INSTRUMENTAL AND SENSORY MEASUREMENT OF BEEF PATTY AND SAUSAGE TEXTURE

Beef sausages and beef patties of different texture were produced by varying the fat content in the raw mix over the range 5–30%. Batter shear stress and strain increased linearly with increased fat level (P<0.09 and 0.001, respectively). Although batter shear stress was not related to sensory scores, shear strain was directly related to moistness and inversely related to grittiness scores (P<0.05). Batter sensory moistness increased and firmness and grittiness deceased linearly with fat content (P<0.001). Changes in fat content did not affect the peak force of cooked patties, and there were poor correlations between patty peak force and sensory scores. Patty juiciness and softness increased and patty cohesiveness and chewiness decreased with fat content (P<0.001). Batter cook yield increased and patty cook yield decreased with increasing fat level (P<0.001). Sensory scores, using trained panelists, were more sensitive to the effect of fat content on patty and sausage texture than instrumental measurements.     

PHYSICAL, CHEMICAL, AND SHELF-LIFE CHARACTERISTICS OF LOW-FAT GROUND BEEF PATTIES FORMULATED WITH WAXY HULL-LESS BARLEY

Ten percent hydrated, cracked waxy hull-less barley was incorporated into 90/10 (percentage lean/percentage fat) ground beef to produce a low-fat beef-barley patty which had substantially higher cook yields and water retention than either of the controls (80/20 beef, 90/10 beef). Instron texture profile analysis revealed that the beef-barley burger was less chewy, springy, cohesive, gummy, and hard than the controls. Aerobic plate counts indicated that, after six days of refrigerated storage, the beef-barley patty did not spoil any faster than the control. Thiobarbituric acid numbers (an indication of lipid oxidation) suggested that waxy barley incorporated into ground beef may have an antioxidant effect when patties are stored frozen for more than 90 days.     

FACTORS AFFECTING COLOR PROPERTIES OF BEEF PATTIES COOKED ON AN OUTDOOR GAS GRILL

Visual and instrumental color properties were obtained on beef patties cooked on an outdoor gas grill. Factors evaluated as to their influence on color were fat content, (20–28% vs 6–10%) patty handling prior to cooking (fresh, thawed either as patties or bulk ground beef), endpoint in cooking (57, 66, 71C, slit in outer edge of patty during cooking showing brown color), lighting conditions and evaluation time post-cooking. Factors resulting in less pink/red color and more brown color in cooked patties were (1) higher fat content, (2) cooking bulk frozen, thawed, then pattied product, (3) higher endpoint temperature and longer time postcooking before evaluation. Termination of cooking by observing brown color in slits in patties cooked on a gas grill was not synonymous with a safe internal temperature.     

Characteristics of low-and high-fat beef patties: effect of high hydrostatic pressure.

The purpose of this study was to analyze the consequences of applying high pressures (100 and 300 MPa for 5 or 20 min) on characteristics such as water- and fat-binding properties, texture, color, microstructure, and microbiology of low-fat (9.2%) and high-fat (20.3%) beef patties. In nonpressurized patties, the low-fat product exhibited significantly poorer (P < 0.05) binding properties and higher (P < 0.05) Kramer shear force and Kramer energy than did high-fat patties. Although high pressure did not clearly influence the binding properties of low- and high-fat beef patties, it did produce a rise in the Kramer shear force and energy which were more pronounced at 300 MPa. High pressures altered patty color, the extent of alteration depending on fat content, pressure, and pressurizing time. Pressurizing high- and low-fat beef patties at 300 MPa not only produced a lethal effect (P < 0.05) on microorganisms, but caused sublethal damage as well.     

PROPERTIES OF BEEF PATTIES COOKED TO ELEVATED INTERNAL TEMPERATURES AS A MEANS OF REDUCING PINK COLOR

Effects of cooking to internal temperatures (81–85C) needed to eliminate the pink color which existed at 71C, was evaluated for beef patties from three processors. Tenderness and compositional properties were affected little by the higher temperatures, but lower cooking yields and juiciness scores resulted from cooking to 81–85C rather than 71C. The higher internal temperatures required longer cooking times and produced greater reductions in patty diameter during cooking, but did not affect fat retention. Even though the three formulations were processed to have the same fat content (18%), formulation differences existed in sensory, shear force, cooking, compositional and color properties. Results from this study indicate that if internal patty temperatures higher than 71C are required to eliminate pink color (possibly due to high pH beef), major detrimental changes in patty properties may not result.     

