Starch Grain Quinoa (Chenopodium quinoa Willd.): Composition, Morphology and Physico-Chemical Properties

Introduction. The main component of quinoa grain is starch, the properties of which affect the quality of quinoa-based food products. There is no information about quinoa starch in the Russian scientific literature. Therefore, the review summarizes and presents foreign knowledge about the isolation, chemical composition, structure, and physicochemical properties of quinoa starch Study objects and methods. The research featured scientific articles and chapters of scientific books on the structure and chemical composition of quinoa published over the past 10 years. The work used empirical and theoretical methods of scientific research. Results and its discussion. Currently, starch from quinoa grain is produced only under laboratory conditions by various methods of grinding and soaking. Most studies point to up to 10% of amylose in quinoa starch. Amylopectin in quinoa starch has a high number of short single chains and a very low number of long single chains, and their ratio is higher than that in other starches. The granule size of quinoa starch is 0.4–2.0 microns, which is significantly smaller than that of most starches. Quinoa starch belongs to polymorphic type A. The gelatinization temperature and enthalpy of quinoa starch are lower than those of amaranth, corn, sorghum, millet, and wheat starch, which is probably due to the fine structure of amylopectin. With an increase in temperature for every 10°C, the swelling force and solubility of quinoa starch increase on average by 21.5–27%. As the temperature rises from 55 to 65°C, the solubility index of quinoa starch increases sharply by 5–10 times. The viscosity of quinoa starch is significantly higher than that of most known starches. It also is more sensitive to enzymes. Conclusion. The work presents the results of scientific research on various matters: methods of starch isolation from quinoa, its chemical composition, and methods of amylose determination; structure of starch grains, their shape, type, and degree of crystallization; physicochemical properties of starch, including gelatinization, swelling, solubility, rheological properties, retrogradation, changes in the transparency of starch gel, and susceptibility to enzymes. The latter determines the choice of technological parameters in the development of formulations and food technologies, including functional foods for people with gluten intolerance (celiac disease). Further studies of the chemical composition of quinoa can help to meet the growing demand for these products and expand the range of the domestic market for gluten-free foods.