Endpoint Cooking Temperature Research Articles

133 The effect of sire lines and endpoint cooking temperature on consumer eating experience and visual appeal in pork loin chops

Abstract Prior research and public perception of pork suggest breed influence visual characteristics like color and size and palatability traits like tenderness and flavor of pork chops. Therefore, the objective of this study was to assess consumer perception of visual appeal and palatability of pork loin chops from three sire lines cooked to two different degrees of doneness (DOD). Boneless pork loins from three sire lines (Duroc, Berkshire, and Synthetic) were aged to 14 d post-mortem. Loin quality was then measured, and 2.54-cm chops were frozen from each loin. Chops from each sire line were overwrap-packaged in sets of two and displayed in a retail case with two representative packages per sire line. Panelists rated each package for color, marbling, and size on a just about right (JAR) scale and then indicated their overall liking of each package. Chops from each sire line were cooked to either 63°C or 71°C, cut into 1-cm cubes and two samples from each chop were served to each consumer. Panelists rated 6 samples, each sire line and DOD, for tenderness, flavor, and juiciness on a JAR scale and then rated overall liking. Data were analyzed as a randomized complete block design (RCBD) in SAS 9.4 with panelist age range serving as an influence effect for all panel data. Berkshire chops did not differ (P > 0.08) in redness from other chops, but required 0.13 kg less force to shear, and had a 16.23 cm2 smaller LEA compared with Synthetic and Duroc chops (P < 0.02). Duroc chops had the greatest marbling (P < 0.04) but did not differ in visual color score from other treatments (P > 0.10). There were no differences in consumer visual evaluations (P > 0.45), with traits from all sire lines averaging between 43 and 57 (JAR = 50). Sire line also did not alter visual liking (P = 0.94). There were tendencies for interactions (P > 0.09) between DOD and sire line for consumer sensory evaluation. In general, consumers rated Berkshire chops cooked to 63°C more favorably than other sire line and DOD combinations. Consumers rated chops with different DOD similarly for tenderness and flavor, but tended to score juiciness of chops cooked to 63°C closer to JAR (P = 0.07). Duroc chops were the least tender and least acceptable (P < 0.05). Berkshire chops were juicer than Duroc and Synthetic chops (P < 0.02). Overall, consumers scored all chops between 3.1 and 12.3 units below the JAR line (100-unit scale) regardless of sire line or DOD for tenderness, juiciness, and flavor with overall acceptability within 10 units of neither like nor dislike, which may be indicative of consumers general negative perceptions of pork loin chops.

414 Awardee Talk: Current Status and Future Opportunities for Fresh Pork Quality

Abstract Pork is often viewed as a “middle-of-the-road” option. It is typically less expensive than beef, but more expensive than chicken. While beef cuts, especially steaks, are viewed as luxury items or high-end dining experiences, pork is more of a staple food featured as a variety of fresh and processed products at breakfast, lunch, and dinner. To increase demand for pork and capture more of the high-end market, improving fresh pork loin quality has been a focus of the industry for many years. There is evidence that these efforts have been successful. Compared with pork of the past, fresh pork loins have increased pH and darker color. Additionally, the incidence of tough pork has been reduced and overall pork tenderness improved. However, per capita consumption of pork by the consumers of the United States has not changed. This suggests that consumer acceptance and demand for fresh pork may not depend on intrinsic characteristics such as pH, color, and tenderness. Extrinsic factors like endpoint cooking temperature may have a larger influence on consumer acceptability of fresh pork loin chops. It is possible that, in terms of pork quality, we have been successful in eliminating the problems of the pork industry like pale, soft and exudative pork, but this is not sufficient to reach a consistently excellent eating experience in pork loins.

