Anotace:
A promising way to increase the use of buckwheat is the wider introduction of technologies for its processing, including grinding of non-hulled grain. It requires the search for new plant materials with more suitable characteristics. In this work, the possibilities to use the grain of a new artificial buckwheat species Fagopyrum hybridum for flour production are studied in comparison with two cultivated species F. tataricum and F. esculentum. Some chemical characteristics of F. hybridum flour were evaluated. According to the size of the kernel fragments in different modes of milling within each species the significant differences were identified within F. esculentum and F. hybridum (p <0.001 and p <0.05, respectively); there were no significant differences within F. tataricum (p >0.1). Fragments of the seed hulls of F. tataricum and F. hybridum compared to ones of F. esculentum were distinguished by the absence of pronounced acute angles. For the cultivated species, amino acid compositions of grain protein of the studied samples manifest no strong deviations from earlier published results. The new species F. hybridum has the amino acid composition similar to ones of the both cultivated species with slight superiority in the content of all essential amino acids. So, the content of Cysteine, Tryptophan, Arginine, Lysine, Methionine, Leucine + Isoleucine, Threonine, Histidine and Valine in seeds of F. hybridum was 5.2, 15.0, 25.8, 30.2, 31.2, 36.0, 38.4, 41.1 and 46.2% higher compared to F. tataricum and 11.1, 43.7, 39.2, 3.7, 31.2, 15.2, 14.8, 20.0, 18.9% higher compared to F. esculentum. Using DPPH it was assessed the antioxidant activity (AOA) of whole grain flour of three buckwheat species and decreasing of the AOA during heating up to 100 °C. After water extraction the AOA was maximal for F. tataricum flour; F. hybridum and F. esculentum manifested similar values with the same decline dynamics during heating. After ethanol extraction the flour of F. hybridum shown higher AOA compared to both cultivated species before temperature treatment (1.3 times) as well as after heating to 100 °C (1.2 times). The results of the analysis of the fractional composition of flour from the whole grain of the three buckwheats shown the fragments of the seed hulls of F. tataricum and F. hybridum compared to ones of F. esculentum were characterized by the absence of pronounced acute angles. Additional experiments are needed to optimize the technology of whole-grain buckwheat flour. But the grain of F. tataricum and F. hybridum looks like more suitable for these purposes than the non-hulled grain of F. esculentum.