Gelatinization and Retrogradation Characteristics of Hydroxypropylated and Cross‐linked Rices

Abstract

Chemically modified rices were prepared by treating with propylene oxide and epichlorohydrin. Gelatinization and retrogradation characteristics of these modified rices were investigated by using DSC and amylograph. Hydroxypropylation of rice caused an extreme decrease in gelatinization temperature from 62°C to 50°C and reduced the retrogradation rate of cooked rice. In rice treated by both hydroxypropylation and cross-linking the retrogradation was reduced more than for hydroxypropylated rice.

The effect of hydroxypropylation on the structure and physicochemical properties of native, defatted and heat-moisture treated potato starches

“…acetylated (Hoover & Sosuskl 1985) and hydroxypropylated (Hoover et al. 1988;Yook et al 1993) groupS Into starch chains has been shown to influence starch retrogradation by retarding amylose and amylopectin chain aggregation during storage. Hoover et al (1988) reported that hydroxypropylated field pea starch showed less retrogradation dunng frozen storage compared to the unmodified starch Takahashi et al (1989) studied the gel properties of wheat and corn starches cross linked after acetylation and hydroxypropylation.…”

Physicochemical properties of chemically modified starches from different botanical origin

“…Yeh and Yeh (1993) also reported that cross-linking increased the heat of gelatinization for rice starch. However, according to Yook et al (1993), the cross-linked rice starch exhibited a lower value of heat of gelatinization than native rice starch because cross-linking reduced the portion of starch granules that could be gelatinized. In this study, the T o, T p and ∆H gel of cross-linked starches from rice, maize and potato were higher than those of their native counterpart starches at the same reaction conditions of 0.3% EPI.…”

Relationship between ?-amylase degradation and the structure and physicochemical properties of legume starches

“…Retrogradation is influenced by starch structure (Russell, 1987;Orford eta!., 1987), storage temperature (Jankowski and Rha, 1986), moisture content (Longton and LeGrys, 1981;Zeleznak and Hoseney, 1986), lipids (Eliasson and Ljunger, 1988;Huang and White, 1993), sugars (Kohyama and Nishinari, 1991;Wang and Jane, 1994), salts (Ciacco and Fernandes, 1979;Bello-Perez and ParedesLopez, 1995), and physical and chemical modifications (Orford et al, 1993;Gunaratne and Hoover, 2002;Yook et al, 1993 (Janecek 2000). It consists of twenty seven different enzyme specificities (Horvathova et al, 2000).…”