Effect of irradiation and packaging type on sensory quality of chill-stored turkey breast fillets

A panel of experienced assessors was used to test the effect of irradiation at 2.5kGy (250krad) on the sensory quality of 1-day and 21-day-old turkey breast fillets stored at 1°C in either oxygen-permeable polythene or an oxygen-impermeable barrier film. In the application of Free Choice Profiling and Generalized Procrustes Analysis, assessors used their own terms to describe the appearance, odour and flavour of the samples.
The irradiated samples showed negligible growth of micro-organisms across 21 days of storage. Radiation treatment resulted in an intense pink colour in the raw and cooked samples, which was maintained during storage in oxygen-impermeable film, but decreased in samples exposed to oxygen during storage. Radiation also produced a set of unpleasant raw odour notes variously described as sour, rancid, mature, bad meat or putrid in the samples stored in oxygen-impermeable film. These notes were unlike the sulphurous notes previously associated with protein denaturation in irradiated chicken and were apparently distinct from the odour notes that developed in corresponding non-irradiated samples.     

High Pressure Effects on Gelation of Surimi and Turkey Breast Muscle Enhanced by Microbial Transglutaminase

High pressure effects on the strength (stress) and elasticity/deformability (strain) of surimi and turkey breast meat gels containing microbial transglutaminase (TGase) were evaluated. Pressurization of muscle proteins at 4°C prior to incubation at 25°C or 40°C (setting) increased gel strength 2–3 fold in uncooked surimi gels, but not in uncooked turkey gels. However, pressurization at 40°C or 50°C prior to setting increased the strength of turkey gels. Similar effects of prior pressurization, but of lesser magnitude, occurred in gels formed by directly or subsequently (following setting) cooking at 90°C. SDS-PAGE confirmed that myosin crosslinking occurred due to TGase activity during the setting treatment, which had survived prior pressure treatment. High pressure rendered protein substrates more accessible to TGase thereby enhancing intermolecular cross-link formation and gel strength.     

Identification of the compound in a potent cranberry juice extract that inhibits lipid oxidation in comminuted muscle

An extract prepared from cranberry juice powder using a mixture of chloroform and methanol was particularly effective at inhibiting lipid oxidation in mechanically separated turkey (MST), providing more than 3 weeks of additional stability during −4 °C storage at a usage level of 0.1% (wet weight basis). The chloroform extract was fractionated by flash chromatography (FC) and analysed using reverse-phased high performance liquid chromatography (RP-HPLC) with UV/vis diode array detection to identify the component(s) present in the fractions. One of the five fractions obtained was effective in delaying the formation of lipid peroxides and thiobarbituric acid reactive substances (TBARS) in MST, while the remaining fractions had little to no inhibitory action. Mass spectrometry (MS) analysis indicated the presence of two flavonols, quercetin and quercetin-3-O-(6″-benzoyl)-β-galactoside in the inhibitory fraction. This fraction (containing quercetin at 467 μmol/kg MST) inhibited lipid oxidation in MST similarly to pure quercetin added to MST at the same concentration. This indicated that quercetin accounted for all or nearly all of the inhibitory capacity in the chloroform extract.     

Prevention of Lipid Oxidation in Precooked Turkey Meat Patties with Hot Packaging and Antioxidant Combinations

The effects of antioxidants or hot packaging and their combination on lipid oxidation were quite variable depending on the additives in turkey meat. The TBARS values of cooked patties were greatly affected by the degree of oxidation in the raw meat, and the effectiveness of antioxidants varied with added prooxidants. Ascorbate and free radical terminators had stronger antioxidant effects than iron chelators, and chelating iron alone could not eliminate lipid oxidation in either raw or cooked meat with added NaCl. The combination of hot packaging and antioxidants provided cooked patties with better protection from lipid oxidation than either treatment alone.     

Three Methods for Determining Nonheme Iron in Turkey Meat

The ferrozine, the Schricker and modified Schricker methods were used to measure the non-heme iron in raw and cooked turkey meat. The ferrozine method gave the lowest non-heme iron values, while results from the Schricker and modified Schricker were not different (p<0.05). When hemoglobin (Hb) was added to breast meat, how-ever, differences (p<0.05) between the Schricker and modified Schricker, and Schricker and ferrozine methods were observed in cooked meat with NaCl. Cooking and addition of NaCl caused increase in measured nonheme iron content and had a synergistic effect on the release of nonheme iron in meat.     

