The aim of the study was to analyse the respective impacts of germination, soaking, drying and cooking of grains on the nutritional components of buckwheat, quinoa and amaranth. Methanol extracts were utilised to determine the contents of free phenolic compounds and soluble conjugates, whilst alkaline hydrolysis of the sample plant matrix was necessary for the determination of bound phenolics content. Individual fractions of phenolics were evaluated using the Folin-Ciocalteu and DPPH assays, respectively. The content of phytic acid was determined with spectrophotometric method. The enzyme-gravimetric method AOAC 991.43 was used for the determination of soluble and insoluble dietary fibre contents. Amongst the preparation techniques of all three pseudocereals, the 96-hour germination is to be highlighted, as it substantially improved the content and extractability of total phenolics, their antioxidant potential and most contributed to the hydrolysis of phytic acid. Germination considerably increased the content of total dietary fibre in buckwheat grains and improved the ratio between the soluble and insoluble fractions. Furthermore, the study found that the process of drying the grains in the oven for 120 minutes is beneficial, which is particularly evident in the case of the dietary fibre of amaranth grains, and the decreased content of phytic acid in buckwheat and quinoa. The regimen also benefited in increasing contents of total phenolics and the efficacy of antioxidants in all three sorts of pseudocereals. Soaking of grains in water resulted as slighty less suitable technique as optimal conditions varied between the given pseudocereals and the analysed parameters. Cooking of grains had a negative impact on most of the investigated parameters and is therefore not recommended.
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