High-oxygen modified atmosphere packaging system induces lipid and myoglobin oxidation and protein polymerization

Beef steaks from longissimus lumborum, semimembranosus, and adductor muscles (n = 10; respectively) were cut at 24 h postmortem, randomly assigned to either high-oxygen modified atmosphere packaging (HiOx-MAP; 80% O₂, 20% CO₂) or vacuum (VAC), and displayed for 9 days at 1 °C. HiOx-MAP packaged beef steaks had a rapid increase in lipid oxidation and a decrease in color stability during display. The steaks in HiOx-MAP had significantly lower tenderness and juiciness scores, and higher off-flavor scores compared to steaks in VAC. HiOx-MAP condition did not affect the postmortem degradation of troponin-T or desmin. Furthermore, autolysis of μ-calpain was not influenced by packaging. SDS–PAGE, immunoblotting, and diagonal-PAGE revealed oxidative cross-linking of myosin heavy chain in meat packaged in HiOx-MAP. These results suggest that the HiOx-MAP system may negatively affect meat quality characteristics by inducing lipid and myoglobin oxidation and cross-linking/aggregation of myosin by protein oxidation.     

Ageing of large cuts of beef loin in vacuum or high oxygen modified atmosphere – Effect on shear force,calpain activity,desmin degradation and protein oxidation

The aim was to investigate the effect of ageing large beef cuts directly in high oxygen modified atmosphere (MA) and how ageing time in vacuum influence meat quality when followed by retail packaging in high oxygen MA. Large cuts (10 cm long) of beef loin (LD) were aged for up to 25 days postmortem in different ageing systems at 4 °C. Ageing solely in high oxygen modified atmosphere (MA, 80% O₂ + 20% CO₂) for 5 or 10 days and ageing in vacuum for 5 or 15 days followed by high oxygen MA for 5 or 10 days were compared with ageing in vacuum for 5, 15 and 25 days. Warner–Bratzler shear force, purge and cooking losses, calpain activity and desmin and carbonyl contents were measured. Shear force decreased to the same level when ageing this large beef cut solely in high oxygen MA for 5 or 10 days as when ageing in vacuum. The activity of μ-calpain disappeared, the activity of m-calpain decreased and purge loss increased between 5 and 10 days, but cooking loss and the contents of desmin and carbonyls were unaffected. The ageing time in vacuum before packaging of this large beef cut in high oxygen MA did not affect the ultimate shear force. The m-calpain activity decreased and the content of carbonyls increased compared with solely in vacuum after 15 days of total ageing, but there was no difference in the content of desmin or cooking loss between these ageing systems at the same ageing time.     

The effects of high oxygen modified atmosphere packaging on protein oxidation of bovine M. longissimus dorsi muscle during chilled storage

Modified atmosphere packaging (MAP) extends the shelf life of beef, especially in the context of visual colour. High O₂ MAP (70-80%) may cause quality deterioration through lipid and protein oxidation, the latter linked to a reduction in meat tenderness. The objective of this study was to investigate the effects of MAP in comparison to vacuum packaging (VP) on protein oxidation and subsequent tenderness of LD (M. longissimus dorsi) beef steaks during chilled storage (4 °C) of periods up to 14 days. Steaks were analysed for carbonyl content, free thiol groups, drip loss, Warner-Bratzler shear force (WBSF) and SDS-PAGE of extracted myofibrillar proteins. Free thiol groups were lower in high O₂ MAP (80% O₂/20% CO₂) steaks, after 14 days of storage, indicating protein oxidation compared to VP steaks. SDS-PAGE (non reducing conditions) showed the presence of high molecular weight cross linked myosin heavy chain aggregates in the high O₂ atmosphere packaged steaks, which were absent in VP steaks.     

Beef quality attributes as affected by increasing the intramuscular levels of vitamin E and omega-3 fatty acids

