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富含抗性淀粉水稻突变体的淀粉特性 总被引：16，自引：0，他引：16
从杂交水稻优异恢复系R7954诱变筛选了1个富含抗性淀粉的突变体RS111。该突变体热米饭中抗性淀粉的含量高达7.0%，是其野生型的2.4倍。突变体的淀粉颗粒形态、DSC和多晶衍射的曲线和参数与野生型明显不同，表现为淀粉颗粒大小较为一致，圆形和卵形淀粉颗粒所占比率较高，溶晶起始温度(TO)、最高温度(TP)、回落温度(TC)、焓变(ΔHGEL)及结晶度更低。突变体的表观直链淀粉、粗脂肪和粗纤维的含量显著提高。 相似文献
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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。 相似文献
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水稻抗性淀粉含量的研究 总被引：2，自引：0，他引：2
抗性淀粉是近年来发展起来的一个新概念,在代谢特性上类似于膳食纤维,具有非常重要的生理功能,可降低糖尿病患者饭后血糖值、控制体重、有效防止肠道疾病及降血脂等功效。开发大米抗性淀粉产品,具有广阔的市场前景。抗性淀粉具有较小的分子结构,是白色无异味的多孔性粉末。抗性淀粉分为四类:RS1(物理包埋淀粉)、RS2(抗性淀粉颗粒)、RS3(回生淀粉)和RS4(化学改性淀粉)。直链淀粉、支链淀粉和基因类型影响着抗性淀粉的含量。通过筛选突变体,可以培育出RS含量较高的水稻新品种(系)。 相似文献
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直链淀粉和支链淀粉含量及其比例是木薯淀粉品质的重要指标。采用双波长法对30个木薯株系的直、支链淀粉的含量进行了测定,根据碘分别与直链和支链淀粉反应生成复合物的吸收光谱,我们最后确定了直链淀粉的和支链淀粉的参比波长和测定波长分别是609和469.5 nm、542和721 nm。根据回归方程得到了30个木薯株系的直链淀粉和支链淀粉的含量。本实验中用于测定木薯的直链淀粉浓度在0~26μg/m L,支链淀粉浓度在0~100μg/m L范围内符合比耳定律。结果表明:SC8不同株系的直链淀粉含量变化范围:14.879%~21.905%,支链淀粉含量变化范围:47.864%~56.955%;SC6不同株系的直链淀粉含量变化范围:15.494%~24.726%,支链淀粉含量变化范围44.292%~57.465%。该方法准确性高、重复性好、效率高,工作量小,适于批量木薯样品分析。 相似文献
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长江下游地区部分优质粳稻品种与越光稻米支链淀粉结构特征及品质性状比较 总被引：6，自引：0，他引：6
为探讨具有优异食味品质的日本粳稻品种越光与中国长江下游地区食味品质好的水稻品种稻米的支链淀粉链长分布和主要品质特征差异,以期为中国优质水稻育种提供理论依据,选用长江下游地区公认的食味品质好的5个粳型水稻品种稻米和日本新泻地区生产的越光稻米为材料,分析支链淀粉链长分布、稻米RVA谱、直链淀粉含量、蛋白质含量、TOYO味度值等主要品质特性的差异及其相关性。越光的稻米支链淀粉链长分布和直链淀粉含量等主要品质指标与长江下游地区食味品质好的品种没有明显差异,支链淀粉长链部分(Fb3)和蛋白质含量显著低于长江下游地区食味品质好的品种,支链淀粉短/长链比(Fa/Fb3)显著高于长江下游地区食味品质好的品种。越光稻米中Mg、K含量以及淀粉谱特性中最高黏度、崩解值均显著高于长江下游地区食味品质好的品种。支链淀粉的短链部分(5≤DP≤12)所占比率与最高黏度值和崩解值呈显著正相关,Fa/Fb3与最高黏度和崩解值均呈显著正相关。由此认为,通过育种手段改善稻米的支链淀粉理化特性,并在栽培措施上通过降低氮肥施用量来降低稻米中蛋白质含量,是提高长江下游地区水稻品种食味品质的有效途径。 相似文献
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以水稻糖质胚乳突变体Sug-11与其野生型对照中花11为材料,通过对两者籽粒中可溶性总糖、蔗糖含量和淀粉含量以及有关淀粉品质理化指标的比较,结合籽粒灌浆过程中糖类物质含量、淀粉合成代谢关键酶活性和相关同工型基因转录表达水平的动态测定,从籽粒淀粉合成代谢角度,对水稻糖质突变体Sug-11的籽粒糖类含量变化和千粒重下降的生理原因进行了分析。结果表明,Sug-11糖质突变体与其野生型在灌浆初期的可溶性糖和蔗糖含量差异并不明显,随着籽粒灌浆进程,两者间的籽粒糖分含量差异在灌浆中后期逐步趋于明显;与野生型相比,Sug-11糖质胚乳突变体的稻米直链淀粉含量和直链淀粉碘蓝值显著下降,而淀粉溶解度和支链淀粉碘蓝值则显著升高,糖质胚乳突变对稻米淀粉的理化特性也产生了明显的影响;在籽粒淀粉合成代谢的几个关键酶中,Sug-11糖质突变体籽粒中的DBE活性及其在灌浆过程中的动态变化与其野生型存在明显差异,揭示了胚乳糖质突变体Sug-11籽粒中淀粉积累减少、糖分含量增加主要是由籽粒灌浆中后期的PUL转录表达水平和DBE活性的大幅下降所引起的,而Sug-11的籽粒灌浆不良和千粒重下降等现象,则与其ADPGase活性在籽粒灌浆前期的显著下降存在一定的联系。 相似文献
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To acquire a better understanding of whether RS influences the dynamics of in vivo starch digestion and seed vigour, the high-RS rice mutant RS4 (RS ca. 10%) and the wild type R7954 were used to investigate total amylase activity, seedling vigour, starch content and starch granule structure during germination. RS4 exhibited similar seed vigour to R7954. Amylose and amylopectin in R7954 showed synchronous degradation throughout the whole process, while amylopectin was hydrolysed significantly faster than amylose in RS4 during the earlier germination stages. The starch residues of RS4 after germination (GD) lost endotherm peaks and showed a special X-ray diffraction pattern with only two peaks at around 16.90° and 21.62°, probably due to remnants of amylopectin and its tight crosslinking with the cell wall. The remaining starch after 10 GD, primarily amylopectin may make a critical contribution to total resistant starch content. These results indicated that RS had no negative impact on seed vigour in rice lines, although RS cannot be hydrolysed by α-amylase from human and animal in vitro. By appropriately increasing the special amylopectin fraction, a new breeding programme of high RS crops and improvement in the eating quality of high RS rice varieties might be achieved. 相似文献
