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.     

Effects of RN genotype and silage feed on fat content and fatty acid composition of fresh and cooked pork loin

This study aimed to establish effects of RN genotype and feed (red clover silage) on intra muscular fat content (IMF) and fatty acid composition (FA) of fresh and cooked pork loin (M. longissimus dorsi). Raw loins from silage-fed pigs compared with those from conventionally fed pigs had lower IMF, lower relative levels (rel.%) of saturated (SAFA) and monounsaturated (MUFA) fatty acids, and higher rel.% of polyunsaturated fatty acids (PUFA, ω6, ω3). Cooked loins, from silage-fed pigs compared with those of conventionally fed pigs, had higher rel.% of ω3, and lower ω6/ω3 ratios. IMF and cooking influenced FA concentrations in a pork portion. The differences in concentrations of SAFA, MUFA, PUFA and ω6 between raw loins of silage-fed pigs and conventionally fed pigs did not remain in cooked loins. The ω6/ω3 ratio, however, remained low, and thus more beneficial in loins from silage-fed pigs after cooking.     

Effect of tumbling and RN genotype on sensory perception of cured-smoked pork loin

Effects of tumbling and RN genotype on sensory perception of cured-smoked loins were studied on loins from 32 crossbred female pigs containing Hampshire blood. Right-side loins were intermittently tumbled during 4 h, whereas left-side loins were left non-tumbled. Tumbled loins were more tender and uniform in cured colour as well as less acidulous in taste compared with non-tumbled loins. Further, the formation of undesirable pores was lower in tumbled loins. Final juiciness tended to be higher and meat taste intensity lower in tumbled loins, whereas initial juiciness did not differ. There were no significant interactions between tumbling and RN genotype for sensory attributes. RN⁻ carriers (RN⁻/rn⁺) were more acidulous in taste, had more pronounced meat taste and were saltier than non-carriers (rn⁺ /rn⁺). Moreover, they tended to have higher initial juiciness and more undesirable pores, and be less homogeneous in cured pink colour. No differences in consumer preference between the four treatments were detected in the ranking test, but most persons ranked non-tumbled loins highest regarding overall liking. Instrumental tenderness measurements agreed well with sensory tenderness scores.     

Strategies to eliminate atypical aromas and flavors in sow loins-part II: consumer acceptance of loins marinated with sodium tripolyphosphate and sodium bicarbonate

An identified challenge in using sow loins as a raw material for value added enhanced whole muscle products is to eliminate or minimize objectionable atypical aromas and flavors (“sow taint,” ST) that may occur in some sow carcasses. The objective of this study was to determine consumer acceptance of sow loins exhibiting atypical aromas and flavors marinated with a solution of salt, sodium tripolyphosphate and sodium bicarbonate. Sow loins (N=34) with atypical aromas and flavors and commodity loins (N=6) were fabricated into anterior and posterior loin sections and marinated with one of four ST marinade treatment combinations (15% pump, 0.5% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.35 M NaHCO₃; and 15% pump, 0.25% PO₄, 0.35 M NaHCO₃), or a control marinade (0.25% sodium tripolyphosphate, 15% injection level) and evaluated by a consumer sensory panel. Sensory ratings determined that ST loin chops injected with a 15% solution of sodium tripolyphosphate (0.50%) and sodium bicarbonate (0.35 M) were not different (P>0.05) than loin chops from marinated commodity control loin sections (N=12) for flavor, texture, juiciness, and overall acceptability. These results indicate that a solution containing sodium tripolyphosphate and sodium bicarbonate minimized the detection of atypical aromas and flavors in sow loins.     

Do all the consumers accept marbling in the same way? The relationship between eating and visual acceptability of pork with different intramuscular fat content

Several reports show that intramuscular fat (IMF) and/or marbling affect the sensory acceptability of meat. The aim of the present work was to (1) investigate using Spanish consumers the eating and visual acceptability of pork with different levels of IMF, (2) understand more about this acceptability by studying segments of consumers and (3) determine which fresh pork characteristics are important at the point of purchase. Loin section (n = 40) were sorted into four IMF groups: 0.96 ± 0.30% (G1), 2.11 ± 0.07% (G2), 3.72 ± 0.26% (G3), and 5.78 ± 0.19% (G4). Consumers (n = 200) evaluated the acceptability, tenderness and juiciness of cooked loin chops from each IMF group and then ranked raw chops according to visual preference. Two groups of consumers--'lean loin lovers' (55.5%) and 'marbled loin lovers' (44.5%)--were identified based on their visual preferences; however, according to their eating acceptability scores, all the consumers preferred loins with higher IMF levels. Accordingly, the minimum IMF content recommended to ensure a good taste is between 2.2% and 3.4%.     

