Thermal and Physicochemical Properties of Rice Grain, Flour and Starch

Abstract

Three types of rices, namely, Thailand rice (Indica), Nipponbare (Japonica), and Himenomochi (Japonica waxy), in grain, flour, and starch forms have been studied for their thermal and physicochemical properties. In grain form, Indica was slender and Japonica rices were bold and thick. Indica had the highest protein and amylose equivalent. Protein contents in isolated starches varied from 0.2 to 0.9%. Cooked Indica grain was hardest and waxy rice was softest; stickiness was highest in Japonica rice. Glass transition temperature (T(g)) was highest in Indica rice flour (approximately 222 degrees C) and almost the same in Japonica rice flours. Melting point was highest for Japonica (approximately 264 degrees C) and almost the same for Japonica waxy and Indica rice flours. T(g) values of starches were almost the same in Indica and Japonica waxy (approximately 237 degrees C); defatting caused reduction in this property in all of the starches. Highest melting point was shown by Indica starch (approximately 276 degrees C) and was almost the same for the other two starches. Protein and fats play a critical role in glass transition and melting points of rice flours and their respective starches. Viscosities of the cooked pastes of flour and starch during cooking in an RVA instrument and their gel and other properties have been discussed.

Differences, Correlation of Compositions, Taste and Texture Characteristics of Rice from Heilongjiang China

“…Amylose and protein not only are the most important nutrients of rice, but also are the significance factors affecting its qualities [11,12]. Chemical composition from different regions rice is shown in Figure 1.…”

Rapid Visco Analyzer Measurements ofjaponicaRice Cultivars to Study Interrelationship between Pasting Properties and Farming System

“…Starch is the major component of rice and described its physiochemical properties, such as gel strength and pasting properties [1][2][3]. The japonica cultivars are the major rice variety used for the preparation of important snacks and food materials in Asian countries.…”

“…Most of the manufacturers prefer rice flour instead of starch for preparing processed products. However, the swelling and pasting properties of starch granule were influenced not only by starch solely but also by lipids, protein, and mineral compounds [1]. The starch granules of rice play active role; if there is less swelling of starch during gelatinization, the peak viscosity of starch paste will be lower [4].…”

Hydration behaviour of food grains and modelling their moisture pick up as per Peleg’s equation: Part I. Cereals

“…World rice varieties have been classifi ed into 8 groups, based on insoluble amylose content as one of the important properties along with other physico-chemical properties like alkali score, stickiness, consistency, viscographic behaviour and EMC and similarly on the same parameters Indian rice varieties have also been classifi ed (Bhattacharya et al 1979a(Bhattacharya et al , 1980. Vasudeva Singh et al (2000) have studied the thermal and physico-chemical properties of rice grain, fl our and starch from indica, japonica (Nipponbare) and japonica waxy rice (Himenomochi) varieties. It was noticed among the physico-chemical properties studied, EMC showed an important differentiation, where indica milled rice had EMC of ~28%, japonica 30% and japonica waxy had 35% on wet basis.…”