Effect of Antioxidant Solubility and Concentration on Discoloration of Beef Vertebrae Marrow during Display

ABSTRACT:  Two experiments were conducted to assess the role of aqueous- and lipid-based antioxidants in preventing or limiting beef lumbar vertebrae marrow discoloration. In experiment 1, lumbar vertebrae ( n = 8 replications) were treated with either 0%, 1.5%, or 2.5% (wt/wt) of ascorbic acid or ascorbate-6-palmitate. Vertebrae color (visual and L*a*b*) was evaluated during 5 d of display at 1 °C in high-oxygen modified atmosphere packaging (MAP; 80% oxygen/20% carbon dioxide). Ascorbic acid treatments minimized ( P < 0.05) discoloration compared with ascorbate-6-palmitate. In experiment 2, lumbar vertebrae ( n = 8 replications) were treated with 0, 0.06 M, or 0.10 M ascorbic acid and ascorbate-6-palmitate, packaged in high-oxygen MAP, and displayed for 5 d (1 °C). During display, vertebrae treated with ascorbic acid had a redder color ( P < 0.05) than those treated with ascorbate-6-palmitate, and both treatments were redder ( P < 0.05) than untreated controls. To better understand the mechanism of beef bone marrow discoloration, future work might address the hydrophobic antioxidants' lack of effectiveness and the potential localization of components responsible for bone discoloration within the aqueous phase of erythropoietic marrow.     

Antioxidant and modified atmosphere packaging prevention of discoloration in pork bones during retail display

The objective of this study was to evaluate the ability of antioxidants to prevent discoloration in pork rib bones. Pork rib bones were removed from carcasses, frozen (−20 °C, 24 h), split lengthwise, exposed to antioxidant solutions (ascorbic acid, citric acid, propyl gallate or ascorbic/EDTA mix), packaged (modified atmosphere [80% O₂ and 20% CO₂] or air), then displayed in a retail case at 4 °C for 8 days. Dark pigment formation was visually evaluated during the display period. Instrumental color was determined at the end of the 8-day display period. Visual bone discoloration increased over time for all treatments. After 2 days of display, samples treated with propyl gallate were visually redder, less discolored and less green/black than samples treated with other antioxidants. After 8 days of display, propyl gallate-treated samples had higher a* and b* values, as well as chroma (intensity). However, this difference was no longer large enough to be visually detected.     

Exclusion of oxygen from modified atmosphere packages limits beef rib and lumbar vertebrae marrow discoloration during display and storage

Visual and instrumental color (L*a*b* and reflectance from 400 to 700 nm) were used to evaluate packaging atmosphere as a way of minimizing beef marrow discoloration. In experiment 1, rib ends (n=24) packaged in 80% O(2)/20% CO(2) discolored more than ribs packaged in 100% N(2), which resulted in a relatively stable purplish marrow color through a 7-day display at 1 °C. In experiment 2, lumbar vertebrae (n=10) packaged in 80% O(2)/20% CO(2) had a rapid and significant discoloration within 24 h after packaging, likely because of the formation of methemoglobin. Conversely, vertebrae packaged in 80% N(2)/20% CO(2) and 0.4% CO/30% CO(2)/69.6% N(2) remained color stable during 2 and 6 weeks of storage at 4 °C, respectively. Exclusion of oxygen from MAP packages and the addition of low concentrations of CO minimized beef rib and lumbar vertebrae discoloration compared with high-oxygen MAP.     

