Goat kefir as a delivery system for algae bioactive compounds: nutraceutical properties and potential peptidomic characterization by Q-TOF LC/MS

In the present study, kefir samples produced using different algae species (A. nodosum, S. platensis and C. vulgaris), which are environmentally friendly rich protein sources, and goat milk were investigated in terms of physicochemical, biochemical and microbiological analyses. The effects of different algae sources used in the production of kefir samples on total solids, ash, pH, titratable acidity, water holding capacity, viscosity, L*, a*, b*, DPPH, ABTS, TPC and ACE inhibitory activity were found to be very significant at p < 0.01 level. In addition, the effect of different algae species on Lactococcus spp. counts was found to be significant at p < 0.05 level, on L. mesenteroides counts at p < 0.01 level, while there was no effect on yeast counts. In the peptide profile analysis of kefir samples, many peptides consisting of 2–4 amino acids was identified and when the potential bioactivities of the peptides were examined through BioPep database, it was observed that they had ACE inhibitory, antioxidant and DPP IV inhibitory activity. In addition, in the amino acid profile, it was observed that the addition of different algae species showed positive contributions in essential and non-essential amino acid contents. As a result, it was observed that the addition of different algae species to goat milk kefirs had variable effects on the analyses and generally provided positive contributions in terms of the parameters examined. In this context, goat milk kefirs with the addition of different algae species were shown to be a promising approach as therapeutic agents instead of synthetic drugs.