Inhibition of Lipid Oxidation and Rancidity in Precooked Pork Patties by Radical‐Scavenging Licorice (Glycyrrhiza glabra) Extract

This study investigated the efficacy of licorice extract (LE) to curtail lipid oxidation and protect sensory attributes of ground pork during refrigerated and frozen storage. Pork patties (20% fat) were formulated with 0%, 0.02%, 0.05%, and 0.1% (meat basis) LE or rosemary extract (RE) as comparison or 0.01% (fat basis) BHA with 0 or 1.5% NaCl. Raw and precooked (75 °C) patties were packaged in polyvinylchloride overwrapped trays and stored at 2 °C up to 7 and 14 d, respectively, or at –20 °C up to 6 mo. Lipid oxidation (thiobarbituric acid‐reactive substances [TBARS]) and sensory attributes of stored patty samples were evaluated, radical scavenging activity of the LE was measured, and the active phenolic compounds were identified. Cooking yield (<85%) was similar among antioxidant treatments, and lipid oxidation was minimal in refrigerated or frozen raw samples. However, TBARS values in refrigerated precooked control patties (0.22 mg/kg) rose to 9.3 to 9.4 mg/kg after 14 d, compared to 3.4 to 4.4 and 4.4 to 6.9 mg/kg in patties treated with 0.1% LE and RE, respectively. In frozen precooked samples, TBARS (0.22 mg/kg) increased to 1.3 mg/kg (P < 0.05) in control patties after 6 mo and had no significant change in patties treated with 0.1% LE or 0.01% butylated hydroxyanisol. Sensory panel evaluation confirmed strong inhibition of rancidity production by LE, corroborating its remarkable antiradical activity due to the presence of multiple phenolics. The results indicate that licorice has great potential as a natural antioxidative additive to extend the shelf‐life of precooked pork.     

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.     

Sensory, Microbial and Chemical Characteristics of Fresh Aerobically Stored Ground Beef Containing Sodium Lactate and Sodium Propionate

Hamburger patties with sodium lactate (NaL; 0, 3, or 4%) with or without sodium propionate (NaP; 0.1, or 0.2%) were stored aerobically at 4°C for 0, 1, 2, or 3 days, and evaluated for sensory attributes, Aerobic Plate Counts (APCs), lipid oxidation, pH, and water activity. NaL slowed microbial growth; addition of 0.2% NaP to 3% NaL increased antimicrobial effects equal to that of 4% NaL. NaL in combination with NaP reduced lipid oxidation over control or NaL patties. Patties with NaL had higher beef/brothy and beef fat scores and were sweeter, springier, more cohesive, and less crumbly than control patties and addition of 0.2% NaP increased juiciness.     

Effect of Acid and Alkaline Pyrophosphate Blends on the Natural Flora of a Cooked Meat System

Cooked pork sausage was prepared by using tetrasodium pyrophosphate (TSPP) and sodium acid pyrophosphate (SAPP) at 0 and 0.4% of the meat weight either separately or in different combinations. Samples were vacuum packaged and held in a refrigerated display case at 5°C for 21 days. Samples were also stored at room temperature (20-22°C) for 24 and 48 hr. Neither phosphate had an effect on microbial counts during refrigerated storage up to 21 days, but SAPP caused significantly lower counts of mesophilic and facultative anaerobic organisms after 48 hr of temperature abuse. The organisms affected were streptococci or very similar coccobacilli.     

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% O₂ + 20% CO₂), or 0.4% CO (30% CO₂ + 69.6% N₂) and stored for 0, 2, or 4 days at 2 °C. After storage, raw surface color and lipid oxidation were measured and patties were cooked to either 66 °C or 71 °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.     

Qualitative Alteration of Phospholipids in Beef Patties Cooked After Vacuum and Nonpackaged, Frozen Storage

Alterations during frozen storage of the phospholipids in high quality and very lean (7.5% fat) beef patties as influenced by vacuum packaging were studied. Meat was obtained from a closely trimmed semimembranosus muscle from a U.S. Choice Grade steer carcass. Ground patties were stored 3 days, 1.5, 3, and 4.5 months at -23 ± 1°C. Lipids were extracted after the patties were thawed and cooked. After the 3 days of frozen storage, the vacuum packaged samples indicated the presence of eight different phospholipid classes in decreasing concentration: phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, lysophosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysophosphatidylethanolamine, and diphosphatidylglycerol, in the nonpackaged samples; diphosphatidylglycerol and lysophosphatidylethanolamine were absent. As storage progressed, the amount of certain phospholipid classes, particularly in the nonpackaged samples, declined. After 3 months of storage in both packaged and nonpackaged samples, trace amount of lysodiphosphatidylglycerol became evident.     