Hot processing and grind size affect properties of cooked beef patties

This study was conducted to further understand the role that hot processing and grind size exert on cooked beef patty tenderness and other properties. Low-fat (10%) hot-processed (HP) and cold-processed (CP) beef were ground either through a 0.32 or 0.40 cm plate. A 20% fat CP product was also manufactured through a 0.32 cm plate. HP patties had higher pH, shorter sarcomere lengths, higher tenderness scores (including greater number of smaller particles during chewing) lower shear force values, higher flavor scores, less well-done cooked color, longer cooking times and higher cooking yields than CP patties (p<0.01). The use of a 0.32 cm rather than a 0.40 cm plate improved tenderness properties, especially for HP patties. Other properties were not greatly influenced by grind size. Sensory evaluation and scanning imagery of patties suggested that the greater tenderness of hot processed patties may be due to the presence of smaller meat particles. Highly contracted muscle, providing resistance to grinding, could be responsible for the small meat particles.     

Acid phosphatase activity and color changes in consumer-style griddle-cooked ground beef patties

The U.S. Department of Agriculture and the Food and Drug Administration have issued temperature requirements to help consumers cook beef patty products that are free of pathogens. Verification of end-point temperature (EPT) is needed in cooked meat products due to concerns over outbreaks of Escherichia coli O157:H7. Acid phosphatase (ACP) activity was studied as a potential method for determination of EPT in ground beef patties cooked nonfrozen, patties frozen 7 days and thawed at room temperature 4 h in a refrigerator or by microwave, and patties made from ground beef frozen in store packages, then thawed in a refrigerator overnight. Pressed-out meat juices were analyzed from patties (n = 314) cooked to 57.2 degrees C (135 degrees F). 65.6 degrees C (150 degrees F), 71.1 degrees C (160 degrees F), and 79.4 degrees C (175 degrees F) target EPTs. Expressed meat juice and internal meat patty color decreased in redness as EPT increased. Freezing whole packs with slow refrigerator or room temperature thawing caused significantly greater loss of redness in expressed cooked meat juice than did other handling methods. Log10 ACP had a significant linear (R2 = 0.99) response to EPT. Results show that the 3- to 5-min ACP test could be used to verify EPT in griddle-cooked hamburger patties.     

Influence of bleached palm oil on the physicochemical and sensory properties of beef patty

The effect of palm oil on the physico-chemical and sensory properties of beef liver patty were studied. Seven batches (3units per batch) of beef liver patty with different palm oil content (5, 10, 20, 30, 40 and 50%) and a control with pork fat (30%) were manufactured by component mix at 1500 rpm for 1 min and cooked in an oven at 90?°C. Physico-chemical analysis of raw and cooked samples showed improvement of emulsion stability, water binding capacity, technological yield and hardness of patties substituted with lower proportions of deodorized bleached palm oil. No significant difference (P?>?0.05) was found between physico-chemical properties of liver patty formulated with 20% palm oil and the control (formulated with 30% pork fat). Sensory attributes generated by a semi-trained panel based mainly on texture, homogeneity (colour and aspect), odour and meltiness of the patties confirmed this tendency.     

Effects of chlorine dioxide, cetylpyridinium chloride, lactic acid and trisodium phosphate on physical, chemical and sensory properties of ground beef

The impact of beef trimmings treated with either 0.5% cetylpyridinium chloride (CPC), 200-ppm chlorine dioxide (CLO), 2% lactic acid (LA) or 10% trisodium phosphate (TSP) and an untreated control (C) prior to grinding, on instrumental color, sensory characteristics, TBARS values, pH and Lee-Kramer shear under simulated retail display were evaluated. Trimmings were ground, pattied and sampled at 0, 1, 2, 3 and 7 days of display. Patties from LA, CPC and CLO treatments were lighter (L*; P<0.05) and TSP patties were redder (a*; P<0.05) than C. Panelists found TSP and CPC patties were similar or superior in beef and off odor to C on days 3 and 7 of display. Therefore, treatment of beef trimmings before grinding with TSP, CPC, CLO or LA may not only improve ground beef safety, but maintain or enhance patty shelf life.     