Research Note: Comparison of 3 methods used for estimating cook loss in broiler breast meat

The objective of this study was to evaluate different methods used for estimating cook loss in broiler breast fillets (pectoralis major). Two experiments were conducted. In the first experiment, intact fillets were weighed, cooked to 75°C, and then subjected to 1 of 3 postcook handling treatments: cooling for 5 min at room temperature before reweighing (5-minute), cooling at room temperature until they reached room temperature before reweighing (RT), or cooling in ice water until they reached room temperature before reweighing (IW). In the second experiment, breast fillet portions were used to compare the effects of endpoint temperature (53°C, 57°C, 68°C, 75°C, or 90°C) on cook loss estimation by the 5-minute and RT methods. Breast fillets were collected from local chicken processing plants and trimmed to similar weight prior to cooking. Cook loss, cook loss retention, and total cook loss after 24 h in cooked fillets were measured for comparisons. Data showed that cook loss (<17%) and total loss (19.3%) estimated with the IW method were lower (P < 0.05) than those with the 5-minute and RT methods (19–21% for cook loss and 21.1–21.3% for total loss), which did not differ from each other. When the endpoint temperature was ≥75°C, no differences in cook loss estimates or moisture loss were noted between the 5 min and RT methods (after 3 h cooling). However, when the temperatures were 53°C to 75°C, cook loss estimations were significantly different (P < 0.05) between the 5 min and RT methods (more than 4%). Reduced endpoint temperature resulted in increasing differences (from less than 5% to more than 9%) in cook loss estimates. These results demonstrate that endpoint cooking temperature and postcooking sample handling methods may affect cook loss estimates in broiler breast meat.

Evaluation of the changes in composition of pork chops during cooking.

The objective was to determine the change in extractable lipid concentration during cooking of boneless pork chops to different endpoint temperatures. Pork loins (152 total) were used and three consecutive chops were cut from each loin. Chop 1 was evaluated raw (not cooked) for intramuscular fat (IMF) percentage. Raw IMF percentages were used to categorize the remaining two chops, from each loin, into low, average, and high marbling bins. The low bin included ≤3% IMF, the average bin included 3–4% IMF, and the high bin included ≥4% IMF. Chop 2 was cooked to 63 °C and chop 3 was cooked to 71 °C to evaluate cook loss, Warner–Bratzler shear force (WBSF), and IMF percentage. When cooked to either 63 or 71 °C, high IMF chops maintained greater (P < 0.001) IMF percentage than average and low IMF chops. Additionally, average IMF chops maintained greater (P < 0.001) IMF percentage than low chops, regardless of endpoint cooking temperature. The three marbling categories did not differ in cook loss (P = 0.28) or WBSF (P = 0.23) when chops were cooked to either 63 or 71 °C. However, both WBSF (2.76 kg) and cook loss (18.72%) were decreased (P < 0.001) in chops cooked to 63 °C compared with chops cooked to 71 °C (3.08 kg, 23.45%). Overall, differences in IMF percentages persisted even after cooking. Furthermore, IMF percentage of pork chops did not affect tenderness.

Sarcoplasmic Proteome Profile and Internal Color of Beef Longissimus Lumborum Steaks Cooked to Different Endpoint Temperatures

The complex relationship between endpoint temperature, sarcoplasmic proteome, and internal color in cooked steaks is yet to be examined. The objective of the present study was to characterize the changes in sarcoplasmic proteome and their influence on the internal color of beef longissimus lumborum (LL) steaks cooked to different endpoint temperatures. Two 2.5-cm-thick LL steaks were fabricated from 9 beef strip loins and were cooked to an internal endpoint temperature of either 60°C (C-60) or 71°C (C-71). Cooked steaks were cooled and sliced parallel to the grilled surface, and internal color was evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using two-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2-fold intensity differences (P &amp;lt; 0.05) were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry. The C-60 steaks demonstrated greater (P &amp;lt; 0.05) redness and color stability than the C-71 ones. Eleven differentially abundant protein spots were identified, and they belonged to 6 functional groups (transport proteins, enzymes in energy metabolism, chaperones, antioxidant proteins, enzymes in amino acid metabolism, and glycolytic enzymes). While 10 spots were overabundant (P &amp;lt; 0.05) in C-60 steaks, 1 spot was overabundant (P &amp;lt; 0.05) in C-71 steaks. The spot overabundant in C-71 samples was identified as myoglobin, suggesting the possible role of post-translational modifications in the heme protein’s thermal stability. The results indicated that the endpoint cooking temperature influenced sarcoplasmic proteome profile and internal color of cooked beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be exploited as potential biomarkers for undercooked beef, which is a source for foodborne infections.

