Cooked Ground Beef Patties Research Articles

Comparison of Raw and Excess Steam Jet-Cooked/Drum-Dried Pinto Bean Flours and Their Effects on Ground Beef Patties

Many types of plant-based materials have been investigated as fat replacers or meat extenders in beef patties and meatballs, including cereal and pulse flours as well as isolated plant proteins. Previously, excess steam jet cooking and drum drying of pulse flours were shown to impart potentially useful properties as food ingredients. In this study, pinto bean flour was jet-cooked and drum-dried (JC-DD) and compared with raw pinto bean flour when added to ground beef patties. The finely milled flours were mixed with ground beef at levels of 6, 12, and 18% along with equal amounts of water. The effects of jet cooking and drum drying on the flour included complete breakdown of starch granules, greatly reduced viscosity upon heating in water, and substantial reduction of several volatile beany flavor components. The highest level of JC-DD flour resulted in the highest cooked patty weight, moisture content, and diameter and the lowest cooking time, springiness, and fat content. There were significant color changes in both raw and cooked beef patties to which pinto bean flour was added, but they were not large due to the native color of bean seed coats. Texture analysis revealed that addition of JC-DD flour to the meat resulted in a greater degree of tenderizing compared to the raw flour. The experiments indicate that further investigation of different flour/water ratios and different pulse types might lead to higher substitution levels. Novelty Impact Statement. The use of pulse flour as a meat extender was investigated with the novel approach of processing the pulse flour by excess steam jet cooking and drum drying. Comparison of the effects of raw and jet-cooked flour on the properties of cooked ground beef patties revealed advantages of jet cooking the flour including higher cooked patty weight, moisture content, and diameter and a greater degree of tenderizing.

Consumer Practices and Risk Factors that Predispose to Premature Browning in Cooked Ground Beef

Premature browning is a condition in which cooked ground beef patties turn brown before the USDA recommended temperature of 71°C. This presents a potential food safety concern, as consumers may be eating undercooked meat. Although various intrinsic and extrinsic factors contribute to premature browning, the current knowledge indicates that the myoglobin form present within the interior of patties has a significant influence on cooked color. The objective of the study was to determine the consumer practices of cooking, methods to determine doneness, and type of packaging of their purchased ground beef. The data utilized in this study came from Food Demand Survey (FooDS), which tracks consumer preferences, food expenditures, price expectations, and awareness and concern for a variety of food issues. The sample size of FooDS on-line survey for this study was 1,030. The survey questions consisted of doneness of patties, cooking time, and packaging type of patties. Pictures of different packaging types such as a tray, vacuum package, film wrapped, butcher wrapped paper, frozen patties, and chub were also included. Approximately 67% of respondents indicated that they determine the doneness of ground beef patties by visual observation, 18% identify the doneness by a certain length of time for cooking, and 13.5% use a meat thermometer. Interestingly, 69% of respondents noted that they like a brown interior color of cooked patties. If the patties were prone to premature browning, the chances of consuming undercooked patties are higher. Only 5.7% of people bought patties packaged in a vacuum, while 60% of respondents bought patties packaged in film wrapped or in a tray. Even after 20 yr of attempt by the USDA to educate consumers about safe cooking, the current practices increase the likelihood of premature browning and food safety concerns.

Effects of feeding wet distillers grains to cattle during different phases of production on lipid oxidation of cooked ground beef patties during storage

<h2>ABSTRACT</h2> As a coproduct of the fuel ethanol industry, distillers grains are commonly included in cattle diets and can alter fatty acid composition and increase lipid oxidation in beef. However, to our knowledge, current research has only evaluated raw beef products. This study investigated how supplementing dried distillers grains with solubles (DDGS) during backgrounding (0 or 0.6% of BW per steer daily) and including wet distillers grains with solubles (WDGS) in finishing diets (0 or 35% inclusion, DM basis) affected beef fatty acid profiles and lipid oxidation in cooked beef patties during refrigerated and frozen storage. Beef shoulder clods (n = 16) were independently ground and evaluated for fatty acid composition. From each clod, beef, salt, and sodium phosphate were mixed, and patties were formed, cooked, and placed in refrigerated and frozen storage. Backgrounding supplementation with DDGS caused a greater saturated:unsaturated fatty acid ratio (<i>P</i> = 0.04). Inclusion of 35% WDGS during finishing resulted in greater C18:0, C20:2, C22:0, and PUFA content (<i>P</i> ≤ 0.04). For cooked beef patties in refrigerated storage, backgrounding DDGS supplementation resulted in greater oxidation (<i>P</i> < 0.01), but including 35% WDGS during finishing decreased oxidation (<i>P</i> = 0.02). A backgrounding × finishing diet interaction (<i>P</i> < 0.01) for lipid oxidation in frozen, cooked beef patties was identified. Backgrounding DDGS supplementation increased lipid oxidation regardless of finishing diet. For cattle without backgrounding supplementation, less lipid oxidation occurred with WDGS inclusion in finishing diets. Although backgrounding DDGS supplementation resulted in few differences in fatty acid composition, it resulted in increased lipid oxidation.

