Destruction of Trichinella spiralis During Cooking

Center cut chops (longissimus dorsi), 2.5 cm in thickness, from 31 pigs experimentally infected with Trichinella spiralis larvae and containing 37 ± 5 larvae per gram were cooked to a final internal temperature of 66, 71, 77 or 82° C by one of eight methods to determine their efficacy in killing encysted larvae. The results indicate that with the time and temperatures used in this study, some rapid methods of cooking pork chops that involved the use of a microwave oven did not completely destroy T. spiralis larvae at 77 or 82° C. The data also showed that cooking pork chops to an internal temperature of 77° C in the conventional oven, convection oven, flat grill, charbroiler or deep fat gryer did inactivate encysted T. spiralis larvae in pork chops.     

Evaluation of Microwave Cooking Procedures and Ovens for Devitalizing Trichinae in Pork Roasts

Pork roasts from pigs experimentally infected with Trichinella spiralis were cooked in five microwave ovens. Twenty-nine procedures, generally recommended by the oven manufacturers or pork interest groups, were used. Infective trichinae were present after cooking in 50 of 189 roasts. Factors affecting infectivity included procedure used, use or nonuse of post-cooking standing or temperature holding, weight of roast, and internal temperatures attained. Five visually well done roasts contained infective trichinae including one in which all five temperatures taken exceeded 76.7°C. One other infective roast, with a small red spot, also had all temperatures at or above the 76.7°C level. Recommendations are made to minimize the potential that trichinae may survive in microwaved-cooked pork.     

Effects of Internal Temperature and Thickness on Palatability of Pork Loin Chops

Three thicknesses (2.54, 1.90 and 1.27 cm) of pork chops were cutl alternately from 20 paired loins of similar quality. Chops were cooked on Farberware grills or in a convection oven to internal temperatures of 60, 70 and 80°C for sensory and objective evaluations. Juiciness, percent moisture and tenderness decreased and cooking losses increased (P < 0.05) as temperature increased for both cooking methods. Pork flavor intensity increased in oven- prepared chops, while no change was observed in grilled chops at each level of increased temperature. Thickness had no effect (P > 0.05) on tenderness, juiciness or total cooking loss of oven-prepared or grilled chops. The thickest chops received the highest (P < 0.05) pork flavor scores.     

Sensory and Cooking Properties of Lamb Chops Cooked With and Without External Fat and Epimysium

When lamb loin chops with or without 0.64-cm subcutaneous fat layer and epimysium (fat-on or fat-off chops) were broiled to an internal temperature of 77°C, cooking losses were higher (P<0.05) for fat-off chops than for fat-on chops. The concentration of ether-extractable fat (g/100g cooked lean) was also higher for the cooked lean from fat-off chops while the opposite was observed for moisture. Sensory properties of the cooked lean were adversely affected by the removal of subcutaneous fat before cooking. TBA-reactive substances in a given amount of the cooked lean, after 4 days of storage at 4°C, were slightly higher (P<0.10) for the lean from fat-off chops than for the lean from fat-on chops.     

RETENTION OF VITAMIN B-6, THIAMIN,VITAMIN E,AND SELENIUM IN GRILLED BONELESS PORK CHOPS PREPARED AT FIVE GRILL TEMPERATURES1

Fresh pork Canadian backs, cut into boneless pork chops, were cooked to 71C internal temperature by grilling at 93, 121, 148, 176, or 204C. Cooking times were significantly longer for chops grilled at 93C than for those grilled at the higher temperatures. Yield, moisture, and crude fat values of the chops in the different treatments were similar. Chops grilled at 204C had significantly lower retention values for thiamin and vitamin E and had lower mean retention values for vitamin B-6. Retention values for selenium were similar for all treatment groups. Shorter cooking times along with higher vitamin retentions were obtained in boneless pork chops grilled at 121, 148, and 176C.     

