Flavor and Oxidative Stability of Ground Beef Patties as Affected by Source and Storage

Chuck muscles and fat from silage plus grain- and forage-fed steers were stored 7 days at 4°C before patty manufacture or processed into patties and stored at 4°C or ?32°C. The thiobarbituric acid values were constant from 0 to 4 days for frozen patties but decreased (P<0.05) for refrigerated patties. Evaluated by an 11-member trained sensory panel, frozen patties had lower (P<0.05) rancid flavor intensity than refrigerated patties; rancid flavor increased from 0 to 2 or 4 days storage in refrigerated patties. Frozen patties from silage plus grain-fed steers had higher (P<0.05) beefy flavor intensity scores than those from forage beef. However, diet source had no effect (P>0.05) on refrigerated patties.     

Application of electron‐beam irradiation pasteurization of ground beef,from steers fed vitamin E fortified diets: microbial and chemical effects

The effects of vitamin E supplementation of diets and electron‐beam irradiation (EBI) processing of ground beef patties on microbial and chemical qualities were investigated during 21 days of storage at 4 °C. Oxidative damage to lipids induced by EBI in ground beef patties containing different fat contents was first determined at 3 day intervals throughout a 7 day storage period at 4 °C. Significantly (P ≤ 0.05) higher values for thiobarbituric acid reactive substances (TBARS) were detected in beef patties of higher fat content (ie at 17 and 30%), which was further enhanced by irradiation at 5 kGy. Since lipid oxidation proceeded to a greater extent in beef patties with higher fat levels, ground beef patties of 30% fat were prepared from steers fed basal (diet I) or basal + 500 IU (diet II) of the antioxidant (vitamin E) supplemented diets. Plasma vitamin E concentrations in cattle fed diets I and II were 1.58 ± 0.42 µg ml^?1 and 2.49 ± 0.40 µg ml^?1 respectively. Patties were processed with three doses (2, 5, or 10 kGy) of EBI and compared with non‐irradiated patties. Microbial indices monitored at 3 day intervals included total aerobic plate count, psychrotrophic counts, and total coliform and Escherichia coli counts. Bacterial growth in ground beef patties stored at 4 °C was significantly (P ≤ 0.05) reduced by EBI at 2 kGy dose. Complete inhibition of bacteria occurred at 5 kGy or higher (P ≤ 0.05) dosage of EBI over 21 days of storage at 4 °C. Quality indices monitored at 3 day intervals throughout a 21 day storage (4 °C) study involving 30% fat ground beef patties made from steers fed vitamin E supplemented diets I and II included TBARS and colour. Results indicated that irradiation at the highest dosages was associated with higher (P ≤ 0.05) TBARS values, which in turn corresponded to lower linoleic acid content. With all three levels of irradiation, Hunter a values of beef patties decreased (P ≤ 0.05) significantly. Lipid oxidation was significantly (P ≤ 0.05) retarded in stored beef patties derived from cattle fed vitamin E (diet II). Copyright © 2003 Society of Chemical Industry     

Effects of Chilling Method on the Sensory, Chemical and Cooking Characteristics of Ground Beef Patties

Hot-boned beef (excised 90 min postmortem) was chilled either by mixing coarse ground beef with CO₂ snow or by immersing ground beef chub packs in a brine chiller (-2°C). Hamburger patties were prepared from both hot and cold-boned chub packed, coarse ground beef after 0, 7, 14, and 21 days of storage (0°C). Microbiological quality of the hot-boned ground beef was either superior or equal to that of the control. Purge present in all the chub packs after 21 days of storage was 1.0%. Patties prepared from CO₂ chilled ground beef were more tender than control patties. Patties prepared from brine-chilled ground beef had greater cooking losses than patties prepared from cold-boned ground beef.     

Fat Level and Freezing Temperature Affect Sensory, Shear, Cooking and Compositional Properties of Ground Beef Patties

Experiments were conducted to determine effects of two targeted fat levels (6, 20%) and two freezing temperatures (?43, ?20°C) on sensory, shear, cooking and compositional properties of beef patties. Select grade beef rounds (IMPS 161) were used as the lean source for patties with U.S. Choice plates as the fat source. The 20% fat formulation had increased beef flavor and initial tenderness (?20°C frozen patties only) scores, but had higher instrumental shear values compared to the 6% fat patties. Freezing patties (especially those of 6% fat) at ?43°C greatly improved sensory and instrumental tenderness. Faster freezing reduced fat retention of 20% fat patties during cooking. Use of Select grade beef rounds coupled with rapid freezing is suggested for producing acceptable low-fat ground beef patties.     

