Egg yolk is a nutrient-dense food ingredient rich in proteins (e.g., ovalbumin, livetin), lipids (cholesterol, phospholipids like lecithin), vitamins (A, D, E), and minerals. Drying egg yolk is critical for extending its shelf life (fresh yolk spoils within 1-2 weeks refrigerated) and enabling its use in powdered form for food processing (e.g., bakery, confectionery, infant formula) and pharmaceuticals. Vacuum microwave drying (VMD)—a hybrid technology combining microwave heating (rapid, internal) and vacuum conditions (low-temperature, oxygen-free)—is uniquely suited for egg yolk. Unlike traditional drying methods (hot-air, freeze drying), VMD preserves heat-sensitive nutrients (e.g., lecithin, fat-soluble vitamins) and avoids lipid oxidation (a major cause of off-flavors in dried yolk).
Egg yolk vacuum microwave drying is the premium technology for producing high-quality dried yolk powder, as it balances low-temperature processing, oxygen exclusion, and rapid drying to preserve nutrients (lecithin, vitamins), flavor, and functional properties. While it requires higher initial investment than hot-air drying, its ability to create a superior product (with 90%+ nutrient retention and no rancidity) makes it economically viable for both small-scale and industrial producers. By optimizing parameters (layer thickness, power, pressure) and addressing challenges like oxidation, VMD ensures dried egg yolk meets the strict quality standards of food, pharmaceutical, and cosmetic industries.
