Donkey Milk for Manufacture of Novel Functional Fermented Beverages

The aim of this work was to investigate on the functional features of a donkey milk probiotic berevage as a novel food. Particularly, it was to study the decrease of lactose content and the antioxidant activity of standard yogurt (YC) and probiotic yogurt (YP; Lactobacillus acidophilus, Lactobacillus casei) from donkey milk during the storage up to 30d at 4 oC. The evolution of lactose content using enzymatic-spectrophotometric kits was analyzed. Antioxidant activity of yogurt was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), and thiol assays. Parallel consumer sensory studies were carried out as consumer test in order to gain information about the impact of these novel fermented beverages on sensory perceptions. The statistical analysis has shown significant effect of studied factors. The results showed that the lactose content gradually decreased during storage in both yogurts, reaching values of 2.36% and 2.10% in YC and YP, respectively, at 30 d (P < 0.05). During storage of both yogurt types, the antioxidant activity increased, but YP showed a higher antioxidant activity than YC. The results suggest that the antioxidant activity of yogurt samples was affected by cultures of lactic acid bacteria (LAB). We conclude that the fermented donkey milk could be configured as health and nutraceutical food, which aims to meet nutritional requirements of certain consumers groups with lactose or cow milk protein intolerance. Practical Application Donkey milk is now configured as pharmafood for its nutritional, nutraceutical, and functional properties. For its biochemistry very close to human milk, it may be considered an alternative food source in children with cow milk protein allergy. However, it has a high lactose content, resulting inadequate for people suffering from lactose intolerance. Therefore, the development and prospects of fermented donkey milk were introduced. LAB are able to hydrolyze lactose, casein, and whey protein with release of a large number of organic acids, peptides, and amino acids that are protective agents to help human body to reduce oxidative damage. This work highlights that the fermented probiotic donkey milk could allow development of novel foods useful to meet the needs of consumers with lactose or cow milk protein intolerance.