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 succinate and pH on cooked beef color

Two experiments were conducted to assess the effects of succinate and pH on cooked beef color. In experiment 1, ten strip loins (M. longissimus lumborum) were divided in half and assigned to either non-enhanced control or 2.5% succinate. Each half-loin was cut into steaks, packaged in vacuum or 80% oxygen, and stored at 1 °C for 0, 6, or 12 days. Steaks were cooked to either 66 °C or 71 °C. Succinate increased (P < 0.05) steak pH, raw a* values, and interior cooked redness when packaged in high oxygen. In experiment 2, to assess the role of succinate in raw and cooked color, succinate or ammonium hydroxide was added to ground beef patties to result in a common meat pH (5.9). At a similar pH, succinate had greater metmyoglobin reducing activity and internal cooked redness compared with ammonium hydroxide (P < 0.05). In addition to ingredient-based changes in muscle pH, succinate may influence color by regenerating reducing equivalents.     

Effects of pyruvate, succinate, and lactate enhancement on beef longissimus raw color

Beef strip loins (n=30) were divided into halves, and each half was assigned randomly to one of four injection enhancements: (1) non-enhanced control, (2) 3% pyruvate, (3) 3% succinate, and (4) 3% lactate. Steaks were cut and packaged in either vacuum, high oxygen (80% O(2)/20% CO(2)), or PVC. Color and lipid oxidation were measured on days 0, 5, and 13 of storage at 1°C. Enhancement had a significant effect on steak pH. On day 13 of storage, steaks enhanced with lactate, pyruvate, and succinate were less discolored (P<0.05) than control steaks in PVC and high oxygen. Enhancement darkened steaks (P<0.05) compared with control steaks. Succinate had the greatest and pyruvate had the least metmyoglobin-reducing activity (P<0.05). Lactate and pyruvate decreased the TBARS values of steaks packaged in PVC (P<0.05) whereas pyruvate was most effective for lowering lipid oxidation in high-oxygen packaging.     

Storage length,storage temperature,and lean formulation influence the shelf-life and stability of traditionally packaged ground beef

The effect of storage length and temperature on the shelf life of three ground beef formulations (lean:fat: 73:27, 81:19 and 91:9) was investigated. Coarsely ground beef was stored at − 1.7 or 2.3 °C for up to 28 d. Traditional overwrap packages were produced every 7 d prior to retail display for 24 h. Lipid oxidation (TBARS), subjective color, instrumental color, and aerobic bacteria were evaluated after 0 and 24 h of display. Formulation influenced initial L* and subjective color values (P < 0.05). Storage temperature did not affect initial color, but product stored at 2.3 °C was more discolored after 24 h (P < 0.05). Aerobic bacteria increased as storage d and temperature increased (P < 0.05). Initial TBARS increased through d 21, but were lower after 28 d. Overall, initial characteristics depended on formulation; however, ground beef shelf-life and stability were largely influenced by storage length and storage temperature.     

Storage and packaging effects on sensory and color characteristics of ground beef

Effects of irradiation (2 kGy) of ground beef patties from trimmings stored aerobically for 0 or 6 days on lean color, odor, and sensory attributes were investigated. Beef trimings were coarse ground and split into 2 groups. Group one was fine ground, pattied, and packaged immediately; group-two was stored 6 days then fine ground, pattied, and packaged. Irradiated beef patties had greater (P<0.05) off-odors, and off-flavors, lower (P<0.05) CIE L^*, a^* and b^* and saturation indexes values (P<0.05) after four days of storage at 0±1 °C. Irradiation of patties produced from trimmings aged an extra 6 days resulted in increased (P<0.05) saturation indexes and b^* values, but not off-odors when compared to non-aged and irradiated patties. Thus, the production of irradiated beef patties should utilize beef trimmings with the shortest postmortem aging time and a dose of less than 2 kGy to minimize discoloration and off-odors.     