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.     

CRANBEFCRY JUICE MARINADE IMPROVES SENSORY AND MICROBIOLOGICAL PROPERTIES OF VACUUM-PACKAGED LAMB CHOPS

Marination was investigated as a means to add value and improve the palatability of lamb chops. Vacuum-packaged whole lamb loins (n = 24) were assigned randomly to a 14 or 20-day aging period. Loins were split and right and left sides were designated to receive one of two treatments: control or marinade with spice rub. Loins were cut into chops and chops were vacuum-packaged and displayed for 0–, 7– or 14-days in a retail display case. Chops from both aging periods assigned to the 0 day retail display period were evaluated for both raw and cooked characteristics by consumers. Consumers indicated that cooked appearance. odor, juiciness, flavor, tenderness, and overall-like were higher for treated chops than for controls (P < 0.05). However, consumers preferred the appearance of raw control chops over the appearance of raw treated chops (P < 0.05). Treated lamb chops had lower aerobic plate counts at 7 and 14 days of retail display for both aging periods (P < 0.05), and lower 2-thiobarbituric acid (TBARS) values than control chops (P < 0.05). A treatment × retail display day interaction (P < 0.05) was observed for TBARS values as treated chops had lower TBARS values than control chops as days of retail display increased. Marinating lamb chops improved palatability traits of cooked lamb chops and extended the shelf-life characteristics of raw lamb chops.     

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.     

Preslaughter resting and hot-fat trimming effects on the incidence of pale, soft and exudative (PSE) pork and ham processing characteristics

Effects of preslaughter rest (0, 1, 2 or 3 h) and hot-fat trimming (HFT, one side) on muscle quality characteristics of hams and loins were tested with 120 pigs. Center-cut loins from each carcass side were vacuum packaged and stored for 7 or 14 days at 2°C. Pigs not rested before slaughter had a skin temperature 3°C higher and ham muscle temperatures 1°C higher than pigs rested 1-3 h (P<0.05). Three hour muscle pH was highest if pigs were rested for 1 h. HFT significantly accelerated carcass chilling rate, but did not affect rate of muscle pH decline. After 14 days of aging, pigs not rested had lower sensory panel ratings for juiciness, tenderness, flavor and overall mouthfeel of loin chops than pigs rested 1 or 2 h. Percentage bound water of hams was highest (P<0.05) if pigs rested 1 or 2 h rather than a shorter or longer times. Pigs should be rested 1 h before slaughter and HFT carried out to allow more rapid carcass chilling and improve muscle quality.     

EFFECTS OF SODIUM LACTATE AND SODIUM PHOSPHATE ON THE PHYSICAL AND SENSORY CHARACTERISTICS OF PUMPED PORK LOINS

Whole, boneless pork loins were pumped to result in a final concentration of 0% to 2% sodium lactate (SL) and/or 0% to 0.4% sodium tripolyphosphate (STP) resulting in a 3 × 3 factorial design. Three replications were randomly presented to 10 trained sensory panelists for evaluation. Physical properties of the loins were also evaluated. Sensory evaluation results suggested that there was a trend for juiciness and tenderness to be enhanced by the addition of STP. Pork flavor, salt intensity, and alkalinity were enhanced by SL. Pump yields increased while purge loss was reduced with the addition of STP. Color was not affected by SL or STP. No difference in peak force and energy required to shear samples was observed. Results from this study suggest that pork loins pumped with SL and STP had enhanced moisture retention with few detrimental effects on sensory characteristics.     

