Antioxidant capacity and identification of radical scavenging peptides from Crema de Chiapas, Fresco and Cocido cheeses

Bioactive peptides may positively impact bodily functions. One of these are the antioxidant peptides which are well documented for a wide variety of food matrices, mostly from plant sources. Nevertheless, information of antioxidant milk-derived peptides is still a little-known field. The present study was aimed to evaluating the antioxidant capacity (AC) in vitro of water soluble extracts < 3 kDa (WSE) from three artisanal Mexican cheeses: Crema de Chiapas (CrC), Fresco (FC) and Cocido (CC). This study was carried out for cheeses of different days of storage (0, 5, 10, 15, and 20) at 4 °C. AC was assayed to the respective WSE by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diamoniun salt (ABTS) and oxygen radical absorbance capacity (ORAC) methods and those WSE that showed the most antioxidant capacity from each cheese were analyzed by using RP-HPLC/MS to identify and characterize the novel specific peptides. All the WSE analyzed show antioxidant capacity, especially those from CrC and CC which display the highest AC at 15 days of storage. Regarding to WSE from FC, the AC was constant during storage. Identified structures reveal that these novel peptides possess high content of specific amino acids, mainly proline, valine, leucine and phenylalanine, of which it has already been shown antioxidant properties. This study demonstrate that these artisanal Mexican cheeses are sources of potential antioxidant peptides.