Development and characterization of omega-3-rich flaxseed oil microcapsules and evaluation of its stability and release behavior in probiotic millet yogurt

The study investigated the encapsulation potential of probiotics (PRO) and flaxseed oil (FS) using different wall materials, including sodium alginate-maltodextrin-inulin (SIN), skim milk (SK), whey protein (WP), and soy protein concentrate (SP) to produce oil-enriched millet yogurt. The microcapsules (SIN-FS-SK, SIN-FS-WP, and SIN-FS-SP) and co-microcapsules (SIN-FS-PRO-SK, SIN-FS-PRO-WP, and SIN-FS-PRO-SP) were characterized by encapsulation efficiency, lipid oxidation, FTIR, SEM, and GC–MS. Thus, the obtained emulsion droplets size was favorable (1.11 to 1.73 μm) for freeze-drying with an encapsulation rate above 95%, better oxidative stability at 4 °C, and microcapsule sizes between 800 and 1600 μm allowing the oil release during intestinal stage (51–65%). Thus, it was possible to obtain flaxseed oil enriched-millet yogurt with good oxidative stability. Adding co-microcapsules also improved the quantities of polyunsaturated fatty acids (PUFAs), particularly alpha-linolenic acid, in the various products, enabling a significant release of PUFAs during intestinal digestion, thus improving the omega 6/omega 3 ratio.