Evaluation of consumer-style cooking methods for reduction of Escherichia coli O157:H7 in ground beef

The objective of this study was to evaluate the thermal inactivation of Escherichia coli O157:H7 in ground beef cooked to an internal temperature of 71.1 degrees C (160 degrees F) under conditions simulating consumer-style cooking methods. To compare a double-sided grill (DSG) with a single-sided grill (SSG), two different cooking methods were used for the SSG: for the one-turnover (OT-SSG) method, a patty was turned once when the internal temperature reached 40 degrees C, and for the multiturnover (MT-SSG) method, a patty was turned every 30 s. Patties (100 g, n = 9) inoculated with a five-strain mixture of E. coli O157: H7 at a concentration of 10(7) CFU/g were cooked until all three temperature readings (for two sides and the center) for a patty were 71.1 degrees C. The surviving E. coli O157:H7 cells were enumerated on sorbitol MacConkey (SMAC) agar and on phenol red agar base with 1% sorbitol (SPRAB). The order of the cooking methods with regard to the cooking time required for the patty to reach 71.1 degrees C was as follows: DSG (2.7 min) < MT-SSG (6.6 min) < OT-SSG (10.9 min). The more rapid, higher-temperature cooking method was more effective (P < 0.01) in destroying E. coli O157:H7 in ground beef. E. coli O157:H7 reduction levels were clearly differentiated among treatments as follows: OT-SSG (4.7 log10 CFU/g) < MT-SSG (5.6 log10 CFU/g) < DSG (6.9 log10 CFU/g). Significantly larger numbers of E. coil O157:H7 were observed on SPRAB than on SMAC agar. To confirm the safety of ground beef cooked to 71.1 degrees C, additional patties (100 g, n = 9) inoculated with lower concentrations of E. coli O157:H7 (10(3) to 10(4) CFU/g) were tested. The ground beef cooked by the OT-SSG method resulted in two (22%) of nine samples testing positive after enrichment, whereas no E. coli O157:H7 was found for samples cooked by the MT-SSG and DSG methods. Our findings suggest that consumers should be advised to either cook ground beef patties in a grill that cooks the top and the bottom of the patty at the same time or turn patties frequently (every 30 s) when cooking on a grill that cooks on only one side.     

Fat, Soy and Carrageenan Effects on Sensory and Physical Characteristics of Ground Beef Patties

Sensory and physical characteristics of beef patties containing 20% fat, 8% fat, or 8% fat plus 20% soy protein isolate (SI), soy flour (SF), soy concentrate (SC), or a mixture (MIX) of carrageenan (0.5%), starch (0.5%), and phosphate (0.2%) were compared after 0, 4, 8, and 12 wks storage at - 18°C. MIX had higher Hunter a* values than other treatments. Cook loss was lowest for MIX and highest for all beef patties. Soy extenders decreased beefy flavor and increased off-flavor scores. Time in frozen storage increased off-flavor, rubbery texture, and TBA value, and decreased red color and Hunter b* value of ground beef patties. Quality may be lowered in frozen-stored high fat, or low-fat-soy extended beef patties.     

PROCESSING PARAMETER EFFECTS ON TEXTURAL CHARACTERISTICS OF REDUCED-FAT PORK SAUSAGE

The objective of this study was to evaluate the effects of fat (10, 20, and 30%, postrigor; 10 and 30% pre-rigor), rigor state, plate size (3 and 5 mm), and mixing time (2 and 5 min) on cooking loss and instrumental texture characteristics of reduced-fat pork sausage. High-fat products exhibited greater cook loss and lower breaking force than low-fat products. Rigor state of raw materials had no effect on the characteristics evaluated. Increasing plate size and mixing time increased initial force required to compress a 2.5 cm core to 20% of its original height but had no effect on other characteristics. Reduction of fat content can be accomplished without addition of nonmeat ingredients by limiting plate size to 3 mm and mixing time to 2 min.     

RELATIONSHIPS AMONG CHEMICAL, COOKING AND COLOR PROPERTIES OF BEEF PATTIES COOKED TO FOUR INTERNAL TEMPERATURES

A study involving five laboratories and nationwide sampling of ground beef was undertaken to determine cooking and color properties of patties cooked to 52.7, 65.6, 71.1 and 79.4C. The design of the study included purchase location (local, distant) and patty handling prior to cooking Pesh, thawed either as patties or bulk ground beef). Purchase location was not a statistically significant influence on cooking and color properties. Patties processed from bulk thawed product had a higher amount of brown cooked color. A strong relationship existed between visual and instrumental measures of red color in cooked patties. However, correlations among other cooking properties were low. Patties with higher fat content were associated with shorter cooking times, lower cooking yields and more brown cooked color. The low relationships between raw and cooked patty properties limits the use of raw ground beef properties as predictors of food safety in cooked beef patties. This further supports the use of instant read meat thermometers in cooking beef patties to at least 71C.     