Cholesterol Content and Sensory Analysis of Ground Pork as Influenced by Fat Level and Heating

Eight treatment combinations for the formulation and heating of fresh ground pork were investigated: four raw fat levels (4, 9, 18, 23%) and two internal end point temperatures (71°C and 77°C). In the raw state, ground pork containing 4 or 9% fat contained less cholesterol, more moisture and was judged to be more red than samples containing 18 or 23% fat. Tenderness, juiciness and amount of mouthcoating increased as fat level in the cooked patties increased. Internal end point temperature (71°C or 77°C) did not affect sensory scores of cooked pork patties. Cooked patty cholesterol content (wet weight) did not differ among the four fat levels. High-fat ground pork retained less cholesterol than low-fat ground pork.     

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% CO₂ (CO-MAP), 80% O₂/20% CO₂ (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). L¹, a¹, and b¹ values, hue angle and chroma were determined on the internal cut surface of cooked chops. Chops packaged in CO-MAP had the highest a¹ values; a¹ 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.     

COOKING AND SHEARING METHODOLOGY EFFECTS ON WARNER-BRATZLER SHEAR FORCE VALUES OF PORK

Pork loin chops from 50 carcasses were used to evaluate the effect of cookery method and shearing methodology on Warner-Bratzler shear (WBS) force values. Chops were cooked to an internal temperature of 70C on either an electric openhearth grill or in a commercial convection oven. After a 2 h cooling period, five 1.27-cm diameter cores from each chop were sheared once through the center of the core with either: (1) a Warner-Bratzler machine; (2) an Instron Universal Testing Machine with a WBS device in compression; or (3) an Instron Universal Testing Machine with a WBS device in tension. Chops cooked in the convection oven had lower (P < 0.03) WBS force values than chops cooked on an open-hearth grill (2.78 vs 2.98 kg, respectively). Shear force values obtained with the Warner-Bratzler machine were lower (1.93 kg; P < 0.01) than those from the Instron with either the WBS device in compression (3.53 kg) or in tension (3.18 kg).     

Electrical Stimulation, Hot-Boning and Prerigor Cookery Effects on Lamb Longissimus Tenderness

Paired halves of 32 lamb carcasses were either electrically stimulated (ES) or not (NES), then assigned to one of the following treatments: (1) hot-boned, cooked prerigor, frozen and reheated (HEPRC); (2) conventionally chilled and boned, cooked, frozen and reheated (CB-ARC); (3) hot-boned, frozen and cooked (HB); and (4) cold- boned, frozen and cooked (CB). Electrical stimulation lowered (P < 0.05) peak force (PF) of chops from CB-ARC, HB and CB treatments. Nonstimulated HB-PRC chops had a lower (P < 0.05) PF than ES, HB-PRC chops. Lower (P < 0.05) compression values were noted for HEPRC and CB-ARC chops than for HB and CB chops. Electrical stimulation reduced (P < 0.05) PF regardless of cooking method. Chops cooked in the microwave had lower (P < 0.05) work values than chops cooked in the convection oven.     

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% CO₂ (CO-MAP), 80% O₂/20% CO₂ (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.     

SENSORY ATTRIBUTES AND THIAMINE CONTENT OF ROASTING CHICKENS COOKED IN A MICROWAVE, CONVECTION MICROWAVE AND CONVENTIONAL ELECTRIC OVEN

Fresh whole roasting chickens were cooked to an internal temperature of 79°C (175°F) in either a microwave, convection microwave or conventional electric oven. The sensory attributes of breast meat samples from chickens cooked in the three ovens were evaluated by untrained and laboratory panels. Untrained panelists found convection microwave cooked samples to be more acceptable in terms of juiciness than microwave cooked samples. Laboratory panelists rated the chicken cooked in the conventional oven as significantly more tender and juicy but similar in flavor intensity to chicken cooked in the microwave ovens. Thiamine retention on a dry weight basis ranged from 77% in conventionally cooked chicken breasts to 98% in microwave cooked chicken legs.     

Effect of Cooking Rates in Electric or Microwave Oven on Cooking Losses and Retention of Thiamin in Broilers

A study was conducted to determine the effect of two microwave oven and two electric oven cooking rates on retention of thiamin and cooking losses with broiler chickens. Thiamin was determined by a microbiological turbidimetric assay of raw and cooked meats. Broilers cooked in the microwave oven retained more thiamin than broilers cooked in the electric oven. There was no difference in thiamin retention between broilers cooked in the microwave oven at 800 and 1600 watts. Broilers cooked in the electric oven at 204°C retained more thiamin than broilers cooked at 121°C. Broilers cooked in a 1600 watt microwave oven had the greatest weight loss. No difference in weight loss occurred between broilers cooked in an 800 watt, 121°C or 204°C oven.     

