CHARACTERISTICS OF MICROWAVEABLE PORK CHOPS

Blade tenderized whole muscle cuts and restructured chops were conventionally cooked (CO), microwave cooked (MW), and precooked/microwave reheated (CMW) and stored for 2, 15, and 21 days. Blade tenderization did not affect (P > 0.05) these sensory traits evaluated with the exception of texture. Precooked products had higher (P < 0.05) TBA values than conventionally cooked samples for both whole and restructured chops. TBA values increased (P < 0.05) with storage time for up to 21 days. Whole muscle chops that were conventionally cooked had the lowest (P < 0.05) peak force values and the highest (P < 0.05) texture scores. After 21 days of storage of whole muscle samples, overall flavor scores decreased (P < 0.05) and juiciness scores improved (P < 0.05) when compared to samples held for 2 days. Storage time had a minimal relationship to peak force values and no effect on sensory scores of restructured samples.     

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.     

EFFECTS OF A CRYOGENIC AND THREE HOME FREEZING METHODS ON SELECTED CHARACTERISTICS OF PORK LOIN CHOPS

SUMMARY— Thirteen pairs of pork loin chops from each of four carcasses were assigned randomly to 13 treatments to study effects of freezing by liquid nitrogen vapor and by three home methods, and effects of 1 and 4 wk of storage in three types of home freezers. Regardless of freezing method, cooking losses (total, volatile and drippingl were higher (P < 0.01) and water-holding capacity of the LD muscle lower (P < 0.05) for frozen than for fresh chops. Acid number, flavor scores and over-all acceptability scores were higher (P < 0.05, P < 0.01, P < 0.01) for fresh than for frozen chops. Both immediately after freezing and after 1 and 4 wk of storage, liquid nitrogen freezing produced chops superior in appearance to home-frozen chops. Total and dripping cooking losses were greater (P < 0.05 and 0.01), and total moisture of the LD lower (p < 0.05) for liquid nitrogen-frozen than for home-frozen chops. Free fatty acid was higher (P < 0.05) in liquid nitrogen-frozen than in home-frozen chops. Tenderness and over-all acceptability scores were higher (P < 0.05) for chops stored in a one-door refrigerator-freezer than for those stored in a two-door refrigerator-freezer or an upright household freezer. Regardless of freezing method or storage conditions, volatile cooking losses and free fatty acids increased (P < 0.05), and over-all acceptability and tenderness scores decreased (P < 0.01) between 1 and 4 wk of storage. The interaction between storage conditions and storage time resulted in greater (P < 0.051 increase in free fatty acids between 1 and 4 wk for chops stored in a one-door refrigerator-freezer than for those stored in the two other types of home freezers. Flavor and over-all acceptability scores decreased (P < 0.05) between 1 and 4 wk for chops stored in either refrigerator-freezer combination, but did not decrease during 4 wk of storage for chops in the upright household freezer.     

EFFECTS OF DIETARY GLYCINE BETAINE ON BLOOD CHARACTERISTICS AND PORK QUALITY

This study was conducted to determine the effects of dietary glycine betaine on pork quality and blood characteristics. A total of 80 female pigs (Landrace  ×  Yorkshire  ×  Duroc) were randomly allotted into one of four experimental diet groups. Each group of pigs fed with a commercial diet (control) added with 0.2 g glycine betaine (T1), 0.4 g glycine betaine (T2) and 0.6 g glycine betaine (T3)/kg diet during 40 days. Glycine betaine concentrations in plasma and loin muscle were significantly increased by dietary glycine betaine; however, triglyceride concentration in serum was decreased by dietary glycine betaine. Creatine phosphokinase concentrations in plasma had no significant difference among the dietary groups. Redness ( a* ) was significantly higher in T2 and T3; however, at the first and seventh days of storage, redness ( a* ) was not significantly different between dietary groups. Shear force was significantly higher in dietary glycine betaine groups at the first day of storage. Cholesterol content was significantly lower in T2 and T3, whereas T1 was not significantly different compared with the control group. In fatty acid composition, the ratio of saturated fatty acids was increased, whereas unsaturated fatty acids were decreased by dietary glycine betaine.

