Influence of Injection, Packaging, and Storage Conditions on the Quality of Beef and Bison Steaks

The combined effects of injection, packaging (modified atmosphere packaging [MAP] with 70% O₂/ 30% CO₂ and vacuum packaging [VP]), storage temperature (‐1 °C and +4 °C), and storage time on the color, microbial and oxidative stability of beef and bison longissimus lumborum (LL) steaks were investigated. Beef LL steaks in MAP retained their bright red color longer than bison steaks. Bison steaks developed higher 2‐Thiobarbituric acid reactive substances (TBARS) during storage, and this might have influenced the resulting rapid loss of redness from the bloomed meat. Storage at ‐1 °C in MAP provided greater color stability and a longer storage life for both meat species studied. Injection of salt/phosphate had a beneficial effect on the color stability of steaks during retail display; however, this positive effect was more pronounced for bison steaks compared with those of beef. Steaks stored overnight under MAP before retail display maintained the highest a* values for up to 5 d compared with those stored under vacuum. MAP‐OV steaks generally maintained the highest OMB content for up to 5 d during retail display compared with those stored under vacuum. Nevertheless, OMB levels were significantly (P < 0.05) lower in bison steaks compared with those of beef irrespective of packaging treatments. Injected steaks and those stored at ‐1 °C had significantly (P < 0.05) higher OMB levels compared with non‐injected counterparts and those stored at +4 °C, respectively. MAP is an excellent option for short‐term storage due to its positive effects on meat color, but for longer storage, VP may be necessary. Storing meat under vacuum and then placing it under MAP just before retail display might be another option to increase shelf life.     

The impact of packaging system and temperature abuse on the shelf life characteristics of ground beef

New ground beef packaging systems have warranted investigation of their spoilage and quality characteristics. Furthermore, analysis of ground beef spoilage in modified atmosphere packaging (MAP) and stored at abusive temperature is lacking. This research aimed to determine the effect of packaging systems and temperature abuse on the sensory and shelf-life characteristics of ground beef. Ground beef patties were packaged using polyvinyl chloride overwrap (OW), HI-OX MAP (80% O₂, 20% CO₂), LO-OX MAP (30% CO₂, 70% N₂), CO-MAP (0.4% CO, 30% CO₂, 69.6% N₂), or vacuum (VAC) prior to color, odor, biochemical, and microbial analyses over display. CO-MAP exhibited more desirable color and consumer acceptability throughout display. Lean discoloration and odor scores were lower for anaerobic packaging than aerobic packaging. Microbial results mirrored sensory preferences for anaerobic packaging. These results indicate anaerobic packaging extends shelf-life properties and desirable sensory attributes throughout display and temperature abuse.     

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.     

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.     

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.     

Nondestructive and Continuous Monitoring of Oxygen Levels in Modified Atmosphere Packaged Ready‐to‐Eat Mixed Salad Products Using Optical Oxygen Sensors,and Its Effects on Sensory and Microbiological Counts during Storage

The objective of this study was to determine the percentage oxygen consumption of fresh, respiring ready‐to‐eat (RTE) mixed leaf salad products (Iceberg salad leaf, Caesar salad leaf, and Italian salad leaf). These were held under different modified atmosphere packaging (MAP) conditions (5% O₂, 5% CO₂, 90% N₂ (MAPC—commercial control), 21% O₂, 5% CO₂, 74% N₂ (MAP 1), 45% O₂, 5% CO₂, 50% N₂ (MAP 2), and 60% O₂, 5% CO₂, 35% N₂ (MAP 3)) and 4 °C for up to 10 d. The quality and shelf‐life stability of all packaged salad products were evaluated using sensory, physiochemical, and microbial assessment. Oxygen levels in all MAP packs were measured on each day of analysis using optical oxygen sensors allowing for nondestructive assessment of packs. Analysis showed that with the exception of control packs, oxygen levels for all MAP treatments decreased by approximately 10% after 7 d of storage. Oxygen levels in control packs were depleted after 7 d of storage. This appears to have had no detrimental effect on either the sensory quality or shelf‐life stability of any of the salad products investigated. Additionally, the presence of higher levels of oxygen in modified atmosphere packs did not significantly improve product quality or shelf‐life stability; however, these additional levels of oxygen were freely available to fresh respiring produce if required. This study shows that the application of optical sensors in MAP packs was successful in nondestructively monitoring oxygen level, or changes in oxygen level, during refrigerated storage of RTE salad products.     