Effects of Metmyoglobin Reducing Activity and Thermal Stability of NADH-Dependent Reductase and Lactate Dehydrogenase on Premature Browning in Ground Beef.

Premature browning is a condition wherein ground beef exhibits a well-done appearance before reaching the USDA recommended internal cooked meat temperature of 71.1 °C; however, the mechanism is unclear. The objectives of this study were: (1) to determine the effects of packaging and temperature on metmyoglobin reducing activity (MRA) of cooked ground beef patties and (2) to assess the effects of temperature and pH on thermal stability of NADH-dependent reductase, lactate dehydrogenase (LDH), and oxymyoglobin (OxyMb) in-vitro. Beef patties (lean: fat = 85:15) were packaged in high-oxygen modified atmosphere (HiOX-MAP) or vacuum (VP) and cooked to either 65 or 71 °C. Internal meat color and MRA of both raw and cooked patties were determined. Purified NADH-dependent reductase and LDH were used to determine the effects of pH and temperature on enzyme activity. MRA of cooked patties was temperature and packaging dependent (P < 0.05). Vacuum packaged patties cooked to 71 °C had greater (P < 0.05) MRA than HiOX-MAP counterparts. Thermal stability of OxyMb, NADH-dependent reductase, and LDH were different and pH-dependent. LDH was able to generate NADH at 84 °C; whereas NADH-dependent reductase was least stable to heat. The results suggest that patties have MRA at cooking temperatures, which can influence cooked meat color.

Effects of Packaging and Temperature on Metmyoglobin Reducing Activity of Cooked Ground Beef Patties

ObjectivesApproximately 47% of ground beef purchased at local stores is susceptible to premature browning (PMB). Premature browning is a condition in which cooked ground beef patties will have a well-done appearance at temperatures insufficient to render ground beef patties safe. Various studies have shown that the form of myoglobin present in the interior of patties at the time of cooking can affect cooked color. However, limited studies have determined the role of metmyoglobin reducing activity (MRA) in cooked patties on cooked color.Therefore, the objective of this study was to determine the role of MRA in cooked color development and premature browning.Materials and MethodsFresh coarse ground beef chubs (85% lean, n = 6) were obtained from a local purveyor on the day of preparation. Coarse ground beef was fine ground using a LEM meat grinder. Patties (1 cm thickness × 10.5 cm diameter; 113 g) were prepared using a patty press. Patties were randomly allotted to vacuum (VP) or high-oxygen modified atmospheric package (HiOx-MAP, 80% oxygen and 20% carbon dioxide). High-oxygen modified atmospheric package patties were placed in Rock-Tenn DuraFresh rigid trays with absorbent pads and sealed with a clear, multi-layer barrier film using a semi-automatic Mondini tray-sealing machine and certified gas blends. Packaged patties were stored in the dark at 0 ± 2°C for 48 h. At the conclusion of storage, two patties from each packaging were cooked to either 65 or 71°C using a George Foreman. One patty from each packaging was utilized for lipid oxidation and raw MRA. Two extra patties were utilized to characterize d 0 (no packaging and storage) pH analysis, lipid oxidation, and MRA. Surface color (a*) and MRA of raw and cooked ground beef patties were measured. Nitric oxide metmyoglobin reduction method was used to determine the reducing activity of both raw and cooked patties. Surface color was determined daily using a HunterLab spectrophotometer. The experiment was repeated six times and the data were analyzed using the Mixed Procedure of SAS (SAS Inst. Inc., Cary, NC). The PDIFF option for protected F-test was utilized to separate least squares means (P < 0.05).ResultsThe average pH of ground beef was 5.73 ± 0.01. There was a significant packaging by temperature interaction for raw surface color and metmyoglobin reducing activity. High-oxygen modified atmospheric package patties had lower (P < 0.0001) cooked internal a* values and MRA compared with VP patties regardless of temperature. There was no difference in cooked patties MRA for HiOx-MAP between 65 and 71°C (P > 0.12). Cooked patty MRA decreased as temperature increased for VP patties (P < 0.041). There was a significant packaging × time interaction observed for lipid oxidation. HiOx-MAP patties had greater (P < 0.0001) lipid oxidation compared with VP patties after 48 h storage and d 0 patties. Storage did not affect lipid oxidation in VP (P > 0.40).ConclusionMetmyoglobin reducing activity in cooked patty suggests that enzymes involved in metmyoglobin reduction retain partial activity at greater temperatures. Developing strategies to increase reducing activity in ground beef has the potential to limit the incidence of premature browning.

