Innovative approaches for the fermentation of black cabbage with improved nutritional and health-promoting traits

Black cabbage can be promising to prepare innovative functional products. This research explores controlled fermentation as a new sustainable food production and stabilization technology to enhance the nutritional traits of black cabbage. Two different approaches were applied: soaking cut leaves in brine and pressing cut leaves adding salt. Lactiplantibacillus plantarum (TB 11–32) and Saccharomyces cerevisiae (LI 180-7) starter strains were employed to drive the fermentation and stabilize the final product for human consumption. Fermenting cut pressed leaves of black cabbage allowed to obtain a pH level below 4.6 and to ensure required safety aspects. Lactic Acid Bacteria fermentation (P-LAB) revealed a higher presence of some alcohols, carboxylic acids, terpenes, phenols, and dimethyl disulphide; the yeast fermentation (P-YST) promoted several esters. The fermented final product was enriched in polyphenol content of 3.7–4.6 times and of 2.7–3.4 times in antioxidant activity in comparison with the raw untreated material. Both P-YST and P-LAB fermented black cabbage favoured gut microbial growth and were beneficial for human health. P-YST specifically increased the production of some short chain fatty acids (SCFAs) and relative esters and carboxylic acids, whereas released phenolics compounds in LAB fermented sample could prevent the formation of reactive free radicals and improve human cardiovascular health.