VACUUM PACKAGING OF LAMB. 1. Microbial Considerations

SUMMARY –Paired loins from 148 lamb carcasses were utilized to determine the subsequent case-life of chops from loins that had been stored in vacuum packages. Bacterial samples which were obtained from the surface of the longissimus muscle were used to evaluate the retail case-life of loin chops. Longer periods of storage in vacuum packages were associated with higher initial psychrotrophic counts for subsequent loin chops. Comparisons between vacuum packaged loins that were stored at 0°C vs. 7°C indicated that storage temperatures of 7°C were more favorable for psychrotrophic bacteria growth and thus resulted in decreased subsequent case-life for chops from these loins. 8 days appears to be a reasonable maximum period for the storage of loins in vacuum packages. Fresh chops that were fabricated 8 days postmortem and displayed immediately exhibited an advantage of 1½1/4 days of increased case-life in comparison to those chops from loins which were vacuum packaged 8 days postmortem, stored under vacuum for 8 days, fabricated and subsequently displayed. The average case-life of fresh chops was 3½1/2 days when stored in a retail case at 0°C. The results of the present study indicate that vacuum packaging of lamb loins may be feasible; however, unless low storage temperatures are maintained and the storage interval is short, the retail case-life of chops will be reduced.     

FAT CONTENT AND SENSORY ANALYSIS OF SELECTED PORK MUSCLES TAKEN FROM CARCASSES WITH VARIOUS BACKFAT LEVELS

Sixteen carcasses from each of four last-rib backfat thicknesses (1.8, 2.3, 2.8 and 3.3 cm) were evaluated. Crude fat, moisture and protein contents were completed on the following muscles: triceps brachii, longissimus, psoas major, gluteus medius, semimembranosus, biceps femoris and semitendinosus. Boneless rib chops and fresh ham (top) steaks were broiled to 77°C and evaluated for crude fat, moisture and protein contents and for sensory attributes. In the raw state, the intramuscular crude fat content of the boneless rib chop (longissimus muscle) from the least backfat class averaged 2.9%, and when averaged over backfat, six of the seven muscles contained crude fat contents of 4.3% or below. Broiled boneless rib chops (longissimus) and fresh ham (top) steaks (semimem-branosus) averaged 4.3 and 3.5% crude fat, respectively, when averaged over backfat. Generally, sensory scores for juiciness of the boneless rib chop increased as backfat level increased. Both juiciness and tenderness of the fresh ham (top) steak increased as backfat level increased.     

Pork loin color relative to sensory and instrumental tenderness and consumer acceptance

Pork loin color categories were established with the intent of demonstrating differences in eating quality between them. Center-cut boneless pork loins (n=64) were divided into three color classifications. Category A included National Pork Producers Council color standards 1 and 2; category B, 3 and 4; and category C, 5 and 6. L* means for categories A, B, and C were 57.00, 50.24, and 45.54, respectively. Warner-Bratzler shear force values were not affected by category (P>0.05), but were negatively correlated with a* and b* values (P<0.05). The "in-home" portion of this study consisted of 47 households that prepared and evaluated chops randomly distributed by category. Consumers reported differences in liking of juiciness and liking of tenderness (P<0.05) due to color category. Eighty-nine percent of the households participated in a simulated retail display where, 20.8% chose chops from category A, 26.4% from category B, and 52.8% from category C. A trained panel evaluated the cooked chops and perceived category C to be more tender, more juicy, and less dry than both A and B (P<0.05). Consumers responded similarly to the trained panel in their perceptions of tenderness and juiciness.     

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.     

PHYSICAL AND MICROBIAL CHARACTERISTICS OF PORK LOINS IN MODIFIED ATMOSPHERE PACKAGES

Bone-in pork loins (n = 45) were selected from a commercial facility, subjected to one of three gas flush packaging treatments: NC: 75% N₂, 25% CO₂; ONC₁: 45% 0₂, 35% N₂, 20% CO₂; ONC₂: 66% O₂, 9% N₂, 25% CO₂, and stored for 7, 14 or 21 days at 0±2C. After storage, treatment and storage effects on visual evaluations, storage characteristics, microbial analysis and retail display characteristics were determined. The ONC¹ and ONC²treated loins had less discoloration after 21 days than NC treated loins, and NC treated chops had the least desirable retail display characteristics (P < 0.05). Fewer (P < 0.05) lactic acid producing bacteria (day 21) were found on NC treated loins, resulting in chops with a shorter retail shelf-life. These results indicate that higher oxygen levels (45 and 66%) are necessary for the modified atmosphere storage of fresh pork loins for 21 days.     

