Effect of acid hydrolysis-autoclaved cycles on sago starch

Nah, Sui Lin (2007) Effect of acid hydrolysis-autoclaved cycles on sago starch. Universiti Malaysia Sabah. (Unpublished)

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Abstract

Response Surface Methodology (RSM) was used to study the effect of time of add hydrolysis (15, 30 and 45 minutes) and number of autoclaving-cooling cycles (1, 2 and 3 cycles) on the physicochemical and functional properties of sago starch. The best combination treatment to obtain the lowest in vitro digestibility sago starch was also determined. Sago starch was subjected to steeping, retrogradation and add hydrolysis to increase the amylose content to 34-40%. Starch hydrolyzate was then autoclaved (121°C for 30 minutes) and cooled (4°C) before undergoing freeze-thaw cycle. The physicochemical properties studied were amylose content and amytose leaching. Whereas, the functional properties studied were swelling power, solubility, close packing concentration, paste clarity and in vitro digestibility. The Increase In time of add hydrolysis Significantly Increased the solubility (P<0.05) and close packing concentration (P<0.001) but decreased the amylose content (P<0.01), swelling power (P<0.001), paste clarity (P<0.001) and In vitro digestibility (P<0.01). Meanwhile, as the number of autoclaving cooling cycles Increased, dose packing concentration (P<0.05) and paste clarity (P<0.001) were Increased. On the contrary, as the number of autoclaving-cooling cycles Increased, the amylose content (P<0.001), solubility (P<0.05), swelling power (P<0.05), and in vitro digestibility (P<0.001) were significantly decreased. Time of acid hydrolysis and number of autoclaving-cooling cycles showed an Interactive effect (P < 0.001) on clarity of the sago starch paste. The number of autoclaving-cooling cycles has more pronounced effect in affecting all the physicochemical and functional properties studied. The lowest digestible (highest 50s and RS content) starch was obtained after 30 minutes of add hydrolysis and three autoclaving cooling cycles. Add hydrolysis and autoclaving-cooling cycles caused tighter structure, Improved crystallinity and decreased the susceptibility of sago starch to a-amylase enzyme. The digestibility of the sago starch after the combination treatment was reduced up to 35.2±2.6%. This study Indicates that combination treatment of add hydrolysis and autoclaving-cooling cycles is an effective method to produce SDS and RS-rich sago starch that can act as a value added starch.

Item Type: Academic Exercise
Uncontrolled Keywords: Response Surface Methodology (RSM), acid hydrolysis, time, autoclaving-cooling cycles, sago starch, in vitro, treatment, amylose
Subjects: T Technology > TX Home economics > Nutrition. Foods and food supply
Divisions: SCHOOL > School of Food Science and Nutrition
Depositing User: Unnamed user with email storage.bpmlib@ums.edu.my
Date Deposited: 11 Nov 2015 08:11
Last Modified: 25 Oct 2017 06:51
URI: http://eprints.ums.edu.my/id/eprint/11277

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