Influence of oat flour characteristics on the physicochemical properties of oat-based milk substitutes

Abstract

This study aimed at investigating the effect of oat composition on the quality characteristics of oat-based milk substitute (OBMS). Raw materials for OBMS consisted of thirty pure cultivar oat flours produced by industrial milling process. The main steps in OBMS preparation included mixing of 10% oat flour with water, starch hydrolysis, solid-liquid separation and formulation of the final product. OBMS was characterised in terms of mass and protein yields, protein content, reducing sugars, particle size, viscosity, dispersion stability and colour. The different composition of oat flours affected the characteristics of the OBMS in terms of mass yield (81.3–88.1%), dry matter yield (56.7–73.8%), protein content (0.63–1.10%), protein yield (31.4–61.6%), content of free reducing sugars (13.1–19.1%), and physical properties including particle size, dispersion stability and viscosity. OBMS mass and dry matter yields correlated positively with both total and damaged starch contents of the oat flour as well as the share of damaged starch of the total starch of the sample, while flour starch content correlated negatively with protein content of OBMS. Protein content of the flour correlated negatively with the mass, dry matter and protein yields and positively with protein content of OBMS. All colour values (L*, a*, b*) of the flour correlated with colour value b* of the OBMS. Protein content and viscosity of OBMS correlated positively with dispersion stability of OBSM. In conclusion, the clear relation between oat composition and the final properties of OBMS suggest relevance of selecting specific oat raw materials to produce good quality OBMS.