MF2314

Randy, Phebus & Curtis Kastner, Steam pasteurization to greatly reduce the incidence of pathogens on beef carcasses, Kansas State University, January 1998

MF2313

Donald Kropf & Curtis Kastner, Color and oxidative properties of irradiated beef, Kansas State University, January 1998

NONLINEAR MODELING OF pH DECLINE IN BEEF CARCASSES

Electrical stimulation speeds the rate of pH decline in beef muscle. A study was conducted to evaluate an electrical stimulation (ES) method for beef sides and its effect on pH decline compared to non-stimulated control counterparts using nonlinear modeling. The pH of each carcass in the study was measured at selected times over a 24-hour time period postmortem. A statistical methodology is described for comparing two treatments based on the mean pH decline over time. The repeated measures structure of the data is incorporated into the statistical procedure. A nonlinear exponential decay model is used to characterize the mean pH decline. Various comparisons of the mean response to treatment are made based on the nonlinear model

MF2315

Melvin Hunt et al, Making ground beef patties and sausage safer, Kansas State University, January 1998

Comparison of Synovex-S® and two levels of Revalor-S® in heavy-weight Holstein steers

In two field trials, 434 Holstein steers averaging 849 lbs were assigned randomly to three single implant treatments: 1) Synovex- S®, 2) Revalor®-S 120 (120 mg trenbolone acetate (TBA) + 24 mg estradiol), and 3) Revalor®-S 140 (140 mg TBA + 28 mg estradiol). Revalor-implanted steers gained .05 to .10 lb per day faster, but this improvement was not statistically significant (P>.05). Both Revalor-implanted groups produced trimmer carcasses with less (P<.05) backfat than Synovex steers. All other carcass characteristics and beef sensory properties, including taste panel evaluations of tenderness, juiciness, and flavor, were not influenced by implant used

Control of Escherichia coli O157:H7 in large-diameter, lebanon-style bologna

Lebanon bologna raw batter was mixed with a five-strain mixture of Escherichia coli O157:H7 to achieve average inoculum levels of 7.79, 7.77, and 7.92 log CFU/g as deter mined on MSA, 202, and PRSA media, respectively. Treatment 1 consisted of a fermentation cycle of 8 hrs at an internal temperature (I.T.) of 80EF then 24 hrs at 100EF I.T., followed by 24 hrs at 110EF I.T. Treatments 2, 3, and 4 included additional heating at 115EF I.T. for 1, 2, and 5 hrs, respectively. All heat treatments resulted in product that was negative (\u3c1.9 log CFU/g detection limit) on all culture media and negative after enrichment on mEC selective medium. This study validates that a five-log reduction of E. coli O157:H7 can be achieved using the described protocol, thus meeting USDA/FSIS requirements

Effects of quality grade, aging period, blade tenderization, and degree of doneness on tenderness of inside round steaks

We used 162 inside rounds to determine the influence of different quality grades, postmortem aging periods, blade tenderization passes, and degree of doneness on thawing and cooking losses and Warner-Bratzler Shear force (WBS, tenderness). Select (SEL), Choice (CHO), and Certified Angus Beef™ (CAB) inside rounds were aged for 7, 14, or 21 days and not tenderized (0X) or blade tenderized one (1X) or two (2X) times. Steaks from each inside round were assigned randomly to final endpoint cooking temperatures of 150, 160, and 170°F. Percentage of thawing loss was higher (P<.05) for steaks aged 7 days than steaks aged 14 and 21 days. For CHO steaks only, cooking loss was higher (P<.05) for the 2X group compared to the 0X and 1X groups. Steaks aged 14 and 21 days had lower (P<.05) WBS than steaks aged 7 days. Cooking loss and WBS were higher (P<.05) with each increase in endpoint cooking temperature. Postmortem aging (14 or 21 days) and lower endpoint cooking temperatures were the most effective methods to improve WBS of inside round steaks

Effects of freezing pork chops on warner-bratzler shear force and cookery traits

Eighty-one boneless pork loins were used to determine the influence of freezing and pH on Warner-Bratzler shear force (WBS) values and cookery traits. Chops with lower pH (<5.5 to 5.5) had higher cooking losses than chops with intermediate pH (5.7 to 5.9) and higher pH (6.0 to >6.2). Similar to cooking losses, total moisture losses decreased with increased pH. Frozen chops had lower WBS values (more tender) than fresh chops. However, fresh chops had a higher total yield (lower moisture loss) than frozen chops

Effects of pH and location within a loin on pork quality

Eighty-one boneless pork loins were used to determine the influence of pH on quality characteristics. With increasing loin pH, instrumental values for L* (lightness) and b* (yellowness) of loins and chops decreased, and cooking losses of chops before 0 d and after 1 d of retail display also decreased. The pH had no effects on package losses or Warner-Bratzler shear force values of chops. Center loin chops (0 d and 1 d) had higher ratios of reflectance than blade and sirloin chops. Sirloin chops had higher ratio of reflectance than blade chops. Center loin chops had lower package losses than blade and sirloin chops. Blade chops had lower (more tender) WBS values than center loin and sirloin chops. Measuring loin pH can predict instrumental color (L*and b*) values as well as cooking losses