The Challenges of Analyzing the Molecular Properties of Starch

Abstract: Popular Abstract in English The Andean region and the Amazon Basin of South America have been identified as regions of origin and the domestication of many plants. Some of the food crops from these regions such as potato and cassava, have gained global import¬ance, while the majority of food crops are hardly know outside their present area of cultivation. In the first part of this study, underutilized Andean starches from canihua (Chenopodium pallidicaule), amaranth (Amaranthus caudatus), maca (Lepidium meyenii), quinoa (Chenopodium quinoa), achira/Indian shot (Canna indica), and Lowland starches from cassava (Manihot esculenta) and gualuza/tannia (Xanthosoma sagittifolium) were investigated, in the hope that studying and evaluating their properties would contribute to increasing interest in their utilization. Granule diameter, and gelatinization and pasting properties were some of the physicochemical properties that were studied in the Andean grains and root starches. The pasting properties (cooking properties) are of great interest, particularly for applications of starch in food processing. Since starches can also be utilized raw (in their native granular form), in vitro enzymatic hydrolysis of C. indica, M. esculenta and X. sagittifolium starch was also performed. Such studies can be of particular interest in animal feed. One of the most important properties of starch is its molecular size, as this can affect the viscosity, gelatinization and pasting properties, among others. Our current understanding of how the molecular size affects these properties (end-use properties) is, however, limited, partially due to the lack of reproducible methods of quantifying the molecular size. In the second part of this study methods for obtaining molecular dissolution of the starch granules were investigated. Two optimum dissolution methods for the starch polymers were found, one involves the use of autoclave heating at 140°C and the other involves the use of DMSO at 100°C.