Effects of antioxidants and gamma irradiation on the shelf life of beef patties.

To improve the storage safety of two types of ground beef patty popular in Korea (general beef patties and bulgogi patties), we added various antioxidants (200 ppm; including butylated hydroxyanisole, ascorbyl palmitate, alpha-tocopherol, and beta-carotene) to typical formulations of patties, cooked the patties to 70 degrees C, and irradiated them at a dose of 1.5 or 3 kGy. During 30 d of storage at 5 degrees C, the number of aerobic bacteria and lactic acid bacteria were determined using total aerobic plate count and phenyl ethyl alcohol-sucrose agar, respectively. The concentration of thiobarbituric acid was also determined in each type of patty. No colonies were observed in patties irradiated at 3 kGy regardless of which antioxidant was added. In control patties and patties with butylated hydroxyanisole that were irradiated at a dose of 1.5 kGy, growth of microorganisms appeared to be more rapid than in patties with natural antioxidants. The microbiological safety of nonirradiated patties could not be ensured for a period of 20 d. Lipid oxidation was retarded in both types of patty when an antioxidant was added. Ascorbyl palmitate had the strongest antioxidant effect among the natural antioxidants. However, butylated hydroxyanisole was more effective than ascorbyl palmitate when used in an equal amount.     

Sensory, Shear, and Cooking Properties of Lower-Fat Beef Patties Made with Inner Pea Fiber

Lower fat (10% and 14%) ground beef patties containing inner pea fiber as dry powder or as part of a high fat mixture were compared to all‐beef patties (10%, 14%, and 18% fat). Patties processed with pea fiber had improved tenderness and cooking yields and showed less change in thickness during cooking, but required longer cooking times to reach 71 °C compared to all‐beef controls. Beef flavor intensity of pea fiber patties did not differ from 10% and 14% fat all‐beef patties. Different forms of pea fiber usage produced similar patty properties. Use of inner pea fiber in lower fat beef patties improved tenderness and cooking yield, without negative effects on juiciness and flavor.     

EFFECTS OF END-POINT TEMPERATURE AND FAT LEVEL ON THE RESIDUAL CHOLESTEROL IN GROUND BEEF PATTIES1

Patties of lean ground beef with 2% fat (L2PF) and 6% fat (L6PF) were used to study the fat and cholesterol composition of raw and cooked ground beef and to determine how the end-point cooking temperature affects the amount of fat and cholesterol in a lean ground beef patty as it would be eaten by the consumer. The two patty types were obtained from the longissimus muscle of steers with marbling scores associated with “Standard” to “Select” and “Select” to “Choice” U.S. carcass grades of beef, respectively. All steers were fed a diet of roughage and concentrates to ensure fat deposition over the 12th and 13th ribs; longissimus muscles between the 7th and 10th ribs were removed, trimmed of all external fat, ground and formed into three 130-g patties. One patty was fried to an internal temperature of 60C, another to 71C and the third was uncooked. After frying, the patties were measured for drip loss, moisture and total fat. The fat extract was used for cholesterol analysis. The cooked L2PF sample had significantly less fat than the cooked L6PF samples, but there was no difference between the L2PF and L6PF in cholesterol. End-point temperature had no effect on the fat and cholesterol contents for either L2PF or L6PF samples, but the higher end-point temperature resulted in a significant loss of moisture.     

Composition and retention of lipid nutrients in cooked ground beef relative to heat-transfer rates

This study documents the effects of different heat transfer kinetics on lipid nutrient composition in regular ground beef patties cooked using high (HHT) and low (LHT) heat transfer frying surfaces. Rate of heating from frying surfaces to ground beef patties was measured using iron-constantan thermocouples and related to the retention of beef pattie color, texture, total crude lipid content, fatty acid and cholesterol composition. Ground beef patties cooked for 1, 3 and 6 min using an HHT frying surface reached a higher (P⩽ 0.05) internal temperature than on the LHT frying surface. This observation was associated with higher (P⩽ 0.05) cook value and cook loss, and greater (P⩽0.05) shear force, L* color value and ΔE values. The fatty acid composition of the HHT cooked patties reflected a greater (P⩽ 0.05) loss in monounsaturated fatty acids, than with patties cooked on the LHT surface. The two frying methods produced little effect on beef a* and b* color values, total crude lipid, or polyunsaturated fatty acid content. Cholesterol content of HHT patties was reduced (P⩽ 0.05) relative to both uncooked patties and patties cooked with a LHT surface. These results indicate that heat conductivity of the cooking surface has an impact on the lipid composition of cooked ground beef patties.     