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Amylopectin Fine Structure and Rice Starch Paste Breakdown 总被引：1，自引：0，他引：1
Ten rice starches with a fairly narrow range of amylose content, but wide variation in RVA pasting curves, were selected to study a possible relationship between amylopectin fine structure and RVA paste viscosity parameters. Amylopectin fine structure was found to significantly correlate with paste breakdown. Proportion of long chains of amylopectin (FrI) was negatively correlated (r=0·84, p<0·01) and proportion of short chains of amylopectin (FrIII) was positive correlated (r=0·89, p<0·001) with paste breakdown. The findings imply that amylopectin fine structure relates to the extent of breakdown of swollen granules and the viscosity after gelatinised starch granule structure is disrupted. The results suggest the possibility that lines can be selected with high proportion of amylopectin long chains for reduced paste breakdown. 相似文献
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淀粉作为稻米胚乳中最主要的成分,其种类、含量及分子结构与水稻品质性状相关性密切。本研究以粳稻品种沈农265与籼稻品种沪恢99杂交后的F10代重组自交系群体为试材,探究环境因子对淀粉特性的影响。结果发现表观直链淀粉(AAC)、长分支支链淀粉(Fb3)以及抗性淀粉(RS)含量表现为沈阳>四川>深圳>江苏,而短支链淀粉(Fa)含量则是沈阳<四川<深圳<江苏,AAC、Fb3、RS含量越高,其Fa含量越低。淀粉特性与大部分环境因子相关性显著,AAC、Fb3以及RS含量基本与光照时间、昼夜温差、夜间温度呈正相关,与日平均温度、白天温度、夜间温度、空气相对湿度、夜间湿度呈负相关,Fa含量上与光照时间、昼夜温差、夜间温度呈负相关,与日平均温度、白天温度、夜间温度、空气相对湿度、夜间湿度呈正相关。 相似文献
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The long-grain, specialty rice cultivars, Bolivar, Cheniere, Dixiebelle, and L-205 are used for wet-pack canning. These cultivars have similar apparent amylose content but showed differences in canning, pasting, and gelatinization properties. Starch fine structures were analyzed to rationalize observed differences in functionality. Cheniere amylopectin had the lowest weight-average molar mass (Mw), shortest average chain length (CL), smallest z-average radius of gyration (Rz), lowest proportion of long chains (DP 37–65), and highest polydispersity; while its amylose had the largest Mw and Rz. These structural features were associated with more leached solids in the canning broth, lower volume expansion, lower peak and final viscosity, and lower gelatinization temperature and enthalpy. Bolivar amylopectin had the largest Mw, longest average CL, largest Rz, highest proportion of long chains (DP 25–65), and lowest proportion of short chains (DP 6–12); while its amylose had the smallest Mw and lowest polydispersity. These structures were associated with lower levels of leached solids, higher volume expansion, and higher peak and final viscosity. L-205 was similar to Bolivar in most structural and functional properties; those of Dixiebelle were either comparable to Bolivar or intermediate to Bolivar and Cheniere. These findings point to the importance of the molar mass of amylopectin and the proportion of long and short chains on the canning stability of rice. 相似文献
