OsESV1基因影响水稻叶片的淀粉合成途径,而对胚乳淀粉合成的影响不明显。     

Growth performance and metabolic utilization of diets with native and waxy maize starch by gilthead sea bream (Sparus aurata) juveniles

The effect of dietary starch source and level on growth performance, feed utilization, apparent digestibility coefficients and liver enzyme activities involved in intermediary metabolism of gilthead sea bream juveniles was studied. Five isonitrogenous (47% crude protein) and isolipidic (15% crude lipids) diets were formulated to contain 10% native (diet NS10) or waxy (diet WS10) maize starch; 20% native (diet NS20) or waxy (diet WS20) maize starch or no starch (control). Diets were adjusted with α-cellulose. Another diet was formulated without carbohydrates, and contained 70% crude protein and 15% crude lipids (diet HP). Each diet was fed to triplicate groups of 30 fish (initial weight: 20 g) for 12 weeks. The HP group was fed to near satiation and the other 5 groups were fed on a pair-feeding scheme according to the group that ingested less feed (control diet group). The reduction of dietary protein level from 70% to 47% by the incorporation of 20% starch did not significantly affect gilthead sea bream growth performance or feed efficiency. Compared to the control diet, neither the level nor the nature of starch had any measurable effect on growth performance and feed efficiency. Digestibility of starch was unaffected by source or dietary inclusion level. Diet had no effect on plasma glucose levels, but liver glycogen was higher in diet groups NS20, WS20 and HP. Dietary carbohydrates increased GK and G6PD enzyme activities and decreased ALAT and GDH enzyme activities while had only a minor effect on FBPase activity. The nature of dietary starch tested (native or waxy) had little influence on performance criteria.     

生物有机肥在马铃薯上施用效应研究

选用3种类型马铃薯品种紫花白、内薯三号、坝薯10号,它们分别为早、中、晚熟和高、中、低淀粉品种,研究了底施生物有机肥、锰肥、锌肥在马铃薯上的施用效果.结果表明,不同品种、不同施肥种类对马铃薯产量和淀粉含量的影响差异显著,它们对产量和淀粉含量的效应为施肥>品种.其中施肥方式对产量和淀粉含量的效应为生物有机肥>锰肥>锌肥;品种对产量的效应为紫花白>内薯3号>坝薯10号,对淀粉含量的效应为坝薯10号>内薯3号>紫花白.     

电子鼻和电子舌单独与联合检测掺大豆蛋白或淀粉的鸡肉糜

为实现掺杂掺假鸡肉的快速、客观评价,该研究利用电子鼻和电子舌联合检测技术对掺杂鸡肉糜进行快速检测,通过对采集的数据进行主成分分析和偏最小二乘法分析,所得结果表明,采用主成分分析,电子鼻和电子舌联合检测掺大豆蛋白鸡肉糜和掺淀粉鸡肉糜的主成分总贡献率分别为99.8%和99.1%;采用偏最小二乘法分析,电子鼻和电子舌联合检测鸡肉糜中掺杂大豆蛋白含量的预测值与真实值之间的决定系数为0.992,均方根误差为2.8%;联合检测鸡肉糜中掺杂淀粉含量的预测值与真实值之间的决定系数为0.996,均方根误差为2.4%。表明电子鼻和电子舌联合检测对鸡肉糜的掺杂情况具有良好的区分和预测能力,并且是一种有效、高精度的肉类掺假检测方法。     

回生抗性淀粉种类对米淀粉凝胶形成的影响

为寻找改善普通米淀粉制品的结构及品质的新型食品添加剂,该文以普通米淀粉为原料,采用快速黏度分析仪、扫描电子显微镜、质构分析仪、全自动X射线衍射仪及示差扫描量热仪等手段,研究添加锥栗、马铃薯与绿豆回生抗性淀粉(retrograded resistant starch,RSⅢ)对米淀粉凝胶微观结构及理化性质的影响。结果表明:添加锥栗、马铃薯及绿豆RSⅢ对米淀粉凝胶的结构及性质产生显著影响(P0.01),以锥栗RSⅢ的作用最为突出。添加锥栗、马铃薯与绿豆RSⅢ对米淀粉糊的黏度特性没有影响(P0.05)。未添加RSⅢ的米淀粉凝胶存在很多不规则、深浅不一的大洞,而加入RSⅢ使米淀粉凝胶的网状结构变得更为规整、致密,且其胶着性与黏聚性变化不大(P0.05);添加锥栗、马铃薯与绿豆RSⅢ后能加速米淀粉凝胶的形成,与未添加RSⅢ的米淀粉凝胶比,其硬度分别增加了2.38、1.97和1.25倍(P0.01),黏着性分别增加2.56、1.99和1.32倍(P0.01),弹性增加1.07、0.81和0.53倍(P0.01)。米淀粉以A-型晶体占优,锥栗RSⅢ以V-型晶体占优,马铃薯与绿豆RSⅢ均以B-型晶体占优;不加或加入RSⅢ的米淀粉凝胶粉末都转变为以V-型晶体为主,且总相对结晶度没有改变(P0.05)。加入RSⅢ后的米淀粉糊除有低温吸热峰外还出现高温吸热峰,是否添加RSⅢ对低温吸热峰的温度参数影响不大(P0.05),但吸热焓显著降低(P0.01);而对于高温吸热峰,添加马铃薯与绿豆RSⅢ的各项参数没有差别(P0.05),但比添加锥栗RSⅢ的显著增高(P0.01)。可见添加不同来源的RSⅢ可以有效改善米淀粉凝胶的结构与品质。该研究结果为抗性淀粉用于提高米制品品质与营养功能的研究和生产提供了重要参考。