Yeast cell-derived delivery systems for bioactives

Yeast cells are an emerging bioinspired delivery carriers owing to the great potential in encapsulation of both hydrophobic and hydrophilic compounds, protection from external environmental stresses, controlled release, biocompatibility, and biodegradability. The promising outcome of research in the recent past on delivery of bioactives suggests their bright future in functional food industries. This review summarizes the latest developments (2015–2021) in yeast cell-derived delivery carriers, covering the intact yeast cells and pretreated yeast cells. Of specific interest is the new trend of integrating yeast cells with other systems such as polymeric hydrogels, layer-by-layer coated microcapsules, nano-in-micro systems, and metal-organic frameworks. The physicochemical principles and key technical information underlying the production strategies, the advantages, and limitations of each of the systems are discussed through some intriguing case studies, where yeast cells have been used for encapsulation, protection, and controlled release of food-related bioactives such as flavors, vitamins, carotenoids, and phenolics. We also highlight the challenges, opportunities, and future directions. The utilization of yeast cell-derived carriers has only recently been expanded to deliver bioactives. The promising results in this review should guide future trends in more efficient yeast cellular formulations and delivery platforms for functional food applications.