Investigation of Physicochemical, Sensory and Rheological Properties of Ultra- Filtrated Feta Cheese Prepared With Peppermint Extract (Mentha Piperita L.) by Response Surface Methodology

The effects of peppermint extract (PE) (220-660 mg/g cheese), starter (1.3-2.7 g/100 Kg retentate), rennet (1.3-2.5 g/100 Kg retentate) and ripening time )10-50 days( were investigated on physicochemical, sensory andrheological properties of Ultra-filtrated Feta cheese. In order to attain properties similar to the commercial UF-Feta cheese, their optimized values were predicted by response surface methodology. Analysis of obtained data showed thatPE had positive effect on pH whereas in sensory quality it had negative effect significantly. None of treatments had effect on dry matter. Rennet had significant effect on storage modulus (G). Significant effects of rennet and significant interaction of PE and rennet were detected on loss modulus (G). In tan(δ), significant effect of PE and rennet was seen simultaneously. Finally, optimized values for preparation of samples similar to commercial UF-Feta cheese were as follows: peppermint extract: 660 (mg/g cheese), starter: 1.63-2.25 (g/100 Kg retentate), rennet: 2.14-2.34 (g/100 Kg retentate) and ripening time of 26 days.