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

Study on <i>Streptococcus thermophilus</i> isolated from Qula and associated characteristic of acetaldehyde and diacetyl in their fermented milk

“…Lactic acid and formic acid could be detected as distinct peaks in our HPLC analysis with retention times of 4.3 and 4.9 min, respectively. The main flavoring agent in yogurt is lactic acid, which contributes to its sour and refreshing taste (Ott et al, 1997).…”

Selection and properties of α-acetolactate decarboxylase-deficient spontaneous mutants of Streptococcus thermophilus

“…diacetylactis and Leuconostoc sp, which are used for the production of cultured 49 cream, cultured butter, buttermilk and fresh cheeses. Diacetyl is also a key aroma compound 50 in yogurt (Imhof et al, 1995;Ott et al, 1997), but in this case, it is mainly produced by 51…”

Redox Potential: Monitoring and Role in Development of Aroma Compounds, Rheological Properties and Survival of Oxygen Sensitive Strains During the Manufacture of Fermented Dairy Products

“…Ott et al [36] identified 91 aroma compounds (GC-olfactometry) in yoghurt among which 21 w e r e d e t e c t e d m o r e f r e q u e n t l y a n d w o u l d t h u s h a v e a m a j o r i m p a c t o n f l a v o u r . Acetaldehyde is found in significant quantities and is responsible for the characteristic smell of yoghurt.…”

“…Acetaldehyde is found in significant quantities and is responsible for the characteristic smell of yoghurt. Diacetyl, pentane-2,3-dione, and dimethyl sulphide also have a major impact on yoghurt flavour [36,37].…”