Strategies to eliminate atypical flavours and aromas in sow loins. I. Optimization of sodium tripolyphosphate, sodium bicarbonate, and injection level

Sow meat has been identified to possess objectionable atypical aromas and flavors we have termed as “sow taint”. The objective of this study was to identify optimum concentrations of sodium bicarbonate (NaHCO₃), sodium tripolyphosphate (PO₄) and percentage marination solution that reduces or eliminates sow taint. Sow loins (N=20) with atypical aromas and flavors were treated with solutions containing sodium tripolyphosphate and sodium bicarbonate with concentrations ranging from 0.25 to 0.50% and 0.35 to 0.70 M, respectively. Injection levels (pump) ranged from 5 to 15% (wt./wt.). Marinated loin chops were evaluated for flavor and textural attributes by a trained sensory panel. Response surface methodology determined four optimum 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) that reduced (P<0.05) metallic aroma, metallic and sour aftertastes, and detectable connective tissue while improving (P<0.05) muscle fiber tenderness, juiciness, and overall tenderness.     

Injection of salt, tripolyphosphate and bicarbonate marinade solutions to improve the yield and tenderness of cooked pork loin

Several marinade solutions were tested for their effects on pork tenderness. Paired loins were removed from eight Large White crossbred pigs. Each pair was cut to give eight pieces and injected to a target of 110% of original weight with one of the following eight solutions (g/100 g water): uninjected (A, control), 5% salt (B), 5% sodium tripolyphosphate (C), 3% sodium bicarbonate (D), 5% salt and 5% sodium tripolyphosphate 5% (E), 5% salt and 3% sodium bicarbonate (F), 5% sodium tripolyphosphate and 3% sodium bicarbonate (G), 5% salt, 5% sodium tripolyphosphate and 3% sodium bicarbonate (H). Samples were left overnight to equilibrate, cooked and assessed for tenderness using a Volodkevich shear force method. Mean pHs for meat injected with phosphate and/or bicarbonate (C-H) ranged from 5.75 to 5.97, compared to 5.45 for the control. All injected loins, had a significantly higher yield than the control (p<0.05), except salt alone which, though higher, did not differ significantly (p>0.05) from the control. Treatment H increased the yield from 70% (control) to 85%. All marinades significantly reduced the shear force (p<0.05), some treatments (D and F) by up to a half compared to the control (5150 g). Individual animal results suggest that marination could be used to good effect even in the toughest samples, whilst improving tender samples still further. Samples treated with bicarbonate had an usual porous structure, probably due to carbon dioxide produced during cooking which may have contributed to the reduced toughness.     

PHOSPHATE MARINATION OF PORK LOINS AT HIGH AND LOW INJECTION PRESSURES

Whole, boneless pork loins, divided into anterior and posterior sections, were injected with deionized water or sodium tripolyphosphate/NaCl solution at an injection pressure of 200 or 345 kPa with a constant injection level of 13%. A vacuum tumbling process subsequent to injection at 345 kPa was also evaluated. Increasing injection pressure of STPP/NaCl marinades improved cook loss, overall yield, but increased Warner‐Bratzler shear values of water‐only injected controls. Overall yield ranged between 84.6–98.1% for phosphate treated loins compared with yields of that ranged between 61.0–67.7% for no treatment and water injected controls. Posterior loin sections exhibited greater weight loss after 4 days storage than anterior sections. A significant marinade/position interaction was observed for total moisture. Tumbling of pork loins after needle injection increased overall yield.     

EFFECT OF PHOSPHATE AND PECTIN ON QUALITY AND SHELF-LIFE OF MARINATED CHICKEN BREAST

Fresh split chicken breasts were injected with 5% sodium acid pyrophosphate (SAPP), 5% sodium tripolyphosphate (STPP), 2.5% Genu pectin (GENU), or the combination of 5% SAPP with 2.5% GENU and 5% STPP with 2.5% GENU. Calcium lactate (0.1 M) solution was sprayed on the surface of chicken marinated in pectin. Marinated samples were stored at 4C for 7 days to evaluate changes in the psychrotrophic bacterial count and quality. STPP injected chicken breast had highest (α=0.05) marinade pickup, net weight increase, cook yield and moisture content. SAPP injected chicken had intermediate marinade pickup, but lowest retention in the muscle among all treatments. Marinades with pectin or pectin combined with phosphate had lower pickup but higher marinade retention compared with SAPP injected breasts. The water holding capacity (WHC) of STPP and GENU injected cooked chicken breast was higher than SAPP injected samples or control. All marinated chicken breasts had significantly lower shear force than noninjected control. Neither phosphate nor pectin had a significant influence on microbial activity of marinated chicken.     

