Exploring the impact of fermentation on bioactive compounds in two different types of carrot pomace

This study assessed the fermentation process of black and orange-colored carrot pomaces utilizing three varieties of lactic acid bacteria: Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus acidophilus. The fermentation process influenced the titratable acidity and lactic acid production, with L. plantarum resulting in the highest increases, particularly noticeable in orange-colored carrot pomace (OCP). Initially, citric acid levels increased, while ascorbic acid levels decreased in all cultures. Black carrot pomace (BCP) fermented by L. casei exhibited the highest phenolic content (611.42 mg GAE/100 g dw) and antioxidant activity on day 3. The total phenolic content of OCP was the highest on day 3 with both L. casei and L. plantarum. The phenolic acid profiles varied by carrot type, with BCP being rich in neochlorogenic and chlorogenic acids, and OCP in gallic and p-coumaric acids. High anthocyanin content was found in OCP, especially cyanidin derivatives, peaking with L. casei. Similarly, OCP showed increased levels of both α-carotene and β-carotene on day 3 with L. casei. Carotenoid analysis revealed that BCP contained only α-carotene, with the highest level observed after 4 days of fermentation with L. plantarum. This study demonstrates that selective fermentation with lactic acid bacteria can alter the phytochemical profile of carrot pomaces, potentially enhancing the nutritional quality in various food applications.