The effect of enhancement with salt, phosphate and milk proteins on the physical and sensory properties of pork loin

Pork loins were pumped to 110% of original weight with solutions containing 5.5% salt and 3.3% sodium tripolyphosphate, 5.5% salt and 3.3% β-lactoglobulin (β-lg) enriched fraction or 5.5% salt and 3.3% whey protein concentrate 80% (WPC80) for comparison with non-enhanced control loins. The enhancement of pork loins significantly increased (p<0.001) the tenderness and juiciness. Warner-Bratzler shear force values were lower (p<0.001) in enhanced then in non-enhanced control chops. The enhanced pork chops had a slightly higher overall flavour and overall acceptability to the control pork chops. Sensory analysis showed that β-lg enriched fraction and WPC80 can be used as replacement ingredients to reduce the amount of phosphate used in enhancement solutions, as they were comparable to salt/sodium tripolyphosphate (salt/STPP) enhancement solution. Consumers rated the tenderness, juiciness and taste of the enhanced chops significantly (p<0.001) higher then the control chops.     

Einflüsse von Braten und Grillen auf Fettqualität,Zartheit und Zusammensetzung von Schweinekoteletts aus verschiedenen Markenfleischprogrammen

Differences in fat quality, tenderness and composition of raw, roasted and grilled pork loin chops obtained from different meat brands Three loin chops obtained from each of a total of 180 pigs within one slaughter house either were left raw or were roasted at 120 °C for 12 min or simultaneously grilled on both sides at 180 °C for 6 min, respectively. Four different groups of 45 animals each were employed: pigs of conventional origin, pigs from a meat brand basing on animal welfare principles (Neuland) and pigs from two sub-systems of another commercial meat brand (Pigour) among others using higher contents of medium chain fatty acids in the feed. With the less intensive roasting, lower cooking losses and shear forces were observed as compared to grilling. The final intramuscular fat content was almost twice as high as the initial value of 1.3% with both cooking procedures. In subcutaneous back fat, cooking resulted in a highly significant reduction of the proportion of the polyenic acids which, however, was of only low numerical extent. The induction period till fat oxidation was significantly increased by 25% with roasting and by 8% with grilling. The clear differences in the quality of the raw chops obtained from the different origins could be almost completely recovered in the cooked chops.     

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.     

Meat Palatability of Duroc and Chinese First-Cross Barrows

Duroc, Meishan, Fengjing and Minzhu boars were mated to White composite gilts. Trained sensory panel evaluation and Warner-Bratzler shear force determinations were made on chops that had been aged 4 days postmortem. No differences (P > 0.05) were found in juiciness, connective tissue amount, flavor intensity, tenderness or shear force values among sire breeds. No differences (P > 0.05) were detected in cooking losses, although meat from the Duroc-sired pigs cooked at a faster (P < 0.05) rate, but required longer cooking (P < 0.05) times than that from the other sire breeds. These data indicate the introduction of currently available Chinese genetics into the U.S. swine population would have little effect on the palatability of pork loin chops.     

Influence of on-farm production practices on sensory and technological quality characteristics of pork loin

Quality of pork from pigs raised either traditionally (outdoor access or bedded settings with no sub-therapeutic antibiotics or growth promotants in feed) or conventionally (commercial indoor) was evaluated. Pork loins (m. longissimus thoracis et lumborum, LTL) from four hundred pigs from either traditional or conventional production systems (n = 200) fed commercially formulated diets ad libitum were harvested at slaughter. Intramuscular crude fat content and lean color (L* and b*) values were significantly decreased in conventional pork loins. LTL from conventionally-raised pig carcasses showed increased (P < 0.05) mean pH, moisture content and reduced cooking loss and shear force values and had increased tenderness and juiciness scores compared to those from traditionally-raised pig carcasses. Results indicated that pork from conventionally raised pigs was superior to that from traditionally raised pigs in terms of tenderness and juiciness, suggesting that consumers may value pork from traditionally raised pigs on the basis of factors other than eating quality and appearance.