Enhanced Production of Galactooligosaccharides Enriched Skim Milk and Applied to Potentially Synbiotic Fermented Milk with 4B15.

In the current study, we first investigated a method for directly transforming lactose into galacto-oligosaccharides (GOS) for manufacturing low-lactose and GOS-enriched skim milk (GSM) and then evaluated its prebiotic potential by inoculating five strains of spp. In addition, fermented GSM (FGSM) was prepared using a potentially probiotic strain and its fermentation characteristics and antioxidant capacities were determined. We found that GOS in GSM were metabolized by all five strains after incubation and promoted their growth. The levels of antioxidant activities including radical scavenging activities and 3-hydroxy-3-methylglutaryl-CoA reductase inhibition rate in GSM were significantly increased by fermentation with the probiotic strain. Moreover, thirty-nine featured peptides in FGSM was detected. In particular, six peptides derived from β-casein, two peptides originated from αs-casein and κ-casein were newly identified, respectively. Our findings indicate that GSM can potentially be used as a prebiotic substrate and FGSM can potentially prevent oxidative stress during the production of synbiotic fermented milk in the food industry.