Effect of Fat Extraction on Rice Quality and Storage Deterioration of Defatted Rice Studies on Cereals (Part 6)

Texture Changes and Storage of Rice

“…Yasumatsu et al (1964) demonstrated that the free fatty acid fraction increases the Amylograph viscosity of Japanese rice flour but Shibuya et al (1977) did not notice any effect of defatting with diethyl ether on Amylogram of unaged and aged Japanese milled rice. Surface defatting, however, did not retard the changes in cooked rice texture (Table 6), as also reported by Moritaka et al (1971). Storage.…”

“…A value of 0.8% was reported by Maniiigat and Juliano (1980) for an indica rice starch with intermediate amylose content. Surface defatting of milled rice has little effect on the Amylograph (Table 6; Barber 1972;Moritaka et al 1971). The defatted rice, except for IR32, did not increase in Amylograph viscosity on storage in contrast to undefatted milled rice indicating that surface extraneous or nonstarch lipids contribute to increase in viscosity.…”

“…The effect of amylose content of starch is mainly in the ratio of nonstarch lipids to starch lipids in milled rice (Choudhury and Juliano 1980). Hexane and petroleum ether mainly extracts nonstarch lipids and has no effect on fat-byhydrolysis [starch lipids (Choudhury and Juliano 1980)] (Moritaka et al 1971). The maximum amount of starch-bound fatty acids (fat-byhydrolysis) for japonica rice seems to be 0.7% (Yasumatsu et al 1964).…”

Near Infrared Spectra of the Outer Layer of Flour of Stored Milled Rice.

“…Although crude protein is distributed more in the outer layer, it was hardly affected by storage. These results correspond to the previous reports that the taste and flavor of cooked rice are improved by increasing the degree of polishing (Kainuma, 1979), thus defatting the milled rice (Moritaka et al, 1971). …”

“…It is well-known that the decrease in the palatability of milled rice during storage is caused by changes in the lipid (Yasumatsu et al, 1964(Yasumatsu et al, , 1965Shibuya et at, 1974) and protein compositions (Moritaka et al, 1971) and their combination with starch (Moritaka & Yasumatsu, 1972). The content of free fatty acids increases due to the degradation of neutral fat during storage (Shibuya et al, 1974).…”