Natural Preservatives and Nanoencapsulation in Dairy Foods: Applications in Khoya and Indigenous Milk Products

The food culture and dairy economy of South Asia is rooted in the importance of indigenous dairy products such as khoya, peda, burfi, kalakand and other traditional milk sweets. Their high moisture content, rich nutrient composition and near neutral pH make them highly susceptible to microbial spoilage, lipid oxidation and quality deterioration during storage and distribution. The growing consumer desire for clean-label and minimally processed foods has stimulated the interest in the use of natural preservatives from plants, essential oils, bacteriocins and other bioactive sources. This review discusses recent developments in the applications of natural preservatives and nanoencapsulation techniques to enhance the safety, stability and shelf life of khoya and indigenous milk products. The review covers the major natural preservatives used in dairy systems, nanoencapsulation techniques such as nanoemulsions, liposomes, lipid nanoparticles, and biopolymer-based nanocarriers and their effect on microbial inhibition, oxidative stability, physicochemical properties, texture, and sensory quality. Available evidence suggests that nanoencapsulation improves stability, controlled release and efficacy of natural preservatives with minimum undesirable flavor changes. Future perspectives comprise smart packaging, AI assisted shelf-life prediction, sustainable nanocarriers and scale-up for commercial application. The use of nanoencapsulation as an aid to natural preservation is a promising approach to develop traditional dairy products that are safer, more stable and acceptable to consumers.