ASSAY AND STORAGE-CONDITIONS AFFECT YIELD OF SALT SOLUBLE-PROTEIN FROM MUSCLE

Pork and beef muscles were used to evaluate assay and storage condition effects on yields of salt soluble protein (SSP). Assay conditions included pH (5.5, 6.0 or 6.5), extraction volume (6, 9, 12 or 15 X sample weight), homogenization time (30, 60, 90 or 120 sec) and centrifugal force (2500, 4000 or 5500 x g). Storage conditions included postmortem aging (4-degrees-C for 0, 7 or 14 days) and freezing conditions (rapid freezing, slow freezing, and freezing-thawing-freezing). Highest yield of SSP was obtained using pH 6.0, extraction volume 15 X sample weight, centrifugation at 4000 x g and homogenization time 90 to 120 sec for both pork- and beef. Freezing conditions did not affect measurement of SSP. Aging beef for 7 and 14 days post-mortem reduced the yield of SSP; however, such differences were not observed for pork.