Effect of lactate-enhancement, modified atmosphere packaging, and muscle source on the internal cooked colour of beef steaks

Earlier studies on lactate-mediated colour stability in beef did not address the possible influence on cooked colour. Our objective was to examine the effect of lactate-enhancement, muscle source, and modified atmosphere packaging (MAP) on the internal cooked colour of beef steaks. Longissimus lumborum (LL) and Psoas major (PM) muscles from 16 (n = 16) beef carcasses (USDA Select) were randomly assigned to 4 enhancement treatments (non-injected control, distilled water-enhanced control, 1.25% and 2.5% lactate), and fabricated into 2.54-cm steaks. Steaks were individually packaged in either vacuum (VP), high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), or carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), and stored for 0, 5, or 9 days at 1 °C. At the end of storage, surface and internal colour (visual and instrumental) was measured on raw steaks. Steaks were cooked to an internal temperature of 71 °C, and internal cooked colour (visual and instrumental) was evaluated. Lactate-enhancement at 2.5% level resulted in darker (P < 0.05) cooked interiors than other treatments. Interior cooked redness decreased (P < 0.05) during storage for steaks in VP and HIOX, whereas it was stable for steaks in CO. Our findings indicated that the beef industry could utilise a combination of lactate-enhancement and CO MAP to minimise premature browning in whole-muscle beef steaks.     

Retail Shelf-Life of Pork Dipped in Organic Acid before Modified Atmosphere or Vacuum Packaging

Modified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N₂:20% CO₂ in MAP was exchanged with 80% O₂:20% CO₂, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P < 0.05) in VP‐PVC compared with MAP. The a* values increased (P < 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P < 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.     

Accelerated Postmortem Aging of Beef Utilizing Electronbeam Irradiation and Modified Atmosphere Packaging

The combined effects of electron-beam irradiation and modified atmosphere packaging (MAP) with 25% CO₂ and 75% N₂ were examined. Steaks from prerigor beef longissimus (lumborum and thoracis) were prepared, placed in MAP, irradiated with 2 kGy, and stored at 15°C or 30°C. Postrigor longissimus steaks from the other half of each carcass were vacuum-packaged and stored at 2°C. Analysis for tenderness, lipid oxidation, color, and microbial growth were conducted over 2 wk. Aging irradiated prerigor beef at 30°C for 2 days with MAP resulted in similar Warner-Bratzler shear values as conventional wet aging at 2°C for 7 or 14 days, and steaks did not show discoloration, lipid oxidation, or microbial spoilage.     

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% O₂ and 20% CO₂). Longissimus lumborum muscles were aged in vacuum for 7 days and then cut into 2-cm-thick slices and repacked using VSP, VP and MAP for another 7 days. Color stability was measured during the next 5 days 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.     

Effect of O2 scavenger on the shelf‐life of catfish (Pangasius sutchi) steaks during chilled storage

BACKGROUND: Active packaging for preserving meat products, including seafoods, has been gaining importance in recent times. The present study was undertaken to assess the effectiveness of O₂ scavenger, the most widely used active packaging technology, on the shelf‐life of catfish steaks in chilled storage conditions. RESULTS: O₂ scavenger was effective in reducing the oxygen concentration inside the packaging to as low as 0.42% within 24 h. This reduction in oxygen in O₂ scavenger packages showed positive effects on quality parameters compared to control air packs. Total volatile base nitrogen (TVB‐N), thiobarbituric acid value and peroxide value of catfish steaks packed in O₂ scavenger was significantly different (P < 0.05) compared to air‐packed samples. Based on the sensory, microbiological and TVB‐N values, the control samples were acceptable only up to 10 days, compared to 20 days in O₂ scavenger‐packed samples, extending the shelf‐life by 10 days. CONCLUSION: O₂ scavenger reduced the oxygen concentration inside the package significantly within 24 h compared to control air packs. By using this technique, the use of a vacuum packing machine can be avoided. Further, O₂ scavenger extended the product's shelf‐life up to 20 days, compared to 10 days in control packs. Copyright © 2007 Society of Chemical Industry     