Effects of cooked temperature on pork tenderness and relationships among muscle physiology and pork quality traits in loins from Landrace and Berkshire swine

The effect of, and associations between, loin muscle morphology and pork quality indicator traits were assessed at three cooked temperatures in loin chops from 38 purebred Berkshire and 52 purebred Landrace swine. Three loin chops from each pig were randomly assigned to cooked temperature treatments of 62, 71, or 79 °C and loin tenderness was assessed as Warner–Bratzler shear force (WBSF). Cooked temperature (P < 0.001), breed (P < 0.001) and breed × cooked temperature (P < 0.001) effects influenced loin chop WBSF, whereby WBSF increased as cooked temperature increased. Chops from Landrace pigs had greater WBSF at each cooked temperature compared with chops from Berkshire pigs. Chops from Landrace pigs became less tender with increasing cooked temperature, whereas chops from Berkshire pigs became less tender only when cooked to 79 °C. In loins from Landrace pigs, Minolta a1 at 62 °C (R² = 0.07), and average muscle fiber diameter at 71 °C and 79 °C (R² = 0.07 and 0.24, respectively), contributed to WBSF variation. In contrast, for loins from Berkshire pigs, loin ultimate pH and intramuscular fat percentage accounted for 27% and 30% of the variation in WBSF at 62 °C and 71 °C, respectively, and loin ultimate pH accounted for 7% of variation in WBSF at 79 °C. Results suggest that loins from Berkshire pigs have properties that resist toughening at greater cooked temperatures and that associations between quality measures and loin tenderness differ between Landrace and Berkshire pigs.     

Effect of Trim Level, Cooking Method, and Chop Type on Lipid Retention, Caloric Content, and Cholesterol Level in Cooked Pork

The effect of external fat trim on fat, caloric, and cholesterol content of pork lean was investigated. Paired top-loin chops (TL), rib chops (RC) and blade steaks (BS) were obtained and trimmed free of all subcutaneous fat before (NF) or after (SF) cooking. Cuts were cooked to 71°C by roasting, pan-frying, braising or microwaving. Lean from TL chops having SF contained more fat and calories and similar amounts of cholesterol compared with NF chops, regardless of cooking method. Few differences were observed in fat and caloric content of RC and BS cooked with SF versus NF, perhaps due to seam fat. Eliminating external fat prior to cooking reduced fat and caloric content of pork lean.     

Cholesterol and Selected Attributes of Pork Tenderloin Steaks Heated by Conventional, Convection, and Microwave Ovens to Two Internal Endpoint Temperatures

Six treatment combinations for determination of cholesterol and selected quality attributes of pork tenderloin steaks were studied with three oven types (conventional, convection and microwave) and two internal endpoint temperatures (71°C and 77°C). In general, pork tenderloin steaks heated in the microwave oven had lower evaporative loss and higher drip loss. Cholesterol (wet weight basis) of the pork steaks was not affected by oven type; however, heating to the higher internal endpoint temperature (77°C) increased (concentrated) the cholesterol. On a dry weight basis, microwave-heated steaks contained more cholesterol when compared to conventional and convection-heated samples.     

External Fat Cover Influence on Raw and Cooked Beef. 1. Fat and Moisture Content

SUMMARY: The fat content of beef semitendinosus muscle, raw and cooked at two oven temperatures, with and without the external fat cover, has been determined. Each muscle was divided into two, an anterior and a posterior roast. The external fat cover was removed from half of the total number of roasts, and all roasts were then cooked to an internal temperature of 58°C at an oven temperature of either 163° or 218°C. Two types of samples were analyzed for their moisture and fat content. These were a separable lean sample and a total sample. The total sample was composed of both the separable lean and the external fat cover. The moisture content of the lean samples was not affected by the oven temperature, the external fat cover or the end of the muscle used. The total samples had moisture contents that reflected the amount of crude fat present. The yield of crude fat from raw or cooked meat was not significantly altered by the use of a polar solvent in place of a nonpolar one. Both of the fat determination methods extracted significantly more fat from the cooked lean samples than from the comparable raw ones. The lean samples from meat roasted at 163°C contained significantly more extractable fat than the samples roasted at 218°C. The presence or absence of the external fat cover did not affect the amount of fat extracted from the cooked lean.     

