Occurrence of 1‐(methylthio)propane producing off‐flavour in fresh beef meat

The identification of compounds producing a characteristic off‐flavour in fresh beef meat obtained from different locations is essential to avoid consumer rejection. The volatile compounds of fresh beef samples were extracted by solid phase micro extraction (SPME) and their odour was evaluated by using olfactometry analysis (GC‐O). The compound responsible for the characteristic off‐flavour was identified by using GC–MS and quantified in different beef samples obtained from different locations. The sniffing analysis revealed eight odour active zones being four of them identified as 2,3‐butanedione, allyl methyl sulfide, 1‐(methylthio)propane and 1‐(methylthio)‐1‐propene (Z). The most potent odorant was 1‐(methylthio)propane described as garlic, cabbage, oxidized iron, solvent and rancid odour. All panellists attributed the characteristic off‐flavour detected in fresh beef to the odour of 1‐(methylthio)propane. A chromatographic method was validated to quantify 1‐(methylthio)propane in fresh beef. Several beef samples were characterized by this off‐flavour although its origin was not elucidated. The identification of a beef off‐flavour characterized by a garlic‐cabbage aroma, was attributed to the presence of 1‐(methylthio)propane by olfactometry analysis. A method was optimized and validated to quantify 1‐(methylthio)propane by SPME‐GC‐MS analysis in fresh beef from different geographical origin.