EFFECT OF RN GENOTYPE ON YIELD AND SENSORY CHARACTERISTICS OF ENHANCED LONGISSIMUS SECTIONS

Pumping treatments with water or 4.5% sodium tripolyphosphate (STP) were evaluated on the fresh longissimus from pigs of different Rendement Napole genotypes. The longissimus muscle (32 RN/rn, 32 rn⁺/rn⁺) was divided into 3 sections and allocated to the: nonpumped, water pumped, and 4.5% STP, treatments. Following aging (14 days) chops were cut, packaged, and frozen. Boneless loin chops were cooked to internal temperatures of either 70C or 80C. Nonpumped loins resulted in the least amount of purge loss, whereas STP loins had the highest raw yield. Pumping loin sections with water and STP increased raw and cooked moisture contents. Pumping with STP increased juiciness and tenderness ratings. Increasing the endpoint temperature decreased juiciness and cooked moisture percentage. Pork from RN/rn⁺ pigs had lower shear force and higher tenderness and juiciness. These data indicate that increasing end point cooking temperature reduced pork palatability while STP pumping and the RN gene improved sensory properties.     

The effect of wholesale vacuum and 100% CO2 storage on the subsequent microbiological, colour and acceptability attributes of PVC-overwrapped pork loin chops

The shelf life of chops cut from pork loins, after either vacuum or 100% CO₂ storage (0, 7 or 14 days), was determined. The PVC-overwrapped chops were assessed, following a shelf life study of 0, 2, 5 or 7 days at 0 or 5°C, regarding quality attributes such as microbiological contamination levels, colour and acceptability. The study indicated that according to the psychrotrophic counts, the PVC-overwrapped retail chops, from the vacuum as well as the 100% CO₂ stored pork loins (0, 7 or 14 days), still attained a conventional shelf life of 3 days.

Lactic acid bacteria and pseudomonads largely represented the psychrotrophic counts. No clear pattern could be detected regarding the colour scores except that the samples displayed at 0°C tended to retain colour longer. These samples were also judged to be more acceptable, although the determination of acceptability was subjective.     

Effect of various additives to marinating baths on some properties of cattle meat

Longissimus dorsi (LD) muscles obtained from young bull carcasses (Holstein Friesian) were marinated, using solutions containing 0.5% sodium tripolyphosphate (STP), 0.5% dicalciumhydrogen phosphate (CHP) and 0.5% citric acid (CA). All solutions, including a blank, contained 2% NaCl. Expressible moisture, cooking loss, marinade uptake, area gain (increase in slice size), colour coordinate values (L*, a*, b*), marinade and meat pH, and the textural properties of samples were evaluated. Marinating with STP and CHP solutions resulted lower cooking losses. Marinade uptake and area gain were lower for control steaks and steaks marinated with the CA solution. The highest lightness was found in steaks marinated with the CA solution. Steaks marinated with STP and CHP solutions were darker. The CA solution resulted in yellowness of steaks. All treatments significantly affected hardness, chewiness and resilience values of steaks. The lowest hardness value was found in steaks marinated with CA. STP and CHP treatments also improved tenderness.     

Effect of modified atmospheres on microbiological, color and sensory properties of refrigerated pork

Pork loin samples were stored (4 °C) in nylon polyethylene plastic bags using different modified atmospheres packaging (MAP): vacuum, 100% CO₂ 99% CO₂ + 1% CO, 100% O₂ or 100% CO followed by vacuum. Throughout the storage period Pseudomonas growth was limited in loins packaged in all MAPs evaluated, except for 100% O₂. Psychrotrophs reached 10⁷ CFU g⁻¹ after 20 days of storage except for the loin samples in 100% O₂ MAP that present count above 10⁸ CFU g⁻¹. The 1% CO/99% CO₂ atmosphere was best for preserving the desirable pork loin color and the L* and a* values remained similar to the fresh meat values using this MAP. Pork loins in 99% CO₂/1% CO MAP obtained the highest consumer acceptance scores after 24 h of storage. These samples and those treated with CO and then vacuum packaged received the greatest acceptance scores even after 20 days of storage.     

