Sensory properties and volatile composition of full and non-fat cheese produce from curd — Ripened fried acid tvarog

The study was aimed at sensory analysis and volatile content determination in fried cheese. Fried cheese was produced under commercial conditions from acid tvarog ripened and fried with no butter added (non-fat) and with an addition of butter at 4:1 (reference cheese). Cheese was evaluated immediately after production and after 6 weeks of storage at 4 °C. Total and casein nitrogen, water and fat were assayed in cheese. Sensory analyses of cheese descriptors were conducted by profiling on a 0–10 scale, while volatiles were isolated by solid phase microextraction (SPME) technique. The dominant aroma in reference cheese was cowy/phenolic and cooked, while in non-fat cheese it was cooked and free fatty acid. Sulphur aroma was least perceptible in reference and non-fat cheese. After 6-week storage the only significant changes were weakened cooked aroma in non-fat cheese and waxy/crayon aroma in reference cheese. Differences in profile analysis of full and non-fat cheese were reflected in amounts of determined volatiles, especially total sulphur compounds, acids, methyl ketones, terpenes and esters.