Texture of Fermented Summer Sausage With Differing pH, Endpoint Temperature, and High Pressure Processing Times

The objective was to evaluate the quality and texture of all-beef summer sausages produced with varying degrees of fermentation, endpoint cooking temperatures, and high pressure processing (HPP) hold times. Across 3 replications, sausages were fermented and (Process A) cooked to pH 4.6 and thermally processed to 54.4°C with smokehouse chilling, (Process B) cooked to pH 5.0 and thermally processed to 54.4°C with smokehouse chilling, (Process C) cooked to pH 5.0 and thermally processed to 54.4°C with rapid ice bath chilling, (Process D) cooked to pH 5.0 and thermally processed to 48.9°C with rapid ice bath chilling, and (Process E) cooked to pH 5.0 and thermally processed to 43.3°C with rapid ice bath chilling. After chilling, the sausages were sliced, layered, vacuum packaged, and subjected to HPP at 586 MPa for 0, 1, 150, or 300 s. Post HPP, the sausages were evaluated for objective color (n = 9), lipid oxidation (n = 9), water activity (n = 9), texture profile analysis (TPA; n = 15), sensory analysis (n = 9), and proximate analysis (n = 9). Neither process (combination of pH and endpoint temperature) nor HPP affected lipid oxidation (P = 0.45 and P = 0.69, respectively). Process A resulted in a lighter color (P &amp;lt; 0.01) compared to the other process treatments. Additionally, Process A was less red (P &amp;lt; 0.01) than all other process treatments, and Processes D and E were the reddest (P &amp;lt; 0.01). TPA and trained sensory analysis indicated that, as endpoint temperature increased, so did sample hardness (P &amp;lt; 0.05). Springiness, cohesiveness, and gumminess decreased (P &amp;lt; 0.05) as the endpoint temperature decreased. Although springiness and gumminess increased (P &amp;lt; 0.05) with longer HPP hold times, the panelists were unable to detect differences among samples with longer hold times. The use of HPP at 586 MPa for up to 300 s may be incorporated into manufacturing processes for semidry beef summer sausages with limited impacts on color and texture.

Endpoint Temperature Influences Sarcoplasmic Proteome Profile of Cooked Beef Longissimus Lumborum

ObjectivesCooking ensures safety and enhances the palatability attributes of meat. Denaturation of myoglobin results in the dull-brown color of cooked meats. The denaturation of sarcoplasmic proteins is influenced by the degree of heat treatment, and their solubility is decreased with an increase in the endpoint cooking temperature. While previous studies examined the relationship between myoglobin denaturation, cooked color, and internal temperature in beef, investigations are yet to be undertaken to characterize the association between endpoint temperature, sarcoplasmic proteome, and color attributes in cooked steaks. Therefore, the objective of the present study was to examine the influence of endpoint cooking temperature (60 and 71°C) on sarcoplasmic proteome and internal color of beef longissimus lumborum (LL) steaks.Materials and MethodsEight (n = 8) beef LL muscles (14 d postmortem; USDA Choice) were obtained from a commercial packing plant. Two 2.5-cm thick steaks were fabricated from the center of the muscles and were cooked to internal endpoint temperature of 60°C (C-60) or 71°C (C-71) in a clam-shell grill. Cooked steaks were immediately cooled in slushed ice, sliced parallel to the grilled surface, and internal redness (a* value) and color stability (R630/580) were evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using 2-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2.5-fold intensity differences (P &lt; 0.05) between C-60 and C-71 were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsThe C-60 steaks demonstrated greater (P &lt; 0.05) a* and R630/580 than their C-71 counterparts. Seven differentially abundant proteins were identified and were over-abundant (P &lt; 0.05) in C-60 compared to C-71. The differentially abundant proteins belong to 6 functional groups, i.e., transport proteins (serum albumin and hemoglobin), energy metabolism (adenylate kinase isoenzyme 1), chaperones (heat shock protein β-1), antioxidant (thioredoxin-dependent peroxide reductase), glycolytic enzymes (fructose-bisphosphate aldolase B), and protease (cytosol aminopeptidase).ConclusionThe findings indicated that the endpoint cooking temperature influences the internal cooked color and the sarcoplasmic proteome profile of beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be utilized as potential biomarkers for undercooked beef, which is a source for foodborne infections.

