EFFECT OF EXTRUSION-COOKING ON THE HYPOGLYCEMIC PROPERTIES OF CITRUS FIBER - AN IN-VITRO STUDY

Orange and lemon peels were extruded under controlled conditions of va rying severity, and their physico-chemical characteristics and effect on the enzymatic hydrolysis of starch and glucose diffusion were studi ed. Extrusion-cooking treatment increased the soluble fraction of diet ary fibre as well as solubilised pectic substances and arabino-galacto mannan chains. The apparent viscosities of aqueous extracts of extrude d fibre were increased slightly for orange and more markedly for lemon fibre. With both fibre sources, viscosities values were higher in Tri s-maleate buffer (0.1 M) than in NaCl (154 mM). However, these modific ations had no effect on starch hydrolysis and glucose diffusion in vit ro.