Effect of the addition of modified starch on gelatinization and gelation properties of rice flour

Abstract

The objective of this work is to research impacts of oxidized (OCS), acetylated (ACS) and cross-linked (CLCS) corn starch on gelatinization properties of rice flour and their gel structure during storage at 4 °C for 1 and 7 days. OCS led to significant increase of pasting temperature and solubility in blend flour but decrease of pasting viscosity and swelling power compared with rice flour, while ACS showed an opposite effect in pasting temperature and viscosity. CLCS remarkably raised pasting temperature and viscosity of blend flour and insignificant increase as increasing concentration, and the mixture showed relatively lower swelling power and solubility than rice flour. During cold storage, OCS and ACS substantially inhibited the reorganization of gel network structure and showed high stability in rheology and texture properties. CLCS accelerated the formation of gel network structure, and the mixture gel appeared to stronger rigid structure and denser microstructure than those of rice gel. Formation distinctions among these three gels were found in rheology properties, texture properties, water migration, FTIR spectra, and microstructure of SEM. Overall, CLCS improved the rice stability in heat-processing, and OCS and ACS reduced the change of rice gel quality during cold storage.

Keywords: Gelatinization property; Gelation property; Modified corn starch; Rice flour.