INFLUENCE OF EXTRUSION VARIABLES ON SUBSEQUENT SACCHARIFICATION BEHAVIOR OF SAGO STARCH

This study reports the effects of substrate concentrations (21.6-38.4 g/100 ml), amyloglucosidase (AMG) concentrations (0.66-2.34 U/g) and h ydrolysis time (14.8-65.2 h) on the saccharification of sage starch ex trudates. Regression analysis established AMG concentration and hydrol ysis time as the most significant factors; a generated regression equa tion adequately predicted the outcome of saccharification. Using 30 g/ 100 ml solid content, 65.2 h and 2.34 U/g of AMG, syrups of highest gl ucose content (87.9%) were attained. Effects of extrusion conditions, i.e. feed moisture content (21.6-38.4), enzyme (Termamyl 120L) concent rations (1.48-6.52%) and mass temperatures in the compression and die zones (70.5-97.5 degrees C) during the combined gelatinisation and liq uefaction of sage starch, on the amount of glucose produced were evalu ated. Enzyme concentrations and feed moisture contents had the most pr onounced effects on saccharification, which ranged from 47.6 to 73.3% (DE = 85-94) and 54.5-93.8% (DE = 90-98) after 24 and 65 h, respective ly. Response surface plots suggest that a higher percent saccharificat ion can be achieved when sage starch is extruded at high Termamyl conc entrations but low moisture contents.