How Close Are We to the Production of Milk in Alternative Systems? The Fat Perspective.

The growing demand for sustainable food systems has led to significant advancements in developing alternatives to animal-derived products. Dairy products are an important dietary source of proteins and fats; however, their production raises environmental concerns, including greenhouse gas emissions, extensive land and water usage, and biodiversity loss. Therefore, there is a need to develop sustainable, scalable solutions that will enable the production of quality replacements for animal-based foods with reduced environmental impacts. Recognizing that replacing animal-based products from a single source is currently not feasible; there is a need for high-quality sources of ingredients that can be combined to mimic the holistic product. In recent years, plant-based dairy alternatives have gained traction; however, their inability to replicate the sensorial experience of real milk-attributed largely to the unique composition and structure of milk fat-remains a key limitation. Cow's milk fat has distinctive characteristics, including a complex fatty acid profile, which is rich in short- and medium-chain saturated fatty acids with specific positional distribution. These characteristics of cow's milk play a role in delivering the aroma, texture, and mouthfeel of dairy products. Recent efforts have focused on leveraging precision fermentation and cellular agriculture to mimic these properties. This review explores the unique lipid composition of ruminant milk, the biosynthesis of milk fats, and the challenges of replicating these features in non-mammalian systems. Emphasis is placed on short-chain fatty acids and chain-termination mechanisms in fatty acid synthesis. By integrating insights from diverse biological systems, we aim to contribute to a deeper understanding of the complex processes related to milk fat synthesis.