In order to investigate the effects of increasing beef n-3 fatty acid content and the protective effects of vitamin E antioxidant activity on meat quality characteristics, 80 feedlot steers were fed 4 different diets (control, high vitamin E, 10% ground flaxseed or high vitamin E-10% ground flaxseed). While dietary treatments had no effect (P > 0.05) on meat composition or tenderness values, the increase in oxidation products was lower (P = 0.046) in meat from vitamin E supplemented steers and higher (P = 0.006) in meat from flaxseed fed animals. The increase in α-tocopherol tissue levels (P < 0.001) in meat from animals fed flaxseed and increased dietary vitamin E resulted in the lowest drip loss values (P = 0.013). As expected, display time had a large effect on retail traits in both steaks and patties (P < 0.001). While retail traits of steaks were not affected by the dietary treatments (P > 0.05), feeding flaxseed decreased (P < 0.05) ground beef retail scores, which were not corrected by higher levels of dietary vitamin E. Finally, although no effect (P > 0.05) was observed among treatments for sensory attributes in steaks, the correlations of a combined n-3:α-tocopherol ratio against retail and sensory attributes (P < 0.05) suggest that increased n-3 fatty acids levels require increased dietary antioxidants, such as vitamin E to avoid negative effects on meat quality from a loss in oxidative stability.     

Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef

We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P < 0.05) redness of patties stored in PVC and CO, whereas it had no effect (P > 0.05) in HIOX. Chitosan patties demonstrated lower (P < 0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P < 0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P > 0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific.     

Effect of varying the gas headspace to meat ratio on the quality and shelf-life of beef steaks packaged in high oxygen modified atmosphere packs

Beef steaks (M. longissimus dorsi) were stored in modified atmosphere packs (MAP) (80% O₂:20% CO₂) with gas headspace to meat ratios of 2:1, 1:1 and 0.5:1 for 14 days at 4 °C. The pH, surface colour, texture and microbiology of beef steaks were unaffected (P > 0.05) by varying the gas headspace to meat ratio. APLSR (ANOVA-partial least squares regression) and jack-knife uncertainty testing indicated that lipid oxidation (TBARS) was significantly positively correlated with days 10 (P < 0.05) and 14 (P < 0.001) of storage. Chemical and sensory detection of lipid oxidation in beef steaks were in agreement on day 14 of storage. The sensory quality and acceptability of beef steaks were similar in gas headspace to meat ratios of 2:1 or 1:1 and unacceptable in 0.5:1. Results indicate that pack size and gas volume can be reduced without negatively affecting fresh beef quality and shelf-life.     

Shelf‐Life Extension of Chill‐Stored Beef Longissimus Steaks Packaged under Modified Atmospheres with 50% O2 and 40% CO2

This study was conducted to compare the shelf‐life of beef steaks stored in different packaging conditions: overwrapped (OW) packaging and 2 modified atmosphere packaging systems (MAP): 80% O₂ MAP (80% O₂/20% CO₂) and 50% O₂ MAP (50% O₂/40% CO₂/10% N₂). Steaks were stored at 2 °C for 20 d. Headspace gas composition, microbial counts, color stability, pH, purge loss, and lipid oxidation were monitored. Among the packaging types, 50% O₂ MAP was superior to OW packaging and 80% O₂ MAP in delaying bacterial growth and extending shelf‐life to 20 d. 50% O₂ MAP also gave steaks an acceptable color during storage. No significant differences were observed in color stability of steaks packaged in both 50% O₂ MAP and 80% O₂ MAP. This study reveals 50% O₂ MAP is a realistic alternative to preserve beef steaks efficiently.     

Effect of aging time in vacuum on tenderness,and color and lipid stability of beef from mature cows during display in high oxygen atmosphere package

The effect of aging time in vacuum on tenderness, and lipid and color stability of modified-atmosphere packaged (MAP) beef during display was evaluated in eight Friesian mature cows. Longissimus thoracis et lumborum (LTL) sections were vacuum packaged and aged for 0, 3, 6, 8, 14 and 21 days. After each aging time, the LTL sections were cut into steaks and packaged in high oxygen atmosphere (80% O₂: 20% CO₂). Meat shear force, and color and lipid stability were evaluated at 0, 3, 6, and 9 days of simulated retail display. Aging for 6 or 8 days improved beef tenderness with color stability, instrumental discoloration (R₆₃₀–R₅₈₀) and visual color evaluation in MAP similar to those of short-time aged (3 d) or un-aged (0 d) beef. Longer aging times (14 and 21 d) resulted in tenderness values similar to those obtained with meat aged for 8 days but affected negatively color and lipid stability and, consequently, reduced the shelf life of beef in MAP.     

