Glycan Profiling of Plant-Based Milk Alternatives by Antibody Microarrays

The growing prevalence of lactose intolerance and cow's milk protein allergy has contributed to a significant increase in consumer demand for plant-based milk alternatives [ <i>Food Res. Int.</i> 2020, 131, 108972, 10.1016/j.foodres.2019.108972]. These products are marketed as nutritionally comparable to dairy milk, but limited data exist regarding their structural glycan composition, which may influence nutritional, functional, and immunological properties. This study aims to profile the glycan (polysaccharide) composition of nine widely consumed plant-based milk types: oat, almond, coconut, hazelnut, cashew, soy, pea, rice, and brown rice. Fifty commercially available samples were collected from UK retailers and analyzed using high-throughput microarray technology. The samples were printed on nitrocellulose membranes using a robotic microarray printer, probed with a panel of monoclonal antibodies and carbohydrate-binding modules (CBMs), and visualized as heat maps. Analysis revealed nine polysaccharide classes. All samples showed presence of heteromannan, pectic, and arabinogalactan-protein (AGP) glycans. Oat milk exhibited particularly high levels of callose and glucuronoxylan. fructose and heteroxylan classes were not detected in any of the products tested. This study provides a comprehensive glycan map of selected plant-based milks, offering valuable insight into their structural diversity and potential health benefits. The findings may support future improvements in plant-based milk formulation, product labeling, and consumer awareness.