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.     

Culinary herbs inhibit lipid oxidation in raw and cooked minced meat patties during storage

The effect of dried spices and the ethanol extract of those spices was studied on the stability of fresh chicken minced meat, and fresh and cooked pork patties pretreated with NaCl during refrigerated and frozen storage. The antioxidant activities of the spices were measured by thiobarbituric acid reactive substances (TBARS) and peroxide value (POV) in meat samples. The lipid oxidation was effectively inhibited in the chicken meat treated with several dry spices diminishing the TBARS to a range of 32% and 83% of those found in the control samples in frozen stored meat for 6 months. Marjoram, wild marjoram and caraway were the most effective dry spices. Ethanolic extracts of the same spices were more potent as antioxidants by lowering the concentration of the TBARS to a range of 20–27% of those found in the control samples. Addition of sodium salt to the minced pork resulted very high concentrations of the oxidation products originated from the polyunsaturated fatty acids. The treatment with ethanolic extract of spices (sage, basil, thyme and ginger) significantly inhibited the lipid peroxidation in refrigerated and chilled pork patties pretreated with NaCl by reducing both POV and TBARS. Heat treatment with microwaves produced significantly elevated levels of both lipid peroxides and TBARS, but the amount of these oxidation products was less than 10% in spice‐treated salted meat samples compared to that in untreated ones. Lipid peroxidation also grew continuously during the storage period at −18°C in raw and cooked samples. Ethanolic extracts of spices had a very strong antioxidative effect inhibiting lipid peroxidation in heat‐treated meat products during frozen storage. The highest antioxidant activity was observed in the case of ginger. High correlation coefficients were found between TBARS and POV both in raw and cooked pork patties (0.86, 0.91, respectively) during frozen storage. It is supposed that these compounds originated from the polyunsaturated fatty acids during oxidation processes but at different stages. Utilization of spices, spice mixtures or spice extracts in semi‐prepared meat products intended to be frozen for up to 6 months or more before consumption is proved to be advantageous in regard of shelf life of the food, as well as of human health, because of the beneficial effect of spices in inhibition of lipid peroxidation during heat treatment and chilling storage. © 1999 Society of Chemical Industry     

Effect of Potassium Sorbate on Refrigerated Storage of Vacuum Packed Scallops

Scallops (Pecten alba) were packaged aerobically, vacuum packaged, treated with 0.1% K-sorbate then packaged, or vacuum packaged and frozen. The initial flora was predominantly Vibrio which grew well in the aerobic packs (? 10⁸ c.f.u./g after 6 days at 4°C) and in the vacuum packs (? 10⁷ c.f.u./g after 6 days 4°C). The microbial counts in the sorbate-treated scallops were low (? 10³ c.f.u./g) after 6 days at 4°C and rose to 10⁵ c.f.u./g by 22 days, remaining at this level until the experiment ended after 48 days. Extensive use of taste panels as an evaluative tool enabled construction of odor and flavor profiles which showed clearly the nature of the changes that occurred during storage. The sorbate-treated scallops stored for up to 28 days at 4°C remained as acceptable as the frozen controls.     

Effect of Inorganic Polyphosphates on Ground Beef Characteristics: Microbiological Effects on Frozen Beef Patties

Microbiological effects of 0.4% sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), and three commercial phosphate blends were studied in frozen (90 days, ?20°C) and subsequently temperature-abused (24–25°C, 24 hr) beef patties. Phosphates did not significantly (p>0.05) reduce mesophilic, psychrotrophic, presumptive 5. aureus and lactic acid bacterial numbers during frozen storage of the patties, but one of the commercial blends and TSPP inhibited bacterial growth upon subsequent elevated-temperature abuse. However, bacterial inhibition by phosphates during temperature abuse was not sufficient to prevent spoilage of the patties.     

Composition and Stability of Goat Meat Patties as Affected by Breed Type and Feeding Regimen

Ground meat patties were made using knife-separable lean (frozen-thawed) composites from meat-type (Spanish, Spanish Boer) goats assigned to two feeding regimens (feedlot or range) and fiber-type (Angora, Spanish Angora) goats assigned to the feedlot regimen. Weight losses from pan-frying (mainly moisture loss) were 17.7 to 21.6%. Range meat-type goat samples had a higher proportion of total saturated fatty acids than the feedlot counterparts. After refrigerated storage, raw or cooked patties (aerobically packaged) from the range goats had lower TBA values than those from the feedlot goats. At – 20°C, all samples, raw or cooked, exhibited low TBA values throughout 120 days of storage.     