Colour stability of steaks from large beef cuts aged under vacuum or high oxygen modified atmosphere

The aim was to investigate the effects of ageing large beef cuts, 10-cm-long longissimus dorsi (LD) and 4-cm-long semimembranosus (SM), on colour stability during subsequent storage of steaks in air for 5 days. Ageing solely in high oxygen modified atmosphere (MA, 80% O₂ + 20% CO₂) for 5 or 10 days or ageing in vacuum for 5 or 15 days followed by high oxygen MA for 5 or 10 days were compared with ageing in vacuum for 5, 15 and 25 days at 4 °C. Ageing system and ageing time influenced colour stability. For short ageing times, 5 to 10 days, large beef cuts could be aged in high oxygen MA without negative effect on colour stability compared with vacuum ageing. Longer ageing times, 15 to 25 days, decreased colour stability. Then vacuum ageing was preferable to ageing in vacuum for 5 or 15 days followed by high oxygen MA.     

Evaluation of antioxidant capacity and colour stability of calcium lactate enhancement on fresh beef under highly oxidising conditions

Fifteen USDA Select beef strip loins were divided individually into four equal width sections, and one of six treatments containing phosphate and/or calcium lactate (CAL) enhancement solutions were assigned randomly to each loin section (n = 10). Steaks from each loin section were packaged with high-oxygen (80% O₂) modified-atmosphere packaging, and/or irradiated at 2.4 kGy, stored 10 days and then displayed for 5 days at 1 °C. Instrumental colour, total reducing activity (TRA), 2-thiobarbituric acid value (TBARS), and NADH concentration were measured. Loins with CAL and phosphate maintained the most stable red colour, increased NADH (p < 0.05), and were the least oxidised. Among irradiated steaks, CAL with phosphate treatment significantly minimised lipid oxidation, increased NADH and TRA, and consequently had a higher a^∗ value. These results suggest that lactate inclusion improves colour stability of fresh beef by providing superior antioxidant capacity and increased reducing activity of myoglobin by elevating NADH concentration.     

Effects of calf diet, antioxidants, packaging type and storage time on beef steak storage

The effect of basal dietary supplemented with vegetable oils plus vitamin E (sunflower, soybean, linseed and a basal diet control), type of packaging (MAP or vacuum), addition of natural antioxidant (grape seed, rosemary) and storage time (0, 7, 14 and 21 days) on lipid oxidation, color stability, vitamin E content, and total aerobic bacterial counts in steaks of Longissimus thoracis was studied. The triple interaction diet × time × packaging affected oxidative stability, redness and yellowness of the meat. TBARS values did not increase with time in vacuum-packaged samples for all dietary treatments. However, samples from MAP and control showed the highest TBARS values after 21 days of storage (0.72 mg MDA/kg of meat, P < 0.05). Both exogenous antioxidant extracts and MAP maintained low total aerobic counts in steaks until the 21st day. Calves should be fed a diet supplemented with L-VE, stored in MAP and treated with grape seed extract to extend the shelf life of their meat.     

Effects of food ingredients and oxygen exposure on premature browning in cooked beef

Premature browning (PMB) in the centre of cooked hamburgers and beef loin (M. longissimus dorsi) steaks was assessed visually and instrumentally. Rosemary extract, ascorbic acid, sodium lactate, polyphosphate or lingonberry juice were added to freshly ground beef with predominant oxymyoglobin, and hamburgers were cooked to 62 °C. In general, the tested ingredients did not reduce the extent of PMB in hamburgers, but polyphosphate tended to reduce PMB due to increased pH. Control burgers made of vacuum packaged meat with deoxymyoglobin were cooked to 62, 69 and 75 °C, and did not express PMB. Beef loins were injected with a solution of sodium lactate, polyphosphate and sodium chloride. Loin steaks were stored under 75% O₂/25% CO₂ for 5 days and also cooked to 62 °C. Injected steaks had less PMB than non-injected controls, but of a low magnitude unlikely to influence the perception of doneness. The study demonstrated that anaerobic packaging is the most efficient measure to avoid PMB in beef.     

Ability of α-tocopherol,taurine and rosemary,in combination with vitamin C,to increase the oxidative stability of beef steaks packaged in modified atmosphere

Fresh beef steaks were sprayed on the surface with vitamin C (500 ppm), taurine (50 mM), rosemary (1000 ppm) and vitamin E (100 ppm), the three latter in combination with 500 ppm of Vitamin C, packaged in modified atmosphere (70% O₂+20% CO₂+10% N₂) and stored at 1±1 °C for 29 days. Metmyoglobin formation, lipid oxidation (TBARS), instrumental colour (CIE a¹), psychrotrophic bacterial counts (PCA) and sensory discolouration and odour were determined. Results demonstrated that surface application of antioxidant combinations resulted in an effective delay of oxidative deterioration of fresh beef steaks. Shelf life was extended beyond that of control, according to evaluation of sensory attributes. Both combinations of vitamin C with either rosemary or taurine significantly (P<0.01) extended the shelf life of fresh beef steaks by about 10 days. Rosemary was the most effective in delaying oxidation processes. The combination of vitamins E and C was significantly (P<0.01) less effective than those combinations in delaying meat oxidation.     

