Effect of heat treatment on the structure and digestion properties of oat globulin

Abstract

Abstract Background and objectives The heat treatment required for deactivation of enzymes was carried out in crop species such as oats to retain its desirable shelf life, but it may lead to a reduction in nutritive value and denaturation of globulin. This study compared the effect of two heat treatments, stirring roasting (240°C, 15 min; OFG) and kiln roasting (140°C, 45 min; OMG), on structure and digestion properties of oat globulins. Findings The results showed that compared with control oat globulin (OCG), both heat treatments decreased the content of amino acid in the oat globulins. The increase in roasting temperature (from 140°C to 240°C) led to the change in the secondary structure in oat globulins, with a decrease in β‐sheet and β‐turn contents, and an increase in α‐helix and random coil contents. Scanning electron microscopy showed that the structure of OFG was fragmented into small clumps. Compared with kiln roasting (140°C), stirring roasting (240°C) decreased average molecular weight, peak viscosity, and denaturation enthalpy but increased viscosity and in vitro digestibility of oat globulin. Conclusions Compared with kiln roasting, stirring roasting increased in vitro digestibility of oat globulin and contributed to the taste, but the nutritional loss was greater. Significance and novelty Two heat treatment methods for enzymatic inactivation were compared regarding the effect on the structure and in vitro digestibility of oat globulin, indicating that higher temperature increased digestibility of oat globulin.