Razor Shear Research Articles

A Novel Laser Air Puff and Shape Profile Method for Predicting Tenderness of Broiler Breast Meat

The potential application of a new laser air puff system to assess poultry meat tenderness was investigated. Ninety broilers were deboned at either 1.25, 4, or 24 h postmortem. The raw breast fillets were scanned on a conveyor belt longitudinally by a laser distance sensor to obtain overall shape profiles and scanned again with a pressurized source of air (206.8 kPa). The 2 resulting profiles were superimposed to quantify the amount of deformation caused by the application of pressurized air. Five parameters including a height and length of each fillet were calculated and used to establish a model to predict tenderness. Tenderness of cooked fillets was determined instrumentally with the Meullenet-Owens razor shear, Blunt-Meullenet-Owens razor shear, and with sensory analysis. Hardness, Meullenet-Owens razor shear energy, and Blunt-Meullenet-Owens razor shear energy were modeled with the parameters extracted from the air puff system. Predicted values obtained from the models and observed values of individual fillets were subjected to logistic regression to classify fillets into tenderness levels. Tender fillets in the air puff predicted tender group represented 82, 81, and 88% based on hardness, Meullenet-Owens razor shear energy, and Blunt-Meullenet-Owens razor shear energy, respectively. The use of this tool resulted in more than a 20% improvement in the number of tender fillets after classification. The results suggested that this new system could potentially be implemented as an online tool for sorting poultry breast fillets by tenderness levels.

Changes in Broiler Breast Fillet Tenderness, Water‐Holding Capacity, and Color Attributes during Long‐Term Frozen Storage

Freezing is the most common and efficient way to maintain the quality of poultry products for long periods of time. However, tougher texture, discoloration, and drying have been reported as a result of long-term frozen storage. The impact of freezing on the tenderness, water-holding capacity, and color of broiler breast fillets was investigated for up to 8 mo. A total of 160 birds were deboned at either 2 or 6 h postmortem (PM). All deboned left fillets were frozen and stored at -18 degrees C for up to 8 mo, while the corresponding right fillets were assessed for texture approximately 24 h after deboning as a control measurement without any freezing treatment. Tenderness was measured by the Meullenet-Owens razor shear. Thaw loss, cooking loss, moisture content, color, and muscle shape profiles were also evaluated. No difference in tenderness was observed during the first 2 mo compared to the control (0 mo), but significantly decreased between 2 and 4 mo. The 8-mo-old fillets were the least tender, with a 31.5% increase in shear energy between 4 and 8 mo. Moisture content of cooked meat gradually decreased, showing a significant drop between 2 and 6 mo of storage, while thaw and cooking loss consistently increased over the entire storage period. The color of the frozen fillets tended to be darker, redder, and less yellow than the control, with increased storage duration. The results suggest that for optimal tenderness, frozen broiler breast fillets are best consumed within 2 mo of freezing.

Meat Quality Evaluation of Minimally Aged Broiler Breast Fillets from Five Commercial Genetic Strains

A total of 1,040 birds from 5 common commercial genetic broiler strains were raised and processed to analyze the effect of strain and deboning time on meat quality. The birds were processed at either 6 or 7 wk of age in 4 replications each. Carcasses were deboned at either 2 or 4 h postmortem (PM; n = 52 birds per treatment). Carcass and breast weights were measured on each bird to calculate breast yield. Muscle pH was measured at time of deboning. Fillets deboned at 4 h PM were measured for length, width, and height to evaluate footprint analysis. At 24 h PM, fillets were weighed to calculate drip loss, and color (L*) was also measured. The fillets were then cooked to 76°C, and cook loss was calculated. Fillets were then subjected to shear analysis using the Meullenet-Owens razor shear method where shear energy (N × mm) was calculated to evaluate tenderness. The strains in this study were chosen for differences in yield; therefore, as expected, breast yield was significantly different among strains. Variation in meat quality attributes existed among strains deboned at 2 h PM, but there was no consistent relationship between meat quality and breast yield. However, at 4 h PM, fewer differences among strains existed in meat quality characteristics (tenderness, water holding capacity, and pH). As expected, deboning at 2 h PM resulted in higher shear energy, higher muscle pH, and lower L* value compared with deboning at 4 h PM in all but one strain. However, water-holding capacity was not affected by deboning time at either age interval. Footprint analysis showed that most differences among strains were in heights measured at the fillet midpoint and caudal end. These results suggest that early deboning may affect meat quality of broiler strains differently, resulting in greater variation within the industry.

Pump rate and cooked temperature effects on pork loin instrumental, sensory descriptive and consumer-rated characteristics

Fresh pork loins ( n = 15; muscle sections, n = 30) were utilized to evaluate the effects of pump rate (0%, 6%, or 12%) with a solution of sodium tripolyphosphate and sodium chloride (0.4% and 1.0% targeted final product concentrations, respectively), and cooked endpoint internal temperature (71 or 82 °C) on instrumental texture, descriptive sensory profiles and consumer acceptance. Loins enhanced at a 12% pump rate had a higher ( P < 0.05) pH than untreated loins. While there were no differences in Warner–Bratzler shear force due to cooked endpoint temperature, chops enhanced at a 12% pump rate had lower ( P < 0.05) shear force values than untreated chops. Additionally, chops enhanced at 6% or 12% pump rates had lower ( P < 0.05) razor shear force values than untreated chops. Descriptive sensory analyses revealed that chops cooked to 71 °C had a more intense ( P < 0.05) blood serum flavor than chops cooked to 82 °C. Consumers found chops cooked to 82 °C to have a more acceptable overall flavor than chops cooked to 71 °C. Untreated chops had less intense ( P < 0.05) pork fat flavor, and more intense ( P < 0.05) blood serum, livery, and cardboard or oxidized flavor characteristics than chops enhanced at 6% or 12% pump rates. Additionally, sensory panelists reported chops enhanced at 6% or 12% pump rates to generally be more tender than untreated chops. Consumers reported a higher ( P < 0.05) overall acceptability for chops enhanced at 6% or 12% pump rates. Furthermore, both sensory panelists and consumers reported chops enhanced at 6% or 12% pump rates to be similar ( P > 0.05) in juiciness, regardless of endpoint temperature. However, untreated chops cooked to 82 °C were less juicy ( P < 0.05) than untreated chops cooked to 71 °C, suggesting retained palatability when enhanced chops are cooked to more abusive temperatures.