Effects of L- or D-lactate-enhancement on the internal cooked colour development and biochemical characteristics of beef steaks in high-oxygen modified atmosphere

The effects of L- or D-lactate on internal cooked colour development of steaks packaged in high-oxygen (80% O₂/20% CO₂) modified atmosphere packaging (MAP) was investigated. Ten USDA Select beef strip loins were divided individually into 4 equal-width sections, and one of four treatments (control, 0.3% sodium tripolyphosphate, 2.5% L-lactate + 0.3% sodium tripolyphosphate, and 2.5% D-lactate + 0.3% sodium tripolyphosphate) was assigned randomly to the loin sections. Loin sections were injected to approximately 10% of their raw weight. Steaks packaged in high-oxygen MAP were stored in the dark at 1 °C for 10 days. Instrumental internal colour of raw and cooked steaks (70 °C), total reducing activity (TRA), NADH concentration, and percent myoglobin denaturation (PMD) were measured. Cooked steaks enhanced with 2.5% L-lactate/phosphate maintained higher a*/b* ratios, lower hue values, higher TRA and NADH concentration, and lower PMD than the control and D-lactate-injected steaks, whereas enhancement with 2.5% D-lactate did not affect cooked colour, TRA, NADH, or PMD. Thus, inclusion of an L-lactate/alkaline phosphate blend increased the reducing activity of muscle tissues by replenishing NADH and subsequently decreased the thermal denaturation of myoglobin by maintaining the reduced state of myoglobin in the high-oxygen package.     

Effect of lutein,sesamol, ellagic acid and olive leaf extract on the quality and shelf-life stability of packaged raw minced beef patties

The effects of lutein (100 and 200 μg/g muscle), sesamol (250 and 500 μg/g muscle), ellagic acid (300 and 600 μg/g muscle) and olive leaf extract (100 and 200 μg/g muscle) on total viable counts (TVCs), lipid oxidation (thiobarbituric acid-reactive substances, TBARS), colour, oxymyoglobin oxidation, pH, water-holding capacity (WHC), sensorial properties of raw beef patties (M. longissimus thoracis et lumborum) stored in modified atmosphere packs (80% O₂:20% CO₂) (MAP) aerobically at 4 °C for up to 8 and 12 days, respectively, were examined. All the nutraceuticals reduced (P < 0.001) TVCs. The addition of sesamol, ellagic acid and olive leaf extract reduced (P < 0.001) TBARS in raw beef patties in both packaging systems. Sesamol addition to beef resulted in lower (P < 0.01) a* redness values and increased oxymyoglobin oxidation. Conversely, lutein and olive leaf extract reduced (P < 0.001) oxymyoglobin oxidation relative to the control. The graded addition of ellagic acid and olive leaf extract improved (P < 0.001) WHC.     

Effect of calcium lactate on m-calpain activity and protein degradation under oxidising conditions

In two experiments, the effects of calcium lactate (CAL) on calpain activity were determined. In the model system, purified porcine skeletal muscle m-calpain was pre-incubated with various combinations of hydrogen peroxide (H₂O₂), calcium chloride, and/or different CAL concentrations. The m-calpain was activated by CAL, and the extent of m-calpain oxidation by H₂O₂ was significantly decreased with increasing CAL concentrations. In the muscle system, a beef longissimus lumborum (1 day postmortem) from each carcass (n = 6) was cut in half, randomly assigned to either 0.2 M CAL or water injection (WAT), and then packaged in a high-oxygen modified atmosphere. The CAL injected steaks resulted in less intact desmin and greater production of a 30-kDa troponin-T compared to the steaks in the WAT group. The CAL injection did not affect colour and lipid oxidation of steaks during display. These results suggest that CAL addition may improve tenderness of meat by enhancing activation of endogenous calpain and by protecting against calpain oxidation under oxidative conditions.     