Effects of Frozen Storage and Cooking on Lipid Oxidation in Chicken Meat

Fresh chicken breast and leg meat samples, which were frozen for 3 months or 6 months at −18°C, were cooked in microwave and convection ovens and then tested for levels of lipid oxidation. After 6 months storage, malonaldehyde in fat from meat samples, as measured by a TBA assay, modified to avoid sample autoxidation, increased 2.5 fold, while the fluorescence excitation (360 nm) and emission (440 nm) spectra increased an average of 34%. Fat from meat cooked in a convection oven averaged 83% higher malonaldehyde concentration and 21% higher fluorescence compared to levels before cooking. Levels of lipid oxidation products in fat from chicken breast and leg meat were not significantly different in microwave compared to convection oven cooking; but certain secondary fluorescent products were higher in meats cooked by convection oven.     

SURVIVAL OF SALMONELLA TYPHIMURIUM IN ROASTING CHICKENS COOKED IN A MICROWAVE, CONVECTION MICROWAVE, AND A CONVENTIONAL ELECTRIC OVEN

Fresh whole roasting chickens were inoculated with Salmonella typhimurium and cooked either in a microwave, convection microwave, or conventional electric oven to an internal temperature of 74°C, 77°C, 79°C, or 85°C. Cooked chickens were tested for the presence of viable Salmonella organisms using an Enzyme Linked Immunosorbent Assay (ELISA). No chicken (0/12) cooked to ± 79°C in the convection microwave or conventional oven tested positive for Salmonella. Two out of three chickens cooked to 79°C and all three chickens cooked to 85°C in the microwave tested Salmonella positive. Tetrathionate broth dilutions from all 11 microwave cooked chickens produced isolated colonies on Brilliant Green Agar. No growth was observed on Brilliant Green Agar plates inoculated with tetrathionate broth dilutions from chickens cooked to an internal temperature of 79°C or 85°C in the conventional oven or to 85°C in the convection microwave.     

Cooking method and endpoint temperature effects on sensory and color characteristics of pumped pork loin chops

The objective of this study was to evaluate the effects of pumping, cooking method and endpoint temperature on quality of fresh pork chops. The longissimus was removed from 30 paired pork sides. One side was pumped to 110% of original weight (0.4% phosphate, 0.4% salt+added water). Chops were cut (2.5 cm thick) then fried or grilled to 70 or 80 °C. As endpoint temperature increased from 70 to 80 °C, pork flavor increased (P<0.05) from 95 to 104 (on a 150 point scale) for pumped samples but remained constant in unpumped samples. Juiciness decreased when unpumped samples cooked to 80 °C (62) rather than 70 °C (78). Warner–Bratzler shear values were lower (P<0.05) in pumped chops than in unpumped controls. Pork flavor was higher and off-flavor was lower in fried chops. Pumping loins appears to enhance sensory attributes of chops even when cooked to abusive endpoint temperatures with limited detrimental effects on physical characteristics.     

Effect of Calcium Carbonate and Sodium Alginate on the Textural Characteristics, Color and Color Stability of Restructured Pork Chops

The effects of factorial combinations of calcium carbonate (0.00 and 0.26%) and sodium alginate (0.0 and 0.7%) on the initial cooked tensile strength and texture profile analysis and the amount of discoloration during three months frozen storage of restructured pork chops were investigated. Calcium carbonate increased (p < 0.05) and alginate had no effect (p>0.05) on the tensile strength of the chops. Alginate decreased the hardness, cohesiveness, springiness, chewiness and gumminess of the restructured chops (p < 0.05). Chops that contained alginate and/or calcium carbonate had more initial discoloration than those that contained (1) no additives, (2) 0.75% NaCl plus 0.5% sodium tripolyphosphate, and (3) 0.75% NaCl plus 0.26% calcium carbonate but they did not discolor further during frozen storage.