Impact of fermentation on biological activities and bioactive compounds of coconut milk kefir

Coconut milk serves as an excellent plant-based substitute for animal milk in fermentation with kefir grains, producing a vegetarian-friendly and allergy-safe fermented beverage. This study examined how fermenting coconut milk with milk kefir grains affects its antioxidant capacity, tyrosinase inhibition, probiotic growth, total phenolic content, and protein profile. Results showed significant improvements in cellular antioxidant and anti-tyrosinase effects, along with enhanced growth of the probiotic Lactobacillus acidophilus during fermentation, especially at 120 h. Conversely, fermentation decreased the overall phenolic content and led to the breakdown of most proteins in the coconut milk. Nonetheless, the process promoted the formation of smaller proteins and peptides around 10 kDa, possibly contributing to the increased antioxidant, anti-tyrosinase, and probiotic growth-promoting effects. These findings offer valuable insights into how fermentation with kefir alters the biological activities and bioactive compounds of coconut milk, helping to identify the optimal fermentation duration for producing a health-enhancing, high-quality fermented beverage.