The associations between proteomic biomarkers and beef tenderness depend on the end-point cooking temperature, the country origin of the panelists and breed

Steaks of 74 animals from 3 young bull breeds (Aberdeen Angus, Limousin and Blond d'Aquitaine) were cooked at two end-point cooking temperatures (55 and 74 °C) and evaluated for tenderness by trained panelists from France (FR) and the United Kingdom (UK). Using principal component regressions, the tenderness scores of each breed, country origin of the panelists and cooking temperature were linked with the abundances of 21 protein biomarkers belonging to five biological pathways. Twelve regression equations were built and explained 68 to 95% of tenderness variability. A high dissimilarity in the retained biomarkers was observed among the equations and differences exist among breeds, cooking temperatures and country origin of the panelists. Among the 21 biomarkers, 6 proteins including structural (MyHC-I, MyHC-IIa, MyHC-IIx), oxidative stress (DJ-1, PRDX6) and proteolysis (CAPN1) were retained robustly in positive or negative directions in the tenderization process of Longissimus thoracis, regardless the breed, the end-point cooking temperature or the country origin of the panelist.

Endpoint Temperature Influences Sarcoplasmic Proteome Profile of Cooked Beef Longissimus Lumborum

ObjectivesCooking ensures safety and enhances the palatability attributes of meat. Denaturation of myoglobin results in the dull-brown color of cooked meats. The denaturation of sarcoplasmic proteins is influenced by the degree of heat treatment, and their solubility is decreased with an increase in the endpoint cooking temperature. While previous studies examined the relationship between myoglobin denaturation, cooked color, and internal temperature in beef, investigations are yet to be undertaken to characterize the association between endpoint temperature, sarcoplasmic proteome, and color attributes in cooked steaks. Therefore, the objective of the present study was to examine the influence of endpoint cooking temperature (60 and 71°C) on sarcoplasmic proteome and internal color of beef longissimus lumborum (LL) steaks.Materials and MethodsEight (n = 8) beef LL muscles (14 d postmortem; USDA Choice) were obtained from a commercial packing plant. Two 2.5-cm thick steaks were fabricated from the center of the muscles and were cooked to internal endpoint temperature of 60°C (C-60) or 71°C (C-71) in a clam-shell grill. Cooked steaks were immediately cooled in slushed ice, sliced parallel to the grilled surface, and internal redness (a* value) and color stability (R630/580) were evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using 2-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2.5-fold intensity differences (P < 0.05) between C-60 and C-71 were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsThe C-60 steaks demonstrated greater (P < 0.05) a* and R630/580 than their C-71 counterparts. Seven differentially abundant proteins were identified and were over-abundant (P < 0.05) in C-60 compared to C-71. The differentially abundant proteins belong to 6 functional groups, i.e., transport proteins (serum albumin and hemoglobin), energy metabolism (adenylate kinase isoenzyme 1), chaperones (heat shock protein β-1), antioxidant (thioredoxin-dependent peroxide reductase), glycolytic enzymes (fructose-bisphosphate aldolase B), and protease (cytosol aminopeptidase).ConclusionThe findings indicated that the endpoint cooking temperature influences the internal cooked color and the sarcoplasmic proteome profile of beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be utilized as potential biomarkers for undercooked beef, which is a source for foodborne infections.

Escherichia albertii Inactivation following l-Lactic Acid Exposure or Cooking in Ground Beef

Escherichia albertii is an emerging foodborne pathogen recovered from young children and adults exhibiting symptoms of gastroenteritis via pathogenesis factors including attaching and effacing lesions, cytolethal distending toxin, and Shiga toxin variants. Study objectives were to determine E. albertii survival following (i) exposure to lactic acid as a function of solution pH and incubation period and (ii) cooking ground beef patties to different endpoint temperatures. E. albertii was incubated in phosphate buffer containing 3.0% l-lactic acid adjusted to pH 3.0, 4.0, 5.0, or 7.0; survivors were determined every 30 min for 150 min. Ground beef patties (80% lean) were cooked to temperature endpoints simulating undercooking (62°C), the minimum temperature for safe cooking (71.1°C), and cooking to well done (76°C). Maximal pathogen reduction was observed after a 30-min exposure to pH 3.0 l-lactic acid. Reductions of 3.9, 4.4, and 4.9 log CFU/g were obtained following cooking ground beef patties to 62, 71.1, and 76°C, respectively, but the reductions did not differ as a function of the endpoint cooking temperature (P ≥ 0.05). E. albertii may be controlled on beef through the proper application of antimicrobial interventions and cooking.

