In Vitro Digestibility and Physicochemical Properties of Huauzontle (Chenopodium nuttalliae) Starch

Abstract

Huauzontle is an undervalued and little-studied pseudocereal crop whose seeds contain relatively high starch contents. There is scarce information on the structural, physicochemical, functional, and nutritional characteristics of native huauzontle starch (HS), and its modification has not been documented until today. HS is modified with citric acid (CA) and octenyl succinic anhydride (OSA) to different degrees of substitution. HS starch granules are irregular, angular, and polygonal in shape, with almost smooth surfaces, and mean diameter of 1.37 ± 0.09 µm. The apparent amylose content of the CA and OSA-modified starches is lower than for HS but increases as the degree of substitution of CA and OSA increases. Deconvolved FTIR spectra shows that the ratio 1047/1022 decreases in the modified starches with increasing CA and OSA concentrations, indicative that both treatments alter the chain packing and generate more amorphous regions. The resistant starch increases with the OSA-modification, while the rapidly digestible starch increases with the CA-modification. Native and OSA-modified starches show higher pasting viscosities than the CA-modified starch. CA-and OSA-modified starches have an improved solubility, swelling power, and water retention capacity than HS. These results indicate that modified huauzontle starch presents highly desirable characteristics for its application in food.