Residual glutamic-oxaloacetic transaminase (GOT) activity in thermally processed poultry and poultry products as an indicator of end-point temperatures

Glutamic-oxaloacetic transaminase (GOT) activities in chicken and turkey thigh and breast meat samples, thermally processed at 60–84°C in a model heat-treating system, were evaluated for use as indicators of end-point cooking temperatures (EPT). Wings, breasts, thighs and legs from commercially cooked, whole, roasted chickens and commercially processed products containing chicken and turkey meat were analyzed also to determine if residual GOT activities would indicate compliance with recent FDA/FSIS EPT recommendations. Activities of samples processed in the model system decreased logarithmically with increasing temperatures. GOT activities were higher (P < 0·05) in thigh meat than breast meat in both chicken and turkey samples; activities were higher in turkey than chicken. GOT values for chicken thigh and breast meat at 74°C, the FDA/FSIS recommended EPT for use by food handlers and retailers, were 735 and 164 Sigma-Frankel units ml^?1 (SFU ml^?1), respectively. Values for turkey thigh and breast meat at this temperature were 1080 and 450 SFU ml^?1, respectively. The range of activities was 7–13 SFU ml^?1 in commercially prepared chicken products and 27–161 SFU ml^?1 in turkey products. Analysis of these products showed adequate cooking and compliance with FDA/FSIS recommended EPT for retail sale. These data indicate that residual GOT activity in processed poultry has potential for use as an indicator of EPT.     

Modeling Heat Transfer During Oven Roasting of Unstuffed Turkeys

A finite element method was used to solve the unsteady state heat transfer equations for heating of turkeys in a conventional electric oven. Breast, and thigh and wing joint temperature in 5.9, 6.8, 8.6, 9.5, and 10.4 kg turkeys were simulated. A surface heat transfer coefficient of 19.252 W/m2K determined by transient temperature measurements in the same oven, was used. Thermal conductivity measured using a line heat source probe from 0 to 80°C was 0.464 W/mK. Simulated temperatures were within 1.33, 1.47, and 1.22°C of experimental values of temperature in the breast, thigh, and wing joint, respectively. Initial temperature 1,2, and 3°C lower than 4°C required additional baking time of 16,22, and 27 min., respectively for the thigh joint to reach the target endpoint temperature.     

Microbiological characteristics of poultry patties in relation to packaging atmospheres

Microbial characteristics under different atmospheres (vacuum, air, MAP₁: 80% O₂/20% CO₂ and MAP₂: 5% O₂/65% N₂/30% CO₂) of poultry patties made of a mixture of ostrich, chicken and turkey meat were evaluated. The meat preparations were examined for changes in pH, colour properties (CIE L*, a*, b*), headspace composition, and bacterial counts (total viable cell, psychrotrophs, Enterobacteriaceae, lactic acid bacteria, Staphylococcus spp., Brochothrix thermosphacta, Pseudomonas spp.). The use of a high O₂ atmosphere (MAP₁) quickly leads to a loss of the appealing red colour. A limited alteration occurred with use of MAP₂ and vacuum. For total viable counts a cell load higher than 8 log cfu g^?1 for the samples packaged in air, MAP₁ and MAP₂ at the end of storage was observed. Whereas, for the vacuum packed samples the cell load never reached values higher than 8 log cfu g^?1. Enterobacteriaceae, B. thermosphacta and Pseudomonas spp. cell load was less with the vacuum (7.60, 5.06 and 7.17 log cfu g^?1, respectively) and MAP₂ packaging (7.08, 5.60 and 7.40 log cfu g^?1, respectively). However, the high microbial loads suggest that an improvement of the microbiological quality of poultry meat is necessary if the producers are going to propose this new meat preparation on the market.     

Gelation of Turkey Breast and Thigh Myofibrils: Effects of pH, Salt and Temperature

Salt concentration >0.1M and pH were important to the development of gel fracture properties. Howcvcr, meat type and salt concentration (0.5–1.0M) did not influence gel shear stress or shear strain. Isothermal heating temperature (55°C or 70°C) affected only gel shear strain. Rheological properties at fracture and nonfracture did not respond alike to changes in gclation conditions. General similarities between breast and thigh myofibril gels implied that protein isoforms were not the main factor influencing gel structure formation.