Pulsed Electric Field (PEF) Processing of Chilled and Frozen-Thawed Lamb Meat Cuts: Relationships between Sensory Characteristics and Chemical Composition of Meat

The effect of PEF processing and chilled storage on the volatile composition and sensory properties of chilled and frozen lamb cuts was investigated in this study. Results showed that PEF-treated chilled and frozen lamb cuts varied in temporal flavour attributes with storage. Storage for 7 days resulted in oxidized flavour, while PEF treatments for all chilled and frozen cuts were associated with browned and livery flavour attributes. Partial least squares regression (PLSR) was applied to determine the predictive relationships between the volatile composition, fatty acid and amino acid profiles, and sensory responses for PEF treated lamb cuts. The results showed that some volatile compounds (2-nonanone, 2-pentylfuran, pyrrole, methyl pyrazine, 2-ethyl-3-methyl pyrazine, and thiophene) correlated well with the meaty and juicy flavour of PEF treated frozen lamb cuts. In PEF treated chilled lamb cuts, meaty and juicy flavours were associated with the presence of fatty acids (C18:0, SFA, 20:5(n-3), and n-3). In contrast, livery and browned perception of both PEF processed chilled and frozen lamb cuts were associated with the presence of amino acids (threonine, phenylalanine, isoleucine, tyrosine, and methionine), and some volatile compounds (heptanal, 2-ethylfuran, pyridine, dimethyl disulphide, dimethyl trisulphide, and 3,5-diethyl-2-methyl pyrazine). Overall, these results imply that careful consideration of type of meat cuts, PEF pre-treatment, and storage are important when subjecting lamb meat to PEF processing.

Retail display evaluation of steaks from select beef strip loins injected with a brine containing 1% ammonium hydroxide. Part 1: Fluid loss, oxidation, color, and microbial plate counts

Select beef loin pairs (n = 10) were injected (10% pump) with brine containing either 4.5% sodium-based phosphates, (CON), or 1% ammonium hydroxide treatment (AHT). Both brines also contained 3.6% NaCl and 1% Rosemary Herbalox. Steaks cut from loins were high oxygen (80% O(2)/20% CO(2)) modified atmosphere packaged, stored 4 d at 4 °C in the dark to simulate transportation, and then placed in retail display for 14 d (4 °C). On day 0, 7, and 14 of retail display steak properties were measured. Purge from AHT steaks was higher than CON (P < 0.05). Panelists were not able to visually discriminate between AHT and CON steaks through the first 6 d of retail display. After day 6, panelists rated AHT steaks higher for muscle color, percent discoloration, and overall color. Steaks from both treatments started at day 0 retail display with similar total plate counts (P > 0.05). Microbial counts increased more rapidly for AHT steaks than CON steaks (P < 0.05). AHT and CON steaks were not different in terms of lipid oxidation through day 7 retail display. By day 14 retail display CON steaks were above the threshold for consumer perception of oxidized flavors in fresh meat. However, results also indicated the AHT and CON steaks were no longer acceptable by day 14 in terms of color, were questionable in terms of microbial load, and likely were beyond their reasonable shelf life. Based on retail display properties, results indicated 1% AHT could successfully replace 4.5% SP in a meat injection brine. Practical Application: The research in this report compares steaks that have been injected with a commercial brine formulated with SP to steaks that have been injected with a brine, where the SP in the formulation are replaced with 1% AHT. Ammonium hydroxide is an USDA-FSIS approved ingredient in brines injected into fresh meats. Successful replacement of sodium phosphate with ammonium hydroxide would allow processors to significantly reduce the sodium content of injected fresh meat.

Comparison of tenderness, palatability, and retail caselife of enhanced cow subprimals with nonenhanced cow and United States Department of Agriculture Select subprimals

The objective of this study was to determine the effects of enhancing cow subprimals on tenderness, palatability, and retail caselife compared with nonenhanced cow and USDA Select subprimals. Strip loin, top sirloin butt, and ribeye subprimals were selected (n = 60 per subprimal; n = 40 cow, n = 20 USDA Select). At 14 d postmortem, one-half of the cow product was randomly selected for enhancement with phosphate, salt, rosemary, potassium lactate, beef stock, ice, and water using a needle injector. All subprimals were fabricated on d 14 postmortem into ten 2.54-cm steaks. Steaks were assigned to analysis for Warner-Bratzler shear force (WBSF), trained sensory panel evaluation, or simulated retail display and assigned randomly to aging periods of 14, 21, or 28 d postmortem. Warner-Bratzler shear force values of ribeye steaks from the nonenhanced cow over all aging groups were significantly greater (P < 0.05) than enhanced cow and USDA Select ribeyes. Furthermore, top sirloin butts from nonenhanced cow had greater (P < 0.05) WBSF values at 14 and 28 d compared with other treatments. Nonenhanced cow strip loin steaks had greater (P < 0.05) WBSF values (4.58 ± 0.15 kg) and greater (P < 0.05) cook loss (20.70 ± 0.68 kg) than enhanced cow (3.90 ± 0.14 kg; 14.32 ± 0.69 kg) and USDA Select steaks (3.09 ± 0.14 kg; 15.01 ± 0.68 kg). Sensory data revealed that enhanced cow steaks from all subprimals were greater (P < 0.05) for initial juiciness for both aging periods, compared with nonenhanced cow and USDA Select. Sensory tenderness ratings for enhanced cow and USDA Select subprimals were greater (P < 0.05) than nonenhanced subprimals. Nonenhanced subprimals received the largest connective tissue amount score by panelists (P < 0.05). Enhanced cow steaks from all 3 subprimals had a greater intensity (P < 0.05) for salty flavor. Panelists detected a more intense (P < 0.05) soapy flavor in enhanced ribeyes. In ribeye and top sirloin butt steaks, grassy/cowy flavor was more intense (P < 0.05) in nonenhanced cow steaks compared with enhanced and Select. Subjective color scores revealed USDA Select ribeye and strip loin steaks aged 14 d were darker red (P < 0.05) when compared with 21- and 28-d aged steaks. Nonenhanced cow steaks from all 3 subprimals had the greatest amount (P < 0.05) of surface discoloration during display. Enhanced cow strip loins had the least (P < 0.05) L* and b* values over all aging periods, while USDA Select strip loins at 28 d had the least (P < 0.05) a* value. The USDA Select top sirloin butt steaks had the greatest (P < 0.05) b* value over all aging periods. Enhanced cow steaks were comparable with or superior to USDA Select steaks for tenderness and juiciness, but additional research is needed to determine consumer acceptability of additional flavors associated with enhancement of cow product and to improve the effects of enhancement on color of cow product.