Carbon Monoxide Modified Atmosphere Packaging Research Articles

Comparison of Gas Treatments of High Oxygen, Carbon Monoxide, and Nitric Oxide on Ground Beef Color in Modified Atmosphere Packaging.

The objective of this study was to evaluate the viability and performance of nitric oxide modified-atmosphere packaging (MAP) as a novel alternative to high oxygen and carbon monoxide MAP for ground beef. Packages of ground beef under high oxygen (HI-OX), carbon monoxide (CO), and nitric oxide (NO) atmospheres were evaluated for descriptive and instrumental color every 12 h during a 120 h display period. Surface myoglobin percentages, internal cooked color, thiobarbituric acid reactive substances (TBARS), and residual nitrite and nitrate were also evaluated. There were gas × time interactions for descriptive color, discoloration, a* values, b* values, deoxymyoglobin percentages, and metmyoglobin percentages (p < 0.05). There were also gas-type main effects for cooked color and TBARS (p < 0.05). Carbon monoxide maintained the most redness and least discoloration throughout the display period, while HI-OX started with a bright red color but rapidly browned (p < 0.05). Nitric oxide started as dark red to tannish-red but transitioned to a dull red (p < 0.05). However, NO had increased redness and a* values for internal cooked color (p < 0.05). Although CO outperformed NO packages, NO exhibited a unique color cycle warranting further research to optimize its use.

Effects of Pork Quality Types, Packaging, and Degree of Doneness on Trained Sensory and Instrumental Tenderness, Color, and Consumer Perception

The objective of this study was to evaluate the palatability and retail display differences of 3 types of pork loins. Enhanced (n = 10), nonenhanced (n = 10), and high-quality (n = 10) pork loins were selected from a commercial food distribution company. Loins were cut into 2.54-cm-thick chops and randomly assigned to retail display, sensory, or Warner-Bratzler shear force analyses. For retail display, chops were randomly assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap, carbon monoxide-modified atmosphere packaging, and high-oxygen modified atmospheric packaging. Instrumental and visual color measurements were taken during 5 d of retail display. For trained sensory panel and Warner-Bratzler shear force analyses, chops were evaluated at 3 different degrees of doneness (63°C, 68°C, and 74°C). Consumer sensory panelists (N = 50) evaluated the overall liking, flavor, juiciness, and tenderness of chops cooked to 68°C. A treatment × packaging interaction (P &amp;lt; 0.05) occurred for L* and a* values. High-quality chops packaged in polyvinyl chloride overwrap were lighter in color (P &amp;lt; 0.05) compared with other treatment and packaging types. However, high- quality chops had lower (P &amp;lt; 0.05) a* values than other treatment and packaging types during retail display. Trained panelists reported no difference (P &amp;gt; 0.05) in tenderness for enhanced chops when cooked at 3 different degrees of doneness. Consumer panelists preferred the enhanced chops for overall liking, tenderness, and juiciness (P &amp;lt; 0.05) compared with high-quality and nonenhanced chops. The results suggest that enhanced, nonenhanced, and high-quality pork loins avail- able in the market vary in color and marbling. Both pork loin type and packaging can influence display color and palatability.

147 Tenderness and Retail Display Evaluation of Non-Enhanced, Enhanced and High-Quality Pork Chops

Abstract Quality variation within the pork industry is commonly associated with intramuscular fat and muscle color. The objective of this study was to determine the effects of packaging, pork quality types, and cooking temperature on color and shear force. Normal, non-enhanced (N, n = 10), Enhanced with salt and phosphate (E, n = 10) and Highly Marbled (H, n = 10) pork loins from a local food distributor. Loins were cut into 2.54-cm-thick chops and assigned to retail display or tenderness evaluation. Retail display chops were assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP) and high-oxygen modified atmospheric packaging (HiOx-MAP). Visual color measurement for muscle color (MC), fat color (FC), surface discoloration (SD), and surface color uniformity (SCU) was recorded on d 0, 2, and 4 of retail display. Pork tenderness was evaluated at 3 different degrees of doneness (63, 68, &amp; 74°C) using Warner-Bratzler shear (WBS) force. There were significant treatment and packaging interactions for muscle color. For muscle color score, E pork loins had a significantly lower (P &amp;lt; 0.05) muscle color score compared with N and H loins indicative of a brighter, more pale pink color. In addition, CO- and HiOx-MAP packaged chops were significantly brighter (P &amp;lt; 0.05) compared to PVC chops. There were treatment and degree of doneness main effects (P &amp;lt; 0.05) for WBS force values. Enhanced pork loins were more tender (P &amp;lt; 0.05) than N pork loins. Furthermore, pork chops cooked to 63 °C were more tender than chops cooked to 68 and 73°C. In conclusion, enhanced chops packaged in CO- or HiOx-MAP result in a brighter color of lean compared non-enhanced and high-quality. Additionally, the results suggest that enhanced, non-enhanced, and high-quality pork products available in market have different quality parameters.

