J.R. Claus

Color stability of ground beef packaged in a low carbon monoxide atmosphere or vacuum

Ground beef was either packaged in an atmosphere of 0.4% CO, 30% CO₂, and 69.6% N₂ (CO-MAP) or vacuum. After storage (48 h, 2-3°C), packages of CO-MAP and vacuum were opened and overwrapped with polyvinyl chloride. Other CO-MAP and vacuum packages were left intact. Packages were initially displayed for 7 days (2-3°C). Intact packages were further displayed up to 35 days before being opened and displayed (1 or 3 days). Intact CO-MAP packaged ground beef was always more red than intact vacuum-packaged ground beef. Color was relatively stable for both types of intact packages over 35 days of display. Upon opening CO-MAP packaged ground beef, the red color decreased slower than in ground beef from vacuum packages.

Preserving pre-rigor meat functionality for beef patty production

Three methods were examined for preserving pre-rigor meat functionality in beef patties. Hot-boned semimembranosus muscles were processed as follows: (1) pre-rigor ground, salted, patties immediately cooked; (2) pre-rigor ground, salted and stored overnight; (3) pre-rigor injected with brine; and (4) post-rigor ground and salted. Raw patties contained 60% lean beef, 19.7% beef fat trim, 1.7% NaCl, 3.6% starch, and 15% water. Pre-rigor processing occurred at 3-3.5h postmortem. Patties made from pre-rigor ground meat had higher pH values; greater protein solubility; firmer, more cohesive, and chewier texture; and substantially lower cooking losses than the other treatments. Addition of salt was sufficient to reduce the rate and extent of glycolysis. Brine injection of intact pre-rigor muscles resulted in some preservation of the functional properties but not as pronounced as with salt addition to pre-rigor ground meat.

Hydrodynamic shockwave tenderization effects using a cylinder processor on early deboned broiler breasts

In separate experiments, chicken broiler breasts were deboned (45 min postmortem, 52 min, respectively) and either exposed to high pressure hydrodynamic shockwaves (HSW) 25 min after deboning (77 min postmortem) or after 24 h of storage (4°C) respectively, and compared to companion control breasts. HSW were produced in a cylindrical HSW processor with 40-g explosive. Warner-Bratzler shear (WBS) values of the HSW breasts treated at 77 min postmortem were not different than the controls. HSW treatment decreased (P<0.05) the WBS values of the stored and cooked breasts by 42.0% as compared to non-treated controls. Cooking losses were not affected by HSW. In general, raw and cooked color characteristics (CIE L*a*b*) were not affected by the HSW. HSW treatment at 25 min after deboning (77 min postmortem) may require a higher pressure front or delayed treatment after postmortem aging to improve tenderness.

Encapsulated phosphates reduce lipid oxidation in both ground chicken and ground beef during raw and cooked meat storage with some influence on color, pH, and cooking loss

Effects of encapsulated sodium tripolyphosphate (STP), sodium hexametaphosphate (HMP) and sodium pyrophosphate (SPP) on lipid oxidation in uncooked (0, 2, 24h) and cooked (0, 1, 7 d) ground chicken and beef during storage were determined. Ten phosphate treatments included a control (no phosphate), three unencapsulated (u) at 0.5% and three encapsulated (e) phosphates (0.5%) each at a low (e-low) and high (e-high) coating level. Two heating rates (slow, fast) were investigated. Cooking loss (CL), pH, color, orthophosphate (OP), TBARS and lipid hydroperoxides (LPO) were determined. A fast heating and uSTP resulted in lower CL (p<0.05). Orthophosphate increased with phosphate incorporation, slow heating and storage (p<0.05). Encapsulated phosphates and increased coating level reduced OP (p<0.05). Unencapsulated STP increased CIE a* and pH, whereas uSPP decreased CIE a* and pH (p<0.05). Encapsulated phosphates and the greater coating level had no effect on the pH in cooked samples. Not increased coating level but encapsulated phosphates decreased lipid oxidation in cooked samples (p<0.05).

Color stability and reversion in carbon monoxide packaged ground beef.

This study investigated the relationship between length (1, 2, 4, or 6 days) of exposure to carbon monoxide (CO) and the subsequent rate of loss of carboxymyoglobin color during display (0, 24, 48, 72 h) after repackaging in an oxygen permeable polyvinyl chloride (PVC) overwrap. In addition, the ability of CO to cause color reversion of metmyoglobin to carboxymyoglobin in brown colored, aged (4 days, PVC) or low oxygen-induced (2 days, (LOX-MAP) ground beef was studied. Extending CO exposure time increased overall mean redness. However, overall mean redness decreased after packages were opened. Day 6 exposed ground beef only maintained about 1.5 Minolta a* units higher than day 1 exposed after opened 72 h. The color of brown ground beef was converted to carboxymyoglobin upon exposure to carbon monoxide, regardless of how the initial brown color was formed. This color changes was relatively faster in LOX-MAP packaged ground beef compared to that formed by aging in PVC. Although color reversion is possible, consideration should be given to the microbiological status of the ground beef at the time of CO packaging.

