Characteristics of wheat starch-pectin hydrolysate complexes by dry heat treatment

The objective of this study was to characterize dry heat-induced wheat starch-pectin hydrolysate (WST/PH) complexes to develop the retrogradation-retarded starch. Native (N-) and protease-treated (P-) WST were used as starch sources. Pectin hydrolysates were mixed independently with N-WST and P-WST to a mixing ratio of 49:1 (based on total solid contents), followed by drying below 10% moisture and dry heat treatment at 130 °C for 4 h. The molar degrees of substitution (MS) was higher for WST/PH complexes than its mixtures, and apparent amylose contents decreased with their MS. Relative to WST/PH mixtures, solubilities were higher for WST/PH complexes, while swelling powers didn't differ. WST/PH complexes showed the lower degree of retrogradation, setback viscosities, slowly gelling tendency, and syneresis. These phenomena were more pronounced in WST/PH mixtures and complexes prepared with P-WST. Overall results suggest that dry heat-induced WST/PH complexes could be a potential retrogradation-retarded starch to replace chemically-modified starches.