Characterization of molecular, physicochemical, and morphological properties of starch isolated from germinated highland barley

Abstract

Germination is a non-chemical and simple approach usually used to improve the bio-availability of crucial nutrients. In this study, the effect of germination on molecular, physicochemical, morphological properties of highland barley starch was investigated. The results of this study revealed that germination for 72 h (GB72) significantly increased amylose content and gelatinization temperatures (To and Tc) to 26.3%, 59.79 °C, and 68.19 °C as compared to 22.81%, 57.56 °C, and 67.05 °C in native barley starch (NB), respectively, and a significant decrease in total starch contents was noticed (31.67%) in GB72 as compared to 45.70% in NB. After germination, the FT-IR intensity ratio of 995/1022 and 1047/1022 bands, pasting temperatures, particle size, and swelling capacity were also decreased. Moreover, average molecular-weight, relative crystallinity, gelatinization temperature ranges, and enthalpy of gelatinization were decreased as compared to NB starch, and the decrease was more obvious in GB72 starches (0.49 × 108 g/mol, 17.64%, 8.40 °C, and 6.41J/g), respectively. This study indicates the effectiveness of germination for the modification of highland barley starch and its potential to enhance starch-based products.