Effect of Amylose Content on Gelatinization, Retrogradation and Pasting Properties of Flours from Different Cultivars of Thai Rice

Abstract

Presently, rice cultivars are categorized according to amylose content into three groups: low, medium and high amylose content cultivars. The correlation of amylose content with gelatinization properties, retrogradation, and pasting properties of eleven cultivars of Thai rice were investigated. Rice flour was prepared from milled rice by the wet grinding process. Onset (To), peak (Tp) and conclusion (Tc) temperatures of gelatinization, (determined by DSC) were found to be highly positively correlated with amylose levels. This correlation could be used for prediction of amylose content of rice flour. Low amylose starch could also be characterized by low degree of retrogradation (%R). The data obtained from RVA‐viscograms (peak viscosity, breakdown, setback, and pasting temperature) can be used only for characterization of the group of low amylose starches (waxy rice). It was demonstrated that low amylose rice starch provided the highest peak viscosity and breakdown and the lowest setback and pasting temperature among the groups investigated.

Effect of green tea powder on thermal, rheological & functional properties of wheat flour and physical, nutraceutical & sensory analysis of cookies

“…The lower value of setback reflects lesser degree of retrogradation of a starch paste. (Varavinit et al 2003). After RVA test, the gelatinized flour gels were stored at 4°C for 24 h for the hardness measurement, during this period, the hardness of flour gels decreased significantly (P≤0.05) as the GTP level increased, especially when the added dose was up to 2 and 4 g/ 100 g. These results suggest that adding GTP could significantly inhibit the retrogradation of the gelatinized wheat flour system.…”

Study on the Gelatinization Properties and Amylose Content of Rice Varieties from Nigeria and Cameroun

“…Varavinit et al [11] reported a positive correlation of amylose to onset, peak and conclusion temperatures (0.84, 0.88, and 0.85, respectively). Their study suggested the prediction of amylose content of rice with gelatinization properties.…”

“…It has been reported that waxy starches usually swell to a greater extent than non-waxy starches [11,12].…”

Effects of Incorporating Polycaprolactone and Flax Fiber into Glycerol-Plasticized Pea Starch

“…Of these physicochemical properties, gelatinization is of importance to starch plastic prospects and is defined according to Atwell and co-workers (1988) as the collapse (disruption) of molecular order within the starch granules manifested in irreversible changes in properties such as granular swelling, native crystallite melting, loss of crystallinity, loss of optical birefringence, and starch solubilization. The amylose content is known to influence starch gelatinization as well as gelation and retrogradation (starch chain realignment on cooling after gelatinization) (Fredriksson et al 1998;Varavinit et al 2003). Other factors that affect gelatinization and swelling properties according to Tester (1997) include amylopectin molecular structure (in terms of unit chain length, molecular weight, degree of branching, and polydispersity), lipid-complexed amylose chains, phosphorous content, and granule structure (crystalline/amorphous ratio).…”