Effect of Gradual Heating and Fat/Oil Type on Fat Stability, Texture, Color, and Microstructure of Meat Batters.

The effects of endpoint cooking temperature (40, 50, 60, 70, 80, and 90°C) on emulsion stability, texture, color, and microstructure of meat batters prepared with different fats/oils were studied. Canola oil treatments showed the highest cooking loss whereas hydrogenated palm oil provided the most stable meat batters. Rendered beef fat was less stable than regular beef fat. Increasing endpoint cooking temperatures resulted in a progressive reduction of water holding capacity in all treatments. As temperature was raised, meat batters showed higher hardness and cohesiveness values, but no appreciable changes in cohesiveness above 60°C. Canola and hydrogenated palm oil treatments showed the highest hardness and chewiness values. Lightness (L(*) ) values of all meat batters increased significantly with increasing temperature from 40 to 60 or 70°C; no major changes observed above 70°C. Light microscopy revealed no substantial changes in the microstructure of all the stable meat batters cooked to between 50 and 70°C. Heating to 90°C changed the microstructure in all meat batters except the hydrogenated palm oil treatments, which still showed nonround fat particles and a less aggregated protein matrix.

Eating Quality Traits of Hanwoo longissimus dorsi Muscle as a Function of End-Point Cooking Temperature.

Interaction between carcass quality grade and end-point cooking temperature on eating quality of Hanwoo m. longissimus was investigated. Ten (10) of steers were sampled from a commercial population; carcasses with QG 1++ (n=5) and QG 1 (n=5) were chosen. Samples were cooked by electric oven at 60 or 82℃ and compared with uncooked control samples. The pH was not affected by cooking temperature but decreased the redness after cooking and steaks cooked at 60℃ were more reddish than steaks cooked at 82℃ in both QG groups. Higher cooking temperature greatly (p<0.05) increased the cooking loss, but there was no significant interaction between cooking temperature and QG on the cooking loss. Moisture is negatively correlated with temperature in both QG while the proportionate relationship between crude fat and end-point temperature found in QG 1++. WBSF values were significantly (p<0.05) high for QG 1, while that was significantly (p<0.05) increased when the temperature continues to increase. The increasing quality grade of beef resulted in significant higher (p<0.01) level of TBARS and cooking temperature increased TBARS content. Fatty acid composition was not altered by cooking at both temperatures and also the amount of fat intake was not changed. The current study indicates that eating quality of beef m. longissimus was greatly influenced by end-point temperature being interacted with QG. However, the amount and composition of fat were stable regardless of end-point temperatures. These results will provide a consumer reference to determine cooking conditions and intramuscular fat content.

HACCP을 적용하여 생산한 김밥의 유통기한 설정

Abstract This study was conducted to estimate the shelf-life of Kimbab manufactured using a Hazard Analysis and Critical Control Point (HACCP). We performed a microbiological verification after applying the HACCP plan to Kimbab. Additionally, the shelf-life of Kimbab at each holding temperature was calculated as a regression equation between the aerobic plate counts and holding time during the storage period. The critical control points of the HACCP plan, that were applied to Kimbab, included: cold-holding of refrigerated foods, checking the endpoint cooking temperature of heated food, and cold-holding of cooked foods. As a result of the microbiological verification of Kimbab, the aerobic plate counts averaged 3.46 log CFU/g. In contrast, the coliforms, E. coli, Staphylococcus aureus, and Salmonella spp. were not detected in any of the samples. The estimated shelf-life of Kimbab was calculated to be 45 hours at 10℃, 29 hours at 15℃, 6 hours at 25℃ and 3 hours at 35℃. In conclusion, manufacturers should apply a prerequisite program and a HACCP system for a safe consumption of ready-to-eat foods and label products with a proper shelf-life. Distributors should control the proper holding time-temperature until sale and consumers should eat immediately after purchasing ready-to-eat foods. Key words : shelf-life, Kimbab, HACCP, prerequisite program, verification1)

Effect of carbon monoxide in modified atmosphere packaging, storage time and endpoint cooking temperature on the internal color of enhanced pork

