Study on Paste Behavior of Native and Modified Canna Starches for Use as a Thickening Agent

Abstract

Paste behavior of native canna starch and its derivatives (hydroxypropyl canna starch with MS of 0.11; HP-canna and canna starch acetate with DS of 0.08; AC-canna) together with the other two starches, namely, cassava and commercial-modified starches, were investigated and used as criteria for evaluation of the starches as a thickening agent in food products. It was found that viscosities of all starch samples increased with an increase in the starch concentration. At 6% (w/w) starch concentration, peak viscosities of HP-canna, native canna, AC-canna, cassava and commercial-modified starches were 227.75, 168.05, 108.42, 96.29, and 49.13 RVU, respectively, whereas the setback viscosity, which indicates the extent of starch retrogradation, was lowest in the case of HP-canna starch. Morphologies of the starch granules after gelatinization as examined by light microscope revealed that the granules displayed more swelling and disintegration when the concentration of starches increased. However, the extents of granule swelling and disintegration depended upon type of starches. The results obtained from these experiments lead to the conclusion that hydroxypropyl canna starch would be a good candidate for use as a thickening agent in food products for it has high viscosity and low retrogradation.