Effects of vacuum or modified atmosphere packaging in combination with irradiation for control of Escherichia coli O157:H7 in ground beef patties

The efficacy of controlling Escherichia coli O157:H7 in ground beef patties by combining irradiation with vacuum packaging or modified atmosphere packaging (MAP) was investigated. Fresh ground beef patties were inoculated with a five-strain cocktail of E. coli O157:H7 at 5 log CFU/g. Single patties, packaged with vacuum or high-CO(2) MAP (99.6% CO(2) plus 0.4% CO), were irradiated at 0 (control), 0.5, 1.0, or 1.5 kGy. The D(10)-value for this pathogen was 0.47 ± 0.02 kGy in vacuum and 0.50 ± 0.02 kGy in MAP packaging. Irradiation with 1.5 kGy reduced E. coli O157:H7 by 3.0 to 3.3 log, while 0.5 and 1.0 kGy achieved reductions of 0.7 to 1.0, and 2.0 to 2.2 log, respectively. After irradiation, the numbers of survivors of this pathogen on beef patties in refrigerated storage (4°C) did not change significantly for 6 weeks. Temperature abuse (at 25°C) resulted in growth in vacuum-packaged patties treated with 0.5 and 1.5 kGy, but no growth in MAP packages. This study demonstrated that combining irradiation with MAP was similar in effectiveness to irradiation with vacuum packaging for control of E. coli O157:H7 in ground beef patties during refrigerated storage. However, high-CO(2) MAP appeared to be more effective after temperature abuse.     

Color Changes of Chicken Leg Patties Due to End-point Temperature, Packaging and Refrigerated Storage

Patties of broiler leg muscle were heated to end-point temperatures (EPT) of 60, 65, 70, 75, 80 or 85°C, packaged in polyethylene bags or vacuum skin packs and stored at 4°C for up to 14 days. As EPT increased, lightness (“L”) and yellowness (“b”) increased whereas redness (“a”) decreased. Patty top surface center color “L” and “a” values correlated highly with the interior cut surface values. Patties stored in plastic zipper bags tended to show a lower “b” (P<0.05) reading than patties stored in vacuum skin packs and plastic film. Storage for 2 wk at 4°C increased “L”, and decreased “a” and “b” for all patties. As EPT increased, the color difference (AE) at the interior cut surface of patties heated to lower EPT and those heated to 85°C were reduced.     

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.     

Quality characteristics of pork patties irradiated and stored in different packaging and storage conditions

Patties were made from pork loin, individually vacuum- or aerobic-packaged and stored either at 4 or -40°C. Refrigerated patties were irradiated at 0, 1.5, 3.0 or 4.5 kGy absorbed dose, and frozen ones were irradiated at 0, 2.5, 5.0, or 7.5 kGy. Samples were analyzed for lipid oxidation, volatile production and odor characteristics. Refrigerated samples were analyzed at 0, 1 and 2 weeks, and frozen ones after 0, 1.5 and 3 months of storage. With vacuum packaging, the lipid oxidation (TBARS) of both refrigerated and frozen patties was not influenced by irradiation and storage time except for the patties irradiated and refrigerated at 7.5 kGy. With refrigerated storage, panelists could detect irradiation odor at day 0, but not after 1 week at 4°C. With frozen storage, however, irradiation odor was detected even after 3 months of storage. With aerobic packaging, the TBARS of refrigerated pork patties increased with storage time. The TBARS of pork patties increased as irradiation dose increased at day 0, but the effect disappeared after 1 week at 4°C. Nonirradiated patties were preferred to the irradiated ones at day 0 because of the significant irradiation odor in the irradiated ones, but the off-odor disappeared after 1 week at 4°C. With frozen storage, patties irradiated at 7.5 kGy had higher TBARS than those irradiated at lower doses. Nonirradiated patties had higher preference scores than the irradiated ones for 1.5 months in frozen storage. Sulfur-containing compounds were responsible for most of the irradiation off-odor, but these volatilized quickly during storage under aerobic conditions. Overall, vacuum packaging was better than aerobic packaging for irradiation and subsequent storage of meat because it minimized oxidative changes in patties and produced minimal amounts of volatile compounds that might be responsible for irradiation off-odor during storage.     

