Biochemical transformations in fermented chili pastes: Impact of cultivar and fermentation type on flavor and bioactive compounds

Fermentation has been demonstrated to alter the gustatory, olfactory and spicy characteristics of chili pastes. However, the application of controlled fermentation remains an area that has received comparatively little research attention. This study reports on biochemical and physical changes in three chili pastes from Capsicum annuum 'Monkey Face', Capsicum chinense 'Habanero Red Caribbean', and Capsicum chinense 'Bhut Jolokia', which were fermented for 72-h using Limosilactobacillus fermentum (LF), Lactiplantibacillus plantarum (LP), and spontaneous fermentation (SF). A significant decrease in sugar content by 50-75 % and a significant increase in lactic acid by more than 100 % were observed in all three fermentation processes. In the presence of LF, ascorbic acid levels diminished by 30-50 %, while phenolic and capsaicinoid levels remained stable, with the exception of a 24 % reduction in capsaicinoids in the 'Monkey Face' sample. Volatile profiles underwent a shift, resulting in the introduction of fermentation-specific compounds, including 3-methyl-oxopentanoic acid and butyl alcohol. LP fermentation resulted in optimal microbial growth and biochemical changes. The 'Monkey Face' cultivar demonstrated optimal performance under SF conditions, while those of a high-pungency nature exhibited enhanced characteristics when subjected to guided fermentation. It is recommended that a 72-h fermentation period with LP is employed in order to achieve optimal taste, aroma, and bioactive compound retention, particularly in the 'Habanero Red Caribbean' cultivar. This research is of paramount importance for the optimization of controlled fermentation in chili pastes, with the potential to markedly enhance their health benefits.