## 4 Discussion  
To date, numerous scientific studies have focused on the development and preparation of new types of fermented products with probiotic and functional properties [48; 49]. Fermentation is a complex system consisting of many partial processes, the continuity, relationship, and interaction of which are diverse. During fermentation, degradation of individual components, structural changes, and formation of new compounds take place. The character and degree of changes are affected by various factors, including microbial strains, substrate composition, and fermentation conditions. The various profiles of enzymes secreted by microbes during fermentation may affect the content and composition of phenolic compounds. Microbial enzymes have the ability to release phenolics from bound forms and to enhance free phenolic content. For example, protease, cellulase, and amylase can hydrolyze the structural components, and facilitate the action of esterase and xylanase, causing the release of insoluble-bound phenolics from their covalent bonds in the cell wall [29; 45; 50]. Glucosidases are able to release phenolic compounds from their  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{5}{c}{**Time**} \\ \cline{2-7}
**Buckwheat Substrate** & **0 h** & **8 h** & **24 h** & **4 d** & **7 d** & **14 d** \\ \hline water + cranberries & & & & & & \\ _+ L. plantarum_ HM1 & 1.157 \(\pm\) 0.006  & 1.391 \(\pm\) 0.010  & 1.393 \(\pm\) 0.005  & 1.353 \(\pm\) 0.006  & 1.425 \(\pm\) 0.005  & 1.462 \(\pm\) 0.012  \\ _+ L. rhamn_ GG & 1.157 \(\pm\) 0.006  & 1.391 \(\pm\) 0.010  & 1.220 \(\pm\) 0.037  & 1.194 \(\pm\) 0.005  & 1.314 \(\pm\) 0.002  & 1.334 \(\pm\) 0.005  \\ milk & & & & & \\ _+ L. plantarum_ HM1 & 0.315 \(\pm\) 0.012  & 0.667 \(\pm\) 0.011  & 0.685 \(\pm\) 0.005  & 0.751 \(\pm\) 0.009  & 0.653 \(\pm\) 0.010  & 0.682 \(\pm\) 0.010  & 0.682 \(\pm\) 0.010  & 0.727 \(\pm\) 0.003  \\ milk & & & & & \\ _+ L. plantarum_ HM1 & 0.315 \(\pm\) 0.012  & 0.667 \(\pm\) 0.011  & 0.660 \(\pm\) 0.006  & 0.315 \(\pm\) 0.012  & 0.353 \(\pm\) 0.001  & 0.667 \(\pm\) 0.001  & 0.660 \(\pm\) 0.006  & 0.315 \(\pm\) 0.010  & 0.484 \(\pm\) 0.005  & 0.473 \(\pm\) 0.017 [FOOTNOTE:2]Footnote 2: The _plantarum_ HM1 and _L. rhamn_soluble conjugated forms, and are often conjugated to sugars as glycosides [51]. Additionally, lactic acid produced by the present microbiota can help release bound phenols to their free forms. Moreover, stability of phenolic compounds is pH dependent, where the structure of phenolics is a determining factor. Anthocyanins and catechins are stable at low pH, but the amount of ferulic acid decreases, and proanthocyanindias may be degraded into flavanols [50; 52; 53]. It should be noted that pH influences the degradation of microbial enzymes. Considering the health benefits of buckwheat, in this study, fermented buckwheat mashes with probiotic potential were prepared. The application of mixed or combined cultures in fermentation technologies causes accelerated and efficient organic acid production within a short fermentation period. Food industries also prefer short fermentation periods in order to reduce microbial contamination and increase plant output. Thus, in our study, cocci of the Fresco DVS 1010 mixed culture were used for lactic acid fermentation within 8 h. [PERSON] et al. [54] also preferred a shorter fermentation time (10 h, 37 \({}^{\circ}\)C) in non-dairy cereal beverages fermented with _L. plantarum_. [PERSON] et al. [55] similarly proved the adequacy of an 8 h fermentation time during lactic acid fermentation of buckwheat products. Within 8 h of fermentation, Fresco culture showed good growth in all our experiments, resulting in a decrease in pH from 4.2 to 4.4, with the exception of the milk-based mash (5.06). In our previous study, the pH values reached after the fermentation with Fresco culture in buckwheat mashes were below 4.5, with the exceptions of milk and milk chocolate mash [56].