Effects of water extract of Urtica dioica L. and modified atmosphere packaging on the shelf life of ground beef

Effects of lyophilized Urtica dioica L. water extract (LUWE) and modified atmosphere packaging (MAP) on the quality and shelf life of ground beef were investigated. Ground beef was stored as aerobic control, MAP (80%O₂ + 20% CO₂), MAP + 250 ppm LUWE and MAP and 500 ppm LUWE at 2 ± 0.5 °C for 14 days. MAP and LUWE had significant effects on mesophilic, psychrotrophic and lactic acid bacteria and Pseudomonas counts. Depending on the level of LUWE, Pseudomonas and psychrotrophic counts decreased. Treatment with 500 ppm LUWE + MAP showed the lowest TBARS values compared to other groups during storage. 80% O₂-MAP increased TBARS values. Treatment had no significant effect on L* and b* values of the exterior of the ground beef, but had significant effects on the color of interior sections.     

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.     

Extending the shelf life of fresh ewe’s cheese by modified atmosphere packaging

This study evaluated the effect of modified atmosphere packaging (MAP) in extending the shelf life of a fresh ewe’s cheese stored at 4 °C for 21 days. Three batches were prepared with 20, 30 or 50% CO₂ with N₂ as filler gas. MAP controlled well the microbial growth, and the best result was obtained with 50% CO₂. Pathogens were not detected in any sample. Softening of cheese was best reduced by 30% or 50% CO₂. The sensory characteristics of the cheeses markedly decreased during storage. Only the sample stored with 50% CO₂ obtained an overall score above the acceptability at 14 days.     

包装方式对牛排贮藏期间微生物数量和演替的影响

为研究包装方式对牛排贮藏期间的品质、微生物数量和演替的影响，牛排分别采用50% O2气调包装（50% O2＋30% CO2＋20% N2）和真空包装在0～4 ℃下贮藏21 d，并检测贮藏期间pH值、肉色、微生物数量和微生物多样性。结果表明：50% O2气调包装组比真空包装具有更好的护色效果；贮藏21 d时，与真空包装组相比，气调包装组菌落总数、乳酸菌数和假单胞菌数降低；两种包装的微生物多样性均随时间延长呈现先升高后降低的趋势，且真空包装牛排比50% O2气调包装牛排具有更复杂的微生物多样性；牛排的初始微生物主要由不动杆菌属、苍白杆菌属、栖热菌属和金黄杆菌属组成，随着贮藏时间的延长，肉食杆菌属逐渐成为真空包装牛排的优势菌群，而环丝菌属、沙雷氏菌属和乳杆菌属则成为50% O2气调包装牛排的优势菌群；贮藏7～14 d是牛排中微生物种类产生变化的关键时间点；相比于真空包装牛排，50% O2气调包装牛排中的微生物群落具有更低的糖代谢和更高的蛋白质代谢能力。本研究结果明确了不同贮藏方法下牛排的品质变化和微生物的演替规律，为定向抑制牛排中的微生物、延长产品货架期提供了参考。     

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.     

Color-stabilizing effect of lactate on ground beef is packaging-dependent

Previous research on lactate-induced color stability in ground beef did not address the potential influence of packaging. The objective of the present study was to examine the effects of lactate on the color stability of ground beef patties stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with either 2.5% potassium lactate or no lactate were packaged in vacuum (VP), high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), or aerobic packaging (PVC) and stored for 0, 2, or 4 days at 2 °C. Lactate-treated patties were darker (P < 0.05; lower L∗ values) than control patties. Surface redness (a∗ values) was greater (P < 0.05) for lactate patties than the controls when stored in PVC, HIOX, and VP. However, lactate’s effects on a∗ values were not evident when packaged in CO (P > 0.05). The color-stabilizing effect of CO could have masked lactate’s effect on surface redness. While lactate patties in PVC and VP demonstrated lower (P < 0.05) discoloration than controls, no differences (P > 0.05) existed between controls and lactate samples in CO and HIOX. Our results indicated that the effects of lactate on ground beef color are dependent on packaging.     

