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The aim of this study was to investigate the effects of germination of spelt seeds under different stress conditions on the antioxidant characteristics of their extractable and bound phenolics. Germination under combined stress of 25 mM NaCl and 50 mM sorbitol without subsequent mechanical stress had considerable impact on total phenolics contents and scavenging activities against different free radicals (DPPH, ABTS + , O 2 - , ROO). Alkaline hydrolysis of extracts from germinated seeds provided the majority of their phenolic acids, where ferulic and p-coumaric acids were the most representative. The phenolics liberated from their bound form also had greater antioxidant activities. For the extractable phenolics, p-coumaric hexoside increased the most (146%), while among the bound phenolics identified, the highest relative increase was for p-coumaric acid (171%). The germinated seeds showed no effects on intracellular oxidation in cells of the yeast Saccharomyces cerevisiae., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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This research aimed to study the dynamic changes in phenolic antioxidants between the germ and the rest of the germinated seed of wheat and spelt and to evaluate the whole grain flour from germinated seeds as a functional supplement. Longer germination resulted in higher TPC, DPPH, and ABTS values when considering the entire germinated seed, while the optimal germination time was not consistent when considering the germ and the remaining germinated seed separately. While in the germinated seed (without germ) the majority of TPC was determined to be bound phenolics (up to 92%), the extractable form dominated in the germ (up to 69%). The most abundant phenolic antioxidants in germinated wheat and spelt seeds, trans-ferulic acid, cis-ferulic acid, and p-coumaric acid, increased significantly with germination. Only breads with 5% germinated spelt or wheat flour were suitable for the production of a food product, showing higher extractable TPC, antioxidant activity, individual phenolic acids, and improved specific volume, and were preferred because of their appearance, aroma, and color. The PCA biplot showed that the addition of 15% and 30% germinated flours had the greatest positive impact on phenolic properties, while breads with the addition of 5% germinated flour had the greatest positive impact on specific volume and color. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine whether the partial replacement of wheat flour with bioprocessed spelt flour contributes to a higher bioaccessibility of the antioxidants in bread. The results showed that the type and amount of bioprocessed spelt flour in a bread recipe has a major impact on the extractable and bound TPC, the content of individual phenolics, their antioxidant activity, and their bioaccessibility as determined by in vitro digestion. Extractable p-coumaric and trans-ferulic acids in breads decreased after digestion, while extractable cis-ferulic and p-hydroxybenzoic acids increased. The bioaccessibility of TPC in the control bread (100% wheat flour), and in bread enriched with 5% "germinated + fermented" spelt flour (GFB5), did not differ. However, the digested GFB5 bread contained 5.2-times more extractable, and 1.3-times more bound, trans-ferulic acid than the digested control bread. trans-Ferulic acid showed the lowest bioaccessibility, up to 2.8%. In GFB2.5 and GFB5 breads, the bioaccessibility of p-coumaric, trans-ferulic, and cis-ferulic acids was higher than in other digested breads. PCA visualized the difference between the undigested and digested breads. The incorporation of germinated and fermented, or germinated and enzymatic, treated spelt flour in a white bread recipe could be an attractive way of providing consumers with nutritionally interesting foods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different fermentation types increased the extractable:bound phenolics ratio of bioprocessed spelt. • Extractable trans -ferulic acid increased the most in yeast-fermented germinated seeds (2922%). • Bound cis -ferulic acid increased the most in yeast-fermented raw spelt seeds (466%). • Spontaneous fermentation of germinated and enzymatic-treated seeds decreased intracellular oxidation the most. • Extractable hydroxycinnamic acids were more efficient in-vivo antioxidants than the bound form. Lactic acid, alcoholic, combined and spontaneous fermentation of raw, germinated and enzymatic-treated spelt seeds significantly improved the content of extractable and bound phenolics and considerably increased the extractable:bound ratio, and therefore positively affected the accessibility of the spelt antioxidants. The highest extractable and bound individual phenolic contents and in vitro antioxidant activities of extracts were obtained following fermentation of germinated spelt seeds with Saccharomyces cerevisiae , while for enzymatic-treated seeds, Lactobacillus plantarum (alone or with S. cerevisiae) was the most effective. For extractable phenolics, trans -ferulic acid increased the most in yeast-fermented germinated seeds (2922%); for bound phenolics, cis -ferulic acid showed the greatest relative increase in yeast-fermented raw spelt seeds (466%). Spontaneous fermentation of germinated and enzymatic-treated samples decreased intracellular oxidation most effectively, probably due to apigenin derivatives. Cellular uptake of bound hydroxycinnamic acids was significantly higher than that of extractable hydroxycinnamic acids; however, the latter were more efficient in vivo antioxidants. [ABSTRACT FROM AUTHOR]