Sodium Lactate/Sodium Tripolyphosphate Combination Effects on Aerobic Plate Counts, pH and Color of Fresh Pork Longissimus Muscle

The objective of this study was to evaluate the effects of sodium lactate/sodium tripolyphosphate pump combinations on the characteristics of pork loins. The product was manufactured to simulate fresh pumped pork loins currently available in the retail market. Paired fresh pork loins (longissimus muscle), pumped to contain 0, 1 or 2% sodium lactate (SL) and/or 0, 0·2 or 0·4% sodium tripolyphosphate (STP) were vacuum packaged and stored at 4°C for 28 days. In pork containing 0·4% STP, samples with 1 or 2% SL had lower pH values than those with 0% SL. Pork containing 1 or 2% SL generally had lower aerobic plate counts than those with 0% SL. Pork with 0·4% STP was darker (lower L* value) and redder (higher a* value) than that with 0 or 0·2% STP. When aerobic plate counts and color characteristics are used as the criteria, the optimum SL/STP combination for solutions used to pump fresh pork loins that are vacuum packaged and held under refrigeration was 1% SL with 0·2% STP.     

Dielectric Properties and Thermal Conductivity of Marinated Shrimp and Channel Catfish

Peeled shrimp (Peneaus spp.) and channel catfish (Ictalutus punctatus) fillets were either mixed with commercial lemon pepper marinade and vacuum tumbled at 4°C for 30 min or soaked in 2% tripolyphosphate solution overnight. Dielectric constant and loss factor of marinated seafood and the penetration depth of microwaves were functions of temperature. When cooking temperature increased, the dielectric constant increased, while the loss factor and depth of penetration decreased. Because of the large variation in thermal conductivity measured for individual shrimp, no correlation between thermal conductivity and temperature was found. At constant temperature, thermal conductivity of 2% sodium tripolyphosphate-treated shrimp was higher than that of both marinated and nonmarinated shrimp as a result of higher moisture content. However, no difference in thermal conductivity was found between marinated and nonmarinated shrimp or catfish.     

EFFECTS OF INJECTION OF A DILUTE PHOSPHATE-SALT SOLUTION ON PORK CHARACTERISTICS FROM PSE, NORMAL AND DFD CARCASSES

Phosphate-salt pump effects were evaluated on sensory characteristics of pale, soft, exudative (PSE) pork, normal and dark, firm and dry (DFD) pork. Water-holding capacity, instrumental color (L*, a*, b*), pH, and muscle color scores were determined at 24 h postmortem on pork loin pairs (n=21 pairs). Based on color score, paired loins were assigned to PSE, normal or dark, firm, dry groups. PSE muscles were lighter, redder and more yellow than normal or DFD muscles; hue angle indicated that DFD muscles were actually closer to the true red axis of the CIE Lab Color Space. Drip and purge losses were higher (p<0.05) in PSE muscles. Paired loins were pumped with water (controls) or 0.3% tripolyphosphate solution (0.25% salt) to 110% of original weight, vacuum packaged, frozen, cut into chops, and cooked to 70 or 80C. Phosphate-salt pumped loins were juicier and more tender (p<0.05) than water-pumped loins regardless of muscle condition. Loins cooked to 70C were juicier, were more tender (sensory) but required more force to shear than those cooked to 80C.     

Effect of carbon monoxide and high oxygen modified atmosphere packaging and phosphate enhanced, case-ready pork chops

The objective of this study was to evaluate the effects of CO-MAP compared to traditional high oxygen MAP (HiOx-MAP) packaging and enhanced with different phosphate on enhanced pork quality. Pork loins were enhanced to 10.5% over initial weight to contain 0.3% salt and 0.4% phosphate (either sodium tripolyphosphate [STP] or a blend of STP and sodium hexametaphosphate) on a finished weight basis. Chops were cut, packaged in atmospheres containing 0.4% CO/30.0% CO₂/69.6% N₂ (CO-MAP) or 80% O₂/20% CO₂ (HiOx-MAP), aged in the dark, then placed in a lighted retail display case for 48 h. Chops packaged in CO-MAP were redder (higher Minolta a^* values) and darker (lower Minolta b^* values) than chops packaged in HiOx-MAP. Based on sensory scores, the CO-MAP chops were pinker than the HiOx chops after cooking. CO-MAP chops also experienced less purge loss than chops in HiOx-MAP. Results indicate that CO-MAP had no effect on flavor or consumer acceptability and only minimal effects on other characteristics.     

Color, Oxidation-Reduction Potential, and Gas Production of Irradiated Meats from Different Animal Species

ABSTRACT: Turkey breasts, pork loins, and beef loins were aerobically or vacuum-packaged and electron beamirradiated at 3 kGy. Irradiation increased the redness of turkey breast regardless of packaging or storage. Irradiation drastically decreased the redness of aerobically packaged beef loin. Irradiated meats produced higher amounts of CO and CH₄ than nonirradiated. The oxidation-reduction potential (ORP) of meats decreased after irradiation, but increased during the storage. Little differences in CO and ORP values among the irradiated meats from different species were detected. This indicated that CO and ORP were not the only factors involved in the color changes of beef loin by irradiation.     

