Dynamics of Bioactive Compounds during Spontaneous Fermentation of Paste Obtained from <i>Capsicum</i> ssp.—Stage towards a Product with Technological Application

Six cultivars of chili (Cherry, Bulgarian Chilli, Cayenne, Fatalii, Habanero, and Carolina Reaper) from two species (<i>Capsicum annuum</i> and <i>Capsicum chinense</i>) have been studied. Anaerobic, spontaneous fermentation of pure chili paste was conducted for 21 days at 20 °C. The unfermented (UCP) and fermented chili pastes (FCP) were both subjected to physicochemical and microbiological characterization consisting of capsaicinoid, ascorbic acid, short-chain organic acids, phenolic compounds, and simple sugars analysis. Cell viability for Lactic Acid Bacteria (LAB) and <i>Leuconostoc</i> was determined before and after fermentation. Results indicate that capsaicinoids are very stable compounds, as notable differences between unfermented and fermented samples could not be seen. Carolina Reaper and Fatalii cultivars were amongst the most pungent, whereas Cherry, Cayenne, and Bulgarian types were low to moderate in pungency. Average loss of total ascorbic acid was 19.01%. Total phenolic compounds ranged between 36.89–195.43 mg/100 g for the fresh fruits and 35.60–180.40 mg/100 g for the fermented product. Losses through fermentation were not significant (<i>p</i> < 0.05). Plate counts indicated low initial numbers for LAB in the fresh samples, values ranging between 50–3700 CFU/g (colony-forming units). After fermentation, day 21, concentration of LAB (3.8 × 10⁶–6.2 × 10⁸ CFU/g) was high in all samples. Fermented chilies paste with enhanced biochemical and bacterial properties might further be used in the technology of vegetable (brining) or meat (curing) products, processes that generally involve the fermenting activity of different microorganisms, especially (LAB). Thus, the purpose of this research was the investigation of biochemical and microbial transformations that naturally occur in fermented chilies with a future perspective towards technological applications in cured meat products.