Effects of Electrical Stimulation, Boning Temperature, Formulation and Rate of Freezing on Sensory, Cooking, Chemical and Physical Properties of Ground Beef Patties

The effects of electrical stimulation vs nonstimulation, temperature of boning (hot vs cold), formulation (USDA Choice chucks with USDA Choice plates vs imported cow lean with USDA Choice plates) and rate of freezing (fast = -50°C vs slow = -20°C) were determined on sensory, cooking, chemical, and physical properties of ground beef patties. Sensory panel ratings for tenderness were highest in patties from formulations processed with either nonstimulated beef, hot-boned beef or Choice chucks. The substitution of imported cow lean for Choice chucks generally reduced cooking losses and changes in patty height during cooking. Fat losses during cooking were higher in patties made from electrically stimulated than nonstimulated beef, while moisture losses during cooking were greater for patties from nonstimulated than stimulated beef. Of the factors involved in this study, hot boning produced the most beneficial results in beef patties. Boneless chucks and plates from electrically stimualted Choice carcasses appear to be suitable raw materials for production of ground beef patties.     

Effects of succinate on ground beef color and premature browning

The objective of this experiment was to determine the effects of succinate on raw and cooked ground beef color. Chubs (n=10) were divided in half and assigned to either succinate (final w/w concentration of 2.5%) or distilled water. Patties (n=14 per chub half) were assigned to initial day 0 color and each of 6 treatment combinations, created by crossing 3 packaging types (vacuum, high-oxygen/80% O(2), and PVC) with 2 storage times (days 1 and 3). After storage, patties were cooked to either 66 °C or 71 °C. Succinate increased (P<0.05) ground beef pH and metmyoglobin reducing activity but had no effect (P>0.05) on raw a* and chroma values. Moreover, succinate decreased (P<0.05) raw L* values, lipid oxidation, and premature browning for patties packaged in PVC and high-oxygen. Succinate may increase cooked patty redness via its influence on meat pH.     

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.     

Replacement of Beef Fat with Partially Hydrogenated Plant Oil in Lean Ground Beef Patties

Partially hydrogenated plant oils (corn, cottonseed, palm, peanut and soybean) were substituted (in part) for beef fat in lean (10% fat) ground beef patties to improve nutrient content of ground beef. Effects of such addition on composition and consumer acceptability were evaluated. Addition of hydrogenated plant oils had little effect on composition of raw or cooked patties. Those containing hydrogenated corn or palm oil were not different (P>0.05) from all-beef patties in cooking loss or overall acceptability. Therefore substitution of hydrogenated oils for beef fat in production of lean ground beef patties may be feasible.     

Storage Stability of Low-fat Ground Beef Made with Lower Value Cuts of Beef

Five combinations of low-fat ground beef treatments were prepared with lower value raw-materials: 90% lean cow trimmings, 50/50 Choice trimmings, 95% lean Choice trimmings, defatted clods and rounds, cow knuckles, and cow chucks. They were compared to a 20% fat control for quality attributes during 24 wk frozen (?20°C) storage. Control patties had greater (P<0.05) cooking loss, shear force, and connective tissue, and lower (P<0.05) juiciness scores than low-fat treatments. All low-fat pattie treatments were rated higher (P<0.05) in flavor intensity than control patties. Low-fat patties manufactured with a majority of lean cow trimmings had a greater color (pigment) and oxidative (lipid) stability.     

Palatability and Appearance Traits of Beef/Pork Meat Patties

Eight beef/pork ground meat blends were made from mature (cows or sows) and youthful (steers or barrow) beef and/or pork lean. Blends were stored at — 27°C for either 14 or 150 days. Storage time decreased overall desirability scores of blends made with 20% pork fat and 80% youthful beef lean. No differences were found for flavor or overall desirability scores within the 14-day storage treatment. The consumer panel did not detect differences among treatments for source of fat or species. Results indicated beef/pork patties containing 40–80% mature lean and a minimum of 10% beef fat were equal to all-beef controls (100% beef patty) for visual and palatability traits.     

Effect of erythorbic acid on cooked color in ground beef

Consumers often use the color of cooked ground beef as an indicator of doneness. For safety reasons, it is recommended that the center of ground beef products be heated to 71°C. In some instances beef may appear done before reaching 71°C, a condition termed premature browning (PMB). Ground beef (15% fat), with added erythorbic acid (ERY) at 0.04 and 0.06% was formed into patties, wrapped in oxygen permeable film, and stored in the dark at 4°C. Patties were stored for either 10 h or 58 h and then cooked to internal end point temperatures of 60, 66, 71 or 77°C. Internal cooked color L(?), a(?) and b(?) values were measured. For beef patties stored 10 h, there was no effect of ERY on internal cooked color. After 58 h storage, ground beef with 0.04 and 0.06% ERY had higher a(?) values than controls at 60°C (P<0.05). Beef with 0.04% ERY cooked to an internal temperature of 66°C had higher a(?) values than 0.06% ERY and controls (P<0.05). There was no effect of ERY on color of beef patties cooked to 71 or 77°C. The presence of 0.04% ERY in ground beef patties stored 58 h appeared to maintain red color at internal temperatures of 60 and 66°C.     