Antioxidant properties of selected Oriental non-culinary/nutraceutical herb extracts as evaluated in raw and cooked meat

Ethanol extracts of white peony (WP), red peony (RP), sappanwood (SW), Moutan peony (MP), rehmania (RE) or angelica (AN) were individually added to ground goat meat at 0.5-2.0% (g dry extract/100 g final meat sample), and raw and cooked samples were aerobically refrigerated for 0, 3 or 6 days. These extracts and rosemary extract (RO) were also individually added to salted or unsalted ground beef at 0.01-0.25% and refrigerated as raw or cooked patties. WP, RP, RE, SW and MP markedly reduced (P<0.05) lipid oxidation in cooked-stored goat meat. With 0.25% of WP, RP, SW, MP or RO in beef, lipid oxidation during storage was minimal in raw and cooked patties (plain or salted); raw patty redness values at day 6 were higher (P<0.05) for SW, WP, RP or MP than RO treatment or the control. At 0.01%, SW was more antioxidative (P<0.05) than the other extracts.     

Binding of Meat Pieces: Influence of Some Processing Factors on Binding Strength and Cooking Losses

Evacuation of the chamber of the press used to form flaked beef into a restructured meat product (patty) did not affect the binding strength of the cooked patty but under some conditions decreased the cooking loss. In studies using patty mixes containing 0–1.0% added sodium chloride, meat binding strength increased with decrease in the temperature of the mix when formed into patties over the temperature range - 1° to -5°C. The largest effect generally occurred between - 1° and -2°C. However, the effect was only noted in patties that were frozen (-30°C) before being cooked for assessment. With decrease below - 1°C of the temperature of patties when pressed, cooking losses increased for the patties without added salt but decreased for those with added salt (0.5% or 1%). Change in the pressure applied to form the patty (in the range 1.4–13.7 MPa) can affect binding strength.     

Effect of a Di-Thermal Storage Regime on Quality and Nutritional Changes and Energy Consumption of Frozen Boxed Beef

Seven types of beef products were commercially packaged, frozen, and stored at top corner pallet positions in three rooms for a year. The storage temperatures were: (1) -23°C, constant; (2) -23°C and -21°C; (3) -21°C and -18°C. Compared to the -23°C, constant room (as reference), a net energy saving of 6 and 14% was obtained for the two di-thermal storage rooms by maintaining the temperatures at the lower levels for one 12-hr period followed by the higher levels for another 12-hr period. The weight loss for most products was negligible, except for bulk-packed hamburger patties which lost over 1%. The results on sensory, nutritional, and other quality attributes of frozen boxed beef products showed no serious quality damage from both constant and di-thermal storage after 1 yr, except for MPB and beef patties whose practical shelf life was limited to 6 months.     

Factors Affecting Properties of Raw-Frozen Pork Sausage Patties Made with Various NaCl/Phosphate Combinations

Whole hog sausage patties made with (1) no phosphate, (2) 0.375% sodium tripolyphosphate (STP) and (3) 0.441% Lem-O-Fos® in combination with salt levels of 1.5, 1.0, 0.5, and 0.0% NaCl were frozen and packaged. Use of phosphates decreased off-flavor and rancidity development, improved binding, and increased pH values, cooking yields and scores for saltiness and juiciness. The prooxidant effect of NaCl was masked by the antioxidant properties of STP and Lem-O-Fos®. Extended periods of frozen storage reduced cooking yields, juiciness and texture scores and enhanced development of off-flavor and rancidity. However, use of phosphates or vacuum packaging exhibited an antioxidant effect during extended periods of frozen storage.     

Rheological Behavior of Frozen and Thawed Low-Moisture, Part-Skim Mozzarella Cheese

Stress relaxation and dynamic profiles of low-moisture, part-skim (LMPS) Mozzarella cheese cylinders refrigerated 14 days (control), frozen and thawed, and stored frozen and refrigerated up to 90 days were compared. Samples were frozen at ?30°C and stored at ?20°C. Thawing and refrigerated storage were at 5°C. Stress relaxation tests were conducted at 20°C and dynamic spectrometry at 20°C and 60°C. The frozen and thawed Mozzarella cheese tested at 20°C became harder and more elastic with storage time, while refrigerated stored samples became softer and more elasticoviscous with time. Upon melting, both go-day-frozen and go-day-refrigerated cheeses were less elastic and less viscous than 14-day-refrigerated samples.