Optimization of superheated steam treatment conditions for wheat aleurone layer flour

Abstract

Although, wheat aleurone layer flour (WALF) is a good source of nutrients, it has certain disadvantages due relatively high levels of lipids and various of microorganisms and enzymes. Therefore, in the current study, the effect of superheated steam (SS) treatment on stabilization of WALF was investigated. This study aims to explore the effects of SS treatment on the degradation of free fatty acids of WALF under different conditions. The optimal process was obtained by an orthogonal optimization experiment, including optimized SS temperature, material moisture and treatment time. Results showed that the free fatty acids content of WALF significantly were decreased with SS treatment as the increase of treatment temperature, material moisture content and treatment times (p<0.05). Therefore, the optimum treatment conditions were selected during SS treatment. Compared with raw WALF, the activity of enzymes, total number of microbial colonies and phytate content in WALF were notably reduced after the SS of optimal condition. Nevertheless, its total dietary fiber content, insoluble dietary fiber content, pentosan content, total phenol content and total antioxidant capacity presented a remarkable increase (p<0.05).

Keywords:
wheat aleurone layer flour; superheated steam; stabilization; dietary fiber; antioxidant activity