Influence of vacuum or high-oxygen modified atmosphere packaging on quality of beef M. longissimus dorsi steaks after different ageing times

The objective of the study was to determine if beef quality parameters differ between steaks in modified atmosphere packaging (MAP; 80% O₂ and 20% CO₂) and in vacuum packaging. Both M. longissimus dorsi (LD) from ten young bulls were cut in steaks day 3 postmortem and frozen either directly or after storage for 5 or 15 days in MAP and/or vacuum. The parameters studied were Warner Bratzler shear force, colour stability, α-tocopherol content, protein oxidation, water holding capacity and sensory attributes. Steaks stored in MAP had higher shear force than steaks stored in only vacuum at all ageing times. Tenderness and juiciness were negatively affected by storage in MAP. Ageing in MAP induced higher levels of metmyoglobin compared with vacuum ageing. In conclusion, high-oxygen MAP negatively influenced shear force, thawing loss, α-tocopherol content and colour stability, as well as the sensory attributes tenderness, juiciness and to some extent meat flavour.     

The influence of forage diets and aging on beef palatability

To investigate the influence of diet and aging on beef palatability, lipid oxidative stability, and fatty acid composition, crossbred steers were assigned to Feedlot S (alfalfa and grain), Forage TR (triticale and annual ryegrass), Forage TK (triticale and kale), or Forage + Feedlot (grazing ryegrass, fescue and orchardgrass, finished on alfalfa and grain) dietary treatments. Heifers were finished on Feedlot H (alfalfa and grain). Longissimus and tricep muscles were sampled from these animals for steaks and ground beef, respectively. Steaks were either dry- or wet-aged for 14 d. Ground beef was dry-aged, wet-aged for 14 d, or not aged. Trained sensory panelists evaluated palatability attributes of steaks and ground beef. Diet did not influence sensory attributes of steaks or ground beef. Aging impacted (P < 0.05) sensory attributes of ground beef. Diet and aging had no impact on lipid oxidative stability but affected fatty acid composition of raw ground beef.     

Effects of dietary vitamin A restriction during finishing on color display life, lipid oxidation, and sensory traits of longissimus and triceps brachii steaks from early and traditionally weaned steers

Our objective was to determine the effects of vitamin A restriction during finishing on color display life, lipid oxidation, and sensory traits of longissimus lumborum (LL) and triceps brachii (TB) steaks from early and traditionally weaned steers. Forty-eight steers weaned at either 137 ± 26 days (EW) or 199 ± 26 days (TW) were supplemented with either 15,400 IU/kg dry matter of vitamin A (HA) or restricted to no supplemental vitamin A (LA) during finishing for 210 and 150 days, respectively. Both LL and TB steaks from the HA steers had the darkest (P < 0.05) color scores after 3 days of retail display in PVC packaging at 2 °C, and the highest (P < 0.05) thiobarbaturic acid reactive substances (TBARS) values. Instrumental a∗, b∗, and saturation index values were lowest (P < 0.05) in LL steaks from the HA steers. Instrumental L∗ values were lower (P < 0.05) on days 4–6 in TB steaks from TW steers fed LA than those from EW steers fed HA. No differences were found in Warner–Bratzler shear force values or sensory traits in either muscle. No supplemental vitamin A versus high levels of vitamin A inclusion in finishing diets has potential to increase color display life and reduce lipid oxidation, with no effects on meat palatability.     

Potential mechanisms of carbon monoxide and high oxygen packaging in maintaining color stability of different bovine muscles

The objectives were to compare the effects of packaging methods on color stability, metmyoglobin-reducing-activity (MRA), total-reducing-activity and NADH concentration of different bovine muscles and to explore potential mechanisms in the enhanced color stability by carbon monoxide modified atmosphere packaging (CO-MAP, 0.4% CO/30% CO₂/69.6% N₂). Steaks from longissimus lumborum (LL), psoas major (PM) and longissimus thoracis (LT) packaged in CO-MAP, high-oxygen modified atmosphere packaging (HiOx-MAP, 80% O₂/20% CO₂) or vacuum packaging were stored for 0 day, 4 days, 9 days, and 14 days or stored for 9 days then displayed in air for 0 day, 1 day, or 3 days. The CO-MAP significantly increased red color stability of all muscles, and especially for PM. The PM and LT were more red than LL in CO-MAP, whereas PM had lowest redness in HiOx-MAP. The content of MetMb in CO-MAP was lower than in HiOx-MAP. Steaks in CO-MAP maintained a higher MRA compared with those in HiOx-MAP during storage. After opening packages, the red color of steaks in CO-MAP deteriorated more slowly compared with that of steaks in HiOx-MAP.