Processing Ingredients Affecting Oxidative and Textural Stability of Restructured Beef Roasts

Restructured beef roasts containing 0.3% sodium tripolyphosphate (STP) and 1% soy protein isolate (SPI); or STP only; or SPI only; or no STP or SPI were cooked at 70 or 100°C to an internal temperature of 65°C, then stored at 4°C for 0 and 3 days. In control roasts, the higher cooking temperature resulted in higher (p ≤ 0.05) TBA values. STP and SPI inhibited oxidation but the effect was not detected sensorially. Significant interactions (p ≤ 0.05) indicated that STP was more effective at higher cooking temperatures and SPI at lower temperatures. Total moisture of the cooked product was significantly greater with STP but no differences in juiciness and tenderness were detected sensorially.     

Heating and Texture Profiles of Packaged Pasteurized Beef Loin Steaks from Precooked Roasts

Precooked beef loin steaks obtained from waterbath cooked roasts, were oasteurized usinge three different temoeratures (65° 85° and 100°C) and rimoved after reaching internal temperatures of 60°, 70° and 80°C. Temperatures of the steaks were monitored at three locations during heating and cooling. Steaks heated to internal temperatures close to the cooking water temperatures had the least differences in temperature between layers. Total cooking losses increased (P<0.05) as internal endpoint temperatures and pasteurization water temperature increased. Texture profiles of steaks cut from precooked roasts were similar to pasteurized steaks.     

Physical and Sensory Characteristics of Fresh Pork Leg Roasts Cooked at Low Temperatures

The effects of oven temperatures of 82, 93, 121 and 163°C were studied using 31 fresh pork leg roasts cooked to 74°C in oven bags. Warmed-over-flavor (WOF) was measured by sensory analysis after holding 3 hr at 68°C and after holding 24 hr at 2°C and then reheating to 68°C prior to serving. Roasts cooked at 82 and 93°C tended to have less WOF after refrigeration and reheating than roasts cooked at 121 and 163°C. Roasts cooked at 93°C had fewer aerobic mesophilic bacteria than those cooked at 121 and 163°C. In general, objective and sensory perception measurements indicated that roasts cooked at 82 and 93°C were of higher quality.     

Vacuum-Packaged Precooked Pork from Hogs Fed Supplemental Vitamin E: Chemical, Shelf-Life and Sensory Properties

Precooked longissimus chops and semimembranosus/adductor roasts from pigs (n = 30) given no supplemental vitamin E (CON) or supplemented with 100 mg vitamin E/kg diet (VITE) were evaluated for lipid oxidation, microbial growth, sensory characteristics, cooking/storage losses and reheating losses. Chops and roasts were vacuum packaged, precooked to 60°C and stored at 2°C for 0, 7, 14, 28, or 56 days. Lipid oxidation was lower in VITE chops and roasts than in CON chops and roasts. Off-flavor intensity scores were more acceptable and storage/ cooking losses were lower for VITE roasts than for CON roasts. Supplementation of vitamin E in a swine diet provided added protection against lipid oxidation and precooking pork under vacuum provided a palatable product with a shelf-life of 56 days.     

Oxidative Stability and Textural Quality of Restructured Beef Roasts as Affected by End-point Cooking Temperatures, Storage and the Incorporation of Surimi

Restructured beef roasts containing either 0 or 3.5% surimi were cooked to end-point internal temperatures of 50, 60, and 70°C to assess treatment effects on textural and oxidative quality after 2 and 5 days of refrigerated (4°C) storage. Surimi did not improve binding, cook yield or sensory tenderness and juiciness. The sensory panel was able to distinguish a slightly more pronounced fishy flavor when surimi was added. End-point internal temperature had no effect on tensile strength, however, tenderness increased and juiciness decreased with increased endpoint temperatures. Higher end-point internal temperature enhanced lipid oxidation, which proceeded more rapidly during refrigerated (4°C) storage. Nonheme iron increased with increasing end-point temperature. During storage, phospholipid content decreased while total lipid remained constant.     

Effects of salt and some antioxidants upon the TBA numbers of meat

The effects of salt alone (2%) or coated with α-tocopherol or with Tenox 4 (BHA-citric acid-propylene glycol) or in a mixture containing BHA and BHT with salt on the TBA numbers of raw and cooked beef were determined after holding for 0 or 2 days at 4°C. Salt accelerated lipid oxidation both during cooking and subsequent storage. The α-tocopherol-coated salt also increased lipid oxidation, but only during storage after cooking. Both Tenox 4-coated salt and the mixture of BHA and BHT with salt completely inhibited lipid oxidation in cooked meat, both during cooking and upon subsequent storage. Results suggest that selected antioxidants can be used to inhibit the development of warmed-over flavor (WOF) in cooked meats.     

