The buttermilk was selected as a wall material to deliver the docosahexaenoic acid (DHA) in this current research, including algal oil encapsulating with pure buttermilk (BMO) and its mixture (buttermilk and maltodextrin (BMMO)). The results showed that the particle growth rate of BMO and BMMO was slower than that of commercial algal oil powders (CMOs) during simulated digestion in vitro. Moreover, in the Morris water maze experiment, the mice in BMO and BMMO groups took less time to find the platform compared to that in CMO group, and their DHA content in the brain was significantly higher. The immunoglobulin detection revealed that feeding BMO and BMMO could improve the immune function of rats. Therefore, buttermilk will be a potential wall material which are able to improve the digestion characteristics of algal oil and the DHA bioavailability, and these results also promote the value-added utilization of by-products in the dairy industry.

This study investigated the effects of five lipases on enzyme-modified cheese (EMC) flavor development. Results showed that lipase 30SD contained high hydrolytic activity for short, medium, and long-chain fatty acids within 24 h incubation time, and the highest content of them among different times could reach 47.24, 475.90, 1 563.92 mg/100 g fat, respectively. Lipase DF15 and MER showed moderate capacity to hydrolyze volatile fatty acids, while lipase F3G had a stronger ability to produce long-chain fatty acids. Twenty-seven new volatiles were formed during lipolysis, most of them were acids and esters. Principal component analysis results showed that EMC produced by lipase 30SD for 18 h was similar to the commercial product with a pungent, rancid, and cheddar flavor. EMCs produced by lipase DF15 were significantly distinguished from other products by their high content of ethyl heptanoate, ethyl nonanoate, and ethyl tridecanoate. The findings might be useful for the researchers who focus on lipolysis or EMC products.