Effects of Enhancement and Modified Atmosphere Packaging on Flavor and Tenderness of Dark-Cutting Beef

The objective of this study was to evaluate the effects of rosemary/beef flavor enhancement and modified atmosphere packaging (MAP) on retail display color and palatability of beef longissimus lumborum muscle. Dark-cutting beef strip loins (n = 8; pH &amp;gt; 6.0) and USDA Low Choice beef strip loins (n = 5) were selected from a commercial packing plant within 72 h of harvest. Dark-cutting strip loins were divided into 2 equal sections and randomly assigned to either nonenhanced or rosemary/beef flavor–enhanced treatments. Dark-cutting enhanced loins were injected to 110% of their green weight with a rosemary/beef flavor enhancement to attain 0.1% rosemary, 0.5% salt, and 0.55% beef flavor in the final product. Six 2.54-cm-thick steaks were cut from nonenhanced USDA Choice, nonenhanced dark-cutting, and enhanced dark-cutting strip loins and randomly assigned to one of 3 packaging treatments: vacuum packaging, carbon monoxide MAP (0.4% CO, 69.6% N, and 30% CO2), and high-oxygen MAP (80% O2 and 20% CO2). Following 3-d retail display, instrumental color measurements were recorded, and one steak from each packaging type was evaluated by a trained sensory taste panel and another used to measure Warner-Bratzler shear force. Enhanced dark-cutting steaks packaged in high-oxygen MAP and carbon monoxide MAP had greater a* values (P &amp;lt; 0.0001) than dark-cutting steaks in vacuum packaging. Enhanced dark-cutting steaks were lighter (P &amp;lt; 0.0001, greater L* values) than nonenhanced dark-cutting steaks. Nonenhanced dark-cutting steaks exhibited a lower (P = 0.03) overall juiciness compared to enhanced dark-cutting steaks. Enhanced and nonenhanced dark-cutting steaks were more tender (P = 0.002) than the USDA Choice steaks. Enhanced dark-cutting steaks had higher (P = 0.006) sour flavor in vacuum packaging than other packaging types. The results suggest that rosemary/beef flavor enhancement has the potential to improve the surface color of dark-cutting beef while improving or maintaining palatability.

The Effect of Modified Atmospheric Packaging on Beef Color Sensory Characteristics of Different Muscle pH Categories

ObjectivesAny deviation from the bright-red color of beef can lead to discounted price or consumer rejection. Fresh beef lean color is influenced by pH. Various packaging techniques have been developed to enhance the lean color of beef steaks. Therefore, the objective of the current study was to evaluate the effects of modified atmospheric packaging on three different beef muscle pH categories.Materials and MethodsThe three categories evaluated for this study were: Normal (pH = 5.57 ± 0.1; N-pH), Moderately high (pH = 5.70 ± 0.09; M-pH), and High (pH = 6.39 ± 0.03; H-pH). The pH was taken on the carcass, at the 12th and 13th rib interface within 72 h of harvest at a commercial beef processing plant. Strip loins were fabricated from each carcass (n = 12) and sent to Oklahoma State University for further analysis. Strip loins were then cut into 2.54 cm steaks and randomly assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2) and high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O2, and 20% CO2). Visual color measurements for muscle color (MC; (1 = extremely bright cherry-red and 7 = extremely dark red), and surface discoloration (SD; 1 = no discoloration [0%] and 7 = extensive discoloration [81–100%]) were recorded on d 2, 4, and 6 of retail display by a trained panel. Data were analyzed using the Mixed Procedure of SAS.ResultsFor all pH treatments, PVC packaging possessed the darkest muscle color (P &lt; 0.05) score compared to CO- and HiOx-MAP. When comparing N-pH, M-pH, and H-pH values, CO-MAP had approximately a 27.3%, 22.2%, and 25.3% improvement in muscle color, indicating a brighter lean color compared to PVC. Additionally, HiOx-MAP had approximately a 10.9%, 17.4%, and 16.5% improvement in muscle color score for N-pH, M-pH, and H-pH, respectively. When packaging steaks in either CO- or HiOx-MAP there was no significant difference (P &gt; 0.05) between d 4 and 6 of retail display for muscle color. However, there was a significant (P &lt; 0.05) darkening in muscle color for steaks packaged in PVC from d 4 to 6 of retail display. By the fourth d of retail, N-pH steaks packaged in PVC had 38.3% and 39.0% greater (P &lt; 0.05) surface discoloration than CO- and HiOx-MAP, respectively.ConclusionThese results suggest that packaging steaks of different pH categories in CO- or HiOx-MAP can improve the surface color compared to PVC packaging.