The objective of this research was to evaluate the effects of gas atmosphere, refrigerated storage time, and endpoint temperature on internal cooked color of injection-enhanced pork chops. Enhanced chops were packaged in 0.36% CO/20.34% CO 2 (CO-MAP), 80% O 2/20% CO 2 (HO-MAP), or PVC-overwrapped (PVC-OW; controls), stored at 4 °C for 0, 12, 19 or 26 days, displayed for 2 days then cooked to six endpoint temperatures (54, 60, 63, 71, 77, and 82 °C). L ∗, a ∗, and b ∗ values, hue angle and chroma were determined on the internal cut surface of cooked chops. Chops packaged in CO-MAP had the highest a ∗ values; a ∗ value began increasing on day 14. The lowest hue angles occurred in chops cooked to lower endpoint temperatures. Chops in CO-MAP had lower hue angles and higher chroma than those in HO-MAP and PVC-OW. Above 71 °C, hue angle and chroma increased. Overall, CO-MAP packaged chops stored for longer time periods then cooked to lower endpoint temperatures appeared reddest. HO-MAP packaged chops were less red, did not change over time, and appeared more well done at lower endpoint temperatures than those in other gas atmospheres. CO-MAP packaged chops retained redness even after cooking at 82 °C.

식염첨가 유무에 따른 계육의 부위별 가열온도에 따른 이화학적 성상과 근장 단백질 밴드의 변화

ABSTRACT This study was performed to measure the pH, proximate composition, physicochemical properties, changes of protein bands, Hunter color values and endpoint cooking temperature of chicken leg and breast muscles during cooking from 64 to 74with 2increments. Chicken leg had higher pH, moisture and fat contents (%) and lower protein solubility (P<0.05) than chicken breast. Although the cooking losses(CLs, %) of chicken muscles increased with increased cooking temperature, the addition of 2% salt did not affect CL. The redness values of chicken leg without 2% salt were higher than chicken breast, however, the addition of 2% salt reduced the differences of the redness. Protein solubility decreased with increased cooking temperatures and were not affected by the addition of salt, and no further changes were observed higher than 68. Protein bands having the molecular weights of 66 and 54 kDa were disappeared in the chicken leg at the cooking temperatures of 6670 , whereas 66, 54 and 34 kDa in the chicken breast. These protein bands could be used potential indicators to determine the endpoint cooking temperature in chicken muscles.(

EFFECT OF HYDRODYNAMIC PRESSURE TREATMENT AND COOKING ON INACTIVATION OF ESCHERICHIA COLI O157:H7 IN BLADE‐TENDERIZED BEEF STEAKS†

ABSTRACT The efficacy of hydrodynamic pressure (HDP) treatment for inactivation of Escherichia coli O157:H7 in blade‐tenderized beef steaks was studied. Beef steaks (N = 48) were inoculated with a five‐strain cocktail of Escherichia coli O157:H7 and treated with blade tenderization (BT), HDP or a combination of BT followed by HDP (BTH). Control and treated steaks were cooked to 54.4C (undercooked), 62.8C (medium rare) and 71.1C (medium) on open‐hearth Farberware grills. HDP treatment reduced E. coli O157:H7 populations by 0.3 log10 cfu/g, which was not different (P &gt; 0.05) from untreated controls. At each endpoint cooking temperature, E. coli O157:H7 survival was always higher in BT‐treated steaks than in untreated steaks cooked to corresponding temperatures. This could be due to migration of surface bacteria to the interior of the muscle thereby protecting bacteria from the lethality of heat. E. coli O157:H7 populations in BTH‐treated steaks cooked to 71.1C were nondetectable and were significantly different from BT‐treated steaks cooked to 71.1C. Results suggest that BT of intact beef muscle does transfer surface bacteria to the interior of the muscle, which would necessitate a combination of elevated cooking temperatures (&gt;71.1C) and a treatment like HDP for inactivation of bacteria.

Influence of quality classification, aging period, blade tenderization, and endpoint cooking temperature on cooking characteristics and tenderness of beef gluteus medius steaks.

