2.2. Sample extraction
Lactate and acetate contents in the RTE meat samples were analyzed according to the procedures of Nassos, Schade, King, and Stafford (1984) and Friedrich (2002). The analytical procedure
consisted of sample extraction, clean-up, and separation of acids using high performance liquid chromatography (HPLC). Samples (50 g) were added with 450 ml of de-ionized water and homogenized in a blender at high speed for 2 min. The homogenized samples were filtered with Whatman No. 113 filter paper under vacuum. An aliquot (filtrate) of 50 ml of each sample was mixed
with 100ml of 0.5 N perchloric acid in a 200ml flask and allowed to stand for 5 min at room temperature to precipitate protein. The sample was filtered again with Whatman No. 4 filter paper under vacuum to remove the protein. The extracts (about 20 ml) were stored in vials at 4 C until HPLC analysis. A final filtration through 0.45 mm Millipore membrane filter was performed prior to injection into the HPLC system.