Consumer Sensory Evaluation of Grass-Fed, Angus, and Commodity Ground Beef

ObjectivesGround beef is one of the major sources of animal protein in the U.S., accounting for approximately 40% of beef consumption per capita. Several studies have looked at the flavor profile between grass-fed and grain-fed beef to identify if omega-3 fatty acids found in grass-fed ground beef play a key role in consumer flavor acceptability. Consumer sensory evaluation was conducted to evaluate consumer palatability ratings of grass-fed ground beef in comparison to Angus and commodity ground beef.Materials and MethodsGrass-fed, Angus, and commodity 80/20 ground beef was obtained from local retail stores and a commercial meat processing facility. For each treatment 14 different production lots were used, and each lot contained 2.26 kg of ground beef. Ground beef patties were manually formed into 113 g patties using a template, crust frozen, vacuum packaged with 2 patties per package, and stored at –40°C for approximately 8 d. The remaining product was vacuum packaged and frozen at –40°C for consumer evaluation and moisture, fat, protein, and pH determination. Frozen ground beef patties were thawed for 24 h prior to consumer sensory analysis. Patties were cooked to 71°C initial internal temperature using a clamshell grill (Cuisinart, East Windsor, NJ) and held for approximately 5 min to allow a post-cook temperature rise to 74°C. Cooked ground beef patties were cut into 4 wedge-shaped pieces, and immediately served to panelists. A total of 98 consumers were recruited from Manhattan, KS and adjacent areas and rated the samples using 100-point continuous line scales with anchors at both ends and the midpoint on electronic tablets. Patties were rated for tenderness, juiciness, flavor liking, texture liking, and overall liking, and each sample was rated as acceptable or unacceptable for each palatability trait.ResultsMoisture, fat, and protein content of commodity, grass-fed, and Angus ground beef used in this study were similar (P > 0.05). Commodity ground beef had a pH that was higher (P < 0.05) than Angus and grass-fed ground beef by 2.6 and 6.8%, respectively, which may have been contributed the result of lean finely textured beef as a component of this treatment. Consumers tended to rate grass-fed ground beef 4 and 6% lower (P = 0.06) for flavor and texture liking, respectively than Angus and commodity ground beef. Angus and commodity ground beef were rated higher (P < 0.01) for overall liking compared to grass-fed ground beef. Consumers found tenderness and juiciness similar (P > 0.05) for all 3 types of ground beef. Overall, Angus ground beef was preferred (P < 0.05) to grass-fed ground beef with an overall acceptability of 94.9 vs. 82.5%, while commodity ground beef had a similar (P > 0.05) overall acceptability to Angus and grass-fed ground beef. Consumers indicated no difference (P > 0.05) for tenderness acceptability, juiciness acceptability, and texture acceptability among the 3 ground beef treatments. Commodity ground beef had the highest (P < 0.05) flavor acceptability, while Angus and grass-fed ground beef had similar (P > 0.05) acceptability percentages for flavor.ConclusionConsumers rated grass-fed, Angus, and commodity ground beef similar for all palatability traits, except overall liking, in which consumers preferred Angus and commodity over grass-fed ground beef.