PRACTICAL APPLICATIONS

Glycine betaine is an amino acid (trimethylglycine) present in most organisms, and is an obligatory intermediate in the catabolism of choline. Glycine betaine has been reported to affect some aspects of pork qualities. As a result of this study, dietary glycine betaine should improve meat redness and reduce cholesterol. However, dietary glycine betaine did not influence creatine phosphokinase levels in plasma. These results will be helpful to the pork industry and meat scientists for improving meat qaulity.     

ENHANCEMENT SOLUTION EFFECTS ON SHELF-LIFE, COLOR AND SENSORY CHARACTERISTICS OF PORK CHOPS DURING RETAIL DISPLAY

Abstract The objective of this study was to evaluate shelf-life, color and sensory characteristics of pork chops from loin sections (n = 12/treatment) injected (110% original weight) with a potassium lactate/potassium acetate solution (2 %) + phosphate (0.35%)/salt (0.35%), compared with those injected with sodium lactate (3%) + phosphate/salt, or phosphate/salt alone, to control loins. After 96 h of display, aerobic plate counts (CFU/cm²) were significantly lower (P<0.05) for chops enhanced with the lactate + acetate combination than for the other treatments. Hue angle (tan^-1 b*/a*) of lactate + acetate enhanced chops was lower (P<0.05) than all other treatments at 96 h indicating that red color did not deteriorate as rapidly as in control, phosphate + salt- and lactate-injected chops. Sensory data suggest that lactate + acetate and lactate-injected chops were juicier, more tender, and less bitter than the noninjected chops. A difference in enhancement solution retention may partially explain differences in plate counts and sensory characteristics.     

PHYSICAL AND SENSORY CHARACTERISTICS OF PRECOOKED, REHEATED PORK CHOPS WITH ENHANCEMENT SOLUTIONS

Pork loins were pumped to 110% of original weight with solutions containing 0.35% salt and 0.35% phosphate (P), salt and phosphate plus 3% sodium lactate (SL), or salt and phosphate plus 2.5% potassium lactate/potassium acetate (PL/PA). Chops were evaluated freshly cooked and precooked, stored (4C, 2 days) and reheated. Chops from SL and PL/PA chops experienced lower cook losses than unpumped controls. Reheating produced additional cook losses which were unaffected by enhancement treatment. Enhancement produced reheated chops with lower shear values and higher tenderness scores than those of freshly cooked controls, and addition of either SL or PL/PA produced even more dramatic results. Warmed-over flavor after reheating precooked chops was reduced by the SL enhancement solution.     

EFFECT OF ULTIMATE pH ON THE QUALITY CHARACTERISTICS OF PORK

A study was conducted to characterize the relationship between Longissimus thoracis ultimate pH(LTpH) and pork quality. Animals (n = 47) were selected based on LTpH measured at 24 h postmortem. Data were analyzed using regression procedures with ultimate pH as the independent variable, and relationships were determined to be linear (L), quadratic (Ql or cubic (C). Ultimate pH explained 79% (C) of the variation in subjective color, which increased as pH increased. Drip loss, purge loss and L* value decreased as LTpH increased (R²= 0.57C, 0.77 Q and 0.68 Q, respectively). Shear force decreased and sensory juiciness increased as LTpH increased (R²= 0.26Q and 0.46C, respectively). However, of flavor intensity increased as LTpH fell below pH 5.2 or exceeded 6.1(R²=0.52C). Increasing LTpH, up to a point, will improve fresh pork quality and processed meat properties, whereas, above approximately 6.1, of-flavor may increase.     

RAW MATERIAL pH, PUMP LEVEL AND PUMP COMPOSITION ON QUALITY CHARACTERISTICS OF PORK

ABTRACT
Boneless, paired pork loins (n=120) were selected based on pH at 14 h postmortem. Ultimate pH, drip loss, instrumental color (L*, a*, and b* values), and proximate analysis were determined prior to pumping. Paired loins were cut into four sections and pumped to 100%, 106%, 112% or 118% of original weight to result in a product containing 0.4% sodium tripolyphosphate (STP) for Experiment 1 (Exp. 1) and 0.4% STP plus 0.4% salt for Experiment 2 (Exp. 2). In Exp. I, additional pump level increased (P<0.05) vacuum package purge. Higher raw materials pH reduced purge. A pump level x pH interaction (P<0.05) occurred for cook loss at 70C. In Exp. 2, increased raw materials pH reduced (P<0.05) purge loss and resulted in juicier, more tender pork. Pumped pork had higher (P<0.05) tenderness, juiciness, and saltiness scores than controls.     

