Influence of type of production on the contents of selected nutrients/phytochemicals in buckwheat grains

On a global level and over a number of years, many researchers have been studying the effects of organic and conventional production methods on the chemical composition of plants and their products. The aim of this study was to determine the potential difference in the contents of several nutrients/phytochemicals in organically and conventionally produced buckwheat grains. Buckwheat was sown in 2016 at a site in Nova Varoš. The experimental plot covered a surface area of 1 ha. The contents of the following nutrients and phytochemicals in buckwheat grains were determined: proteins, pigments (chlorophyll a, chlorophyll b, carotenoids), soluble sugars, starch, free and bound polyphenols and flavonoids, and phytosterols. In addition, the antioxidant properties of the grains were assessed using the ABTS •+ ((2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) test (ability to inhibit ABTS •+ radical cations). There was no statistically significant difference in the contents of proteins, chlorophyll a and free phenols or in regard to the % of antioxidant capacity. On the other hand, two different production methods caused differences in the other chemical parameters. In organic grains, higher contents of carotenoids (6.998 µg g-1 dry matter (DM)), soluble sugar (6.48 mg 100 g-1 DM), starch (2.46 mg 100 g-1 DM), bound polyphenols (1034.3 mg (FAE) kg kg-1 DM), free flavonoids (1094.7 mg (QE) kg-1 DM) and bound flavonoids (1087.2 mg (QE) kg-1 DM) were detected, while in conventional buckwheat grains, there were higher levels of chlorophyll b (24.16 µg g-1 DM) and phytosterols (185.15 mg kg-1 DM). The study showed no clear influence of the production method on the examined parameters.