Effect of a dietary vitamin E supplementation on colour stability and lipid oxidation of air- and modified atmosphere-packaged beef

The effects of dietary vitamin E supplementation on tissue α-tocopherol level and on the susceptibility of fresh and modified atmosphere-packaged beef on myoglobin and lipid oxidation were investigated. Charolais cattle, aged 32-44 months, were fed diets containing 75 (control, n=8) or 1000 mg (supplemented, n=8) α-tocopheryl acetate/kg feed/day for 111 days prior to slaughter. Following vacuum packaging, M. Longissimus lumborum and M. triceps brachii were aerobically packaged and held under refrigerated display (3°C) for 9 days or packaged under modified atmosphere (MAP; 20% CO(2): 80%O(2)) and held under refrigerated display (8°C) for 13 days under fluorescent light. α-tocopherol concentrations were significantly higher (P<0.05) in meat from the supplemented group than from the basal one. Whatever the measured colour characteristics (a*, R(630)-R(580),% MetMb), the vitamin E supplementation had a positive but non-significant effect on the rate of discoloration. But by visual assessment, essentially with MAP, a significant and positive effect of vitamin E supplementation was noted to lower discoloration (P<0.05). TBARS values were significantly lowered (essentially at the end of storage time for the two packaged modes) after an α-tocopheryl acetate-supplementation.     

Effect of irradiation and modified atmosphere packaging on the microbiological and sensory quality of pork stored at refrigeration temperatures

The effect of combining low-dose irradiation (1.75 kGy) with modified atmosphere packaging (MAP) on the microbiological and sensory quality of pork chops stored at refrigeration temperatures was studied. The microflora of irradiated MAP pork was almost exclusively composed of lactic acid bacteria, predominantly Lactobacillus spp. Modified atmospheres containing either 25 or 50% CO₂, balance N₂, resulted in the best microbial control in irradiated pork held at 4°C, compared to an unirradiated MAP control, and these atmospheres were subsequently used in sensory studies. The atmosphere containing 25% CO₂ 75% N₂ maintained the uncooked colour and odour of irradiated pork chops more effectively than 50% CO₂ 50% N₂. Therefore packaging in a modified atmosphere containing 25% CO₂, balance N₂, followed by irradiation to a dose of 1.75 kGy is recommended to improve the microbiological and sensory quality of pork chops.     

Behaviour of non-stressed and stressed Listeria monocytogenes and Campylobacter jejuni cells on fresh chicken burger meat packaged under modified atmosphere and inoculated with protective culture

Numerous investigations have provided evidence that chicken products are a source of Listeria monocytogenes and Campylobacter jejuni. Different strategies applied in final products are needed to prevent consumers' contamination. In this work, the combination of modified atmosphere packaging (MAP) and protective culture to control the growth of freeze stressed and non-stressed L. monocytogenes and C. jejuni on fresh chicken meat burger was studied. Meat burgers were inoculated with L. monocytogenes, C. jejuni and Leuconostoc pseudomesenteroides PCK 18, as protective strain against L. monocytogenes. Prior to the addition of the protective culture, half of the L. monocytogenes and C. jejuni - inoculated meat was frozen at -18°C for 48h to subject cells to stress. Following the addition of the protective culture, meat burgers were packaged in air or MAP (50% CO(2)/50% O(2)) and stored under refrigeration conditions. L. monocytogenes counts were not reduced by the freezing temperature applied; however, the addition of Lc. pseudomesenteroides PCK 18 reduced its counts for 0.90 log cfu/g when chicken meat burgers were packaged under MAP. Furthermore, freezing stress was an effective strategy to reduce C. jejuni counts but only in combination with a high-O(2) MAP, it was completely eliminated. Chicken meat burgers' shelf-life under aerobic packaging conditions was reduced by the effect of freeze-thawing, while the use of MAP extended the product's shelf-life till 21days. Therefore, the combination of freezing, protective culture and MAP could extend the shelf-life and enhance the food safety of this kind of chicken products.     