Visual color and doneness indicators and the incidence of premature brown color in beef patties cooked to four end point temperatures

An interlaboratory study was undertaken to assess the frequency that cooked color of ground beef patties appeared brown at internal temperatures of 52.7 degrees C (135 degrees F), 65.6 degrees C (150 degrees F), 71.1 degrees C (160 degrees F), and 79.4 degrees C (175 degrees F). In general, as internal cooked temperature of the patties increased, the following results were observed in the patties: (i) more brown meat color, (ii) less pink or red juice color, and (iii) more cooked texture. However, brown meat color occurred prematurely at the two lower internal temperatures (57.2 degrees C/135 degrees F and 65.6 degrees C/150 degrees F) that are insufficient to eliminate foodborne pathogens without holding times. The common consumer practice of freezing bulk ground beef, followed by overnight thawing in a refrigerator, led to substantial premature brown color in patties cooked from this product. In addition, at 71.1 degrees C (160 degrees F), recognized to be the lowest temperature for cooking ground beef safely in the home, meat color, juice color, and texture appearance were not fully apparent as doneness indicators. In fact, at no temperature studied did 100% of the patties appear done when evaluated by the criteria of no red or pink in the meat, no red or pink in the juices, or by texture appearance. Patties in this study were evaluated under a set protocol for forming the products, cooking, and viewing under the same lighting conditions. Other preparation conditions are possible and may produce different results. Thus, temperature to which patties have been cooked cannot be judged by color and appearance. This study provided the evidence to support the message to consumers regarding cooking of beef patties of "use an accurate food thermometer and cook beef patties to 160 degrees F (71.1 degrees C)" in place of messages based on consumer judgment of cooked color.     

EFFECTS OF HOT PROCESSING, PATTY FORMATION BEFORE OR AFTER FREEZING-THAWING AND SOY USAGE ON VARIOUS PROPERTIES OF LOW-FAT GROUND BEEF

This study was designed to evaluate the effects of combinations of boning temperature (hot = HP, cold = CP), time when patties were processed (immediately after grinding and before freezing = BF; after freezing and thawing of bulk ground beef = AF), and use of texturized soy concentrate (% usage = 0 or 20% substitution, rehydrated either in a ratio of 2.6:1 or 1.5:1) on sensory, Instron and cooking properties of ground beef patties. With the exception of HP -0% soy patties, both sensory and instrumental measures of tenderness revealed AF patties to be more tender than BF patties. BF patties received higher juiciness scores and cooking yields than AF patties. Soy usage reduced Instron values, juiciness scores, cooking loss, patty shrinkage during cooking and beef flavor intensity scores. These results indicate that the use of HP beef in combination with soy should not detrimentally affect ground beef as used in the school lunch program.     

Use of electrical stimulation, hot processing and carrageenan for processing low-fat ground beef patties

Three studies were conducted to determine the effects of electrical stimulation, hot processing and carrageenan usage on sensory, shear force and cooking properties of low-fat (5, 10%) beef patties. The right or left sides of beef carcasses assigned to electrical stimulation (ES) received 600 V pulsating current for 120 s. Non-stimulated (NS) sides were also included for comparisons. Sides subjected to hot processing (HP) were boned 90 min post-exsanguination. Cold processing (CP) was initiated 48 h post mortem. Formulations for the manufacture of patties included the use of carrageenan [none, 0.5% iota (ι), 0.5% kappa (κ)]. Patties from NSHP beef had higher pH and cooking yields, less shrink in patty dimensions during cooking and lower shear force values than patties from NSCP controls (P < 0.05). ES improved tenderness and juiciness of CP patties, while ESHP patties exhibited higher cooking yields than NSCP patties. Tenderness was improved in two of the three studies as a result of increasing the fat content from 5 to 10%. Use of ι-carrageenan provided improvements in tenderness and juiciness over patties receiving no carrageenan or κ-carrageenan. Processors should consider HP with 1.0% added salt (improved cooking yields, patty configuration, tenderness) and the use of ι-carrageenan (improved tenderness and juiciness) for low-fat beef patties.