Physicochemical properties of Maori potato starch affected by molecular structure

New Zealand Maori potatoes (Taewa) represent underutilized genetic resources for potato quality. Rheological and thermal properties of starches from 5 Maori potato varieties were studied. Variations in swelling power and solubility, flow and pasting behaviors, dynamic oscillatory properties, gelatinization, and retrogradation were recorded among the starches. Compared to starches of modern potato varieties, Maori potato starches had similarities as well as differences in the properties. Analysis of structure-property relationships of starch components showed the importance of amylopectin structure and starch composition. In particular, some amylopectin internal structural parameters such as the amount of the majority of short B-chains significantly correlated with some physicochemical properties of Maori potato starch. The amylopectin internal structure was not the sole contributor to the starch properties. Structure-property correlation patterns for Maori potato starches contradicted with results of some previous studies, suggesting the importance of the starch type used in analyzing the relationships.