Impacts of Low and Ultra-Low Temperature Freezing on Retrogradation Properties of Rice Amylopectin During Storage

Abstract

Amylopectin retrogradation is a serious problem in starch-based ready meals. In the current research, rice amylopectin was frozen by low temperature (−20, −30, and −60°C) and ultra-low temperature (−100°C), and then stored at 4°C for 21 days or at −18°C for up to 5 months to evaluate the retrogradation properties. Amylopectin retrogradation enthalpy of rice was determined by a differential scanning calorimetry. The results showed that low temperature and ultra-low temperature freezing can effectively retard amylopectin retrogradation during the freezing process and during frozen storage (−18°C) for at least 5 months. However, rice amylopectin still retrograded after the freezing process during chill storage at 4°C. The methods of low and ultra-low temperature freezing combined with frozen storage might be potentially very useful for food industry to produce high quality starch-based ready to eat meals.

Relationship between intrinsic viscosity, thermal and retrogradation properties of amylose and amylopectin

“…These results indicated that amylopectin retrogradation depended not only on intrinsic viscosity but also on molecular weight and extent of molecular branching. This kind of retrogradation behaviour was observed in earlier studies (Mua & Jackson 1998;Yu et al 2009Yu et al , 2012b.…”

“…As shown in Table 5, the retrogradation enthalpy of amylopectin increased with storage time within 7 days, and then changed slowly with storage time. Similar results were observed during the rice amylopectin retrogradation process within 14 days storage (Yu et al 2012b). However, the relationship between amylopectin retrogradation enthalpy and intrinsic viscosity changed with storage time, and amylopectin retrogradation was negatively related to intrinsic viscosity on the first day (r = -0.978, P < 0.01) (Table 6), and then there were no obvious relations.…”

“…Amylose and amylopectin were extracted from different kinds of starches by earlier reported methods with some modifications (Zhong et al 2006;Chen et al 2008;Yu et al 2012b). Starch (10 g dry basis -DB) was soaked with 10 ml of ethanol and 350 ml of 0.5 mol/l NaOH, and dissolved by placing in boiling water with stirring for 30 min, then the solution was centrifuged (5000 g, 10 min) and the supernatant was collected.…”

Effects of preprocessing at low or ultralow temperatures combined with sodium alginate on retrogradation properties of normal cornstarch during chill storage

“…The results suggested that NCS recrystallized much more slowly by preprocessing at ultralow temperature than low temperature during chill storage for less than 14 days. It is possible that the preprocessing at ultralow temperature could make NCS pass through the maximum retrogradation temperature zone much more quickly than low temperature and retard the formation of an ordered region among the shorter chains in the amylopectin . The above results of the Δ H r values indicate that low or ultralow temperature could inhibit starch recrystallization.…”

Ultrasound assisted nucleation of some liquid and solid model foods during freezing

“…As a result, ultrasound can be used to improve the quality of the frozen product by controlling nucleation. In the freezing of tissue foods, formation of large ice crystals which are mostly extracellular, results in significant damages to the tissue (Ahmad, Yaghmaee, & Durance, 2010;Delgado, Zheng, & Sun, 2009;Kiani & Sun, 2011;Ming, Rahim, Wan, & Ariff, 2009;Streit, Corrieu, & Béal, 2010;Yu, Ma, Zheng, Liu, & Sun, 2011). On the other hand, formation of fine crystals that are evenly distributed both inside and outside the cells, leads to the quality of the final product to be better preserved due to less damages to the tissue .…”