Kefir is a fermented dairy product that is gradually becoming more and more common to see on the shelves of Spanish shops and supermarkets. Since it is a milk-based product, made from lactic acid and alcoholic fermentation, it is assumed to have several health-enhancing functions resulting from its protein and peptide content with biological activity (molecules made up of amino acids, smaller than proteins, that are beneficial for one’s health).
However, to date there had never been a complete analysis of what kinds of peptides goat milk kefir has. So, a University of Cordoba research team made up of researchers from the Biochemistry, Proteomics and Biology of Plant and Agroforestry Systems Group as well as from the Headquarters for Research Support (abbreviatd to SCAI in Spanish) led by Professor Manuel Rodríguez decided to characterize the peptidome (set of peptides) of this product in order to open the doors to the study of kefir’s positive characteristics.
In order to accomplish this detailed result, they focused on 22 proteins and applied the technique of tandem mass spectrometry to kefir in three fermentation times (12 hours, 24 hours and 36 hours) to detect, in addition to the advantageous compounds, the peaks of concentration depending on fermentation time. A gradual increase in peptide content was found to occur during fermentation for 24 hours. When the 24 hour mark was reached, the concentration was highest and began to descrease.
Once the peptides present in goat milk kefir and their quantities according to fermentation time were determined, the University of Cordoba team had detected 11 beneficial compounds related to antihypertensive, antioxidant and antibacterial activity.
These kinds of exploratory studies will enable different research teams to continue delving deeper into understanding the health benefits of this product, and may well breathe new life into the goat sector.
Izquierdo-González, J., Amil-Ruiz, F., Zazzu, S., Sánchez-Lucas, R., Fuentes-Almagro, C., Rodríguez-Ortega, M. (2019): Proteomic analysis of goat milk kefir: Profiling the fermentation-time dependent protein digestion and identification of potential peptides with biological activity, Food Chemistry, Vol. 295, pp. 456-465, https://doi.org/10.1016/j.foodchem.2019.05.178.