Evaluation of the anti-nutritive and hypocholesterolemic effects of a [beta]-glucan preparation extracted from New Zealand barley : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutritional Science at Massey University

The present study evaluated the anti-nutritive as well as the hypocholesterolemic effects of barley β-glucan through the use of a commercially prepared barley β-glucan extract. Two experiments with broiler chickens were performed. In the first experiment (Chapter 3), a commercially prepared barley β-glucan extract was added (15 g/kg diet) to a synthetic diet based on cornstarch and casein. In addition, the diet was heated to evaluate the effects of heat treatment on the anti-nutritive effects of β-glucan. The diet was fed to twenty 15-day-old male broilers for 7 days. Diets containing β-glucan reduced (P0.05). Serum TG levels were decreased (P0.05). In addition, it is suggested that the hypocholesterolemic effects of the β- glucan extract used were due to a decrease in lipid absorption in the small intestine,which was caused by the β-glucan inducing a gel formation, which delayed nutrient absorption. This gel formation induced by the β-glucan extract is considered to be one of the main factors responsible for the hypocholesterolemic effects of the β-glucan extract. It is concluded that the anti-nutritive and hypocholesterolemic effects of barley β-glucans were demonstrated through the use of a commercially prepared barley β-glucan extract, and that the gel formation induced by the β-glucan extract could be one of the main mechanisms responsible for the anti-nutritive and hypocholesterolemic effects of this NSP, which could be equally important to increases in viscosity induced by intact β-glucan