Abstract #M114

# M114
Effect of extraction conditions on the extraction efficiency for the HS-SPME-GC/MS analysis of volatile compounds in Turkish white cheese using central composite rotatable design.
P. Salum*1, Z. Erbay2, H. Kelebek2, S. Selli3, 1Department of Food Engineering, Institute of Natural and Applied Sciences, Cukurova University, Adana, Turkey, 2Department of Food Engineering, Faculty of Engineering and Natural Sciences, Adana Science and Technology University, Adana, Turkey, 3Department of Food Engineering, Faculty of Agriculture, Cukurova University, Adana, Turkey.

Aroma of cheese is one of the most important features due to the product quality and consumer’s acceptance. Although most of the studies related to the analysis of volatile compounds of cheeses were carried out with headspace solid-phase microextraction (HS-SPME) method, there is lack of information about the effects of SPME parameters on extraction efficiency. In this study, the effects of principal extraction conditions (extraction temperature, time, and agitation speed) on the extraction rates of volatile compounds with HS-SPME-GC/MS method for the volatile analysis of cheese by using Carboxen/Polydimethylsiloxane fiber were investigated. Turkish white cheese ripened for 6 mo was used as a test material. A central composite rotatable design with 20 experimental conditions was utilized. Experiments were carried out at the extraction temperature range of 30–60°C, for the extraction time range of 30–100 min, and with the agitation speed range of 250–750 rpm. All experiments and analyses were triplicated. The principal effects of extraction conditions on the extraction efficiency were evaluated by using response surface methodology. Experimental data were processed with multiple linear regression analysis and second order polynomial models were created to predict the FID areas for volatile compounds. As a result, the variations of FID areas for 26 volatile compounds were successfully modeled. While 10 of these volatile compounds were acids, there were 7 alcohols, 3 ketones, 3 esters, 1 aldehyde, 1 lactone, and 1 phenol. The extraction temperature, time and their interaction effects were found to be significant on all volatile compounds (P < 0.01). On the other hand, the effect of agitation speed on FID areas for 8 volatile compounds (especially for acids) was not statistically important. Consequently, the most important factor was determined to be extraction temperature, followed by extraction time. This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) [project no: 115O229].

Key Words: SPME, volatile, response surface methodology