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

Zehra Güler, Young W. Park

.

DOI: 10.4236/ojas.2011.11001                

Abstract

Ten most popular brands of commercial Turkish set-type yoghurts were collected from local retail outlets in Hatay, Turkey for two separate periods, and analyzed for basic nutrients, physico-chemical properties, volatile aroma compounds 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 variations in physico-chemical indices, volatile aroma compounds and volatile free fatty acid profiles among the yoghurt brands, which ultimately influence the flavor quality of the product. 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, followed by hexanoic, octanoic and butanoic acids. These differences in detected chemical compositions of volatile compounds and free fatty acids would be applicable to predict flavor, nutritional value, quality control or shelf-life of the commmercial set-type Turkish yoghurts.

Keywords

Turkish yoghurt, free fatty acids, volatile compounds, physico-chemical properties

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	AOAC. (2003) Official Methods of Analysis. Vol.I.17th ed. Association of Analytical Washington, DC, USA
[2]	Beshkova, D., Simova, E., Frengova, G. and Simov, Z. (1998) Production of flavour compounds by yogurt starter cultures. J. Ind. Micro. Biotechn. 20: 180-186.
[3]	Calderon, I., De Peters, E. J., Smith, N. E. and Franke, A. A. (1984) Composition of goat’s milk: Changes within milking and effects of a high concentrate diet. J. Dairy Sci. 67: 1905-1911.
[4]	Deeth, H. C., Fitz-Gerald, C. H. and Snow, A. J. (1983) A gas chromatographic method for the quantitative determination of free fatty acids in milk and milk products. New Zealand J. Dairy Sci. and Techn. 18: 13-20.
[5]	FAO (2006) Food Agricultural Organization. www.faostat.fao.org
[6]	Güler, Z. (2007) Changes in salted yoghurt during storage. Int. J. Food Sci. and Techn. 42: 235-237.
[7]	Güler Z. (2008) Evaluation of lipolysis in set-type fermented milks made with different commercial yogurt starter cultures during storage. Milchwissenchaft. 33: 73-77.
[8]	Güler,Z. and Park, Y.W. (2009) Evaluation of chemical and color index characteristics of goat milk, its yoghurt and salted yoghurt. Trop. and Subt. Agroecosystems, 11: 37-39.
[9]	Güler, Z.,Ta?delen, A., ?enol, H., Kerimo?lu, N., Temel, U. (2009) The determination of volatile compounds in set-type yoghurts by using static headspace gas chromatographic method, Turkish J. Food. 34 (3): 137-142.
[10]	Hekmat, S. and McMahon, D. (1997) Manufacture and quality of iron fortified yoghurt. J. Dairy Sci. 80: 3114.
[11]	Hassan, A.N., Ipsen, R., Janzen, T. and Qvist, K.B. (2003) Microstructure and rheology of yoghurt made with cultures different only in their ability to procedure exopolysaccharides. J. Dairy Sci. 86: 1632-1638.
[12]	Hutchings, J.B. 1999. In: Food Color Appearance. 2nd Ed. Springer, 610 pages.
[13]	Kaminerides, S., Stamou, P. and Massouras, T. (2007) Comparison of the characteristics of set type yoghurt made from ovine milk of different fat content. Int. J. Food Sci. and Techn. 42:1019-1028.
[14]	Kang, Y., Frank, J.F. and Lillard, D.A. (1988) Gas chromatographic detection of yoghurt flavour com- pounds and changes during refrigerated storage. Cul. Dairy Prod. J. 11: 6-9.
[15]	Kneifel, W., Ulbert, F., Erhard, F. and Jaros, D. (1992) Aroma profiles and sensory properties of yoghurt and yoghurt related products. I. Screening of commercially available starter cultures. Milchwissenchaft. 47: 362-365.
[16]	Lee, J.H., Melton, S. L., Waller, J. C. and Saxton, A. M. (2004) Modification of physicochemical characteristics of goat milk fat by feeding protected high oleic sun- flower oil supplements. J. Food Sci. 69: 280-286.