A RESEARCH NOTE CHEMICAL, PHYSICAL, AND SENSORY CHARACTERISTICS OF COLOR MODIFIED PORK RESTRUCTURED CHOPS

Restructured pork chops were manufactured from the lean tissue of dressed sows that were color modified(CM) with a potassium buffer rinse to attain lighter appearance. This product was compared with counterpart samples that were not color modified(C). Measurements included CIE L*, a*, b* values, visual traits, sensory traits, shear force, pH, and percentage of moisture, fat, protein, protein solubility, and cooking loss. The CM samples were lighter colored (P<0.05), exhibited less (P<0.05) flavor intensity, had a higher (P<0.05) pH, and sustained less (P<0.05) cooking loss. No differences (P>0.05) between the CM and C samples were found in juiciness, tenderness, Warner-Bratzler shear force, and soluble protein. The CM samples exhibited less protein content and lower Lee-Kramer shear force values. Results confirm that sow meat can be lightened without adversely affecting functional properties and taste attributes of restructured pork chops.     

THE EFFECTS OF CARCASS DECONTAMINATION ON RETAIL CASE LIFE OF PORK CHOPS

Pork carcasses were treated with solutions of acetic/propionic acid (pH 2.6), sodium hypochlorite (pH 7.9) or sodium hypochlorite (pH 6.0) and examined for microbial numbers after 24 h. Rib and loin chops from these carcasses were overwrapped with polyvinylchloride film and stored in a retail case (2 °C) until judged unmarketable by a trained panel. Carcasses sprayed with acetic/pro-pionic acid had fewer microbial numbers when sampled after 24 h compared to those sprayed with hypochlorite solutions (pH 7.9), however, the lowest survival rate was from carcasses sprayed with hypochlorite (pH 6.0). Chops from carcasses sprayed with acetic/propionic acid exhibited an acceptable retail case appearance for an additional 2 days beyond chops from carcasses decontaminated with hypochlorite solutions.     

THE EFFECTS OF FROZEN STORAGE ON THE RETAIL ACCEPTABILITY OF PORK LOIN CHOPS AND SHOULDER ROASTS

Uncured shoulder roasts and loin chops were utilized to evaluate the effects of frozen storage for different intervals (0, 56, 84, 112, 140, 168 and 196 days) in different protective storage wraps (oxygen–permeable retail wrap, polyethylene bags, aluminum foil, and freezer paper) upon factors contributing to their retail acceptability after thawing and 24 h of subsequent display. The composite results of this study indicate that uncured pork cuts can be successfully frozen and stored for at least 196 days at ?30° C in still air, in the dark, in any of the protective storage wraps evaluated, and be thawed for 24 h at 2° C prior to being retailed and generally be as acceptable as their fresh counterparts during 24 h of retail display.     

UTILIZATION OF RESPONSE SURFACE MODELING TO EVALUATE THE EFFECTS OF NONMEAT ADJUNCTS AND COMBINATIONS OF PSE AND RFN PORK ON THE TEXTURE OF BONELESS CURED PORK

Combinations of pale, sop, and exudative (PSE) and red, firm. and nonexudative (RFN) semimembranosus muscle were utilized to manufacture chunked and formed, cured pork. Response Surface Methodology was utilized to investigate the effects of soy protein concentrate (SPC), sodium caseinate (SC), and modified food starch (MFS) on bind and texture profile analysis. Fifteen adjunct formulations for five PSE and RFN combinations provided 75 treatments for each of three replications. As CIE L* values of raw muscle increased, protein-protein bind decreased (P<0.05). MFS, SC, and SPC decreased (P<0.05) cohesiveness. MFS and SC decreased (P<0.05) chewiness, and MFS decreased (P<0.05) hardness. Utilizing these adjuncts demonstrated that MFS improved texture in PSE and RFN pork. This research demonstrated that diluting RFN pork with no more than 25% PSE pork permits the formation of a high quality boneless deli ham roll.