Kefir is an acidic-alcoholic fermented milk that can provide probiotic benefits such as intestinal microecological balance regulation, antibacterial activity, and anti-inflammatory activity. In this study, Lactobacillus fermentum grx08 isolated from longevous people was used to further improve the health properties of kefir. L. fermentum grx08 and kefir grains obtained from Xinjiang, China were mixed at ratios of 1:1, 5:1 and 25:1 as starters. The 6 Gram-positive and Gram-negative foodborne pathogens were able to grow in the supernatant of kefir, but not in the supernatant of kefir with L. fermentum grx08. With the increasing of amount of inoculated L. fermentum grx08, the antibacterial activity of the mixed fermented kefir gradually increased. The contents of lactic acid, fumaric acid and malic acid in the mixed fermented milk were significantly increased by adding L. fermentum grx08 (P < 0.05), while the content of acetic acid decreased with the increase of L. fermentum grx08, and the content of citric acid was unaffected. This study suggest that the addition of  L. fermentum grx08 shortened the fermentation time, improved the acidity and retained the quality of fermented milk. Moreover, the antibacterial properties of kefir is enhanced by increasing the production of certain acid.

This study explored the effects of two mixed fermentation methods: one was fermenting a soymilk and milk mixture by a lactic acid bacteria fermenting agent at 0.1 g/kg and 42 °C until the acidity was 70 °T, which was set as the MFSM method, and the other was fermenting milk alone by lactic acid bacteria at 42 °C for 12 h, placing it in a 4 °C refrigerator after acidification for 24 h and then mixing it with soymilk at a 1.5:1 ratio and storing the mixture at 4 °C, which was set as the SMFSM method. The quality and flavor of the soymilk and milk mixture products were investigated on the 0th, 15th and 30th days during storage. The changes in acidity, pH, number of viable bacteria, viscosity, water-holding capacity, texture, rheological properties, sensory quality and volatile flavors were determined. The results showed that compared with the fermented soymilk and milk mixtures under the MFSM method, the samples of fermented soymilk and milk mixtures under the SMFSM method showed a significant slowdown of acidification during storage, so that the sensory quality of the products was almost unaffected by acidity on the 30th day of storage. Furthermore, the number of viable bacteria was greater than 7 log cfu/mL. The water holding capacity did not change significantly until the 30th day. There was also no whey precipitation, indicating good stability. The samples in SMFSM mode had higher aromatic contents and beans during storage than the fermented soymilk and milk mixtures in MFSM mode. The rich variety of volatile flavors and the presence of acetoin, 2-heptanone, and (E,E)-3,5-octadien-2-one throughout the storage period allowed the samples to maintain a good sensory flavor during storage.

No abstract

Surface‐segregated micelles (SSMs) have shown potential applications in drug delivery, bioimaging, and Pickering emulsions due to their adaptive characteristics. A diverse set of SSMs are prepared by reversible addition–fragmentation transfer (RAFT)‐mediated polymerization‐induced self‐assembly (PISA). However, the obtained self‐assembled structures are mostly limited to spherical forms, and SSMs with a hierarchical structure are not yet prepared. In this study, SSMs with various hierarchical structures are generated by the dispersion polymerization of benzyl methacrylate (BzMA) co‐mediated by a binary mixture of poly(2‐(dimethylamino)ethyl methacrylate) and polydimethylsiloxane as macromolecular chain‐transfer agents (macro‐CTAs). The obtained structures include cylinders, vesicles, large compound micelles, and bundles of hoops. The morphological evolution of these structures and vesicle size can be readily tuned by varying the composition of the binary mixture of macro‐CTAs. This study expands the scope of RAFT‐mediated PISA for synthesizing well‐defined polymer nano‐objects with higher‐order morphologies for various applications.

No abstract