Highly stable emulsion gels with micellar casein based on the jamming transition, for bioactive molecule delivery

Abstract

Emulsion gels have numerous practical applications in the pharmaceutical and food industries, the preparation of which involves multiple processing steps including the production of emulsions and transition of emulsions into gels. Improving the stability of emulsion gels and simplifying their preparation process are key issues. By exploiting the properties of micellar casein (MC), pectin (P) and sodium alginate (SA), a highly stable emulsion gel with 70% oil was created through one-pot homogenization based on the jamming transition. Emulsion gels prepared with an SA-MC ratio of 3:7 exhibited high stability during acidification, heating and with addition of Ca2+, maintained their stability after more than 810 days of storage. It also prolonged the release rate of caffeic acid phenethyl (CAPE) while protecting proanthocyanidin (PC) from degradation during simulated gastrointestinal digestion. Interestingly, P/SA-MC (3:7) emulsion gels containing PC and CAPE prevented the cytotoxic effects of PC and CAPE on human colon epithelial NCM-460 cells, but still allowed PC and CAPE to exert a strong anticancer effect on Caco-2 colon cancer cells. Our approach not only eliminates additional pre- and/or post-treatments used to prepare or stabilize the emulsion gel, but also provides a promising carrier for bioactive molecules.