[17]	Ligor, M., Jarmalaviciene, R., Szumski, M., Marugka, A. and Buszewski, B. (2008) Determination of volatile and non-volatile products of milk fermentation processes using capillary zone electrophoresis and solid phase microextraction coupled to gas chromatography. J. Sept. Sci. 31: 2707-2713
[18]	Macciola, V., Candela, G. and De Leonardis, A. (2008) Rapid gas-chromatographic method for the determination of diacetyl in milk, fermented milk and butter. Food Control. 19: 873-878.
[19]	Molimard, P. and Spinnler, H.E. (1996) Compound Involved in the Flavor of Surface Mold-Ripened Cheeses: Origins and Properties. J. Dairy Sci.79: 169-184.
[20]	Monnet, C. and Corrieu, G. (2007) Selection and properties of [alpha]-acetolactate decarboxylase-deficient spon- taneous mutants of Streptococcus thermophilus. Food Microbiology. 24 : 601-606.
[21]	Ott, A. and Fay, L.B., Chaintreau, A.(1997) Deter- mination and origin of the aroma impact compounds of flavour. J. Agric. and Food Chem. 45: 850-858.
[22]	Ott, A., Germond, J.E., Baumgartner, M. and Chaintreau, A. (1999) Aroma comparisons of traditional and mild yogurts: headspacegas chromatography quantification of volatiles and origin of α-diketons. J. Agric. Food Chem. 47: 2379-2385.
[23]	Ott, A., Germond, J.E. and Chaintreau, A., (2000) Vicinal diketone dormation in yoghurt: 13C precursors and effect of branched-chain amino acids. J. Agric. and Food Chem. 48: 724-731.
[24]	Park, Y.W. (1994) Basic nutrient and mineral compo- sition of commercial goat milk
[25]	yogurt produced in the U.S. Small Rumin. Res. 13: 63-70
[26]	Ozer, B., Kirmaci, H.A., Oztekin, ?., Hayaloglu,A. and Atamer, M. (2007) Incorporation of microbial transglutaminase into non-fat yogurt production, Int. Dairy J. 17: 199-207.
[27]	Rasic, J.L. and Kurman, J.A. (1978) Yoghurt. Volume I, Technical Dairy Publishing House. Copenhagen, Den- mark.
[28]	Serra, M., Trujillo, A.J., Guamis, B. and Ferragut, V. (2009) Flavour profiles and survival of starter cultures of yoghurt produced from high-pressure homogenized milk. Int. Dairy J. 19: 100-106.
[29]	Stelios, K., Stamou, P. and Massouras, T. (2007) Comparision of The Characterstics of Set Type Yohurt Made From Ovine Milk of Different Fat Content. International J. Food Sci. and Techn. 42: 1019-1028.
[30]	Tamime, A. and Deeth, H. (1980) Yogurt: Technology and Biochemistry. J. Food Protect. 43: 939-977.
[31]	Tamime, A.Y., Robinson, R.K. (2001) Yoghurt Science and Technology. CRC Pres. New York, US.
[32]	TSI (2006) Yogurt. TS 1330. Ankara : Turkish Standar Institution.
[33]	Tsau, J.L., Guffanti, A.A. and Montville, T.J. (1992) Convertion of pyruvate to acetoin helps to mantain pH homeostasis in Lactobacillus plantarum. Appl. and Envirom. Microbi. 58: 991-994.
[34]	Ulbert, F. and Kneifel, W. (1992) Aroma profiles and sensory properties of yoghurt and yoghurt-related products. II. Classification of starter cultures by means of cluster analysis. Milchwissenchaft. 47: 432-434.
[35]	Urbach, G. (1995) Contribution of lactic acid bacteria to flavour compound formation of dairy products. International Dairy Journal, 5, 877-903.
[36]	Vargas, M., Chafer, M., Albors, A., Chiral, A. and Gonzalez-Mart?nez, C. (2008) Physicochemical and sensory characteristics of yoghurt produced from mixtures of cows’ and goats’ milk. Int. Dairy J. 18: 1146-1152.
[37]	Warsy, J.D. (1983) Production of volatile aroma com- pounds in Dahi. J. Agric. Res. 21 (1): 31-36
[38]	Xanthopoulos, V., Picque, D., Basit, N., Boquien, C.Y. and Corrieu, G. (1994) Methods for the determination of aroma compounds in dairy products: a comparative study. J. Dairy Res. 61: 289-297.