Spectra of Pigments Responsible for Pink Color in Pork Roasts Cooked to 65 or 82°C

Undenatured oxymyoglobin and deoxymyoglobin were the pigments responsible for pink color in pork roasts cooked to 65°C. Roasts cooked to 82°C had gray internal color after cooking, but panelists noted development of pink internal color after refrigerated storage. Reflectance spectra of pink slices from roasts cooked to 82°C, then stored for 12 days at 2°C, were characteristic of denatured globin hemo-chromes or related nonnitrosyl hemochromes.     

Palatability and Storage Characteristics of Precooked Beef Roasts

The palatability and storage characteristics of fresh, frozen and precooked beef chuck roasts prepared using added phosphate-salt and vacuum cooking bags were evaluated. Palatability attributes (tenderness, juiciness, beef flavor intensity, and off-flavor intensity) of precooked roasts prepared in vacuum cooking bags with phosphate-salt were as good or better than freshly cooked roasts. Precooked roasts in vacuum cooking bags had the lowest total bacterial counts after storage for 14 and 28 days. A palatable precooked roast beef product was developed that can be stored for 28 days at 4°C.     

Thiamin Retention and Other Characteristics of Cooked Beef Loin Roasts

Beef loin roasts were prepared by three procedures that simulated home, foodservice or commercial methods for precooking meat prior to vacuum packaging. Roasts were prepared by conventional electric (176.5°C), cook-in-package waterbath (70°C water), or smokehouse (ambient temperature) heating. Yield, thiamin, fat, water content, and Instron tenderness of roasts were determined. Raw roasts had higher (P<0.05) water and free water content. All cooked roasts were significantly lower in thiamin content (dry, fat free basis) and thiamin retention (true and dry, fat free basis) than raw roasts (P<0.05). No differences were observed between cooking procedures evaluated (P>0.05), suggesting that most heat processing treatments used for precooking packaged meat result in similar quality products.     

Sensory and Chemical Characteristics of Fresh Pork Roasts Cooked to Different Endpoint Temperatures

Pork roasts cooked to various endpoint temperatures were evaluated by sensory and chemical analyses. Increased endpoint temperatures were associated with increased cooking losses; decreased juiciness, pink color, and metallic flavor; increased graininess, brown color, and pork flavor. Increased endpoint temperatures also led to a concentration of lipid, protein and certain fatty acids. Cholesterol levels were not significantly influenced by endpoint temperature. Lipid content was decreased by removal of external fat before cooking. To minimize pink color in some muscles and maximize other sensory characteristics and yield of cooked meat, at least 71.1°C and no more than 76.6°C is recommended as the endpoint temperature for fresh pork roasts.     

Antioxidative activity of α-tocopherol in cooked and uncooked ground pork

The effect of α-tocopherol (0, 100, 200 ppm) on lipid oxidation either in cooked or uncooked ground pork was studied during aerobic storage at 4°C and -20°C. Lipid oxidation was measured using the 2-thiobarbituric acid (TBA) method and rancidity development was scored by a trained sensory panel. Alpha-tocopherol slowed the rate of oxidation in cooked ground pork stored at either 4°C or -20°C and uncooked samples refrigerated for extended periods of time (12 days). In cooked product stored at 4°C where oxidation development was intense and off-flavors were strong, panelists did not detect flavor differences due to treatments. But in cooked product stored at -20°C sensory results were consistent with TBA analysis. Pre-rigor grinding, known to induce a high pH and inhibit lipid oxidation in uncooked fresh pork, had no protective effect on lipid oxidation as measured by TBA values in cooked ground pork, regardless of storage condition. TBA numbers increased during storage of cooked product at 4°C with an increase in internal cooking temperature between 50°C and 80°C. Internal cooking temperatures of 70°C or higher induced a rapid rate of oxidation when stored at 4°C.     

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.     

Cooked yields, color, tenderness, and sensory traits of beef roasts cooked in an oven with steam generation versus a commercial convection oven to different endpoint temperatures

A CVap steam generation oven was compared with a Blodgett convection oven to examine effects on yields, cooked color, tenderness, and sensory traits of beef Longissimus lumborum (LL), Deep pectoralis (DP), and Biceps femoris (BF) muscles cooked to 1 of 3 temperatures (65.6, 71.1, or 76.7°C). Four roasts were cooked in the CVap for a constant time, and 2 roasts were cooked in the Blodgett until they reached target temperatures (3 replications). Cooking yields were higher (P<0.05) for BF and LL roasts in the CVap. Slice shear force (SSF) for BF roasts was lowest (P<0.05) in the CVap but lowest (P<0.05) for DP roasts in the Blodgett. No oven effect (P>0.05) was found for LL roasts. Sensory tenderness for BF roasts in the CVap was higher (P<0.05) than those in the Blodgett. Juiciness was higher (P<0.05) for LL roasts in the Blodgett. The CVap oven offers some tenderization (BF) and cooking yield advantages (BF and DP) over forced-air convection cooking.     

