Development of a microencapsulated functional ingredient formulated with the neurotransmitter GABA and the Lactiplantibacillus plantarum K16 produced through biotechnological processes

Résumé

This PhD thesis has developed a new functional ingredient characterised by the novelty of combining anew L. plantarum K16 strain, isolated from the fermented food Kimchi, with the postbiotic metaboliteGABA produced by a fermentation process using agri-food by-products as substrate media. According tothe scientific literature, this functional ingredient intends to exert a beneficial effect on human health byacting in the intestine, guaranteeing a synergistic effect of the probiotic and GABA. The first step in thedeveloping process was focused on isolating and characterising a GABA-producer lactic acid strain fromfermented food kimchi. Then, am evaluation of the ability to produce GABA by this strain wasconducted, firstly, using commercial MRS broth where the effect of different parameters was assessed.Next, several agri-food by-products have been selected to be used as fermentation media due, on onehand, to their high environmental impact and, on the other hand, to their nutritional value for developinglow-cost culture media. Finally, one of this agri-food by-products was chosen to grow the isolatedbacteria and to produce GABA with it, for finally develop a microencapsulated functional ingredient.