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Texture determinants in cooked, parboiled rice. I: Rice starch amylose and the fine stucture of amylopectin 总被引：3，自引：0，他引：3
The constituent starches from eleven cultivars of non-waxy rice with different degrees of cooking hardness were subjected to detailed analysis. No significant differences were observed in the granule morphology, crystallinity and size distribution of the starch granules that could be correlated with the textures of the cooked, parboiled rices. Differences in the contents of amylose and the fine structures of amylopectin were detected, however, which did correlate with texture. It appeared that the texture of the rices was critically controlled by the proportion of the longest (DP 92–98) and shortest (DP&lE25) amylopectin chains but not the intermediate (DP 43–68) chains. Hard cooking rice tended to have a higher amylose content (or amylose:amylopectin ratio) and more longer chain amylopectin than soft cooking rice, which feature is thought to encourage more extensive intra and/or inter molecular interactions with other components in rice grain, such as protein, lipid and non-starch polysaccharides and results in a firmer texture. The different amylopectin structures may explain why rices that possess similar amylose contents can have different textural properties. Such a correlation suggests that the structure of the starches determined from the SE–HPLC profile of the debranched amylopectin could be useful as a sensitive screening method in the classification of cooked rice texture. 相似文献
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Starch digestibility and the estimated glycemic score of different types of rice differing in amylose contents 总被引：1，自引：0，他引：1
Peisong Hu Haijun Zhao Zhiying Duan Zhang Linlin Dianxing Wu 《Journal of Cereal Science》2004,40(3):541
Three types of rice cultivars (indica, japonica and hybrid rice) with four levels of amylose were selected for assessing variability in starch digestibility. A vitro enzymatic starch digestion method was applied to estimate the glycemic index in vivo based on the kinetics of starch hydrolysis in vitro. The results indicated that significant differences in term of glycemic response were observed in three types of rice. Amylose content had an obviously impact on the estimated glycemic score (EGS) value and resistant starch (RS) content. The contents of RS were increased with the increasing amylose in the same type of rice. Japonica rice was significantly lower in RS content compared to indica rice and hybrid rice with similar amylose. The high amylose rice cultivar ZF201, which was characterized by low major RVA parameters, i.e. peak viscosity (PKV), hot paste viscosity (HPV) and cool paste viscosity (CPV), were obviously higher in RS content and lower in EGS. The retrogradation of cooked rice led to a reduction of HI and EGS of all varieties. Starch hydrolysis tends to be more quick and complete for the waxy and low amylose rice than for the intermediate and high amylose rice. 相似文献