EFFECT OF FROZEN STORAGE AND PROTECTIVE WRAP UPON THE COOKING LOSSES, PALATABILITY, AND RANCIDITY OF FRESH AND CURED PORK CUTS

Of the fresh and cured pork cuts evaluated, ham steaks were the only cut consistently displaying increased cooking losses following frozen storage. Although the tenderness of fresh cuts tended to increase during frozen storage, the tenderness of cured cuts decreased; and the juiciness of both fresh and cured cuts decreased. In addition, flavor and overall palatability of both fresh and cured cuts decreased during frozen storage and such deterioration in these attributes appeared to result from rancidity development. The results of this study indicate that fresh chops and roasts, ham, and bacon can be stored for over 196, 196, and 112 days respectively, in any of the protective wraps evaluated without the loss of palatability.     

COOKING EFFECTS ON TITIN IN FRESH AND PROCESSED BEEF PRODUCTS

Fresh bovine longissimus thoracis muscle samples, heated at 73C for 0, 5, 15, 30, 45, 60, 90 and 120 min, were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blot analysis. Titin was both aggregated into large protein masses and degraded into smaller fragments (two apparently independent processes) in fresh muscle samples heated 15 min or more at 73C. Samples removed at various points during the manufacture of a tumbled cured beef product were also subjected to electrophoresis and western blot analysis. Titin was primarily degraded into smaller polypeptide fragments during the manufacture of this product with no large titin aggregates observed. Commercially manufactured meat products, when examined by these techniques, contained both titin aggregates and degradation products. These results suggest that titin can be aggregated into large protein masses and degraded into smaller polypeptide fragments during the heating of fresh or processed meat products.     

SODIUM LACTATE EFFECTS ON THE STABILITY OF FRESH AND CURED PORK LONGISSIMUS

Boneless pork loins sliced into 1.9 cm fresh chops were dipped to retain 0, 1.5 or 3% sodium lactate (SL) and packaged in polyvinylchloride (PVC) or vacuum-packaged (VP), Color of fresh chops was monitored visually and objectively. Boneless pork loins were cured by injection with 0, 1.5 or 3% SL, or were dipped after slicing to retain 0, 1.5 or 3% SL. Cure for the dipped loins contained no SL. Color and aerobic plate count (APC) of vacuum-packaged chops were evaluated over 70 days of retail storage (4C). Visual color was darker (P < 0.05) and L* values were lower (P < 0.05) for 3% SL-dipped fresh chops. Fresh chops containing 1.5 and 3% SL had higher a* values than controls. Surface discoloration of 3% SL fresh chops was lower (P < 0.05) than control chops. Cured injected chops (3% SL) had lower (P < 0.05) L* values than dipped chops or injected controls. L*, a* and b* values of cured dipped chops (3% SL) were not different (P > 0.05) from controls. No consistent trends were found in APC of cured chops. Injection of SL prior to cooking darkened the color of cured pork loin chops.     

PALATABILITY OF BONELESS FRESH PORK HAM AND LEG OF LAMB PREPARED BY INTERRUPTED COOKING PRIOR TO FROZEN STORAGE

SUMMARY –Boneless fresh pork hams and legs of lamb were scored acceptable or above in palatability when prepared by the "roasteak' procedure, involving preroasting to 44°C, slicing and chilling or freezing for as long as 6 months before grilling. Significant differences in means for flavor and juiciness indicated that an antioxidant dip (sodium tripolyphosphate-sodium ascorbate) is advisable for pork roasteaks subjected to freezing, but no such advantage was noted for antioxidant treatment of lamb roasteaks. Although there were differences in tenderness due to muscle within roasteak slices, meat from both muscles of both species was acceptable to the panel in this attribute. Total cooking losses for the roasteak method were higher than for one-step roasting.     

EFFECTS OF VARIOUS FRESH MEAT STORAGE METHODS ON THE COLOR OF COOKED GROUND PORK

The effects of microbial growth in raw materials on cooked pork color were investigated. In two trials with sow meat held aerobically at 2C for 3 weeks, microbial load reached spoilage levels (10⁷ cfu/g), pH increased to 6.46, and samples cooked to 71C had red exudate, shown by absorption spectroscopy to contain myoglobin and cytochrome c. Samples cooked to 82C also received high panel ratings for red color, due to red, flocculent precipitate in the exudate, but undenatured myoglobin levels were low. In sow meat held frozen or vacuum-packaged at 2C, pH after 3 weeks was 6.03 and 6.18, and plate counts were 10⁴ and 10⁷, respectively, but exudates after cooking were much less red. In five trials with fresh pork legs, total plate counts also reached 10⁷ cfu/g by 3 weeks storage, and pH increased to 6.37, but cooked samples were not red. Higher myoglobin levels in sow meat probably accounted for the red color and level of undenatured myoglobin remaining after cooking of high pH, spoiled samples.     