Tenderization of chicken and turkey breasts with electrically produced hydrodynamic shockwaves

Eighty early deboned (45 min, post mortem) postrigor chicken breasts were exposed (24 h post mortem) to two levels (number of pulse firing networks, PFN; 45% energy) of electrically produced hydrodynamic shockwaves (HSW). In addition, 21 turkey breasts (72 h post mortem) were HSW treated (two PFN, 72% energy). Samples were water cooked in bags (78°C internal). Two PFNs were required to decrease (P<0.05) chicken Warner-Bratzler shear (WBS) force by 22% from the control (4.67 kg). WBS force of the HSW treated turkey breast decreased (P<0.05) by 12% from the control (3.20 kg). Cooking loss was higher (P<0.05) in the turkey breast portions but not in the chicken breasts. The electrically produced shockwave process has the potential to provide chicken processors with the ability to early debone and produce tender breasts and to provide turkey processors with tenderness-enhanced fillets.

Citric acid and sodium citrate effects on pink color development of cooked ground turkey irradiated pre- and post-cooking.

The effects of citric acid (0.15%, 0.3%) and sodium citrate (0.5%, 1.0%) on pink color development in ground turkey following irradiation (0, 2.5, 5.0kGy) were examined. Citric acid and sodium citrate had little effect on pink color when samples were irradiated prior to cooking. In contrast, when samples were cooked prior to irradiation, citric acid (0.3%) and sodium citrate (1.0%) reduced redness as indicated by eliminating a reflectance minimum at approximately 571nm, lessening greater reflectance in the red wavelength region, and preventing greater reducing conditions caused by irradiation. Citric acid significantly reduced pH and yields whereas sodium citrate reduced pH and yields to a lesser extent. Both citric acid and sodium citrate are potential ingredients that can be added during processing to prevent undesirable pink color in precooked irradiated ground turkey and therefore can result in greater acceptance of irradiated products by consumers.

Nitrite-embedded packaging film effects on fresh and frozen beef color development and stability as influenced by meat age and muscle type.

Muscles (Longissimus lumborum, LL; Psoas major, PM, semitendinosus, ST) were aged (2, 9d postmortem), cut into steaks, anaerobically packaged (nitrite-embedded film, NEF), and displayed (fresh, 19d; frozen, 39d). Fresh NEF increased (P<0.05) in redness (first 48h). Upon opening fresh NEF (d 6) and overwrapping in PVC film, redness declined (P<0.05). NEF cooked LL had more red surface compared to non-NEF. Meat age influenced NEF color. Intact NEF maintained acceptable red color throughout display. Residual nitrite and nitrate associated with fresh NEF and nitrate in NEF cooked LL were found (P<0.05) in the outer layer. Consideration should be given to providing sufficient time for nitric oxide myoglobin development when using NEF which may be influenced by meat age and muscle differences. NEF packaging has potential to extend fresh beef color display life. NEF appears to offer the opportunity to display bright red beef in frozen display by limiting typical effects of photooxidation.

Identifying constituents of whey protein concentrates that reduce the pink color defect in cooked ground turkey

Whey protein concentrate constituents were tested for their ability to reduce naturally occurring pink color defect and pink cooked color induced by sodium nitrite (10ppm) and nicotinamide (1.0%) in ground turkey. β-lactoglobulin (1.8%), α-lactalbumin (0.8%), bovine serum albumin (0.15-0.3%), lactose (1.0-3.0%), potassium chloride (500-1500ppm), and ferrous iron chloride (0.3-30ppm) had no effects on cooked pink color. Lactoferrin (30-5000ppm) increased or decreased pink color depending on its concentration in samples without added sodium nitrite or nicotinamide. Annatto (0.1-1.0ppm) reduced pink color whereas the higher concentration of magnesium chloride (22-88ppm) and ferric iron chloride (0.3-30ppm) increased pink color in samples with added nicotinamide. Calcium chloride (160-480ppm) was the only tested constituent that consistently reduced pink cooked color in samples with and without added nitrite and nicotinamide. Due to the variability of whey protein concentrates and the number of constituents that do not reduce pink cooked color, the addition of calcium alone or dried milk minerals containing calcium, phosphate, and citrate, represents a better means to regularly prevent the pink color defect in cooked ground turkey.

Systematic review of emerging and innovative technologies for meat tenderisation

Consumers are the final step in the meat supply chain and meeting consumer expectations of quality and tenderness are important for satisfaction and repeat purchase. High pressure processing, shockwaves, ultrasound, pulsed electric field and muscle stretching can be applied to pre- and post-rigor meat for tenderisation. These non-thermal and thermal innovative technologies can be used with varying levels of success to cause physical disruption to muscle structure, enhanced proteolysis and ageing and muscle protein denaturation and solubilisation resulting in changes to texture and juiciness. Results of a meta-analysis are used to compare the effects of these technologies on meat tenderisation. In the future, a combination of new and innovative technologies will be ideally suited to deliver a range of desired textures for meat products.