Application of osmotic pressure in modification of Amaranthus viridis starch

The modification of Amaranthus viridis starch by osmotic pressure using central composite design (CCD) and artificial neural network (ANN) was studied. The amount of starch, saturated sodium sulphate (Na2SO4) solution and reaction time were established as significant (p < 0.05) factors. The extent of involvement of process variables were identified as 37.89%, 35.67% and 26.45% for saturated Na2SO4 solution, reaction time and starch solids, respectively. Optimal condition of starch (150 g), saturated Na2SO4 solution (250 mL) and time of 20 min with corresponding total amylose (36.77%), free amylose (27.31%) and lipid-complexed amylose (9.46%) were established for CCD. The ANN gave optimal condition of 149.04 g (starch), 248.40 mL (saturated Na2SO4 solution) and time (19.41 min) with corresponding total amylose, free amylose and lipid-complexed amylose of 36.38%, 28.01% and 8.37%, respectively. The high amylose content of the starch indicated that it has high degree of flakiness. The presence of lipid-complexed amylose showed its potential in improving colonic health microflora and lower glycemic index. Pareto charts showed that the most significant (p < 0.05) term was starch solids x reaction time for total amylose. The results itemized basic information on development of thrifty and efficient process for derivation of osmotic pressured starch from A. viridis grain.