Production and characterisation of alcohol-insoluble dietary fibre as a potential sourcefor functional carbohydrates produced by enzymatic depolymerisation of buckwheat hulls

Abstract

We examined the potential use of buckwheat hulls as a raw material for producing soluble dietary fibre. The insoluble fibre fraction obtained from buckwheat hulls was hydrolysed by two commercial enzymes (Celluclast 1.5L for the cellulose fraction and Viscozyme L for the hemicellulose fraction) to obtain soluble fibre hydrolysates. Alcohol-insoluble dietary fibre (AIF) was separated from the freeze-dried soluble hydrolysate by treatment with 85% ethanol. The water-holding, oil-binding, and swelling capacities of AIF were increased by enzymatic hydrolysis. AIF had significantly (P < 0.05) higher functional properties than the control. AIF from the hemicellulose fraction effectively hindered the diffusion of glucose and bile acid from dialysis membranes, and had a significantly (P < 0.05) greater bile acid inhibitory effect than carboxymethylcellulose or pectin. It can be concluded that AIF from buckwheat hulls by enzymatic hydrolysis can used as dietary supplement and additive in the food industry.

Keywords

• agricultural by-products
• enzymatic hydrolysis
• hypoglycaemic effect
• hypolipidaemic effect
• soluble dietary fibre