Olive oil and coconut oil improved the quality and digestibility of set soybean yoghurt

The results of GC-MS analysis showed that the set soybean yoghurt without oil contained only two esters and one alcohol: delta-dodecalactone, 5-decanolide, and R-(-)-2-butanol. The set soybean yoghurt with olive oil was characterized by five volatile flavors: hexanoic acid, 2-nonanol, phenylacetaldehyde, 3-heptylacrolein, and acetylpyrazine. The set soybean yoghurt with coconut oil was characterized by nine volatile flavors: 5-hydroxyoctanoic acid lactone, ethyl caprylate, ethyl caprate, ethyl laurate, 2-tridecanone, dihydro-2-methyl-3(2H)-thiophenone, lauric acid, 1-octanol, and 2-decanol. Gas chromatographic analysis showed that free fatty acid species increased in set soybean yoghurt after oil addition, which were positively correlated with volatile flavor substances. By confocal laser microscopy observation, the oil droplets in the three groups of set soybean yoghurt were reduced after digestion. Research has proved that adding an appropriate amount of olive oil or coconut oil to set soybean yoghurt can improve the flavor and does not increase the digestive burden.