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

Development and characterization of potato amylopectin-substituted starch materials

This study characterized the blends of corn starch with potato amylopectin (PAP) and PAP hydrolysates treated with branching enzyme (BR), pullulanase (PL), and BR-BL cocktail. PAP/PAP hydrolysates were deposited or bound (particularly in intact and PL-treated PAPs) on the surfaces of corn starch granules. Although PAP/PAP hydrolysates rarely affect the X-ray diffraction patterns of the blends, their relative crystallinities decreased. Relative to native starches, the swelling power was higher for all blends. Solubility was higher for normal starch-based blends but lower for waxy starch-based blends. All blends exhibited higher gelatinization temperatures and lower gelatinization enthalpies. Although the pasting viscosities of blends with intact PAP were higher than those of native starches, the opposite trends were found in blends with BR-, PL-, and BR-PL cocktail-treated PAPs. Overall, the PAP structures diversified the characteristics of the corn starch-PAP blends. BR- and BR-PL cocktail-treated PAPs could function as stabilizers for stable paste consistency.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00919-7.

Impact of starch granule-associated channel protein on characteristic of and λ-carrageenan entrapment within wheat starch granules

This study investigated the physicochemical characteristics of protease-treated wheat starch (PT-WST) to understand the role of starch granule-associated proteins (SGAPs) and the potential capability of PT-WST to provide a nutrient delivery system (NDS). Protease treatment was conducted at 4 °C and 37 °C (PT04 and PT37), respectively. A model delivery system was assessed with PT37 granules infiltrated by λ-carrageenan (λC) under variations of molecular size (λC hydrolysates produced from 0, 2.5, 100, and 500 mM HCl solution), agitation time, and temperature. Protein-specific (3-(4-carboxybenzyl)quioline-2-carboxaldehyde) or non-reactive (methanolic merbromin) fluorescent dye staining revealed that removal of SGAPs on surfaces and channels were more effective for PT37 than for PT04. Consistent amylose content, swelling, and gelatinization temperature before and after protease treatment suggested minimal impact on the starch structure. PT37 presented higher solubility and pasting viscosity than PT04. This resulted from excessive SGAP removal, which enhanced entrapment capacity. λC molecular size and agitation temperature showed a negative correlation with the content of λC entrapped within PT37, and this content depended on the interplay between the agitation time and λC molecular size. As λC molecular size decreased, the λC distribution became uniform throughout the granules, which confirmed the potential of PT-WST as a carrier for NDS.