COLLAGEN AS A HAMBURGER EXTENDER

Bovine hide collagen was added to ground beef at 0, 10 or 20% level replacing lean meat and stored at ?15°C up to 2 weeks to evaluate the effect of collagen level and storage time on the quality. Beef patties with collagen were found to be superior (P<0.05) in juiciness by the taste panel while the flavor, texture and overall acceptability decreased as the collagen level increased. However, no significant differences were observed for these attributes due to storage time. Collagen was found to bind moisture as indicated by no significant cooking loss due to replacement levels or storage. Chemical rancidity decreased significantly as the collagen level increased but was not influenced by length of storage. The addition of collagen to ground beef resulted in a lighter colored patty which was influenced by collagen level and storage time. The patties tended to become less cohesive as collagen level increased but the texture improved upon storage.     

Lipid Oxidation in Ground Beef Patties as Affected by Time-Temperature and Product Packaging Parameters

Oxidative rancidity in fresh and stored ground beef samples was measured using a thiobarbituric acid (TBA) assay with antioxidant protection. The independent variables were fat concentration (15 or 30%), package type (polyethylene or vacuum-packaged), freezer storage temperature (-12.2°, -23.3° or -34.4°C) and storage time (4, 8, 12, 16, or 20 weeks). At the end of each storage time samples were thawed and TBA values were determined on the samples before and after cooking. TBA values increased during the first 12 to 16 weeks after which time it decreased for both the cooked and uncooked samples. The higher fat samples, packaged in polyethylene, had higher TBA values for both cooked and uncooked patties. Uncooked patties stored at - 12.2°C had higher TBA values than those stored at -23.3°C or -34.4°C but cooked sample TBA values showed no dependence on storage temperature.     

Processing, Microbial and Sensory Characteristics of Cooler and Freezer Stored Hot-Boned Beef

Weiners were prepared from preblended hot-boned (prerigor) beef raw materials stored up to 21 days at 2°C and up to 28 days at -10°C. The addition of salt was necessary for maintenance of desirable sausage-making characteristics of hot-boned beef stored at 2°C for 7 days. The addition of salt for the maintenance of desirable functional properties does not appear to be necessary, if the prerigor materials are stored at freezer temperatures (-10°C). Flavor problems may develop in products from preblended raw materials stored at -10°C beyond 14 days postmortem.     

Soy Protein and Oil Effects on Chemical, Physical and Microbial Stability of Lean Ground Beef Patties

Effects of isolated soy protein (ISP), frozen, textured isolated soy protein (FTISP), soybean oil (SO), and hydrogenated soybean oil (HSO) addition on chemical, color, sensory, and microbial stability of lean (>90%) ground beef patties (LGBP) were evaluated. Soy oil was incorporated as an emulsion (SE). Nine treatments, including two all beef controls (20 and 10% fat), were formulated to contain combinations of SE, HSO and FTISP. Sensory panelists found LGBP with 25% FTISP (10% fat from beef) to have as intense beef flavor (P>0.05) as all beef controls. Lipid oxidation and pigment discoloration rates were slowed by fat adjustment to 10% with SO and/or HSO. Soy had no effect (P>0.05) on microbial stability.     

Fat content and ascorbic acid infusion influence microbial and physicochemical qualities of electron beam irradiated beef patties

The effects of fat content and post-slaughter ascorbic acid (AA) infusion on microbial and physicochemical qualities of beef patties processed by electron beam irradiation were investigated in a 4 °C storage trial. Beef muscles from AA-infused or control animals were ground and mixed with tallow to achieve a final fat content of 4%, 17% and 30%, respectively. Beef patties were irradiated at 5 and 10 kGy with a linear electron beam accelerator. Non-irradiated and non-infused ground beef patties served as a control. The addition of fat significantly (p<0.05) increased aerobic, total coliform, E. coli, and psychrotrophic bacteria counts in beef patties during storage. Irradiation at both dosages exerted a pasteurization effect on psychrotrophic bacteria for up to 7 days of storage. No viable aerobic, total coliform, or E. coli bacteria were detected in any irradiated beef patties during storage. Physicochemical changes caused by lipid oxidation and surface discoloration of beef patties were significantly (p<0.05) increased by both the addition of fat and irradiation processing. Beef patties made from AA-infused animals did not alter bacterial counts. Instead, post-slaughter infusion of AA exerted a pro-oxidant effect in the beef patties that led to a significant (p<0.0.5) increase in lipid oxidation and surface discoloration of stored patties.     