Quality Characteristics of Fresh and Cooked Ground Beef can be Improved by the Incorporation of Lean Finely‐Textured Beef (LFTB)

AbstractGround beef was formulated into six treatments of 82 or 93% lean with 0, 10, or 20% lean finely‐textured beef (LFTB). Batches (n = 5/treatment) were ground and formed into patties, then aerobically packaged for 5 days of simulated retail display to measure fresh color and lipid oxidation (TBARS). Additional patties were cooked to 71.1C before measuring external and internal cooked color, TBARS, and Lee‐Kramer shear force (LKSF). Lightness (L*), redness (a*), and pH of fresh patties increased (P &lt; 0.05), whereas TBARS values were decreased (P &lt; 0.05) on days 1, 2, and 4 of display, with increasing LFTB percentage. Cooking loss was lowest (P &lt; 0.05) in 20% LFTB patties, whereas LKSF declined (P &lt; 0.05) with increasing LFTB inclusion. Thus, LFTB incorporation up to 20% improved the quality of fresh ground beef patties and tenderness of cooked patties, without detrimentally impacting (P &gt; 0.07) cooked color.Practical ApplicationsLean finely‐textured beef (LFTB) is a product made using an advanced meat recovery system from high‐fat, beef trimmings, and LFTB is treated with food‐grade ammonia to increase product pH and reduce potential pathogenic bacteria contamination. Even though LFTB has received considerable negative media coverage since 2012 (Yadavalli and Jones ), results of this research indicate that the inclusion of LFTB up to 20% could lend many positive quality characteristics to both fresh and cooked ground beef patties. Decreased lipid oxidation along with improved fresh color could result in a product with greater quality attributes, especially a more appealing color to consumers. With no negative effects on cooked color or cooking loss and the potential for increased tenderness, LFTB inclusion is a viable way to produce a desirable product while ensuring more complete utilization of beef carcasses.

Effect of the Programmed Nutrition Beef Program on moisture retention of cooked ground beef patties and enhanced strip loins

This study evaluated the influence of the Programmed Nutrition Beef Program and exogenous growth promotants (ExGP) on water holding capacity characteristics of enhanced beef strip loins. Sixty, frozen strip loins, arranged in a 2×2 factorial treatment arrangement with dietary program serving as the first factor and use of ExGP as the second factor, were thawed, injected with an enhancement solution, and stored for 7days. Loins from ExGP cattle possessed the ability to bind more (P<0.05) water before pumping and bind less (P<0.05) water after pumping and storage. Loin pH across treatments was similar (P>0.10) before injection, but increased post-injection and after storage (P<0.01). Treatments did not affect loin purge loss, steak cook loss, and expressible moisture (P>0.10). The Programmed Nutrition Beef Program and use of ExGPs minimally impacted water holding capacity of enhanced frozen/thawed beef strip loins.

Effect of Low‐Dose Electron Beam Irradiation on Quality of Ground Beef Patties and Raw, Intact Carcass Muscle Pieces

The objectives of this study were to determine the effects of a low-dose (≤1 kGy), low-penetration electron beam on the sensory qualities of (1) raw muscle pieces of beef and (2) cooked ground beef patties. Outside flat, inside round, brisket and sirloin muscle pieces were used as models to demonstrate the effect of irradiation on raw beef odor and color, as evaluated by a trained panel. Ground beef patties were also evaluated by a trained panel for tenderness, juiciness, beef flavor, and aroma at 10%, 20%, and 30% levels of fat, containing 0% (control), 10%, 20%, 50%, and 100% irradiated meat. With whole muscle pieces, the color of controls appeared more red (P < 0.05) than irradiated muscles, however, both control and treatments showed a gradual deterioration in color over 14 d aerobic storage at 4 °C. Off-aroma intensity of both control and treatments increased with storage time, but by day 14, the treated muscles showed significantly (P < 0.05) less off-aroma than the controls, presumably as a result of a lower microbial load. It was found that a 1 kGy absorbed dose had minimal effects on the sensory properties of intact beef muscle pieces. Irradiation did not have a significant effect (P > 0.05) on any of the sensory attributes of the patties. Low-dose irradiation of beef trim to formulate ground beef appears to be a viable alternative processing approach that does not affect product quality.

