Characteristics of physico-chemical properties, volatile compounds and free fatty acid profiles of commercial set-type Turkish yoghurts

Abstract

Ten most popular brands of commercial Turkish set-type yoghurts were collected from local re-tail outlets in Hatay, Turkey for two separate pe-riods, and analyzed for basic nutrients, phys-ico-chemical properties, volatile aroma com-pounds and free fatty acid profiles to compare their differences among the yoghurt products. The results showed that there were significant differences (P < 0.05, 0.01, or 0.001) and varia-tions in physico-chemical indices, volatile aro-ma compounds and volatile free fatty acid pro-files among the yoghurt brands, which ulti-mately influence the flavor quality of the pro-duct. Acetaldehyde was predominant volatile compound in yoghurts, which followed by acetone, acetoin, diacetyl and ethanol. The level of diacetly was inversely related to titratable acidity, acetaldehyde and ethanoic acid. From ketones with high carbones 2-undecanone and 2-pentadecanone were higher than 2-butanone, 2-nanonane and 2-tridecanone. These ketones are related to fat content of yoghurt. Among short chain free fatty acids, ethanoic (acetic) acid was the most abundant in yoghurts, fol-lowed by hexanoic, octanoic and butanoic acids. These differences in detected chemical compo-sitions of volatile compounds and free fatty ac-ids would be applicable to predict flavor, nutri-tional value, quality control or shelf-life of the commmercial set-type Turkish yoghurts.