Binary blends of normal corn starch and cow cockle starch for the slow-thickening behavior upon pasting

Abstract

Corn starch with slow thickening property may facilitate more efficient heat transfer and safety of corn starch-thickened foods. Partial substitution of normal corn starch (NCS) with slow-pasting behavior of cow cockle starch (CCS) was hypothesized to impart binary starch blend with slow-thickening effect during hydrothermal heating. To test hypothesis, a series of starch blend dispersions (with weight ratios of CCS to NCS = 75:25, 50:50, 25:75) were prepared at various starch concentrations (6 %, 8 %, 10 %, and 12 %) and subjected to the Rapid Viscosity Analysis (RVA). RVA viscographs of starch blends were compared with that of NCS, suggesting that nearly all starch blends at various concentrations showed longer time span of pasting and lower pasting rate. Although CCS and NCS blend gels exhibited lower Young's modulus and hardness based on textural profile analysis, the sensory panels revealed that 6 % and 8 % starch blend gels (with weight ratio of CCS to NCS = 25:75) showed the mouthfeel analogous to NCS gel. These findings highlight a viable non-chemical modification strategy that enables binary blends of CCS and NCS as a novel gelling agent with slow-pasting property and may aid in safety and high-quality processing of hydrogel foods.