Abstract

(1) Background: Multiple attempts have been conducted to correlate milk keeping quality with chemical, physical or bacteriological parameters. These methods only measure the chemical changes in milk produced by bacteria. Headspace solid-phase micro-extraction (HS-SPME) is an economic and recent method used to measure both volatile compounds and microbial load in milk, also allowing to keep the quality of the milk product.(2) Methods: The present study was conducted to identify and measure the off-flavoring volatile compounds through gas chromatography coupled with flame ionization detector (GC-FID) and the microbial load of pasteurized fluid milk stored at different temperatures, as a possible indicator of its keeping quality. (3) Results: The highest results were obtained to acetone, followed by butanone, pentanal and ethanol. These mean values were significantly enhanced from the 0 to 19th day of storage, at 10 degrees C. At day 19th, the minimum score for aroma, flavor and overall acceptability were also recorded as 4.33 +/- 0.17, 4.02 +/- 0.06, 4.00 +/- 0.04, respectively. Likewise, maximum values for standard plate count (Log(10) CFU 15.54 +/- 0.40 mL(-1)) and total psychotroph count (Log(10 )CFU 11.67 +/- 0.30mL(-1)) were reported at 10 degrees C and 4 degrees C. (4) Conclusion: HS-SPME/GC-FID methodology revealed to be very sensitive and capable to be applied in volatile compounds quantification in pasteurized milk produced during the storage period at different temperatures.