Morphological, Structural, Thermal, Pasting, and Digestive Properties of Starches Isolated from Different Varieties of Rice: A Systematic Comparative Study

Abstract

The aim of this study was to compare the properties of isolated starches from ten commonly consumed rice varieties in China and to investigate their possible association. In addition, principal component analysis (PCA) and correlation analysis were performed to demonstrate the weight or relevance of different properties. The starch granules had an irregular polyhedral structure. The crystalline structure had an orthogonal arrangement, which is characteristic of A-type starch with nanocrystals with an orthorhombic crystal structure. In addition, higher levels of rapidly digestible starch (72.43 to 74.32%) and resistant starch (2.27 to 2.3%) were found in glutinous rice starch. The highest content of slowly digestible starch (59.48%) was found in starch isolated from black rice, which may be an ideal rice variety for controlling blood glucose and weight. Starch isolated from red Hani terrace rice showed the highest thermal stability during cooking and the highest resistance to a high shear force treatment. In addition, the PCA suggests that the amylose content of starch largely determines the functional properties of starch and positively correlates with the peak viscosity and setback viscosity of the starch pasting. The results of this study will enrich the scientific knowledge of various rice starches and promote their application in the food industry and other industries.

Evaluation Method of Texture of Glutinous Rice Cakes (Niangao) and Its Key Impact Indicators

“…In this study, peak viscosity was negatively correlated with the texture quality of Niangao. This is probably due to the small clusters of starch chains or molecules that could be easily dissociated, hydrated, and swollen during gelatinization with excess water, thus contributing to an increase in pasting viscosity [23]. Tester and Morrison reported that swelling of starch granules was inhibited by complexes formed with amylose and lipids which results in a lower peak viscosity, the complexes could significantly affect the texture of products [24].…”