Effects of enzymatic/alkali protein removal and particle size reduction on physicochemical and functional characteristics of okara dietary fibre

The combined effects of enzymatic/alkali protein removal treatments and superfine grinding on the characteristics of okara dietary fibre (DF) were investigated. Protein removal could effectively increase the obtained DF content and further enhance water-holding capacity (WHC), swelling capacity (SC) and oil-holding capacity (OHC). The DF with Alcalase treatment and superfine grind through 500-mu m mesh size had the highest total dietary fibre, WHC (12.5 g g(-1)), SC (12.7 mL g(-1)) and OHC (2.7 g g(-1)). Decreasing particle size will trigger a redistribution of some fibre composition from the insoluble to the soluble fraction. The WHC and SC of the sieved DFs decreased with reducing mesh size (500-40 mu m). The OHC of DF with Flavourzyme treatment reduced with decreasing mesh size (500-100 mu m), but improved with mesh size less than 100 mu m.

Automated summary

The combined effects of enzymatic/alkali protein removal treatments and superfine grinding have been studied on the characteristics of okara dietary fibre (DF). Protein removal can effectively increase the DF content and enhance water-holding capacity, swelling capacity, and oil-holding capacity. Particle size reduction leads to a redistribution of fiber composition from the insoluble to the soluble fraction. Suitable treatment methods and mesh size selection can improve the characteristics of okara DF.