Marinades of different pH were prepared from O.lM phosphate buffers ranging in pH from 3.25 to 10.15, O.lM sodium chloride, 0.4M phosphoric acid or 0.7M acetic acid. Beef cores were marinated and composition, texture, and structural properties were evaluated. Low and high muscle pH after marinating had positive effects on texture and resulted in increased water-binding capacity, moisture content and decreased cooking losses. Electron microscopy indicated a loss of the M-line at low pH and a loss of Z-line material at high pH. Overall, both high and low marinade pH altered the textural properties of meat although, more rapid changes occurred at lower pH.

Ten pairs of beef strip loins were obtained 48 h postmortem from ten good grade beef carcasses. Three steaks (2.5 cm thick) were cut from the loin end of each strip loin and the remaining portion retained as the subprimal. Steaks and subprimals were aged for 7 days at 2 "C in the following treatments: polyvinyl chloride ovenvrapped steaks (PVC-ST), vacuum packaged steaks (VP-ST), vacuum packaged subprimals (VP-SP), and subprimals heM in air (Air-SP). Afrer aging of the subprimal, 3 additional steaks were cut for evalwtion. The steaks from all treatments were evaluated for palatability and chemical characteristics. Palatability characteristics did not differ sign$cantly (P > 0.05) between treatments with the exception of the off-flavor intensity of PVC-ST which was higher (P < 0.05) than other treatments. Warner-Bratzler shear values were similar for all treatments. No significant diferences (P > 0.05)were observed between treatments for percent moisture, percent lipid, pH or TBA number. The results of this study indicate that aging method (air or vacuum) or type of cut (steaks or subprimals) had little efect on the palatability attributes or chemical characteristics of the beef strip loins.

A study was designed to evaluate the use of low levels of sodium (0.25, 0.5, 1%) and potassium (0.25, 0.5%) bicarbonate on the sensory, microbial and functional properties of frankfurters. Both sodium and potassium bicarbonate resulted in higher pH values than control (no bicarbonate) on day 0 but differences diminished after storage at 4°C for 22 days. At the 0.5% level of addition, both sodium and potassium bicarbonate treatments had lower percent free water when compared to controls. The addition of high levels of bicarbonate resulted in diminished sensory properties; however, low levels had sensory characteristics in the acceptable range. No differences were detected between treatments for aerobic plate counts, anaerobic plate counts or yeast and mold counts. Results indicate an acceptable product can be produced using low levels of either sodium or potassium bicarbonate. The use of low levels of bicarbonate also results in beneJicial changes of some physical properties.