A central composite second-order response surface design was employed to determine the influences of added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) on the predicted growth rate of Listeria monocytogenes in cured ready-to-eat (RTE) meat products. Increased amounts of both sodium diacetate (P < 0.11) and potassium lactate (P < 0.001) resulted in significant reductions in the growth rate constants of L monocytogenes. Increased finished-product moisture (P < 0.11) significantly increased growth rate constants. The nfluence of sodium chloride was not statistically significant. The second-order statistical factor for lactate was significant (P < 0.01), but all two-way interactions were not. In general, predicted growth rates exceeded actual growth rates obtained from inoculation studies of four cured RTE meat products (wieners, smoked-cooked ham, light bologna, and cotto salami). The final model will be useful to food technologists in determining formulations that will result in finished cured RTE meat products in which L. monocytogenes is not likely to grow.

Nine combinations of sodium chloride (NaCl), potassium chloride (KCI), and magnesium chloride (MgCI,) at high and low ionic strengths (IS) (0.42 and 0.21 respectively) and low IS with 0.13% tripotassium phosphate (K, PO,) were used to determine the effects of a reduction or partial replacement of sodium on bologna characteristics and acceptability. The NaCl-MgCl, had significantly (P < 0.05) less stable and firm emulsion and compression hardness than NaCl or NaCl-KC1 treatments. Low IS treatments had significantly less stable and firm emulsions and lower compression hardness than high IS treatments. Adding PO, to low IS treatments produced products similar to high IS treatments. Only slight textural changes occurred in products after 14 days of cooler (I'C) storage. High IS NaCl and NaCl-KC1 and low IS NaCl-PO, , NaCl-MgCl, -PO, and NaCl-KCl-PO, were found acceptable for flavor, texture, and color by consumer panels.

Two studies involving 20 red deer (Cervus elaphus) stags were conducted to determine the effects of season on venison quality. In each study, five sexually mature red deer stags were slaughtered immediately preceding the rut (autumn) and five were slaughtered after the rut. Stags slaughtered postrut had lower carcass weights (25 to 30%) than those slaughtered prerut. Average bodywall thickness measurements above the 12th rib (an indicator of fat thickness) were approximately 31 mm prerut compared with 3 to 7 mm postrut. Individual muscles and retail cuts (which included subcutaneous and intermuscular fat) were heavier in prerut carcasses. There were significant decreases in intramuscular fat in both the longissimus muscle and the semimembranosus muscle. Postrut longissimus muscle steaks appeared brighter and(or) fresher than the other groups; color acceptability was negatively correlated (P less than .05) with fat content. Prerut streaks from both muscles were more tender than postrut steaks from those muscles. Overall desirability and tenderness were highly correlated (r = .94 and .82 for longissimus muscle and semimembranosus muscle, respectively).

Abstract:The objective of this study was to evaluate the effects of marbling texture on consumer and trained sensory panel ratings of beef strip loin steaks from 3 USDA quality grades. Beef strip loins (n = 117) were selected from 3 quality grades [Top Choice (Modest 00 -Moderate 100 marbling), Low Choice (Small 00 -Small 100 marbling), and Select (Slight 00 -Slight 100 marbling)] to equally represent three different marbling texture groups: fine, medium, and coarse, via visual appraisal. There were no quality grade × texture interactions (P > 0.05) for all of the traits evaluated. Consumers (n = 104) rated all marbling texture groups similar (P > 0.05) for tenderness, juiciness, flavor, and overall liking, as well as rated a similar (P > 0.05) percentage of samples from each marbling texture group acceptable for each palatability trait. Moreover, consumers indicated no preference (P > 0.05) among marbling texture groups for visual desirability or likelihood to purchase. However, trained sensory panelists rated coarse marbled steaks higher (P < 0.05) than fine or medium marbled steaks for both beef flavor intensity and sustained juiciness, as well as higher (P < 0.05) for initial juiciness than medium textured steaks. There were no differences (P > 0.05) among marbling texture groups for Warner-Bratzler shear force, slice shear force, and pressed juice percentage. Low Choice steaks were rated higher (P < 0.05) than Select steaks by consumers for tenderness, flavor liking, and overall liking, but similar (P > 0.05) to Top Choice. Results from this study indicate marbling texture had no impact on consumer evaluations of eating quality and only minimal effects on trained sensory panel palatability ratings and therefore provides no palatability-based evidence for the exclusion of coarse marbled carcasses from current and future branded beef programs.

A central composite response surface design was used to determine the time to growth of Listeria monocytogenes as a function of four continuous variables: added sodium chloride (0.8 to 3.6%), sodium diacetate (0 to 0.2%), potassium lactate syrup (60% [wt/wt]; 0.25 to 9.25%), and finished-product moisture (45.5 to 83.5%) in ready-to-eat cured meat products. The design was repeated for ready-to-eat uncured meat products giving a fifth categorical variable for cure status. Products were stored at 4 degrees C. The results were modeled using a generalized regression approach. All five main effects, six two-factor interactions, and two quadratic terms were statistically significant. The model was used to show the boundary between growth and no-growth conditions at 4 degrees C using contour plots of time to growth. It was validated using independent challenge studies of cured and uncured products. Generally, the model predicted well, particularly for cured products, where it will be useful for establishing conditions that prevent the growth of L. monocytogenes. For uncured products, there was good agreement overall between predicted and observed times to growth, but the model is less thoroughly validated than for cured products. The model should initially only be used for screening of formulations likely to prevent growth of Listeria monocytogenes in uncured products, with recommendations subject to confirmation by challenge studies.