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.     

CHEMICAL PROPERTIES OF GROUND BEEF PATTIES EXHIBITING NORMAL AND PREMATURE BROWN INTERNAL COOKED COLOR

Premature browning is a condition in which ground beef looks well-done at lower than expected temperatures. To study this color pattern, chemical properties were measured on raw and cooked patties (55, 65 and 75C) that developed normal (NRM) and premature brown (PMB) color when cooked to 55C. NRM patties were visually and instrumentally redder at all temperatures (P<0.05) than PMB patties. Visual color of PMB patties at 55C and NRM patties at 75C were similar (P>0.05). Heme and nonheme iron, total pigment and pH did not differ (P>0.05) between groups. Nonheme iron increased (P<0.05) as endpoint temperature increased. Patties with NRM color had lower (P<0.05) TBA values and oxidative-reduction potentials and higher (P<0.05) total reducing activity than patties with PMB. No difference (P>0.05) occurred in precipitation of juice extracts from NRM and PMB patties during heating (40 to 75C). Premature browning was related to patty oxidation.     

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.     

EFFECTS OF COOKING AND SUBSEQUENT REHEATING ON THE PROPERTIES OF LOW-FAT BEEF PATTIES

Low-fat (10%) beef patties manufactured with 0.5% iota carrageenan, were subjected to one-time cooking from the raw to fully cooked state or precooking and later reheating before evaluating sensory, shear force and cooking properties. The samples were reheated in a convection oven or in a simultaneous top and bottom contact grill set either at 121 or 191C. Precooking followed by reheating produced only slight changes in sensory properties (reduced tenderness, increased juiciness and increased beef flavor). Convection oven cooking improved tenderness only for one-time cooked patties. With the double contact grilling system, the 121C surface temperature enhanced tenderness (sensory and shear force) and cooking yields of precooked-reheated patties. Low-fat beef patties formulated with iota carrageenan appear capable of being subjected to a variety of cooking approaches and temperatures without major changes in cooked patty properties.     

PATTY FORMATION METHOD, THICKNESS AND WEIGHT EFFECTS ON PROPERTIES OF COOKED LOW-FAT BEEF PATTIES

Effects of patty thickness (0.95 and 1.27 cm), weight (90 and 113 g) and type of patty fill method (traditional gravity fill = FF and twisted through holes into mold = TF) were evaluated using low-fat (10%) ground beef. An increase in patty thickness from 0.95 cm to 1.27 cm, resulted in a decreased (P<0.01) sensory firmness and peak load (Newtons) and increased (P<0.01) initial juiciness. TF fill method and 1.27 cm thick FF treatments improved tenderness and juiciness over 0.95 cm thick FF patties. This study revealed that improvements in tenderness and juiciness of low-fat beef patties can be attained through use of appropriate patty formation procedures.     

COOKED COLOR OF PATTIES PROCESSED FROM VARIOUS COMBINATIONS OF NORMAL OR HIGH pH BEEF AND LEAN FINELY TEXTURED BEEF

Color of cooked patties prepared from beef with a pH of 5.7 (normal = N) or pH = 6.2 (dark cutting = DC) beef and with either 0, 25, 50 or 75% lean finely textured beef (LFTB) was evaluated. Patties were cooked to 68.3C, 71C, or until >75% were "well-done". Inclusion of LFTB in N patties resulted in higher a*-values, but did not affect either visual color scores or myoglobin (Mb) denaturation. Inclusion of LFTB in DC patties did not affect pH. A higher LFTB content resulted in lower a*-values, higher hue-angle, a more well-done visual color and increased Mb denaturation. To appear well-done, DC patties without LFTB had to be cooked to 89C, whereas DC patties with 75% LFTB had to be cooked to 83C. Possibly, conditions during production of LFTB are responsible for the increased heat sensitivity of Mb from LFTB.     

INSTRUMENTAL MULTIPLE TEXTURE PROFILE ANALYSIS OF COOKED GROUND BEEF PATTIES AND SMOKED BEEF

An instrumental texture profile for cooked hamburger patties was obtained by repeated tests on the same samples in the wire extrusion cell of the Ottawa Texture Measuring System. The correlation between sensory and instrumental texture profile parameters was increased when two or more instrument test cycles were applied to each sample in the same test cell. Tests with smoked beef and hamburger patties showed that the change in textural characteristics with repeated cycles depended on the texture of the food.     

RELATIONSHIPS of PHYSICAL PROPERTIES of FAT-SUBSTITUTES, COOKING METHODS and FAT LEVELS WITH QUALITY of GROUND BEEF PATTIES

Ground beef patties containing 2 fat levels (5%, 10%), and 3 fat-substitutes (LeanBind, Rice* Complete 3, and Sta-Slim 171) were processed using 3 cooking methods (microwave, roasting, and pan-frying). Correlation analyses between patty quality and the physical properties of the fat-substitutes, as well as the composition of both raw and cooked patties were conducted. Regression models of patty quality parameters as functions of the physical properties of the fat-substitutes, and as the function of the patty composition were developed. This work demonstrated that the fat-substitutes can be evaluated based on regression models relating patty quality to the physical properties of the fat-substitutes.     