Effects of enhancement with differing phosphate types, concentrations, and pump rates, without sodium chloride, on beef biceps femoris instrumental color characteristics

Enhancement of beef biceps femoris muscles (n=45) with solutions comprising sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, with the exclusion of sodium chloride, was performed to observe the independent phosphate effects on instrumental color during simulated retail display. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. All three phosphate types maintained higher (P<0.05) L* values than untreated steaks (CNT) through 5 days-of-display, and SHMP had higher (P<0.05) L* values than STPP and TSPP through 7 days-of-display. Additionally, steaks with 0.2% phosphate inclusion were lighter (L*; P<0.05) than CNT throughout display, and were lighter (P<0.05) than steaks enhanced with 0.4% phosphates through 7 days of display. Steaks enhanced with TSPP had higher (P<0.05) a* values than CNT on days 5 and 7 of display, whereas SHMP- or STPP-enhanced steaks generally had similar (P>0.05) a* values as CNT after 3d of display. Direct comparison of phosphate concentrations revealed no differences (P>0.05) in a* values. Only steaks enhanced with TSPP were more vivid (P<0.05) and had higher (P<0.05) proportions of oxymyoglobin than CNT on days 5 and 7 of display. However, direct comparison of phosphate types indicated that TSPP- and STPP-enhanced steaks had similar (P>0.05) oxymyoglobin proportions during display. Phosphate inclusion at 0.4% maintained higher (P<0.05) oxymyoglobin proportions than 0.2% phosphate inclusion through 5 days-of-display. These results indicate that while 0.2% phosphate concentrations maintain lighter color, 0.4% concentrations can more effectively retain oxymyoglobin during display. Additionally, only steaks enhanced with TSPP were redder, more vivid, and had higher oxymyoglobin proportions than untreated steaks during the latter stages of display.     

Effect of time of measurement on the relationship between metmyoglobin reducing activity and oxygen consumption to instrumental measures of beef longissimus color stability

Contributions of initial and retained levels of oxygen consumption and reducing capacity to animal variation in color stability were evaluated. Instrumental color values were determined on longissimus steaks (n=257) during 6 d of display. Oxygen consumption (OC), nitric oxide metmyoglobin reduction (NORA), initial metmyoglobin formation (IMF), and post-reduction metmyoglobin (PRM) were measured on d 0 and 6. During display, color variables, OC and reducing ability decreased (P<0.05). Color stable steaks had greater (P<0.05) reducing ability on d 0 and 6 and lower (P<0.05) OC on d 0 than unstable steaks. Color change was correlated to OC, NORA, and PRM on d 0 (r=0.19, -0.44 and 0.45, respectively) and to NORA and PRM on d 6 (r=-0.50 and 0.52, respectively). These data suggest that initial capacity for OC and reducing ability, combined with retained reducing ability contribute to animal variation in color stability.     

The effect of storage temperature and time on the consistency and color of sterilized processed cheese

The effect of sterilization (117 °C for 20 min) on the color and consistency of processed cheeses was evaluated. The sterilization resulted in a darker shade (darker color) and increased firmness and elasticity of processed cheeses (P < 0.05). During the storage period (24 months) of sterilized processed cheeses, their color as well as consistency changed depending on the temperature tested (8 and 23 °C). The color change of sterilized processed cheeses was more significant at a higher storage temperature (23 °C) in comparison with the products kept at cold storage temperature (8 °C) (P < 0.05). The firmness of sterilized processed cheeses stored at 8 °C increased during the 24 months. The rise in firmness achieved in the products stored at 23 °C was followed by its decrease in the second year of storage.     

Predicting beef tenderness using color and multispectral image texture features

The objective of this study was to investigate the usefulness of raw meat surface characteristics (texture) in predicting cooked beef tenderness. Color and multispectral texture features, including 4 different wavelengths and 217 image texture features, were extracted from 2 laboratory-based multispectral camera imaging systems. Steaks were segregated into tough and tender classification groups based on Warner-Bratzler shear force. The texture features were submitted to STEPWISE multiple regression and support vector machine (SVM) analyses to establish prediction models for beef tenderness. A subsample (80%) of tender or tough classified steaks were used to train models which were then validated on the remaining (20%) test steaks. For color images, the SVM model correctly identified tender steaks with 100% accurately while the STEPWISE equation identified 94.9% of the tender steaks correctly. For multispectral images, the SVM model predicted 91% and STEPWISE predicted 87% average accuracy of beef tender.     

