Determination and Origin of the Aroma Impact Compounds of Yogurt Flavor

Abstract

Yogurt exhibits a delicate and low intense flavor which requires mild sample isolation techniques and sensitive identification means. This paper decribes the application of two new flavor separation techniques: combined static and dynamic headspace, and preparative simultaneous distillation−extraction under vacuum. Of the 91 components identified by mass spectrometry, 21 were found to have a major impact on the aroma using a new method for the treatment of GC−sniffing data. One of these compounds, 1-nonen-3-one, was identified by spectral means for the first time in a flavor. Its odor detection threshold of 8 pg/kg appears to be one of the lowest among known flavor compounds. On the basis of the peak areas of yogurt and milk aromagrams, some compounds seem to be already present in milk, others appear to be generated by the strains. Keywords: Yogurt aroma; headspace; GC−olfactometry; impact-compound; composition