PHYSICAL-PROPERTIES OF STARCH FROM 2 GENOTYPES OF AMARANTHUS-CRUENTUSOF AGRICULTURAL SIGNIFICANCE IN CHINA

Starches were isolated from the two genotypes of Amaranthus cruentus m ost widely cultivated in China, R104 and K112. These starches, plus a corn starch standard were mixed with either distilled water or a 1% Na Cl solution and characterized for gelatinization parameters by Differe ntial Scanning Calorimetry (DSC), pasting properties using a Rapid Vis co-Analyzer (RVA), and texture of the cooled gels. Significant finding s were: 1. A. cruentus starches had higher gelatinization temperature and higher endothermic energy than corn starch; 2. Wide differences in pasting properties were found between the two A. cruentus genotypes, although the waxy line R104 had lower hot-paste viscosity and set-back than K112; 3. The pasting properties (peak viscosity and set-back), o f K112 were similar to those of corn starch. 4. In 1% NaCl solution, c ompared to distilled water, corn starch set-back decreased while that of the A. cruentus starches increased. Where Amaranthus starch is to b e used in food processing applications, careful selection of genotype is necessary to achieve desired functionality.