Effects of lactate-enhancement on surface reflectance and absorbance properties of beef longissimus steaks

A completely randomized block design was used to assess the effects of lactate-enhancement on surface reflectance and absorbance properties of beef longissimus steaks. Loins were divided into sections, assigned to one of four treatments (non-enhanced day 0, non-enhanced day 5, water-enhanced, and 3% lactate), vacuum packaged, stored for 5 days at 4 °C, and then cut into steaks that were used to prepare 100% of deoxy-, oxy-, met-, and carboxymyoglobin according to AMSA (1991). Surface color was analyzed using a HunterLab Miniscan Plus Spectrocolorimeter. Lactate-enhanced steaks had the least overall surface reflectance and the darkest surface color (lower L*; P < 0.05). For 100% of each myoglobin form, K/S values and ratios (isobestic wavelengths ÷ 525 nm) at 474, 525, 572, and 610 also were influenced by lactate-enhancement. Hence, when estimating surface myoglobin forms using K/S ratios, separate 100% myoglobin reference standards should be prepared from both non-enhanced and enhanced steaks.     

Effects of conjugated linoleic acid on color and lipid oxidation of beef patties during cold storage

The effects of conjugated linoleic acid (CLA) on color and lipid oxidation of beef patties were investigated. Ground beef was divided into three batches. The control patties were prepared with 90% lean meat and 10% tallow. The second treatment consisted of 90% lean meat with 9.5% tallow+0.5% CLA sources. The third treatment consisted of 90% lean meat with 8% tallow+2% CLA sources. The patties were wrap-packaged and then stored at 4° for 14 days. The CLA concentration significantly increased (P<0.05) by substituting CLA sources for fat. Storage of the patties did not alter the CLA concentration in beef patties. The treatment substituted with CLA sources had significantly lower TBARS (2-thiobarbituric acid-reactive substances) values (P<0.05) than the control. For oxymyoglobin contents and a* value, substituted CLA sources treatments had significantly higher values than the control. However, L* value significantly increased by substituting CLA sources for fat.     

Relationship between lipid peroxidation and fat content in Japanese Black beef Longissimus muscle during storage

We examined the relationship of crude fat content to lipid peroxidation of beef during storage. Longissimus muscle samples (fat content; 6.5–39.4%) from 27 Japanese Black beef steers were stored for 1, 4, 7 and 10 days, and thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were determined. TBARS values increased significantly (P<0.05), but LOOH did not change during the 10- day storage period. TBARS values were negatively correlated (P<0.05) with fat content in samples stored for 1, 4, 7 and 10 days. LOOH values, however, were not significantly correlated with fat content except on day 1. Phospholipid contents were correlated (P< 0.01) with LOOH values on each measurement day, but not significantly correlated with TBARS values except on day 1. These findings indicated that: (1) high-fat beef had high preservative properties, and that; (2) TBARS formation was correlated with LOOH derived from phospholipid oxidation in the initial period of storage, and was correlated directly with fat content in a later period.     

Effect of freeze-thaw cycles on physicochemical properties and color stability of beef semimembranosus muscle

The effects of freeze-thaw cycle on the physicochemical properties and color stability of beef semimembranosus muscle during cold storage were investigated. Meat was tested for effects on color (CIE L^?, a^?, b^?), myoglobin content (%), metmyoglobin reducing ability (MRA), thiobarbituric acid reactive substances (TBARS), heme pigment content (ppm), SDS-PAGE profile, and tissue microstructure. Fresh meat showed significantly (p < 0.05) higher values of CIE a^?, CIE b^?, and oxymyoglobin content (%) compared to freeze-thawed meat during cold storage. However, metmyoglobin content (%) was higher in freeze-thawed meat than in fresh meat during 7 days of cold storage. There were no significant differences (p > 0.05) in MRA among the treatments during cold storage. The TBARS value (0.387 mg/kg) of fresh meat was significantly (p < 0.05) higher than those of freeze-thawed meats after 5 days of cold storage. These results suggest that the freeze-thaw process could accelerate the deterioration of meat color.     