LIPID OXIDATION IN MUTTON: SPECIES-RELATED AND WARMED-OVER FLAVORS

Effects of lipid oxidation in cooked mutton on species-related flavor and warmed-over flavor (WOF) intensities were studied using various additive treatments and post-cooking storage (versus no additive/no storage) as means to produce samples of varied lipid oxidation. Ground mutton was treated with 200 ppm sodium nitrite, 0.5% sodium tripolyphosphate, 0.05% sodium ascorbate, 3% sodium lactate, 0.002% propyl gallate, or water only (control), cooked to 74C, and aerobically stored at 4C for 0, 2, or 4 days. Nitrite-treated samples showed the least lipid oxidation as determined by the 2-thiobarbituric acid reactive substances (TBARS) and had more intense species-related (muttony) flavor than all other treated samples. Some samples exhibited high TBARS after 4 days but were still rated "slight" for WOF intensity, probably due to the strong species-related flavor that could have made WOF less perceivable. Accordingly, correlations, although statistically significant, were low between TBARS and WOF intensity or between species flavor intensity and WOF intensity.     

Differences Between Conventionally Cooked Top Round Roasts and Semimembranosus Muscle Strips Cooked in a Model System

Roasts cooked at 177°C by dry (OR) or moist (OFB) heat to 60°C were compared with muscle strips cooked in a model system to 60°C at a rate similar to oven raosting 1.4-kg roasts at 177°C. OFB roasts were less tender, less juicy, had less rare beef flavor, less red and yellow color, more total cooking loss, and shorter cooking time than did OR roasts. Strips had lower values for Instron measurements of hardness, chewiness, shear cohesiveness, and firmness than did OR or OFB roasts. Although strips were cooked in a moist atmosphere, they were more like OR roasts than like OFB roasts. Variance for a given measurement was similar between roasts and strips.     

Palatability and Storage Characteristics of Precooked Pork Roasts

Pairs of boneless pork loins (n=10) were pumped to contain 0.5% tripolyphosphate or water and allotted to three treatments: PVC wrapped, convection oven cookery (CO); vacuum packaged, precooked and reheated in a water bath (PC); and vacuum packaged and cooked in a water bath (VP). Paired loins (n = 30) were injected with tripolyphosphate and allotted to the following treatments and storage (0, 14 or 28 days) conditions: Control (?20°C) [CO]; precooked (?20°C) [PCPR]; precooked (4°C) [PCRF]; vacuum packaged (?20°C) [VPFR]. VP and PC phosphate injected roasts were more tender and had lower cooking losses than CO roasts. After 28 days, all PC roasts had lower microbial counts than other treatments, and PC and VP roasts had improved palatability compared with CO roasts.     

Effect of Soybean Cooking Temperature on the Texture and Protein Digestibility of Miso

Miso samples were prepared with soybeans cooked for 10 min at different temperatures (up to 100°C). Appreciable changes in the amount of 0.2 M trichloroacetic acid-soluble nitrogen (TCA-soluble N) and the pattern of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of fermented miso samples were observed in the temperature range between 90°C and 100°C. No further changes in the TCA-soluble N and SDS-PAGE pattern of miso were observed when the cooking time was prolonged up to 3 hr at 100°C. On the other hand, a 2 hr cooking period at 100°C was required to achieve a level of softness for cooked soybeans to give an acceptable texture of miso.     

Sensory and Cooking Properties of Lamb Chops Cooked With and Without External Fat and Epimysium

When lamb loin chops with or without 0.64-cm subcutaneous fat layer and epimysium (fat-on or fat-off chops) were broiled to an internal temperature of 77°C, cooking losses were higher (P<0.05) for fat-off chops than for fat-on chops. The concentration of ether-extractable fat (g/100g cooked lean) was also higher for the cooked lean from fat-off chops while the opposite was observed for moisture. Sensory properties of the cooked lean were adversely affected by the removal of subcutaneous fat before cooking. TBA-reactive substances in a given amount of the cooked lean, after 4 days of storage at 4°C, were slightly higher (P<0.10) for the lean from fat-off chops than for the lean from fat-on chops.     

Effect of marination and microwave heating on the quality of Semimembranosus and Semitendinosus muscles from Friesian mature cows

Semimembranosus (SM) and Semitendinosus (ST) muscles from 8 mature cows were used to evaluate the effect of marination, power of microwave heating, and internal temperature of cooking on the quality of calibrated beef roasts. Four treatments, using combinations of power (182W and 654W) and temperature (60 and 80°C) were applied to marinated (10% added brine: salt, sodium lactate, lactose, and ascorbate) and control roasts from SM (15×5×3cm) and ST (10×4×3cm) muscles in a 2×2×2 factorial arrangement. Microwave cooking was heterogeneous resulting in a gradient of temperatures within the roasts. Either high or low microwave power were appropriate for cooking ST roasts, but SM roasts cooked at 654W showed higher cooking losses, and lighter and less red cooked color than 182W. Cooking to 80°C increased cooking and color losses in both muscles and decreased tenderness of SM roasts compared with 60°C. Marination can be used successfully to enhance beef tenderness of ST and SM muscles cooked in microwave.