包装方式和宰后不同时间包装对羊肉品质的影响

为探究包装方式和宰后不同时间包装对羊肉贮藏品质的影响,本研究对宰后1 h热分割羊肉和冷却成熟24 h后的分割羊肉分别进行热收缩包装、真空包装、贴体包装、50%（体积分数,下同）O2+50%CO2气调包装,测定其在（2±2）℃贮藏过程中pH值、色泽、贮藏损失率、蒸煮损失率、离心损失率、剪切力、挥发性气味的变化。结果表明：与宰后24 h包装相比,宰后1 h包装羊肉pH值在贮藏14 d时更高,但其贮藏期间色泽较好,色泽稳定性更高,贮藏损失率更低。从整体来看,3种真空处理（热收缩包装、真空包装、贴体包装）羊肉嫩度均优于气调包装羊肉,且宰后1 h包装时真空条件处理对羊肉嫩化效果最好,宰后24 h羊肉在贮藏前期气调包装对羊肉嫩化效果较好;而无论何时包装,热收缩包装和气调包装羊肉贮藏损失率均显著小于其他处理组（P<0.05）,在贮藏前期色泽及稳定性较好,但贮藏后期色泽稳定性下降明显,气调包装羊肉在14 d时已部分发绿,贮藏21 d时挥发性气味变化显著。综上,宰后1 h包装有利于提高羊肉贮藏期间色泽及持水力,改善真空处理羊肉嫩度,宰后24 h包装可提高50%O2+50%CO2气调包装羊肉贮藏前期...     

Methyl jasmonate coupled with modified atmosphere packaging to extend shelf life of tomato (Lycopersicon esculentum Mill.) during cold storage

The effects of methyl jasmonate coupled with modified atmosphere packaging (MJ+MAP) on the quality and shelf life of mature green tomato ( Lycopersicon esculentum Mill.) were investigated during cold storage at 5 °C. Tomatoes were treated with 10⁻⁴  m MJ and packaged under 5%O₂/5%CO₂/90%N₂ in a plastic bag. The effects of MJ+MAP were compared with control as well as heat treated (HT) samples. Control samples were tomatoes packaged under atmospheric air. HT samples were prepared by dipping tomatoes in hot water at 50 °C for 3 min and packaged under atmospheric air. The results showed that MJ+MAP and HT could delay ethylene production during tomato ripening and consequently slowed down the softening rate. MJ+MAP tomatoes showed better quality and less chilling injury (CI) symptoms than HT and control samples. Based on a nine-point score, shelf life criteria assumed that rejection would occur when the sensory attributes declined below 5. Control and HT overall acceptance scores were shown to fall below 5 scores after 3 and 6 weeks storage, while MJ+MAP had overall acceptance scores above 5 for up to 9 weeks. Control and HT samples could be stored for about 4 and 6 weeks, respectively, while MJ+MAP tomatoes could be stored for up to 9 weeks.     

Shelf life of Turkish whey cheese (Lor) under modified atmosphere packaging

In this study, the shelf life of Lor cheese stored under different atmosphere compositions was assessed and compared. Lor cheeses were held in four different atmospheres containing: vacuum packaging (VP), 40% CO₂/60% N₂, 60% CO₂/40% N₂ and 70% CO₂/30% N₂ (modified atmosphere packaging). Control cheeses were stored in air. All cheese samples were kept in the refrigerator at 4°C for 45 days and investigated for physicochemical, microbiological and sensory properties. The acidity index value was significantly higher ( P  < 0.05) in the control and vacuum packaged samples than in those stored for the same period under CO₂. Microbiological results showed that modified atmosphere packaging delayed microbial growth compared with air and VP samples. Of the three modified atmospheres, gas mixtures 60% and 70% CO₂ were the most effective for inhibition of growth of micro-organisms. Sensory evaluation (odour and taste) results showed that Lor cheese packaged under modified atmosphere packaging (60% CO₂/40% N₂ and 70% CO₂/30% N₂ ) retained good characteristics for 45 days of storage, while vacuum and control samples were sensorily unacceptable after 10 days of storage.     