Original article: Effect of modified atmosphere packaging using different CO2 and N2 combinations on physical,chemical, microbiological and sensory changes of fresh sea bass (Dicentrarchus labrax) fillets

The effect of different modified atmosphere packaging (MAPs) on physical, chemical, microbiological and sensory changes of sea bass fillets when stored at 4 °C and standard light conditions was investigated for up to 21 days and compared to a control batch stored in overwrap. Sea bass fillets were packed using different CO₂ and N₂ combinations (40% CO₂–60% N₂; 50% CO₂–50% N₂; 60% CO₂–40% N₂), and quality assessment was based on instrumental, chemical, microbiological and sensory analysis. The results showed that MAP extended shelf‐life of sea bass fillets from 7 days (overwrap packaging) to 14 days. Drip loss, pH values and thiobarbituric acid reactive substances (TBARS) measurements were higher in overwrap samples but no differences (P ≤ 0.05) were found between MAP samples. Bacteria grew most quickly and showed higher counts in overwrap samples followed by 40% CO₂–60% N₂; 50% CO₂–50% N₂ and finally 60% CO₂–40% N₂. Sensory analyses were in good relation with chemical and microbiological results establishing best scores and an extended shelf‐life for MAP samples especially in MAPs with high CO₂ levels.     

Modified atmosphere packaging of filleted rainbow trout

Shelf‐lives of filleted rainbow trout (Oncorhynchus mykiss) packaged in over‐wrap, vacuum and gas mixture conditions and stored at 1 ± 1 °C were compared by measurement of pH, total volatile bases (TVB), hypoxanthine content, lipid oxidation (TBARS value), superficial counts of aerobic psychrotrophic flora and sensory analysis (colour, odour and flavour). The gas mixtures evaluated were 10% O₂ + 50% CO₂ + 40% N₂, 10% O₂ + 50% CO₂ + 40% Ar, 20% O₂ + 50% CO₂ + 30% N₂, 20% O₂ + 50% CO₂ + 30% Ar, 30% O₂ + 50% CO₂ + 20% N₂ and 30% O₂ + 50% CO₂ + 20% Ar. Sensory quality deterioration was delayed and bacterial growth as well as increases in pH, TVB and hypoxanthine levels were reduced by modified atmosphere packaging (MAP). Lipid oxidation was higher in gas packages with 20 and 30% O₂ than in those with 10% O₂. Vacuum‐packed fillets presented the lowest TBARS values. In summary, MAP gave rise to a significant extension of shelf‐life when compared with vacuum and over‐wrap packaging. No significant differences were found between the packages containing either N₂ or Ar. The best evaluated atmosphere consisted of 10% O₂ + 50%CO₂ + 40% N₂/Ar. © 2002 Society of Chemical Industry     

Sensory comparison of commercial low and high oxygen modified atmosphere packed sirloin beef steaks

The objectives of this study were to investigate the effects of using commercially low and high modified atmosphere packaging (MAP) on quality characteristics of sirloin beef steaks. Gas mixtures used included 80% O₂:20% CO₂ (O₂80), 70% O₂/30% CO₂ (O₂70) and 50% O₂/30% CO₂:20% N₂ (O₂50) and for commercial packs O₂75 ± 5%, CO₂25 ± 5%, < 5% N₂-(O₂Com). All samples were packed in similar tray and packaging film formats. The experimental parameters monitored included microbiological, physiochemical and sensory measurements (naïve assessors). Microbial counts did not exceed the recommended legal ranges over the storage period. However the numbers of LAB (lactic acid bacteria) were the highest for commercially-packed samples (O₂Com) in comparison to laboratory packaged samples (O₂80, O₂70 and O₂50). Commercially-packaged samples eventually spoiled due to the occurrence of off-flavours and off-odours and subsequently were the least acceptable to sensory naïve assessors.