MODIFIED-ATMOSPHERE PACKAGING OF BONE-IN PORK LOINS

Paired bone-in pork loins (n = 110 pairs) trimmed to 3.2 and 6.4 mm subcutaneous fat were placed five per box in modified-atmosphere packages (MAP) and stored for up to 19 days at 1°C. Using commercial conditions and a single flush of 0.61 1/kg of meat of carbon dioxide (CO₂), the resulting CO₂ concentration was 78.5%, which then decreased to 55.1% (day 3) and 41% (day 19). Oxygen, 3.1% initially, increased to 7.2% (day 3), decreased to 3% (day 15), then increased to 7.1%. Although microbial counts increased from 3 to 19 days, those through 9 days of MAP (331 CFU/cm²) were lower than prior to MAP (653 CFU/cm²). Longer storage increased (P < 0.05) loin weight loss; off-odor; and discoloration of the blade and sirloin lean, subcutaneous fat, and bone surface. Off-odor intensity and microbial levels were acceptable at day 19, thus discoloration was the limiting factor in loin shelf-life and retail chop display color stability.     

Effects of L- or D-lactate-enhancement on the internal cooked colour development and biochemical characteristics of beef steaks in high-oxygen modified atmosphere

The effects of L- or D-lactate on internal cooked colour development of steaks packaged in high-oxygen (80% O₂/20% CO₂) modified atmosphere packaging (MAP) was investigated. Ten USDA Select beef strip loins were divided individually into 4 equal-width sections, and one of four treatments (control, 0.3% sodium tripolyphosphate, 2.5% L-lactate + 0.3% sodium tripolyphosphate, and 2.5% D-lactate + 0.3% sodium tripolyphosphate) was assigned randomly to the loin sections. Loin sections were injected to approximately 10% of their raw weight. Steaks packaged in high-oxygen MAP were stored in the dark at 1 °C for 10 days. Instrumental internal colour of raw and cooked steaks (70 °C), total reducing activity (TRA), NADH concentration, and percent myoglobin denaturation (PMD) were measured. Cooked steaks enhanced with 2.5% L-lactate/phosphate maintained higher a*/b* ratios, lower hue values, higher TRA and NADH concentration, and lower PMD than the control and D-lactate-injected steaks, whereas enhancement with 2.5% D-lactate did not affect cooked colour, TRA, NADH, or PMD. Thus, inclusion of an L-lactate/alkaline phosphate blend increased the reducing activity of muscle tissues by replenishing NADH and subsequently decreased the thermal denaturation of myoglobin by maintaining the reduced state of myoglobin in the high-oxygen package.     

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.     

响应面法优化鸭胸肉保水工艺中复合磷酸盐配比

以鸭胸肉为材料,采用响应面分析法研究不同质量分数焦磷酸钠、三聚磷酸钠和六偏磷酸钠对鸭胸肉保水性的影响。结果表明,在相同的实验条件下,添加的焦磷酸钠和三聚磷酸钠对鸭胸肉的保水性有极显著的影响（P＜0.001）,六偏磷酸钠的影响非常显著（P＜0.01）。焦磷酸钠与三聚磷酸钠的交互作用、三聚磷酸钠与六偏磷酸钠的交互作用对鸭胸肉保水性的影响非常显著（P＜0.01）,焦磷酸钠与六偏磷酸钠的交互作用对鸭胸肉保水性的影响不显著。结果表明：焦磷酸钠、三聚磷酸钠、六偏磷酸钠添加量分别为0.25%、0.29%、0.13%时,鸭胸肉的实际保水率达到32.28%。     

Colour changes and consumer acceptability of bulk packaged pork retail cuts stored under O(2), CO(2) and N(2)

A centralised bulk packaging technique, utilising various gas mixtures, c. 100% CO₂ + oxygen scavenger, c. 80% O₂:20% CO₂ and c. 25% CO₂:50% N₂:25% O₂, was evaluated in terms of consumer acceptability and colour. The inclusion of an oxygen scavenger ensured that pork retail chops bulk packaged in a 100% CO₂ were as acceptable after 0, and 14 days bulk storage and subsequent retail display than chops stored in oxygen-enriched atmospheres. The study also indicated that a saturation level of 10 and higher indicated that the appearance of the pork chop was acceptable to the consumer panel. From the results of this study it is apparent that consumers find pork retail packs, bulk packaged in oxygen depleted atmospheres, as acceptable as pork chops stored in oxygen enriched atmospheres.     

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.     

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.