Effect of Acetylation on the Physical and Functional Properties of Industrial and Laboratory Cassava (Manihot esculenta Crantz) Starches

摘要

Aim: Acetylated potato starch (APS) is commercially available and used widely in the food industries. It is imperative to study the physical and functional properties of acetylated cassava ( Manihot esculenta Crantz) cultivar Tropical Manihot Series (TMS) 30572 and industrial starches for possible substitution/ replacement of expensive APS in food system. Study Design: The properties of acetylated cassava starches were compared with those of commercially available acetylated potato starch (APS) and native cassava starches. Place and Duration of Study: The experiment was performed in the Department of Food Science and Technology, Federal University of Technology, Akure Nigeria from June 2011 to January 2013. Methodology: Industrial starch and starch extracted from cassava TMS 30572 were acetylated by standard procedure. The acetylated starches were analyzed for the physical as well as functional properties. Results: The yields after acetylation ranged between 96-98% and 80-93% for TMS 30572 and industrial starches, respectively. Acetylated cassava starches showed improved physical and functional properties over the native cassava starch and these increased with increasing concentration of acetic anhydride in the reaction medium. At >2.50% acetylation, starch concentration of 5.5% had the same hot paste viscosity of 1500 cPa.s with commercial APS at 5% concentration. Also at 2.50% acetylation the starch was stable until the third freeze-thaw cycles and exhibited better stability than commercial APS. Conclusion: Acetylation improved the yield of starch from cassava during processing. The industrial starch showed higher degree of acetylation than TMS 30572 starch under the same experimental condition. Acetylated cassava starches (at >2.50-2.70% acetylation) has improved functional properties and lesser tendency towards retrogradation thus could be a potential replacement to the more expensive APS as ingredient in food system.