Top sirloin butts (n = 162) were used to investigate the influence of quality classification, aging period, blade tenderization passes, and endpoint cooking temperature on the tenderness of gluteus medius steaks. Top sirloin butts (gluteus medius) from Select (SEL), Choice (CHO), and Certified Angus Beef (CAB) carcasses were obtained, aged for 7, 14, or 21 d, and either not tenderized or blade tenderized one or two times. Three steaks from each top sirloin butt were randomly selected and assigned to a final endpoint cooking temperature of 65.5, 71.0, or 76.6 degrees C. Cooking characteristics and Warner-Bratzler shear force (WBSF) were analyzed as a split-plot with a 3 x 3 x 3 factorial treatment structure of quality classification, aging period, and tenderization passes in the whole plot and endpoint cooking temperature in the subplot. Sensory panel data for CHO steaks cooked to 70 degrees C were analyzed with a 3 x 3 factorial treatment structure of aging period and tenderization passes. Thawing loss was greater (P < 0.05) for steaks aged 7 d than those aged 21 d. Cooking loss was greater (P < 0.05) for steaks aged for 14 and 21 d than those aged 7 d, and increased (P < 0.05) with each increasing endpoint temperature. Each increase in aging period resulted in lower (P < 0.05) WBSF values. In addition, steaks blade tenderized two times had lower (P < 0.05) WBSF values than steaks blade tenderized once or not at all. Within each quality classification, WBSF values increased (P < 0.05) as endpoint cooking temperature increased. When cooked to 71 or 76.6 degrees C, CHO and CAB steaks had lower (P < 0.05) WBSF than SEL steaks. Steaks blade tenderized one or two times received higher (P < 0.05) sensory panel ratings for myofibrillar and overall tenderness than steaks not blade tenderized. Connective tissue amount and overall tenderness ratings were higher (P < 0.05) for steaks aged 21 vs. 7 d. Postmortem aging and blade tenderization of gluteus medius steaks can improve tenderness, as measured by WBSF and sensory panel, without decreasing flavor or juiciness. When cooking to higher endpoint temperatures, higher quality classifications should be selected to minimize toughness due to cooking.

식염 및 지방을 함유한 분쇄돈육의 이화학적 성상 및 최종가열온도 측정을 위한 근장단백질의 이용

본 연구는 식염과 지방 그리고 여러 가열조건에 의한 pH 및 일반성분, 가열감량 및 단백질 용해성의 변화에 따른 단백질 분획의 변화에 대해 분석하였다 처리구에 따른 가열감량 (CL, %)은 지방의 첨가에 상관없이 식염을 2%첨가한 경우 식염을 첨가하지 않은 경우에 비하여 약 1/2배 정도 낮은 가열감량을 보였다. 한편, 식염 무첨가구의 경우 지방을 첨가한 경우 가열감량은 유의적으로 낮았으나, 식염 2%첨가구는 지방 첨가에 따른 가열감량의 유의적 차이가 나타나지 않았다. 그리고 가열온도에 따른 가열감량은 <TEX>$66^{\circ}C$</TEX>까지는 점진적으로 증가하다가 <TEX>$68^{\circ}C$</TEX> 보다 높은 가열온도에서 유의적으로 증가하는 경향을 보였다. 식염 무첨가구와 식염 2% 첨가구 사이에서는 단백질 용해성의 유의적인 차이가 없었으나 지방이 첨가된 경우 상대적인 단백질 함량의 감소로 단백질 용해성이 유의적으로 감소하였다. 가열 온도가 높아짐에 따라 용해성의 감소가 현저히 나타났으나 <TEX>$68^{\circ}C$</TEX> 이상의 가열온도에서는 단백질 용해성이 유의적 차이 없이 일정한 수준을 유지하였다. 추출한 근장 단백질이 각 처리구별 가열온도에 따른 단백질 분획을 분석하기 위해 전기영동을 실시한 결과 식염, 지방 그리고 가열에 따라 특이적으로 반응한 것은 36 과 66 kDa의 분자량을 가진 근장 단백질 분획이었다. 이러한 단백질 분획은 최종가열온도가 66 <TEX>${\sim} 70^{\circ}C$</TEX>에서 급격히 thtlfehladmfhTJ 돈육의 최종 가열온도 측정을 위한 지시제로 사용될 수 있을 것으로 판단된다. Processed meals, such as a ground meat and hamburger patty, are required to ensure that no pathogens remain in the final products. However, there was no rapid method available to verify that the recommended end-point cooking temperature(EPT) was reached. Thus, the objective of this study was to rapidly determine EPT of ground pork hams using sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SOS-PAGE), based on the disappearance of sarcoplasmic proteins after cooking. Fresh pork hams were added two levels of salt(0, 2%) and fat(15, 25%) combinations, and stored in refrigerator overnight, and cooked to internal cooking temperatures of <TEX>$64^{\circ}C$</TEX> to <TEX>$74^{\circ}C$</TEX> with <TEX>$2^{\circ}C$</TEX> increments. Cooked pork hams were measured cooking loss(CL, %), protein solubility(PS) and SOS-PAGE. CL(%) was reduced with the addition of 2% salt, as compared to the control, regardless of fat contents. It was also increased with increasing eooking temperature. Protein solubility was affected by the cooking temperature, resulting in reduced PS up to <TEX>$64^{\circ}C$</TEX>(P < 0.05), but remained constant higher than <TEX>$68^{\circ}C$</TEX>. In SOS-PAGE analysis, protein bands with the molecular weights of 36 and 66 kDa were affected by the addition of salt and fat combinations. regardless of treatments. These protein fractions were decreased gradually with increased cooking temperatures up to <TEX>$68^{\circ}C$</TEX> <TEX>${\sim}$</TEX> <TEX>$70^{\circ}C$</TEX> and might be good indicators for the determination of EPT in ground pork hams.