Quality Changes of Prerigor Filleted Atlantic Salmon (Salmo salar L.) Packaged in Modified Atmosphere Using CO2 Emitter, Traditional MAP, and Vacuum

ABSTRACT:  Pieces of prerigor salmon fillets were packaged in modified atmosphere (60% CO₂ and 40% N₂) and in vacuum. The MA packages had a gas to product volume ratio (g/p ratio) of 3/1 (traditional MAP) and 1/1 (packaged with a CO₂ emitter). All the samples were stored at 1.2 °C for 25 d. The MA packages had lower bacterial growth during storage compared to vacuum packages. The analyses of 16S rRNA at day 22 indicated a similar bacterial diversity, independent of packaging methods, dominated by  Photobacterium phosphoreum . The results therefore suggest that CO₂ inhibited total bacterial count, including,  P. phosphoreum . Negative odors and liquid losses were detected earlier for the vacuum-packaged samples (8 d) compared to the MA samples (15 d) and higher levels were detected at the end of the storage period. The breaking strength (firmness) tended to be lower for the MA packaged samples compared with the vacuum samples after 15 d of storage, whereas the redness ( a * value) and the yellowness ( b * value) were significantly higher for the MA samples. In conclusion, MA packaging preserved the quality better during storage than vacuum packaging. MA packaging with a CO₂ emitter and reduced g/p ratio gave similar or better results compared with traditional MAP, thus CO₂ emitters are well suited for reduction of volume of MA packaged farmed salmon fillet pieces.     

Display, Packaging, and Meat Block Location Effects on Color and Lipid Oxidation of Frozen Lean Ground Beef

Ground beef chuck (15% fat) was packaged (500g) in vacuum bags, Saran Wrap^TM overwrapped with aluminum foil or polyvinyl chloride (PVC), exposed to retail display light (4°C) for 24 hr and then held frozen (?18°C) for 52 wk. Instrumental and visual color of PVC-packaged beef was affected most by display and by frozen storage. During frozen storage, as oxygen permeability of packaging material increased, TBA, visual brownness, and metmyoglobin increased while visual redness, acceptability, a* value, red color contributed by oxyrnyoglobin, and deoxymyoglobin decreased. Location on the meat block (exterior vs interior) affected (p<0.05) visual red and brown color, lightness, and acceptability, L*, a*, and b*, and TBA values.     

Microbiological and physicochemical properties of red claw crayfish (Cherax quadricarinatus) stored in different package systems at 2 degrees C

ABSTRACT:  This study compared 3 package systems for their influence on the stability of shell-on red claw crayfish tail meat stored at 2 °C for 14 d. Modified atmosphere packaging (MAP, with 80% CO₂/10% O₂/10% N₂) suppressed ( P < 0.05) the growth of aerobic bacteria and coliforms when compared with aerobic packaging using polyvinylchloride (PVCP) and vacuum packaging (VP). MAP and VP tended to retard lipid oxidation, inhibited Ca-ATPase activity change, but produced more intense protein denatuation when compared with PVCP. The MAP packaging enhanced proteolysis and resulted in more ( P < 0.05) cooking losses and a higher ( P < 0.05) shear force than VP and PVCP for samples stored for 6 and 14 d ( P < 0.05). Sensory panel results were in general agreement with the physicochemical changes, suggesting that the specific package systems had a significant impact on the quality of refrigerated red claw crayfish raw meat.     

Effects of dietary vitamin e supplementation and packaging on the quality of minced beef