Modified Atmospheric Packaging and Antioxidant Enhancement Improves Redness of Atypical Dark-Cutting Beef

ObjectivesDark-cutting carcasses occur when muscle pH does not decrease sufficiently during rigor mortis because of antemortem glycogen depletion. Typical dark-cutting beef have a pH &gt; 6.0, however, atypical dark-cutting (ADC) beef have a pH around 5.7- 5.9 but have a darker lean color similar to dark-cutting beef. Previous studies noted that greater muscle pH in dark-cutting beef increase oxygen consumption and decrease myoglobin oxygenation. However, limited research has determined the biochemical basis of ADC. Therefore, the objectives of this study were to characterize the biochemical basis of ADC beef carcasses and to utilize modified atmosphere packaging (MAP) and rosemary enhancement to improve appearance during retail display.Materials and MethodsStrip loins from ADC and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, OK. Control (C) and ADC steaks (prior to enhancement and packaging) were utilized to measure pH, color, oxygen consumption, and proximate compositions. Loin sections were cut into halves and randomly assigned to combinations of packaging types and enhancement treatment. Packaging included high-oxygen MAP (HiOx-MAP; 80% oxygen and 20% carbon dioxide), carbon monoxide MAP (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and PVC. Enhancement includes 0.1% rosemary oleoresin pumped to 10% of loin green weights. Following enhancement and packaging, steaks were displayed under retail conditions for 6 d to measure color changes using a HunterLab spectrophotometer. The data were analyzed using the Mixed Procedure of SAS, and the experiment was replicated 13 times (n = 13).ResultsThere were no differences for initial pH or proximate compositions (P &lt; 0.05) between C and ADC. However, ADC had lower initial lightness (L* values), redness (a* values), and red intensity (chroma) compared with C. Further, ADC had greater (P &lt; 0.05) oxygen consumption than C. There was a significant packaging × enhancement × display time interaction resulted for L*, a*, and chroma. CO-MAP and HiOx-MAP in combination with rosemary enhancement improved (P &lt; 0.05) redness of ADC by 61.7% and 42.3%, respectively, compared with ADC in PVC packaging. Similarly, MAP and enhancement improved lightness (L* values) and chroma compared with ADC in PVC. By Day 6 of display, enhanced ADC steaks packaged in both HiOx-MAP and CO-MAP had similar color parameters to control choice steaks; however, non-enhanced ADC steaks had significantly lower a* (P &lt; 0.0001) and chroma (P &lt; 0.01) values when packaged in HiOx-MAP when compared to both C and enhanced ADC.ConclusionThe results suggest that ADC beef has greater oxygen consumption than C steaks even at similar muscle pH. Use of modified atmospheric packaging in combination with enhancement has the potential to improve surface color of ADC beef.