Endpoint temperature, cooking method, and marbling degree have different effects on Warner-Bratzler shear force of beef strip loin, bottom round, and brisket muscles (2004)

Our objective was to determine the effects of endpoint temperature, cooking method, and marbling on Warner-Bratzler shear force (WBSF; an objective method for determining tenderness) of three beef muscles. Eighteen subprimals of a muscle containing low content of connective tissue, longissimus lumborum (strip loin), and two muscles containing a high content of connective tissue, biceps femoris (bottom round) and deep pectoralis (brisket), were selected from USDA Select and Choice (Certified Angus Beef) carcasses. After 14 days of aging, subprimals were frozen, fabricated into steaks, and stored frozen until cooking. Steaks were assigned to one of two cooking methods, the Magikitch'n® electric belt grill (a rapid conduction method) or a water bath (a slower, convection method); and one of nine endpoint cooking temperatures, 104, 113, 122, 131, 140, 149, 158, 167, or 176°F. According to WBSF results, optimum tenderness for the strip loin occurred around 131°F. Higher marbling protected tenderness at higher endpoint temperatures. Tenderness increased in bottom round and brisket muscles as endpoint temperature increased from 104 to 140°F, then tenderness decreased as endpoint temperature rose from 149 to 176°F. Endpoint temperature was the only significant factor affecting bottom round tenderness. Steaks cooked in the water bath had higher WBSF and, therefore, were less tender than those cooked on the belt grill. This was true for both the strip loin and brisket. The effect of increasing endpoint temperature on WBSF of the strip loin was different than for the bottom round and brisket.

Palatability of bison semimembranosus and effects of marination

The present study was conducted to investigate the palatability of bison semimembranosus muscle (SM) and the effects of injection with sodium chloride and sodium tripolyphosphate on cooking yield, colour, shear force and consumer acceptability. Twenty paired SM were obtained from 10 intact male bison (aged 24–30 months); each of these muscles was divided longitudinally into two sections. One section was injected to 110% of its original weight to contain 0.5% sodium chloride and 0.3% sodium tripolyphosphate, while the other was kept as a non-injected control. HunterLab a* (redness) and b* (yellowness) values did not differ ( P>0.05) between injection treatments; however, injected steaks had lower L* values (darker) compared to controls. Control samples from bison SM were very lean and high in protein but not very tender. Marination by injection was able to significantly reduce shear force values of SM; that is, injected steaks/roasts had significantly ( P<0.001) lower shear force values (63.9 N) compared to control samples (102.3 N). Cooking yields for the steaks/roasts from the injected sections were significantly ( P<0.001) higher compared to those from control non-injected sections when cooked to either 71 or 77 °C. Bison samples cooked by moist-heat had significantly ( P<0.001) lower cooking losses and shear force values compared to those cooked by dry-heat. As expected, steaks/roasts were more tender and had higher cooking yields when cooked to a medium level of doneness (71 °C) compared to an internal temperature of 77 °C (well done). A panel of 80 consumers preferred injected steaks cooked to 77 °C endpoint over other combinations, followed by non-injected steaks cooked to 71 °C, whereas injected steaks cooked to 71 °C and non-injected steaks cooked to 77 °C were equally but least preferred. Hence, injection seems to be protecting against moisture loss at high end-point cooking temperatures.