Myoglobin Analysis for Determination of Beef, Pork, Horse, Sheep, and Kangaroo Meat in Blended Cooked Products

This method allows the concurrent detection of several types of animal muscle meat in comminuted, cooked meat products. Meat proteins were dissolved in a solvent containing 8M urea and dithioerythritol and separated by electrofocusing on an ultra-thin polyacrylamide gel, containing urea. The proteins were then transferred to nitrocellulose by electroblotting and the blot was incubated with anti-human myoglobin serum, a linking antibody, peroxidase-antiperoxidase (PAP) immune complex, and enzyme-substrate. Detection of less than 10% pork, horse and sheep meat was possible in a beef-based meat product which had been heated to an internal temperature of 120°C for 5 min. The method is not suitable for detection of chicken and turkey meats.     

Sodium Tripolyphosphate and Sodium Ascorbate Monophosphate as Inhibitors of Off-flavor Development in Cooked, Vacuum-packaged, Frozen Turkey

Sodium tripolyphosphate (STP) or sodium ascorbate monophosphate (SAsMP) in water solutions (0.3 and 0.5% levels) or water only were added to ground turkey which was cooked, vacuum packaged, and stored frozen. Soapy flavor was higher, but rancid flavor and hexanal and bathophenathroline-chelateable (nonheme) iron contents were lower in samples with phosphate salts. Samples without phosphates contained the greatest amount of bathophenathroline-chelateable iron; samples with 0.5% STP contained the least. The addition of phosphate salts decreased cooking losses and increased moisture but did not affect the fat content. Generally, intensity scores for stale and rancid aroma and flavor attributes were low, < 1 for all samples.     

Sodium Tripolyphosphate Stability and Effect in Ground Turkey Meat

Ground turkey meat, cooked and uncooked, was prepared with and without 0.5% sodium tripolyphosphate (SIP) and stored at 5°C for different periods of time. STP stability was evaluated by determining soluble orthophosphate. Water-holding capacity (WHC), pH, and mi-crobial count were also measured. STP hydrolyzed rapidly in uncooked samples. Refrigerated storage time (up to 6 days) did not affect STP hydrolysis in cooked turkey meat. Heating accelerated the rate of STP hydrolysis. End point temperatures (65, 75, and 85 °C) did not affect the extent of STP hydrolysis. STP increased WHC in both cooked and uncooked samples. STP did not inhibit total microbial growth in cooked or uncooked ground turkey meat.     

Pink Color Development in Turkey Meat as Affected by Nicotinamide, Cooking Temperature, Chilling Rate, and Storage Time

Consumers associate pink color in cooked turkey with undercooking. “Pinking” has been attributed to several factors, but remains a problem in the poultry industry. Effects of temperature, chilling rate, and storage time were investigated relative to pink color intensity of turkey meat cooked in the presence of 2% nicotinamide. As final cook temperature increased, sensory pinkness increased as did CIE a* values. Slower chilling rate resulted in higher CIE a* values and lower CIE b* values. Increased storage time generally increased CIE a* values and decreased b* values while CIE L* values were not affected.     

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.     

Color and Color Stability of Frozen Restructured Beef Steaks: Effect of Sodium Chloride, Tripolyphosphate, Nitrogen Atmosphere, and Processing Procedures

This study investigated the effect of mixing and grinding, tempering, addition of sodium chloride and sodium tripolyphosphate and processing under a nitrogen atmosphere on the color of restructured beef steaks initially and at 1-month intervals for 3 months of frozen storage. Mixing and grinding and manufacture under a nitrogen atmosphere had the greatest detrimental effect on the extent of discoloration initially; this was probably due to low oxygen concentration. Tempering and the addition of sodium chloride without sodium tripolyphosphate produced the most rapid increase in rate of discoloration during frozen storage. Tripolyphosphate partially counteracted the detrimental effect of sodium chloride, however, this effect did not appear to be due to the higher pH produced by the phosphate or the chelating ability of the phosphate. Surface discoloration and overall color were highly correlated with surface metmyoglobin (r= -0.87) and overall met-myoglobin (r= -0.94).     