Friesian cattle, aged 26-27 months, were fed a diet supplemented with 2000IU α-tocopheryl acetate/kg feed/day and another group was fed a basal diet (20IU/kg feed/day) for approximately 50 days prior to slaughter. Following frozen storage (-20°C for 8 weeks) semimembranosus muscles from basal and α-tocopheryl acetate supplemented cattle were minced and vacuum packaged, aerobically packaged or packaged under modified atmospheres (MAP) (30% O(2): 70% CO(2); 70% O(2): 30% CO(2); 80% O(2): 20% CO(2)). Samples were held under refrigerated (4°C) display (fluorescent lighting, 616 lux) for eight days. Vacuum-packaged samples were held under similar conditions but in complete darkness and allowed to bloom for a minimum of 4hr prior to taking colour readings. TBARS values and Hunter a values in minced beef were measured every two days. α-Tocopherol concentrations were significantly (p<0·05) higher in minced meat samples from the supplemented group than in the basal group. Significant (p<0·05) reductions in α-tocopherol concentrations in supplemented meat samples were observed with increased concentrations of oxygen in different packaging systems after eight days of refrigerated storage. TBARS values were reduced over the whole retail display period for all packaging systems when α-tocopheryl acetate supplemented beef was used. TBARS values increased as oxygen levels increased in MAP. Hunter a values showed that vitamin E supplementation in combination with vacuum packaging and MAP improved the colour stability of meat during the first 4 days of storage, however, the failure of MAP to extend meat colour for longer periods of time was probably the result of prior storage at -20°C for 8 weeks.     

Chemical and sensory changes in haddock and herring stored under modified atmosphere

The effectiveness of storage in atmospheres with increased proportions of CO₂ to extend the shelf-life of haddock and herring was examined. Using a 40: 30: 30/CO₂: O₂: N₂ atmosphere with haddock no useful extension of shelf-life was achieved at +5°C and only limited extension at 0°C. A more useful extension of shelf-life at 0°C was obtained by storing haddock in a 60: 20: 2O/CO₂: O₂: N₂ atmosphere and with herring in a 60:40/CO₂::N₂: atmosphere. Total volatile bases (TVB) and hypoxanthine values (Hx) correlated with the cooked flavour. There were no significant differences in drip-loss between the modified atmosphere packaging (MAP) stored samples and the controls. Peroxide values (PV) in herring were lower in MAP stored samples. Whole haddock and whole herring were found to have a longer shelf-life when stored in MAP at 0°C than when stored as fillets.     

Some effects of modified-atmosphere packaging and vacuum packaging in combination with antioxidants on quality and storage life of chilled potato strips

A modified-atmosphere packaging system for chilled fresh potato strips, which rapidly produced oxygen levels < 3%, was identified. This system enclosed the strips within 25 μ low density polyethylene film heat sealed to a fibre tray lined with Surlyn-PVdC-Surlyn, and the package flushed with an initial atmosphere of 5% O₂, 10% CO₂. An equilibrium-modified atmosphere of 3–4% CO₂, 1–2% O₂ was established after 3 days' storage at 5°C. This modified-atmosphere package, used in combination with dipping of potato strips in a 10% ascorbic acid solution, inhibited enzymatic discoloration for 1 week at 5°C. Vacuum packaging within a Surlyn/PVdC-coated polyester film, with or without dipping in ascorbic acid solution, inhibited discoloration of chilled potato strips stored at 5°C for at least 2 weeks.     

Effectiveness of active and modified atmosphere packaging on shelf life extension of a cheese tart

This study evaluated the shelf life extension of a cheese cake subjected to modified atmosphere (MAP) and active packaging (AP). Cheese cakes were packaged under different N₂/CO₂ ratios (70/30 and 20/80) (MAP batches), by placing a sachet of an iron oxide-based oxygen absorber inside trays (AP batch) and with air (air batch). Changes in microbial growth, in-package gas composition, chemical–physical parameters including texture and sensory attributes were monitored for 48 days at 20 °C. AP allowed a mould-free cheese cake shelf life of 48 days, MAP extended the shelf life of samples packaged under 30% and 80% CO₂ up to 14 and 34 days, respectively, whereas tarts stored with air spoiled after 7 days. MAP resulted in a significant increase in hardness after 14 days of storage, whereas AP tarts recovered the initial texture after 48 days. Panellists judged AP tarts over the acceptability threshold during the whole shelf life of cheese tarts.     