Improvement of Pigment and Lipid Stability in Holstein Steer Beef by Dietary Supplementation with Vitamin E

Pigment and lipid oxidation was investigated in fresh ground sirloin from control and vitamin E-supplemented (370 I.U./head/day) Holstein steers. Alpha-tocopherol levels were higher (P<0.05) in muscle from supplemented animals than from controls. During 6 days storage at 4°C, metmyoglobin accumulation and lipid oxidation (TBA) were greater (P<0.05) in beef from control versus supplemented animals. TBA value and % metmyoglobin were highly correlated in the control (r = 0.91) and supplemented (r = 0.72) groups. TBA values of cooked sirloin slices subsequently stored for 2 days at 4°C, and for frozen ground sirloin patties stored at -18°C for 1.5 and 3 months, were lower (P<0.05) in beef from supplemented animals than from controls. Meat which contained in excess of ca. 0.3 mg α-tocopherol/100 g tissue displayed the least oxidation of both pigments and lipids.     

Precooked Reduced-Fat Beef Patties Chemical and Sensory Quality as Affected by Sodium Ascorbate, Lactate and Phosphate

Beef-carrageenan (BC; 10% fat) patties—with sodium ascorbate (0.05%), sodium lactate (3%), sodium tripolyphosphate (0.3%), ascorbate-phos-phate, ascorbate-lactate, or none—and 20%-fat all-beef patties were cooked, aerobically or vacuum packaged, and stored at 4°C or ?20°C. Fat level had a greater effect on texture than did additives. Lactate and phosphate increased cooking yield of BC patties. Phosphate was antioxidative but not antimicrobial. Ascorbate was antioxidative and reduced aerobic plate counts (APCs) of aerobically packaged refrigerated BC. Lactate reduced APCs of both aerobically and vacuum packaged BC patties. Lactate had a prooxidative effect in aerobically-packaged/frozen patties but showed no such effect in vacuum-packaged/frozen patties or refrigerated patties. Ascorbate-phosphate was most effective in minimizing flavor deterioration in refrigerated BC patties.     

EFFECT OF PROTEIN EXTENDERS ON FATTY ACIDS,CHOLESTEROL, SENSORY QUALITY AND COOKING LOSS OF BEEF PATTIES1

Ten different formulations of beef patties were processed to contain 20–50% fat from lean beef containing not more than 7% fat and beef fat consisting of not less than 90% fat and were extended with different levels of textured soy protein (TSP) at 5, 10 and 20% and single cell protein (SCP) at 2.5, 5 and 7.5%. The patties were stored at ?18°C for 6 months. Sensory quality evaluation showed that patties with 80% lean and 20% fat and patties with 40% lean, 40% fat and 20% TSP were the least acceptable, but lower levels of TSP and SCP addition were found to improve panel rating. A 17% increase in protein content and a reduction of about 13.5% in fat content was observed due to TSP and SCP incorporation. An average cooking loss in the different formulations was 33%, addition of protein extenders was found to reduce cooking loss by about 22% while fat loss averages 30.2%. A reduction of 21.1% of 18:1 and a reduction of approximately 18.7% of total FAME and 32% cholesterol were observed due to the addition of TSP and SCP.     

Chitosan inhibits premature browning in ground beef

Our objective was to evaluate the effect of chitosan on premature browning in refrigerated ground beef patties stored in different packaging systems. Ground beef patties (15% fat) with chitosan (1% w/w) or without chitosan (control) were individually packaged either in vacuum (VP), aerobic packaging (AP), carbon monoxide modified atmosphere packaging (LO-OX; 0.4% CO+19.6% CO(2)+80% N(2)), or high-oxygen modified atmosphere packaging (HI-OX; 80% O(2)+20% CO(2)), and stored for 0, 1, or 3 days at 1°C. At the conclusion of storage, raw surface redness was evaluated, patties were cooked to internal end-point temperatures of either 66°C or 71°C, and internal cooked color was measured. The incorporation of chitosan increased (P<0.05) the interior redness of patties stored in AP, VP, and LO-OX, but not in HI-OX. The results of the present study suggest that the incorporation of 1% chitosan minimizes premature browning in ground beef patties stored under AP, VP, and LO-OX.