77 Improving lean muscle color of atypical dark- cutting beef by antioxidant-enhancement and modified atmospheric packaging

Abstract Any deviation from the bright-red color of beef leads to discounted price or consumer rejection. Atypical dark-cutting beef represents darker color of lean around a pH 5.6 – 5.8. However, limited studies have determined the postharvest practices to improve the lean color of atypical dark-cutting beef. Therefore, the objective was to evaluate the effects of rosemary-enhancement and modified atmospheric packaging on atypical dark-cutting beef. Atypical dark-cutting beef strip loins (n = 13, pH=5.70 ± 0.09; ADC) and USDA Choice beef strip loins (n = 6, pH=5.57 ± 0.1; CH) were selected within 72 h of harvest. Atypical dark-cutting strip loins were divided into 2 sections, and randomly assigned to one of the following enhancement treatments: control non-enhanced (ADC), or a 1.1% rosemary-enhanced treatment (ADCE). After enhancement, 2.54 cm steaks were cut from CH, ADC, and ADCE strip loins and assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O2 and 20% CO2). A HunterLab MiniScan was used to determine color during the 6 d simulated retail display. Visual color measurement for muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were recorded on d 2, 4, and 6 of retail display. There was a significant enhancement x packaging interaction for instrumental and visual color measurements. For all packaging types, ADCE steaks possessed greater L* values than DC steaks. In addition, ADCE steaks packaged in HiOx-MAP or CO-MAP had brighter-red color than ADC steaks. Furthermore, ADCE and C steaks had less muscle darkening compared with ADC steaks for MD and MC attributes. The results suggest that enhancement and modified atmospheric packaging have the potential to improve the surface color of atypical dark-cutting beef.

The Effect of Modified Atmospheric Packaging on Beef Color Sensory Characteristics of Different Muscle pH Categories

ObjectivesAny deviation from the bright-red color of beef can lead to discounted price or consumer rejection. Fresh beef lean color is influenced by pH. Various packaging techniques have been developed to enhance the lean color of beef steaks. Therefore, the objective of the current study was to evaluate the effects of modified atmospheric packaging on three different beef muscle pH categories.Materials and MethodsThe three categories evaluated for this study were: Normal (pH = 5.57 ± 0.1; N-pH), Moderately high (pH = 5.70 ± 0.09; M-pH), and High (pH = 6.39 ± 0.03; H-pH). The pH was taken on the carcass, at the 12th and 13th rib interface within 72 h of harvest at a commercial beef processing plant. Strip loins were fabricated from each carcass (n = 12) and sent to Oklahoma State University for further analysis. Strip loins were then cut into 2.54 cm steaks and randomly assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2) and high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O2, and 20% CO2). Visual color measurements for muscle color (MC; (1 = extremely bright cherry-red and 7 = extremely dark red), and surface discoloration (SD; 1 = no discoloration [0%] and 7 = extensive discoloration [81–100%]) were recorded on d 2, 4, and 6 of retail display by a trained panel. Data were analyzed using the Mixed Procedure of SAS.ResultsFor all pH treatments, PVC packaging possessed the darkest muscle color (P < 0.05) score compared to CO- and HiOx-MAP. When comparing N-pH, M-pH, and H-pH values, CO-MAP had approximately a 27.3%, 22.2%, and 25.3% improvement in muscle color, indicating a brighter lean color compared to PVC. Additionally, HiOx-MAP had approximately a 10.9%, 17.4%, and 16.5% improvement in muscle color score for N-pH, M-pH, and H-pH, respectively. When packaging steaks in either CO- or HiOx-MAP there was no significant difference (P > 0.05) between d 4 and 6 of retail display for muscle color. However, there was a significant (P < 0.05) darkening in muscle color for steaks packaged in PVC from d 4 to 6 of retail display. By the fourth d of retail, N-pH steaks packaged in PVC had 38.3% and 39.0% greater (P < 0.05) surface discoloration than CO- and HiOx-MAP, respectively.ConclusionThese results suggest that packaging steaks of different pH categories in CO- or HiOx-MAP can improve the surface color compared to PVC packaging.

Modified Atmospheric Packaging and Antioxidant Enhancement Improves Redness of Atypical Dark-Cutting Beef

