Yeast-Derived Plant Phenolic Emulsions as Novel, Natural, and Sustainable Food Preservatives

Food preservatives are ubiquitously used to increase the shelf life of manufactured foods. Current synthetic preservatives offer negligible health benefits, while healthier alternatives such as botanical extracts are hindered by unsustainable production means. Here, we developed a natural, functional food preservative via a combination of sustainable food technologies: food-grade yeast engineered to produce natural plant compounds combined with emulsifiers valorized from milk whey and fruit pectin. Chemical compositional analysis of the yeast phenolic extract (N2) revealed naringenin, phloretin, phloretic acid, and p-coumaric acid as the key plant phenolic compounds present, with negligible traces of biomolecular contamination. N2 demonstrated improved antibacterial and antifungal activities compared to those of commercial preservatives in antimicrobial assays. When used in tandem with whey protein-pectin conjugate emulgents, N2 successfully extended the shelf life of fresh apple juice. Our results pave the way toward health-promoting preservatives as well as real food applications for similarly sustainably engineered food ingredients.