Sensory Detection and Population Thresholds for Sodium Tripolyphosphate in Cooked Ground Turkey Patties

Sodium tripolyphosphate (STP) at levels of 0.1, 0.2, 0.3, 0.4, and 0.5% by weight was added to ground turkey meat to determine if a flavor difference could be detected when STP was present. Detection thresholds for STP in ground turkey meat were determined for 30 female respondents. Two population thresholds were determined using information from the detection thresholds. Two-thirds of the respondents detected a difference between samples with no STP and those with 0.5% STP or less. STP added at less than 0.3% was undetected by more than 50% of the tested population.     

Cooked Color in High pH Beef Patties as Related to Fat Content and Cooking from the Frozen or Thawed State

Beef patties were processed from high pH (>6.0) beef to contain 5, 10, 15, 20 or 25% fat. Patties were cooked to 71°C from the frozen or thawed state before evaluating color. Neither fat content nor state of patties when cooked exerted any major influence on color, but linear effects (p<0.01) in association with increased fat content included higher L* values and hue angles and lower a* values (15.2% reduction). Higher values for L*, b* (but not for 5% fat patties), and hue angles were observed for patties cooked thawed rather than frozen. The use of high pH beef lessened the effects of increased fat and cooking from the thawed state on increased brown color in cooked patties.     

Color Characteristics of Irradiated Aerobically Packaged Pork, Beef, and Turkey

Color changes in irradiated meat were species-dependent. Irradiated pork and beef became less red as a result of irradiation and display time. The redness values of turkey increased after irradiation but decreased during display time. The yellowness of the irradiated samples, for all species, increased as a result of irradiation and display. Visual evaluation of irradiated pork and beef indicated an increase in brownness, whereas turkey increased in redness as dose increased. The surface color of irradiated pork became less uniform than unirradiated pork. Reflectance spectra indicated that irradiation induced a metmyoglobin-like pigment in pork and beef, whereas the pigment in turkey was unchanged.     

Temperature, pH and Bacterial Populations of Meat as Influenced by Home Freezer Failure

Consumers are concerned about the fate of frozen meat products in home freezers when electrical power is interrupted. We investigated this concern by using an upright home freezer. Fourteen trials were conducted with packages of either beef or pork with varying trial load weights (Range = 43–128 kg). Meat samples were frozen, power was disconnected, and packages within each lot were analyzed daily for 9 days for temperature, microbial count, and pH. After about 36 hr without electrical power, bacterial populations reached log 6 and the meat product's wholesomeness for consumption or possible refreeze became questionable.     

Effects of Storage Time, Sodium Chloride and Sodium Tripolyphosphate on Yield and Microstructure of Comminuted Beef

Cook loss, pH and microstructure of comminuted beef made with four NaCl (1.3, 2.0, 2.6, 3.3%) and two sodium tripolyphosphate levels (0, 0.4%) were evaluated. The addition of phosphate reduced cook loss and raised the pH of the raw product to 6.0. Scanning electron micrographs showed that samples with low cook loss had a fine protein matrix. Phosphate addition helped to reduce cook loss and overcome decreased functionality when using aged meat.     

Effects of Sodium Tripolyphosphate on Physical and Sensory Properties of Beef and Pork Roasts

Six paired beef round and pork loin roasts were used to determine the effects of sodium tripolyphosphate (STPP) on fresh and reheated roasts. Roasts were pumped 10% of their weight with distilled water (control) or with distilled water containing 4.75% STPP. Roasts were cooked to internal temperatures of 70°C (beef) or 75°C (pork) and evaluated after 0, 1 or 3 days (roasts were reheated to cooked temperatures). This study indicates that phosphate in pork and beef roasts allowed them to be reheated after 1 and 3 days of refrigeration with minimal losses of juiciness, tenderness or flavor intensity, Phosphate injection reduced warmed-over flavor in reheated pork roasts but was not successful in decreasing the incidence of warmedover flavors in reheated beef roasts.     

Flavor of Cooked, Ground Turkey Patties with Added Sodium Tripolyphosphate as Perceived by Sensory Panels with Differing Phosphate Sensitivity

The flavor of cooked, ground turkey patties, with and without sodium tripolyphosphate, was profiled by two panels. One panel had a lower threshold for STP in ground turkey. Flavor profiles indicated that turkey patties without phosphate had more intense protein, serumy, brothy, and metallic character and less intense turkey and soapy character than the samples with phosphate. Both panels found similar characteristics for turkey with added phosphate, although the characteristics had a slightly different order of appearance. The panel with a lower threshold for STP found a more intense soapy character that tended to linger in the phosphate-treated samples.     

Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.     

Color Characteristics and Functional Properties of Flaked Turkey Dark Meat as Influenced by Washing Treatments

Effects of potassium phosphate and sodium acetate washing procedures on the composition, color characteristics, and functional properties of turkey dark meat were determined. All evaluations were compared to control thigh and breast tissues. Higher moisture and lower protein, fat and ash (P < 0.05) were found in tissues subjected to washing. Concentration of sarcoplasmic protein was reduced (P < 0.05) by washing. Hunter L, a, and b color values were changed (P < 0.05) to a color similar to breast meat by washing. Washed tissues, due to higher moisture, had less cooking loss in water and their protein solubility values increased with salt concentration. Emulsifying capacity (EC) values were not reduced (P > 0.05) due to washing. Phosphate-washed tissue stabilized a test emulsion better than the control and acetate/phosphate-washed thigh tissues.     

Moisture Retention and Textural Properties of Ground Chicken Meat as Affected by Sodium Tripolyphosphate, Ionic Strength and pH

Batches of ground chicken meat were mixed with 10% solutions containing 0.0–5.0% sodium tripolyphosphate and sufficient NaCl to adjust the ionic strength (IS) of the solutions from <0.7 to 6.0 at pH 6.5 to 9.5 in a 6 × 4 × 7 factorial experimental design. Patties prepared from the mixtures were evaluated for pH, cooking loss, and objective texture characteristics. Most effects of STPP were attributable to the direct effect of STPP on IS. However the ability of the phosphate to alter textural properties was greater at a pH value near the pK_a of the phosphate.     

Characterization of the Residual Pink Color in Cooked Turkey Breast and Pork Loin

The residual redness was characterized in well cooked meat from turkey breast and pork loin. A simple method of scanning thin slices by transmission spectrophotometry was used to evaluate the meat pigments in situ. Absorption bands at 414, 520, and 550 nm of the spectra obtained from cooked meat led to the conclusion that residual pink color was caused by cytochrome c. The method was further modified to study the effect of air contact on meat color after cooking. Other pigments were spontaneously oxidized as soon as meat surface was exposed to air. The concentrations of hemoproteins in turkey and pork were determined and found to be related to cooked meat color.     

Composition of Broiler Meat as Influenced by Cooking Methods and Coating

Broiler meat was cooked, by five different cooking methods and analyzed. Cooking methods affected cooking losses as follows: baked < broiled < microwave heated < panfried < pressurized deepfat fried. A coating greatly reduced moisture loss. Protein was highest in breasts, in coated rather than uncoated meat, and in parts microwave heated, deepfat fried and panfried. Crude fat was higher in uncoated thigh meat, cooked by deepfat frying, but the differences in cooking methods were not significant. Higher concentrations of minerals, where significant differences were found, were in poultry after being microwave heated and in uncoated rather than coated meat. Those minerals that were affected by cooking methods on an‘as is’basis included Fe, Mg, Na, and Zn and Fe on a dry weight basis. Those not affected included Ca, P, K, S, Cu, and Mn.     

Carrageenans in Beaker Sausage as Affected by pH and Sodium Tripolyphosphate

We investigated effects of meat pH or sodium tripolyphosphate (STPP) on performance of carageenans (kappa, iota or lambda) in low-fat beaker sausage model systems. Adding STPP or using high-pH meat affected performance of the meat batter in similar ways. High-pH meat batters or those containing STPP had lower force values when extruded, lower cooking losses, and were firmer when cooked. The addition of lambda-carrageenan produced the softest texture. Kappa- and iota-carrrageenan improved water retention of low-pH meat batters. After staining, light microscopy revealed different structural effects of the carrageenans.     

Thermal Gelation of Pork, Beef, Fish, Chicken and Turkey Muscles as Affected by Heating Rate and pH

Effects of heating rate (3°C or 0.7°C/min) and pH (5.5, 6.0, 6.5, or 7.0) on thermal gelation properties of different muscle systems were evaluated (10% protein, 2% NaCl) using pork, beef, fish, and chicken and turkey (breast and thigh) muscles. Results indicated that, at pH 6.5 and 7.0, force required to rupture the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index (Ni), using a slow heating rate, were higher than with rapid heating. All muscles (except breast muscles with the slow heating rate) yielded higher (P<0.05) gel strength (Fp, Pf) at pH 6.0 than at the other pHs.