Department of Food Engineering & Technology, Sant Longowal Institute of Engineering & Technology, Longowal, Punjab, India.
J Texture Stud. 2017 Apr;48(2):151-159. doi: 10.1111/jtxs.12226. Epub 2016 Sep 14.
In the present study, the effect of storage temperature and time on the textural and rheological properties of starch gels from seven different rice cultivars having higher amylose content than the hybrid rice varieties were evaluated. Water solubility and swelling power increased with every 10C increase in temperature due to granule swelling and solubilization of starch wherein the maximum solubility was found in starch of Koshkari rice cultivar (0.721 to 13.50) and swelling power in starch of Zag rice cultivar (3.688 to 10.806). However, syneresis in the analyzed rice starch gels had shown a fluctuating trend for each individual cultivar at different storage periods in which the cultivars Zag had shown the highest values of syneresis during storage (4.123 to 4.957%). In the texture profile analysis of starch gel of these cultivars, Mushki Budgi had the highest value of hardness (0.723N), gumminess (36.262) and chewiness (31.056). The turbidity values of gelatinized starch suspensions from different rice cultivars increased progressively during the first 4 days of storage followed by a decrease in the 5th day coupled with slight increase in the 6th day. The highest turbidity was found in Zag ranging from 1.47 to 1.67 during refrigerated storage after 6 days. The rheological analysis revealed that Zag indicated the highest value of TG' (76.96C) whereas cultivars Koshkari and Mushki Kandi had shown the lowest value of TG' (74.34C) upon heating cycle.
Rheological properties of starch are affected by amylose contents, lipid contents, branch chain length distribution of amylopectin. The starch from different varieties depicted variable textural and rheological properties at various time: temperature combinations. No research has been reported to explore the effect of time and temperature on the textural and rheological properties of starch isolated from these traditional rice cultivars. The starches from traditional rice cultivars (native or indigenous rice cultivars of a region) indicated novel characteristic as compared to other cultivars in terms of their higher amylose content, starch yield, purity, clarity, solubility, syneresis, turbidity, and rheology. The novelty of this research was to exploit the desirable properties of starch obtained from traditional rice cultivars that had better characteristics than the hybrid varieties. This in turn led the various agencies to motivate the farmers to encourage their cultivation, provide an essential platform to scientists to inherit their valuable characteristics.
在本研究中，评估了储存温度和时间对七种不同稻米品种淀粉凝胶的质构和流变特性的影响。这些品种的直链淀粉含量高于杂交水稻品种，随着温度每升高 10°C，其水溶解度和膨胀力增加，这是由于颗粒膨胀和淀粉溶解所致。其中，Koshkari 大米品种的最大溶解度（0.721 至 13.50）和 Zag 大米品种的最大膨胀力（3.688 至 10.806）。然而，在所分析的稻米淀粉凝胶的应变收缩中，每个品种在不同的储存期都呈现出波动趋势。在储存期间，Zag 品种的应变收缩值最高（4.123 至 4.957%）。在这些品种的淀粉凝胶的质地分析中，Mushki Budgi 的硬度（0.723N）、胶粘性（36.262）和咀嚼性（31.056）最高。不同稻米品种的糊化淀粉悬浮液的浊度值在储存的前 4 天内逐渐增加，随后在第 5 天下降，第 6 天略有增加。在冷藏储存 6 天后，Zag 的浊度最高，范围为 1.47 至 1.67。流变分析表明，Zag 指示了 TG'的最高值（76.96°C），而 Koshkari 和 Mushki Kandi 品种的 TG'的最低值（74.34°C）在加热循环中。
淀粉的流变特性受直链淀粉含量、脂质含量、支链淀粉分支链长分布的影响。不同品种的淀粉在不同的时间和温度组合下表现出不同的质构和流变特性。目前还没有研究报道探讨时间和温度对这些传统水稻品种分离的淀粉的质构和流变特性的影响。与其他品种相比，传统水稻品种（一个地区的本土或本地水稻品种）的淀粉在直链淀粉含量、淀粉产量、纯度、透明度、溶解度、应变收缩、浊度和流变学方面表现出独特的特性。本研究的新颖之处在于利用传统水稻品种获得的淀粉的理想特性，这些特性优于杂交品种。这反过来促使各机构鼓励农民种植，为科学家提供一个重要的平台来继承他们的宝贵特性。