EFFECTS OF SOY PARTICLE SIZE AND COLOR ON THE SENSORY PROPERTIES OF GROUND BEEF PATTIES

A study was conducted to assess the effect of both size and color of textured soy protein particles on the visual and textural properties of extended (20% replacement) ground beef patties. A trained texture profile panel judged the hardness, cohesiveness, chewiness, moistness, and oiliness of nine different samples. In addition, judgments of the visual attributes of darkness, size of particles, and density of particles were made. Significant effects of soy ingredient were found for all judged attributes. It was concluded that soy ingredients having particle sizes smaller than the diameter of the openings of the grind plate used to process the meat/soy mixture produced the greatest change in the texture of the ground beef patties, because these particles passed through the grind plate unscathed, producing an easily discernable matrix of large meat particles and small soy particles. It was also concluded that carmel-colored soy ingredients produced less lightening of the cooked samples than uncolored soy ingredients.     

PHYSICAL, CHEMICAL, AND PALATABILITY TRAITS OF RAW AND PRECOOKED GROUND BEEF PATTIES

Boneless beef (U.S. Utility chucks or triangles; U.S. Choice plates) was ground (0.95 cm plate), standardized to 26% fat, reground (0.38 cm plate) and divided into two lots. One lot remained in Plant A and the other lot was shipped via air-freight to Plant B. On the same day and at the same time, meat at both Plants was formed into patties. Half of the patties at Plant A were precooked in a moisture-controlled oven broiler, half of the patties at Plant B were precooked in an open-hearth broiler; the remaining patties at each Plant were not precooked and were frozen in the raw state. Precooked and raw patties at both Plants were frozen (°30°C) in spiral air blast freezers, boxed, air-freighted to College Station, Tex. and Beltsville, Md. and stored at °20°C. Frozen patties were cooked to 63°C (11 mm at 190°C) and palatability was evaluated by an 84-member consumer panel and by an 8-member trained panel. Pre-cooking of ground beef patties: (a) reduces cube space-weight dimensions, thus economies would accrue in packaging-transportmg-distributing such product in comparison to requirements for raw patties; (b) increases total weight loss by approximately 1.8–9.4 percentage points; (c) resulted in increased moisture retention but increased loss of fat during final heating of product; (d) increases incidence of off-flavors by 7–16 percentage points and decreases flavor desirability if performed by use of a moisture-controlled oven broiler; (e) increases tenderness of heated patties; and (f) has no apparent effect on amount of organoleptically detectable connective tissue, flavor intensity or ready-to-serve appearance. It is very doubtful that the advantages in size reduction and tenderness are sufficient to offset the disadvantages in off-flavor incidence, in cooking-freezing-heating losses, in energy required to cool trie product after precooking, and in the necessity to use heat twice (once for precooking, once for heating prior to being served) to prepare the product for ultimate consumption.     

EFFECTS OF SOY PROTEIN AND FREEZING TREATMENTS ON COOKING LOSS AND COMPOSITION OF BEEF PATTIES

All-beef and soy-extended patties were frozen to −18°C in either 24, 48, 72 or 96h and stored at −23, −18 or −7°C for 6, 9, 12, 18 or 24 months. The addition of soy resulted in a substantial reduction in cooking loss for patties cooked from the frozen state with a greater retention of moisture in cooked patties. Freezing reduced cooking loss for soy-extended patties, but increased cooking loss for all-beef patties. Faster freezing (-18°C in 24 h vs. −18°C in 96 h) reduced cooking loss and produced higher moisture values in all-beef patties. Patties stored at –7°C lost more moisture during cooking. Increased frozen storage time had a minimal effect on cooking losses, moisture and fat levels. Where it is essential for frozen patties to sustain minimal cooking losses with maximal moisture in cooked patties, the inclusion of soy protein concentrate, faster freezing, and storage at –18°C or colder are suggested.     

RELATIONSHIPS OF INSTRUMENTAL TEXTURAL PROPERTIES AND MUSCLE FIBER TYPES TO THE SENSORY PROPERTIES OF BEEF

Longissimus muscle steaks from 94 cattle were used to determine the relationship between sensory tenderness ratings and instrumental textural properties of beef and to determine the role of muscle fiber type characteristics to sensory and instrumental textural properties. It was determined that ease of fragmentation, amount of detectable connective tissue, and tenderness ratings were all measurements of the same attribute. Peak load was found to be the best predicator of tenderness and the use of additional instrumental textural properties in regression equations did not substantially improve predictability. White muscle fiber characteristics were found to be positively correlated to sensory tenderness ratings.     

AROMA,COLOR, AND TEXTURE OF GROUND BEEF PATTIES TREATED WITH FUMARIC AND LACTIC ACIDS1

Ground beef patties without acid or with added fumaric (FA) or lactic acids (LA) at 1, 3, and 5% concentrations were vacuum-packaged and stored for 1, 3, 5, 7, 10 and 14 days at 4C or tested without storage (0 days). The FA or LA treatments caused small sour aroma increases. Spoiled aroma was lowest for samples with 1% FA at 10 or 14 days or 1% LA at 10 days of storage. Initially, 3 or 5% FA and LA samples had fading. Lightness scores of 1% FA or LA did not differ from the control initially or for up to 14 days of storage. Shear force values for 1 and 3% FA treatments were not significantly different (P>0.05) from the control. The 5% FA patties required significantly less shear force when compared with controls at 0, 1, 5, 7, and 10 days of storage.