Effects of lactate and modified atmospheric packaging on premature browning in cooked ground beef patties

Our objectives were to determine the effects of lactate and modified atmosphere packaging on raw surface color, lipid oxidation, and internal cooked color of ground beef patties. Eight chubs (85% lean) were divided in half and each half was either assigned to the control (no lactate) or mixed with 2.5% lactate (w/w). Following treatment, patties were prepared and packaged in either vacuum, PVC (atmospheric oxygen level), high-oxygen (80% O(2)+20% CO(2)), or 0.4% CO (30% CO(2)+69.6% N(2)) and stored for 0, 2, or 4days at 2 degrees C. After storage, raw surface color and lipid oxidation were measured and patties were cooked to either 66 degrees C or 71 degrees C. Lactate improved (p<0.05) color stability of PVC, high-oxygen, and vacuum packaged raw patties, but had no effect (p>0.05) on the a * values and visual color scores of patties in 0.4% CO. Lactate decreased (p<0.05) lipid oxidation in all packaging atmospheres. Nevertheless, high-oxygen and PVC-packaged patties had more (p<0.05) lipid oxidation than patties in CO and vacuum. Lactate had no effect (p>0.05) on premature browning, whereas patties packaged in high-oxygen demonstrated premature browning. Conversely, cooked patties in 0.4% CO and vacuum were more red (p<0.05) than both high-oxygen and PVC-packaged patties. Although lactate improved raw color stability, it did not minimize premature browning in cooked ground beef patties.

Spectroscopic evaluation of the nutrient value of ground beef patties

In this study, visible-near-infrared (VNIR) spectroscopy along with proximate analysis was employed to develop and validate partial least square regression (PLSR) models for predicting cholesterol, fat, calories, and moisture content of fresh and cooked ground beef patties. The refined PLSR model utilized 51 bands from the NIR, green and red regions for raw patties, and 50 bands from NIR and blue regions for cooked patties. The PLSR models resulted in high validation R 2 values of 0.72–0.94, with the standard error of prediction varying from 1% to 8.9%. However, the residual predictive deviation (RPD) was acceptable only for calories and fat in both raw and cooked patties, and moisture in raw patties. This study indicated that VNIR spectroscopy in combination with PLSR modeling can be used for screening fat and calories in both raw and cooked beef patties, and may hold the potential for cholesterol screening.

The triacylglycerol preparation of conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties

It is proposed that conjugated linoleic acid (CLA) would depress the lipid oxidation caused by irradiation of cooked, aerobically stored ground beef patties. The free fatty acid (FFA–CLA) and triacylglycerol (TAG–CLA) preparations of CLA were added at 0%, 1%, 2%, or 4% during the grinding process. Patties were irradiated at 1.5–2.0 kGy and frozen at −20 °C. Subsequently, the patties were tempered to 4 °C, cooked to 70 °C and held at 4 °C for 7 d. Enrichment of ground beef with CLA increased the cis-9, trans-11 and CLA trans-10, cis-12 CLA isomers in ground beef patties, even after cooking. Weight loss ( P = 0.03) and percentage fat ( P = 0.05) were higher in irradiated beef patties than in control patties. Irradiation decreased the concentration of α-linolenic acid (18:3 n − 3) in the ground beef by over 60% ( P = 0.07), whereas thiobarbituric acid reactive substances (TBARS) values were higher ( P = 0.004) in irradiated beef patties than in control patties. The 1% concentration of added TAG–CLA reduced TBARS in irradiated ground beef patties, whereas 2% and 4% FFA–CLA depressed TBARS (CLA type × percentage interaction P = 0.04). Irradiation increased the cardboard and painty aromatic attributes ( P ⩽ 0.05), and FFA–CLA preparation increased the painty aromatic attribute and afterburn aftertaste, but these effects were not observed with the TAG–CLA preparation (CLA type × treatment interaction P < 0.04). Adding 1% TAG–CLA to ground beef during grinding can reduce lipid oxidation in irradiated, cooked ground beef patties without the negative aftertastes associated with the FFA–CLA preparation.

Identification of 2-amino-1,7-dimethylimidazo[4,5-g]quinoxaline: an abundant mutagenic heterocyclic aromatic amine formed in cooked beef.