THE INFLUENCE OF COOKING METHOD ON THE QUALITY OF PORK PATTIES

Pork patties were subjected to traditional frying, cooking in a microwave oven (microwaves  +  grill), hot air cooking in a cyclojet (Electrim JI-9101 RP, Taiwan) and cooking in a steam-convection (combi) oven (hot air  +  30% steam) (BECK FCV 4 EDS, BECK GmbH, Jagsthausen, Germany). Products cooked in the combi oven (BECK FCV 4 EDS) were characterized by the smallest cooking loss, the highest retention of water and the lowest content of fat compared to other samples. The content of hydroxymethylfurfural in fried and cyclojet-cooked patties was almost twofold higher than in microwave and combi oven-cooked samples. The intensity of lipid oxidation was also higher in fried and cyclojet-cooked meat than in the other two products. The intensity of meat flavor was the strongest in the combi oven-cooked patties. All products were characterized by a low intensity of fatty flavor. The highest scores for overall acceptability were given to the combi oven-cooked patties, whereas the lowest scores were given by the panelists to the microwave-cooked patties.

PRACTICAL APPLICATIONS

Pork patties are an important meat product both in catering production for direct consumption and in convenience food industry when intended for refrigerated or frozen storage. As cooking is a main stage in preparation of patties for consumption, it is essential to use a method of cooking that ensures the high nutritional and sensory quality of products. Most often, pork patties are subjected to deep frying or traditional frying; however, several other cooking methods can be used. The present work shows that the combi oven cooking enables production of patties of desirable nutritional and sensory characteristics and low content of unfavorable compounds.     

HALOTHANE GENOTYPE, CHILLING AND LOCATION WITHIN MUSCLE: EFFECTS ON PORK QUALITY

Intact sides were subjected to accelerated chill (AC: −30C for 2.5 h, 4C for 20–22 h) or conventional chill (CC: 4C for 22–24 h). Color, drip loss, and pH were evaluated 24 h postmonem at three sites (inner, mid, and outer) in the Semimembranosus (SM) and Biceps femoris (BF) with the inner site closest to the femur. Zle Longissimus thoracis (LT) and the Longissimus lumborum (LL) were also evaluated. Accelerated chill improved color and drip loss of the Longissimus muscle. Accelerated chill had no fleet on the quality measurements of the ham, although site differences occurred. The fleets of genotype on color, drip loss, and pH in the loin and ham muscles were not consistent in the muscle groups studied. Compared to CC, AC has beneficial fleets on fresh pork quality of the Longissimus muscle, but not the ham muscles.     

SENSORY PROPERTIES OF PORK, AS INFLUENCED BY COOKING TEMPERATURE AND BREED

Samples of M. longissimus dorsi were taken from identically reared pure bred pigs of the Hampshire (n= 50), Swedish Landrace (n= 30) and Swedish Yorkshire (n= 51) breeds and sensory evaluated after being fried to 60, 68 and 80°C. A sensory profile comprising three juiciness attributes, i.e., visible juiciness, initial juiciness and dryness in mouth, four tenderness attributes, i.e., hardness, stringyness, chewing time and chewing residual, and the attribute elasticity was developed. The relationships between the different attributes were to some extent influenced by final frying temperature. A final frying temperature of 68°C — or even somewhat lower — seems to be the most suitable one from a sensory point of view. The meat is then juicy and tender, no longer having any “rawness” left, as at 60°C. There is a marked influence of breed on the eating quality. Hampshire is more tender and more juicy than Swedish Landrace, which in turn is more tender and more juicy than Swedish Yorkshire. A breed difference was also noted in the susceptibility to heating. A higher loss in eating quality was noted for Hampshire and Swedish Landrace than for Swedish Yorkshire when the final frying temperature was increased. Hampshire had a somewhat higher frying loss than the other two breeds, but it did not result in the least juicy product which indicates that the sensory property juiciness is not directly correlated to the cooking yield.