STORAGE PROPERTIES OF PRIMAL CUTS OF HOT- AND COLD-BONED BEEF

One side from each of 10 carcasses was selected for electrical stimulation and hot-boning within 1 h postmortem while the opposite side was chilled for 48 h at 2 to 3 C before boning. Ten boneless primal cuts were removed from the hot- and cold-boned sides. Each cut was evaluated for lean color, fat color and shape. Hot- and cold-boned primal cuts were vacuumized and stored for 20 days at 2 to 3 C. After the storage period, all cuts were again evaluated for lean and fat color and shape. Weight loss during storage was calculated for each cut. After 20 days of storage, hot- and cold-boned cuts did not differ significantly in lean color; hot-boned cuts had fat that was significantly whiter than that of cold-boned cuts; cold-boned cuts were more nearly normal in shape than were hot-boned cuts; and hot-boned cuts retained their vacuum longer and lost considerably less weight during storage than cold-boned cuts.     

MICROBIOLOGY OF BEEF SHELL FROZEN WITH LIQUID NITROGEN

SUMMARY— The effect of freezing primal cuts of beef with liquid nitrogen on the subsequent microbiological quality of their retail cuts was studied. Cryovac-packaged loins were shell frozen by spraying with liquid nitrogen and held for 2 or 3 days at room temperature (25–27°C) in insulated styrofoam boxes. Frozen packaged loins were also aged at 2°C for 21 days and at 22°C for 3 days before being cut into steaks. Steaks from each treated loin and steaks from fresh loins (controls) were packaged and stored in a display case at about 5°C. Examination was made of the loins and packaged steaks during storage to determine total anaerobes, fluorescent Pseudomonas , coliforms, enterococci, Clostridium perfringens , and incidence of Salmonellae and coagulase-positive staphylococci. Initial contamination on steaks increased with loins aged for a long time at low temperatures. Aging of loins at 22°C for 3 days promoted multiplication of C. perfringens and resulted in the steaks having the highest occurrence of coagulase positive Staphylococcus . Recovery of Salmonella from the steaks was more closely related to the source and level of contamination of the fresh meat than to time and temperature of holding of the wholesale cuts. These findings have application to shell freezing of beef with liquid nitrogen for air transport and to possible commercial aging practices.     

COAGULATION OF FISH PROTEINS FROM FROZEN FISH MINCE WASH WATER BY OHMIC HEATING

A batch-type ohmic heating device was developed to investigate the possibility of coagulating fish proteins from frozen fish mince wash water. At constant voltage (90 VAC), the temperature of wash water samples was raised to different set points (40, 50, 60, 70, and 80C, respectively). Effect of heating on coagulation of proteins and removal of COD, TS, and TSS was investigated. When the temperature reached 70C, 33.0%, 59.3%, 33.3%, and 92.1% protein, COD, TS, and TSS, respectively, were removed from the wash water. Holding samples at constant temperatures for longer time periods did not improve solids removal, except at 40C. The highest heating temperature for effective coagulation of proteins and removal of solids is 70C. The relationship between heating temperature and heating time followed a second order polynomial model. Apparent electrical conductivity and energy consumption increased linearly with the heating temperature. At the early stage of heating, almost all electric energy was converted to heat energy. As the temperatures rose, energy efficiency began to decrease linearly with the temperature. Overall energy efficiency was above 86%.     

EFFECTS OF DIETARY SUPPLEMENTATION OF VITAMIN E ON FROZEN STORAGE STABILITY OF PRECOOKED BEEF CRUMBLES

Holstein steers supplemented for 122 days with 0, 300 or 1300 IU/day vitamin E (EO, E300, E1300) provided semimembranosus muscle for manufacturing crumbles processed with 1.5% salt and possessing either 10 or 20% fat. They were precooked, packaged (nonvacuum), frozen at -29C and stored at -18C. Following storage for 2, 90 or 180 days, lipid oxidation was measured by TBA and a trained flavor panel. TBA values at 2 days were higher (P < 0.01) for EO than E300 and E1300 crumbles. These values at 180 days for E1300 crumbles were similar to EO and E300 samples at 90 days. Lower TBA values were obtained for 10% vs 20% fat crumbles at 90 days for both E300 and E1300 treatments. Intensity ratings for rancid flavor at 90 days were highest for EO and lowest for E1300 (P < 0.001). Vitamin E exhibited antioxidant properties but additional protection is needed for this product.     

EFFECT OF THAWING METHODS ON TEXTURAL QUALITY OF SOUS-VIDE STEWED BEEF ASSESSED BY SENSORY AND INSTRUMENTAL ANALYSES

This study compared four different thawing methods using sensory test with magnitude estimation, preference test with hedonic scale and physical analyses. The four methods were tap‐water, refrigeration, microwave reheating, and boiling‐water reheating. For physical analyses, there were differences (p≤0.001) among treatments in drip loss and expressible juice. For drip loss, the microwave reheated samples were the highest and the refrigeration and tap‐water treated samples were the lowest. For expressible juice, tap‐water and refrigerated samples were higher (p≤0.01) than the microwave and boiling‐water reheated samples. Microwave and boiling‐water reheated samples had higher hardness and cheviness and lower juiciness and fiber‐looseness. The refrigerated and tap‐water thawed samples had reverse sensory properties. Naive panelists preferred the refrigerated and tap‐water treated samples to the microwave and boiling‐water reheated samples for juiciness, tenderness, and overall preference. Physical parameters from textural profile analysis were not different among the thawing methods. Expressible juice was the best indicator for sensory hardness, juiciness, fiber‐looseness and chewiness among the physical parameters. Usually a quadratic regression model fit best when expressible juice was used to predict sensory textural properties.