Changes in the content of biologically active polyamines during beef loin storage and cooking

Dietary polyamines putrescine (PUT), spermidine (SPD) and spermine (SPM) participate in numerous human physiological processes, including tumour growth. Reliable information on their contents in foods is thus needed. Data for processed beef are very limited. Nine experiments with beef loin (longissimus lumborum) were, therefore, carried out. Loin cuts were stored at −18 °C for 178 days or beef was stored aerobically, vacuum-packaged (VP) and packaged in a modified atmosphere (MA; 70% N₂ and 30% CO₂, v/v) at +2 °C for 9, 21 and 21 days, respectively. The effects of three usual cooking treatments were also tested. Polyamines were determined after extraction with perchloric acid as dansyl derivatives using an HPLC method. Only SPM was detected at initial levels of 23.5–27.5 mg kg⁻¹, PUT and SPD contents were below the detection limits of 1.2 and 1.7 mg kg⁻¹, respectively. SPM content increased during the initial weeks of frozen storage and then gradually decreased to about 70% of the initial values at the end of the storage period (P < 0.05). No apparent SPM decrease was observed during aerobic storage for 9 days, while in VP and MA variants the losses were about 20% of the initial values on day 21 (P < 0.05). Slightly higher mean SPM losses were observed during boiling and stewing with and without added water. The differences among the cooking treatments were not significant. However, significant differences were observed among the loins used.     

Influence of vacuum skin packaging on color stability of beef longissimus lumborum compared with vacuum and high-oxygen modified atmosphere packaging

The objective of this study was to investigate how color stability of beef is affected by vacuum skin packaging (VSP) compared with vacuum packaging (VP) and high-oxygen modified atmosphere packaging (MAP; 80% O(2) and 20% CO(2)). Longissimus lumborum muscles were aged in vacuum for 7days and then cut into 2-cm-thick slices and repacked using VSP, VP and MAP for another 7days. Color stability was measured during the next 5days in air and samples for α-tocopherol and NADH analyses were obtained at the beginning and end of aerobic storage. Color stability, α-tocopherol and NADH of steaks were affected by packaging methods and storage time in air (P<0.05). Higher a* value was obtained in VSP on day 5 compared with VP. Steaks packed in VSP had better color stability than in VP and their color was similar to MAP at the end (day 5) of storage.     

Nitrite-embedded packaging film effects on fresh and frozen beef color development and stability as influenced by meat age and muscle type

Muscles (Longissimus lumborum, LL; Psoas major, PM, semitendinosus, ST) were aged (2, 9 d postmortem), cut into steaks, anaerobically packaged (nitrite-embedded film, NEF), and displayed (fresh, 19 d; frozen, 39 d). Fresh NEF increased (P < 0.05) in redness (first 48 h). Upon opening fresh NEF (d 6) and overwrapping in PVC film, redness declined (P < 0.05). NEF cooked LL had more red surface compared to non-NEF. Meat age influenced NEF color. Intact NEF maintained acceptable red color throughout display. Residual nitrite and nitrate associated with fresh NEF and nitrate in NEF cooked LL were found (P < 0.05) in the outer layer. Consideration should be given to providing sufficient time for nitric oxide myoglobin development when using NEF which may be influenced by meat age and muscle differences. NEF packaging has potential to extend fresh beef color display life. NEF appears to offer the opportunity to display bright red beef in frozen display by limiting typical effects of photooxidation.     

Impact of muscle type and sodium chloride concentration on the quality, sensory, and instrumental color characteristics of solution enhanced whole-muscle beef

