EFFECTS OF SPIRULINA ON YOGURT STARTER CULTURES GROWTH AND THE IN VITRO DIGESTIBILITY OF THE RESULTING YOGURT

Abstract

The effects of SP on LAB growth and the in vitro digestibility of resulting yogurt was studied by microbial analysis, nuclear magnetic resonance (NMR) spectroscopy, rheology analysis and confocal laser scanning microscopy (CLSM). The promoting effect of SP on the growth of LAB was identified but there it lacked dose dependency because 0.5% or 1% of SP fortified samples shown no statistical difference. In addition, a total of 36 metabolites were identified, including amino acids, fatty acids and a few monosaccharides. The data shown that SP addition enhanced the release of those metabolites during in vitro digestion in comparison with that of the 0% SP fortified yogurt. Surprisingly, however, yogurt containing 0.75% of SP fortified yogurt decreased the release of some metabolites in comparison with that of 0.5% SP fortified yogurt. Therefore, SP might affect the metabolic pathways of amino acids, fatty acids and carbohydrates, according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis.Addition of SP was found to reduce the viscosity of yoghurt both before and after in vitro digestion, which might enhance the release of metabolites during digestion.