Plant-based Milks: A Review of the Science Underpinning Their Design, Fabrication, and Performance

Many consumers are interested in decreasing their consumption of animal products, such as bovine milk, because of health, environmental, and ethical reasons. The food industry is therefore developing a range of plant-based milk alternatives. These milk substitutes should be affordable, convenient, desirable, nutritional, and sustainable. This article reviews our current understanding of the development of plant-based milks. Initially, an overview of the composition, structure, properties, and nutritional profile of conventional bovine milk is given, because the development of successful alternatives depends on understanding the characteristics of real milk. The two main production routes for fabricating plant-based milks are then highlighted: (i) disruption of plant materials (such as nuts, seeds, or legumes) to form aqueous suspensions of oil bodies; (ii) formation of oil-in-water emulsions by homogenization of oil, water, and emulsifiers. The roles of the different functional ingredients in plant-based milks are highlighted, including oils, emulsifiers, thickeners, antioxidants, minerals, and other additives. The physicochemical basis of the appearance, texture, and stability of plant-based milks is covered. The importance of the sensory attributes and gastrointestinal fate of bovine milk and plant-based alternatives is also highlighted. Finally, potential areas for future work are discussed.