In recent years consumers knowledge about probiotics and their positive effects on human health and consequently probiotic food production has increased. Most probiotic have low survival rate even when they are stored at low temperature and the number of viable bacteria are actually below the desired level(10 7 CFU/g).There are several ways for protecting probiotics, one of them is encapsulation. In this study Lactobacillus plantarum A7 which is a native probiotic strain was encapsulated with alginate and coated with whey proteins and was added to low fat mayonnaise. The morphology of the microcapsules was observed using scanning electron microscope (SEM) and optical microscope. The survival of bacteria as either free cells or encapsulated were studied in 12 weeks storage at 4 . Meanwhile the pH changes, sensory properties, viscosity and color of sample were evaluated. The results showed that the beads were globular in shape with the mean diameter of 80 microns. After 12 weeks, the number of viable cells in mayonnaise containing alginate beads coated with whey proteins was more than 10 7 CFU/g. While for samples containing alginate beads, number of viable cells was less than 10 7 CFU/g in less than 5 weeks. . This reduction might be due to the release of bacteria into mayonnaise as alginate beads are partially degraded which represents whey protein as a suitable coating material for alginate beads. Changes in pH of mayonnaise treatments throughout refrigerated storage were not significant (P 0.05).Viscosity and color of samples had also no significant differences. But in sensory properties the samples containing capsules get lower scores except for odor. The panelists, reported slight grittine in mayonnaise with probiotic capsules. This study showed that alginate beads coated with whey proteins is suitable for L. plantarum A7 protection in low fat mayonnaise. For industrial production there should be more studies for enhancing the texture and taste of this probiotic product. Key Words: Encapsulation, Low fat mayonniase, Lactobacillus plantarum A7 , Alginate, Whey proteins.
