Updated Insights into Probiotic Nut-Based Dairy Alternatives: Microbiological, Antioxidant, and Sensory Aspects

Plant-based "milks" have gained increasing attention as functional beverages due to their nutritional properties, consumer acceptance, and potential for probiotic fermentation. Lactose intolerance, milk allergies, and growing interest in sustainable plant-based diets have contributed to the rapid expansion of nut-based beverage (NBBs) markets. This review summarizes recent advances in processing and nutritional characteristics of NBBs as dairy alternatives. Although rich in bioactive compounds, including antioxidants, minerals, unsaturated fatty acids, and vitamins, NBBs generally exhibit lower nutritional density than bovine milk, particularly in protein content and mineral bioaccessibility due to antinutritional compounds present in plant matrices. Fermentation with lactic acid bacteria (LAB) can confer probiotic properties, increase the bioaccessibility of bioactive compounds, and improve sensory properties by reducing off-flavors and promoting the formation of desirable aromas. Pistachio- and almond-based beverages generally exhibit more consistent fermentation performance, favoring probiotic growth and sensory improvement, whereas coconut- and walnut-based milks often require additional stabilization strategies due to limited emulsifying capacity or oxidative instability. Overall, fermented NBBs represent a promising category of functional foods with increasing technological and nutritional relevance. Future research should focus on optimizing starter cultures and processing conditions, improving scalability and industrial feasibility, and elucidating microbial/matrix interactions through integrated omics approaches.