10-6 |
Effect of heat-moisture treatment (HMT) on the physicochemical properties of tuber and root starches |
D. M. ANIL GUNARATNE and R. Hoover. Department of Biochemistry, Memorial University of Newfoundland, St John's, NF A1B 3X9, Canada The carbohydrates of tuber and roots crops are mostly starches. These starches have not benefited from the kind of value added product development research required for competitiveness on an international scale. As a result, modified cereal starches continue to dominate world markets for starch in food and non-food uses. Our objective was to investigate the structure and properties of starches from Dioscorea species, Manihot esculenta, Xanthosoma species, and Alocassia species, and to determine the influence of heat-moisture treatment on starch properties. Differential scanning calorimetry, X-ray diffraction, gel permeation chromatography, Brabender amylography and AACC approved methods were used in this study. The starches varied widely in amylose content, lipid content, granular swelling, X-ray pattern, crystallinity, amylose leaching, Brabender viscosity, gelatinization parameters, susceptibility towards acid (2.2N HCl) and enzyme (µì -amylase) hydrolysis, extent of retrogradation and chain length distribution. The above properties showed significant changes on heat-moisture treatment. The extent of these changes varied with the moisture content, time of heating and starch source. The result indicated that the extent of starch chain associations within the amorphous region and the degree of crystalline order of the starch granules are altered during heat-moisture treatment. This study will help us to diversify the use of root and tuber starches in foods. Many of the starchy crops used in this study are indigenous to less developed countries, accordingly, our research would help these countries to compete more effectively in the world markets in both food and non food sectors.
Session 10, International: Division Lecture and Paper Competition
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