A previously unknown isomer of the carcinogenic heterocyclic aromatic amine (HAA) 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx) was recently discovered in the urine of meat eaters and subsequently detected in cooked ground beef (Holland, R.D., et al. (2004) Chem. Res. Toxicol. 17, 1121-1136). In this current investigation, the identity of the analyte was determined through a comparison of its chromatographic tR by HPLC and through UV and mass spectral comparisons to the synthesized isomers of 8-MeIQx. Angular tricyclic isomers of 8-MeIQx were excluded as potential structures of the newly discovered HAA, on the basis of dissimilar tR and product ion mass spectral data. The linear tricyclic isomers 2-amino-1,6-dimethylimidazo[4,5-g]quinoxaline (6-MeIgQx) and 2-amino-1,7-dimethylimidazo[4,5-g]quinoxaline (7-MeIgQx) were postulated as plausible structures. Both compounds were synthesized from 4-fluoro-5-nitro-benzene-1,2-diamine in five steps. The structure of the analyte was proven to be 7-MeIgQx, on the basis of co-injection of the compound with the synthetic isomers, and corroborated by comparisons of the UV and mass spectral data of the analyte and MeIgQx isomers. 7-MeIgQx induced 348 revertants/microg in the S. typhimurium tester strain YG1024, when liver S-9 homogenate of rats pretreated with polychlorinated biphenyls (PCBs) was used for bioactivation. This newly discovered 7-MeIgQx molecule is one of the most abundant HAAs formed in cooked ground beef patties and pan-fried scrapings. The human health risk of 7-MeIgQx requires investigation.

Influence of Cooking Rate, Endpoint Temperature, Post-cook Hold Time, and Myoglobin Redox State on Internal Color Development of Cooked Ground Beef Patties

Three experiments investigated cooking rate, endpoint temperature, post-cook holding time, and raw myoglobin redox-state effects on ground beef internal cooked color. In Experiment 1, patties were cooked to endpoint temperatures of 65.6 °C, 71.1 °C, 76.7 °C, 82.2 °C, or 87.8 °C rapidly (1 °C/s), slowly (0.2 °C/s), or rapidly with 6-min post-cook holding time at 104 °C. Patties cooked slowly to less than 76.7 °C were more well done (P 0.05). In Experiment 3, patties cooked rapidly to 71.1 °C, 76.7 °C, or 82.2 °C from a predominantly raw oxymyoglobin state were less pink and had more denatured myoglobin than did those cooked from a predominantly deoxymyoglobin state (P < 0.05). Prediction equations determined that 80% of myoglobin must be denatured to create a well-done appearance. Using a slow cooking rate, post-cook holding time, or cooking from a highly oxygenated state will increase myoglobin denaturation and foster a well-done appearance.

Color of cooked ground beef patties is affected by cooking rate and post-cooking holding time (2006)

Two experiments investigated the effects of cooking rate and post-cooking holding time on the internal cooked color of ground beef patties. In Experiment 1, patties were cooked rapidly (1.8ºF/second) or slowly (0.4ºF/second). At temperatures below 180ºF, rapidly cooked patties were redder and appeared less well done than those cooked slowly. All slowly cooked patties appeared well done, even at unsafe final internal temperatures. In Experiment 2, patties were cooked rapidly and held for 1, 3, 6, or 12 minutes after cooking. Increasing the post-cooking holding time to 6 minutes after rapid cooking decreased pinkness and maximized well-done appearance. This allowed ground beef patties to be cooked to a lower temperature, likely preserving juiciness and flavor. Employing either a slow cooking rate or rapid cooking with a post-cooking holding time will foster a well-done appearance. Internal cooked color is not an adequate indicator of ground beef doneness. Only strict temperature control and monitoring can ensure product safety.

