Abstract

The effects of the addition of turmeric grates (0 to 2.5 g/150 g dry starch samples) on some physicochemical and pasting properties of native cassava starch, with and without lactic acid were studied with a view to examine the possibility of using the active components in turmeric grates as natural product modifying agents for non-fermented and lactic acid fermented cassava starch. Treatment of native cassava starch, with and without lactic acid using turmeric grates exerted cross-linking properties as shown by the increase in peak viscosity: 407 to 433 rapid visco analyzer unit (RVU) vs. 391 RVU for samples without lactic acid; and 350 to 363 RVU vs. 350 RVU for samples with lactic acid. Native cassava starch with lactic acid on treatment with turmeric grates gave improvement in paste stability (BDV = 241 to 251 RVU) in comparison to the breakdown viscosity (BDV = 250 RVU) of native cassava starch with lactic acid. Susceptibility of native cassava starch with lactic acid to retrogradation was reduced on treatment using turmeric grates. Treatment of native cassava starch with and without lactic acid using turmeric grates modifies the pH with a slight improvement in the swelling power of the products. This suggests that components in turmeric grates can be used to modify native cassava starch with and without lactic acid.

Key words: Cassava starch, lactic acid, turmeric treatment, pasting properties.