Beef biceps femoris (n = 10; muscle sections, n = 20; BF), infraspinatus (n = 10; muscle sections, n = 20; IS), and longissimus (n = 10; muscle sections, n = 20; LM) muscles were utilized to evaluate the effect of enhancement with phosphate and varying levels of sodium chloride in beef muscles differing in composition and palatability. Muscles were untreated or solution enhanced to 112% of raw product weight with sodium tripolyphosphate at 0.4% of product weight (STPP), or STPP and sodium chloride (NaCl) at 0.5%, 1.0% or 1.5% of product weight. There was a quadratic relationship (P = 0.04) for percent free water to decrease and a linear relationship (P < 0.01) for cook yield to increase as the level of NaCl increased. The IS steaks required less (P < 0.05) shear force than either the BF or LM, with the BF and LM having similar (P > 0.05) shear force values. There was a linear relationship (P < 0.01) for shear force values to decrease with increasing salt concentration. Steaks from all four enhancement treatments had lower (P < 0.05) shear force values than untreated steaks. Sensory overall tenderness ratings revealed that the IS and LM were similar (P > 0.05) and superior (P < 0.05) to the BF in tenderness. Steaks enhanced with STPP and 0.5%, 1.0%, or 1.5% NaCl all were rated more tender (P < 0.05) than untreated or STPP-only treated steaks. The BF exhibited the lowest (P < 0.05) L* (lightness) and a* (redness) values, as well as decreased (P < 0.05) vividness. The LM generally exhibited superior color to the other two muscle types. There was a linear relationship (P < 0.01) for L*, a*, b* (yellowness) values, and vividness to decline with increasing salt concentration, but steaks enhanced with STPP and 0.5% NaCl were similar (P > 0.05) in a* values and vividness to untreated steaks. These results suggest that across three different muscles varying in composition and palatability, enhancement with 0.4% STPP and 0.5% NaCl allowed for improvements in palatability while minimizing the color deterioration associated with phosphate/salt enhancement.     

Effect of grape seed extract on oxidative, color and sensory stability of a pre-cooked, frozen, re-heated beef sausage model system

To compare grape seed extract (GSE) to common antioxidants in a pre-cooked, frozen, stored meat model system sausage was manufactured from lean beef (70%), pork fat (28%), and salt (2%). Antioxidants added for comparison with control included grapeseed extract (100, 300, and 500 ppm), ascorbic acid (AA, 100 ppm of fat) and propyl gallate (PG, 100 ppm of fat). Product was formed into rolls, frozen, sliced into patties, cooked on a flat griddle to 70 °C, overwrapped in PVC, then frozen at - 18 °C for 4 months. GSE- and PG-containing samples retained their fresh cooked beef odor and flavor longer (p < 0.05) than controls during storage. Rancid odor and flavor scores of GSE-containing samples were lower (p < 0.05) than those of controls after 4months of storage. The L* value of all samples increased (p<0.05) during storage. Thiobarbituric acid reactive substances (TBARS) of the control and AA-containing samples increased (p < 0.05); those of GSE-containing samples did not change significantly (p > 0.05) over the storage period.     

Effects of fibre orientation, myoglobin redox form, and postmortem storage on NIR tissue oximeter measurements of beef longissimus muscle

To determine near-infrared tissue oximeter responses to muscle fibre orientation, display time, and surface colour differences of beef longissimus lumborum steaks, beef loins were cut into steaks either perpendicular or parallel to the muscle fibre orientation. Surface colour differences were created by packaging steaks in vacuum (VAC), 80% O₂ and 20% CO₂ modified atmosphere packaging (HiOx MAP), polyvinyl chloride film overwrap (PVC), and HiOx MAP converted to PVC (HiOx-PVC) after 2 days. Changes in surface colour and subsurface pigments during display (0, 2, 4, 10, and 15 days at 2 °C) were characterized by using a reflectance-spectrophotometer and a near-infrared tissue oximeter, respectively. Fibre orientation, storage, and packaging affected (P < 0.05) colour, total pigment, deoxymyoglobin, and oxymyoglobin content. Tissue oximetry measurements appear to have potential for real-time monitoring of myoglobin redox forms and oxygen status of packaged meat, but fibre orientation needs to be controlled.     

牛肉肠褪色反应机制及控制

对牛肉肠易氧化褪色的原因进行了研究，认为牛肉自身色素蛋白含量高及产品不饱和脂肪酸含量高，是造成牛肉肠易褪色的主要原因。同时，提出了用切断油脂自动氧化的链锁反应、螯合金属离子、调整ｐＨ值、减少氧化残留量等措施，来延缓产品褪色反应的进行。