Internal Premature Browning in Cooked Ground Beef Patties from High‐Oxygen Modified‐Atmosphere Packaging

ABSTRACT: This study examined the effects of location within a package and display time on the incidence of premature browning in patties made from ground beef packaged in a high‐oxygen modified atmosphere (80% oxygen and 20% carbon dioxide) or in vacuum for up to 14 d. On days 3, 5, 8, 10, 12, and 14 of display, patties were formed from both top and bottom portions of tissue exposed to high‐oxygen. These patties contained predominantly oxymyoglobin and metmyoglobin at the time of formation and cooking. As display progressed, the percentage of oxymyoglobin decreased (P &lt; 0.05) and metmyoglobin increased (P &lt; 0.05) in the patties for both locations, whereas the percentage of deoxymyoglobin remained stable at less than 2%. Samples that were vacuum‐packaged contained predominantly deoxymyoglobin. Patties from high‐oxygen packages cooked to a temperature of 71.1 °C were prematurely brown (P &lt; 0.05) compared with vacuum‐packaged samples. Patties containing predominantly deoxymyoglobin remained pinker than patties cooked directly from high‐oxygen packages (lower visual color score, higher a* value; P &lt; 0.05) on the interior after cooking. Data in this study clearly demonstrate that, regardless of time in display, nearly 100% of patties formed from high‐oxygen‐packaged ground beef would be prematurely brown when cooked and could pose a food safety problem if not cooked to an endpoint temperature ensuring safety.

Conjugated Linoleic Acid Reduces Lipid Oxidation in Aerobically Stored, Cooked Ground Beef Patties

ABSTRACT: The effect of direct addition of conjugated linoleic acid (CLA) on lipid oxidation was studied. CLA and/or fat trim (4% by weight) were added to the lean trim (96%). Thiobarbituric acid reactive substances (TBARS) were determined on days 0, 3, and 7 for cooked or raw patties stored aerobically at 4 °C. Addition of CLA during the grinding process increased CLA isomers in both raw and cooked ground beef and decreased TBARS production (P &lt; 0.01). CLA caused a greater reduction in TBARS over storage time in cooked patties than in raw patties (P= 0.006). The concentrations of 18:2n–6 and CLA isomers decreased with storage time. CLA increased 18:2n‐6, whereas most fatty acids were decreased by the addition of CLA. CLA did not affect percentages of fat and moisture, cooking loss, or meat color (L*, a*, b*) (P &gt; 0.60).

Effects of reducing agents on premature browning in ground beef

This study was performed to investigate the effects of food-grade reducing agents on counteracting premature browning (PMB) and to determine the relative heat stability of different redox states of bovine myoglobin (Mb). Sodium erythorbate (SE), erythorbic acid (EA), sodium ascorbate (SA), ascorbic acid (AA) and ascorbyl palmitate (AP) were added to ground beef (15% fat) at a concentration of 2.3 mM; patties were prepared and stored at 4 °C and at −18 °C. Surface redness ( a* values), lipid oxidation and total reducing activity (TRA) were measured on raw beef, and a* values recorded from cooked internal surfaces. Bovine Mb was purified from biceps femoris muscle and heat capacity was measured using differential scanning calorimetry. All reducing agents decreased lipid oxidation and increased TRA relative to controls ( p < 0.05). In general, SE and SA were more effective at maintaining red color in cooked ground beef patties than other reducing agents ( p < 0.05). The temperature at peak heat capacity, T m, of metmyoglobin appeared lower than that of oxymyoglobin and deoxymyoglobin. Reducing agents can maintain Mb in the reduced state, and their addition to ground beef may be one method of preventing PMB.

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

Abstract 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.

Evaluating the Cooking and Chemical Characteristics of Low-Fat Ground Beef Patties

Ground beef patties (n=504), manufactured to contain 5, 10 or 15% fat, were evaluated to determine the effects of preparation, storage and cooking methods, and degree of doneness on cholesterol, total lipid, protein, moisture, and energy content. Differences between fresh, hand-made patties and frozen, machine-made patties were statistically significant for some nutrients. However, these differences may be insignificant to consumers because actual differences were small. The greatest difference in composition of the cooked ground beef patties was observed between patties cooked from the frozen state versus fresh patties. Patties cooked from the frozen state were higher in total lipid for each cooking method. An evaluation of cooking methods revealed small differences in total lipid content at the 5% level; however, at the 10 and 15% total lipid levels, microwaved and reheated patties contained the lowest amounts of total lipid while those baked, pan-fried, and broiled contained higher levels. In all total lipid levels and cooking methods except 5% fat broiled/reheated patties, reheating led to a decrease in fat content. Decreases in total lipid content were seen for reheated pan-fried patties at the 5 and 10% levels and reheated patties at the 15% level.