包装对羊肉冷藏过程中热休克蛋白表达及羊肉品质的影响

为探究不同包装方式下羊肉冷藏过程中热休克蛋白27(heat shock protein 27,Hsp27)、Hsp70表达量的变化及其与羊肉品质间的关系,以宰后1?h羊背最长肌为研究对象,进行托盘、真空、高氧气调(O2、CO2体积比75:25)和低氧气调(O2、CO2体积比50:50)包装,分析Hsp27和Hsp70表...     

Application of Modified Atmosphere Packaging and Active/Smart Technologies to Red Meat and Poultry: A Review

This paper reviews the current advances in modified atmosphere packaging (MAP) of red meat and poultry products. This type of packaging results in shelf-life prolongation by inhibiting microbial growth and promoting oxidative stability, compared to those packaged aerobically. High O₂ modified atmosphere packaging results in the desirable red colour, but it also enhances both lipid and pigment oxidation and promotes the growth of aerobic spoilage microorganisms. The presence of high levels of CO₂ in modified atmosphere packages inhibits microbial growth but can also cause meat discoloration through oxidation. Low O₂ MAP atmospheres limit microbial growth but change the colour of meat to purple. The use of CO gives promising results due to its positive effects on colour and microorganism growth inhibitions which result in shelf-life prolongation during wider distribution of case-ready products. The use of MAP can lead to an effective growth reduction of pathogenic microorganisms like Listeria sp. and Salmonella sp. The combination of MAP and vacuum with other treatments can be an effective tool in delivering safe minimally processed foodstuffs. In response to the changes in consumer demand and market trends, the area of active and intelligent/smart packaging is becoming more and more important. These relatively new technologies are capable of providing better results regarding product safety and shelf-life prolongation as well as communicating information on several quality characteristics of packaged food during transportation and storage.     

Effects of Carbon Monoxide Packaging on Color and Lipid Stability of Irradiated Ground Beef

ABSTRACT: The effects of packaging atmosphere (aerobic, vacuum, or modified atmosphere with carbon monoxide) on ground beef treated with ionizing radiation were investigated. Measurements of color (CIE L*, a*, b*), lipid oxidation (TBA value), and sensory quality were conducted during 28 d of storage at refrigerated (0 to 2°C) temperatures. Irradiation significantly ( p > 0.001) decreased color scores and increased TBA and off-odor scores. The MAP + CO treatments increased the L* and a* values ( p < 0.001), regardless of irradiation dose. The TBA values for MAP + CO-packaged samples were well below the levels considered "rancid" (about 1.0). In addition, sensory scores indicated minimal production of irradiation off-odors with MAP + CO packaging.     

The Effects of Residual Oxygen on the Storage Life of Retail-Ready Fresh Beef Steaks Masterpackaged Under a CO2 Atmosphere

ABSTRACT:  Retail-packed rump ( Gluteus medius , GM) and striploins ( Longissiumus dorsi, LD) steaks were masterpackaged under carbon dioxide (CO₂) and stored at 1 °C ± 1 °C for 14, 28, 35, and 42 d. A commercial oxygen (O₂) scavenger (ATCO HV1000®, Standa Industrie, Caen, France) was used in the masterpacks to achieve an O₂-free atmosphere. Similar packages without the O₂ scavengers were also prepared. At each storage time, 2 masterpacks of each treatment were opened and the retail trays were placed in a display case at 4 °C ± 2 °C for 1 and 48 h for microbiological and sensorial evaluations. The low growth rate of aerobic psychrotrophic flora on the stored beefsteaks demonstrated the bacteriostatic effect of CO₂ during storage. The maximum level of psychrotrophic aerobic bacteria reached during storage was approximately 10⁶ CFU/g. The steaks stored in masterpacks with scavengers bloomed to the desirable red color associated with freshly cut meat in the display case for all of the storage periods, except in the case of GM steaks, which showed a cycle of transient discoloration. GM and LD steaks were well accepted (65% and 82%, respectively) after 42 d under CO₂ at 1 °C ± 1 °C. The GM and LD steaks stored without the O₂ scavenger showed variable fractions of discoloration that significantly detracted from the appearance of the samples.