Özet:
Spoilage problem in Turkish white cheese characterized by off-odor occurs occasionally and leads to serious economic losses. It is called as putrid by manufacturer and occurs in the later stages of ripening. This study was carried out to identify key odorant compounds associated with main off-odor (putrid) in Turkish white cheese and to estimate the possible causal factors. A total of 14 putrid and 5 normal cheese (control) samples were obtained from local cheese manufacturers from Kirklareli province, Turkey. A total of 65 volatile compounds were identified by employing solid-phase micro-extraction-gas chromatography-mass spectrometry method. They were composed of carboxylic acids (19), alcohols (13), esters (12), ketones (4), aldehydes (5), and miscellaneous (12). Thirty-five of them were not found in control cheese samples. Carboxylic acids, such as isovaleric acid (42.72 ppm), hexanoic acid (71.17 ppm), octanoic acid (48.81 ppm), and decanoic acid (38.37 ppm), and sulfur compounds, such as methanethiol (0.33 ppm), mercaptoethanol (0.45 ppm), dimethyl disulfide (0.75 ppm), and dimethyl trisulfide (0.38 ppm), were remarkable volatiles in samples of putrid cheese. The results indicated that the off-odor problem in Turkish white cheese probably originated from sulfur compounds that are only found in putrid cheese samples and are characterized by odor of a rotten, boiled cabbage-cauliflower and over-ripened cheese, and carboxylic acids that arise by metabolism of undesirable microorganisms.
