Influence of ripening temperature on the volatiles profile and flavour of Cheddar cheese made from raw or pasteurised milk

Cheddar cheeses were made from raw (R1, R8) or pasteurised (P1, P8) milk an d ripened at 1 degrees C (P1, R1) or 8 degrees C (P8, R8). Volatile compoun ds were extracted from 6 month-old cheeses and analysed, identified and qua ntified by gas chromatography-mass-spectrometry. A detailed sensory analysi s of the cheeses was performed after 4 and 6 months of ripening. The R8 che eses had the highest and P1 the lowest concentrations of most of the volati le compounds quantified (fatty acids, ketones, aldehydes, esters, alcohols, lactones and methional). The R8 and P8 cheeses contained higher levels of most of the volatiles than R1 and P1 cheeses. Ripening temperature and typo of milk influenced most of the flavour and aroma attributes. Principal com ponent analysis (PCA) of aroma and flavour attributes showed that pi and R1 had similar aroma and flavour profiles, while R8 had the highest aroma and flavour intensities, highest acid aroma and sour flavour. The age of chees es influenced the perception of creamy/milky and pungent aromas. PCA of the texture attributes separated cheeses on the basis of ripening temperature. The R8 and P8 cheeses received significantly higher scores for perceived m aturity than P1 and R1 cheeses. The P1 and R1 cheeses had similar values fo r perceived maturity. In a related study, it was found that concentrations of amino acids and fatty acids were similar in R1 and P1 during most of the ripening period, and R1 anti Pt cheeses had low numbers of non-starter lac tic acid bacteria (NSLAB). The panel found that ripening temperature, type of milk and age of cheeses did not influence the acceptability of cheese. I t is concluded that NSLAB contribute to the formation of volatile compounds and affect the aroma and flavour profiles and the perceived maturity of Ch eddar cheese. (C) 2000 Elsevier Science. Ltd. All rights reserved.