ObjectivesDark-cutting carcasses occur when muscle pH does not decrease sufficiently during rigor mortis because of antemortem glycogen depletion. Typical dark-cutting beef have a pH > 6.0, however, atypical dark-cutting (ADC) beef have a pH around 5.7- 5.9 but have a darker lean color similar to dark-cutting beef. Previous studies noted that greater muscle pH in dark-cutting beef increase oxygen consumption and decrease myoglobin oxygenation. However, limited research has determined the biochemical basis of ADC. Therefore, the objectives of this study were to characterize the biochemical basis of ADC beef carcasses and to utilize modified atmosphere packaging (MAP) and rosemary enhancement to improve appearance during retail display.Materials and MethodsStrip loins from ADC and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, OK. Control (C) and ADC steaks (prior to enhancement and packaging) were utilized to measure pH, color, oxygen consumption, and proximate compositions. Loin sections were cut into halves and randomly assigned to combinations of packaging types and enhancement treatment. Packaging included high-oxygen MAP (HiOx-MAP; 80% oxygen and 20% carbon dioxide), carbon monoxide MAP (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and PVC. Enhancement includes 0.1% rosemary oleoresin pumped to 10% of loin green weights. Following enhancement and packaging, steaks were displayed under retail conditions for 6 d to measure color changes using a HunterLab spectrophotometer. The data were analyzed using the Mixed Procedure of SAS, and the experiment was replicated 13 times (n = 13).ResultsThere were no differences for initial pH or proximate compositions (P < 0.05) between C and ADC. However, ADC had lower initial lightness (L* values), redness (a* values), and red intensity (chroma) compared with C. Further, ADC had greater (P < 0.05) oxygen consumption than C. There was a significant packaging × enhancement × display time interaction resulted for L*, a*, and chroma. CO-MAP and HiOx-MAP in combination with rosemary enhancement improved (P < 0.05) redness of ADC by 61.7% and 42.3%, respectively, compared with ADC in PVC packaging. Similarly, MAP and enhancement improved lightness (L* values) and chroma compared with ADC in PVC. By Day 6 of display, enhanced ADC steaks packaged in both HiOx-MAP and CO-MAP had similar color parameters to control choice steaks; however, non-enhanced ADC steaks had significantly lower a* (P < 0.0001) and chroma (P < 0.01) values when packaged in HiOx-MAP when compared to both C and enhanced ADC.ConclusionThe results suggest that ADC beef has greater oxygen consumption than C steaks even at similar muscle pH. Use of modified atmospheric packaging in combination with enhancement has the potential to improve surface color of ADC beef.

Effect of packaging atmospheres on storage quality characteristics of heavily marbled beef longissimus steaks

The objective of this study was to investigate the effects of modified atmosphere packaging (MAP) systems on shelf-life and quality of beef steaks with high marbling. Four packaging types were used including 80% O2 MAP (80% O2+20% CO2), 50% O2 MAP (50% O2+30% CO2+20% N2), carbon monoxide MAP (0.4% CO+30% CO2+69.6% N2) and vacuum packaging (VP). Steaks were displayed under simulated retail conditions at 4°C for 12days. Purge loss, pH, color stability, oxidative stability and microbial counts were monitored. Aerobically packaged steaks exhibited a bright-red color at the first 4days. However, discoloration and oxidation became major factors limiting their shelf-life to 8days. Compared with aerobic packaging, anaerobic packaging extended shelf-life of heavily marbled beef steaks, due to better color stability, together with lower oxidation and microbial populations. Among all packaging methods, CO-MAP had the best preservation for steaks, with more red color than other packaging types.

Volatile compound characterization of modified atmosphere packaged ground beef held under temperature abuse

The effect of modified atmosphere packaging (MAP) on headspace volatile compounds of raw ground beef, as profiled by solid phase microextraction (SPME), was studied. Raw ground beef patties (81:19 lean:fat) were packaged in high oxygen MAP (80% O2, 20% CO2) or carbon monoxide MAP (COMAP) (69.6% N2, 0.4% CO, and 30% CO2) atmospheres. Packages were stored at 22 °C under continuous fluorescent lighting (1530 lux). Package headspace was sampled over a three consecutive day trial by SPME and then analyzed by gas chromatography/mass spectrometry. In total, 20 volatile compounds were separately identified in the headspace of COMAP and high oxygen MAP packages; the progression of time evidenced development of known spoilage-associated compounds including several hydrocarbons and hexanal. The identification of compounds in similar relative abundance in both package types suggest their development via alternative oxidation and non-oxidation pathways.

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 0day, 4days, 9days, and 14days or stored for 9days then displayed in air for 0day, 1day, or 3days. 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.

Chitosan inhibits premature browning in ground beef

Our objective was to evaluate the effect of chitosan on premature browning in refrigerated ground beef patties stored in different packaging systems. Ground beef patties (15% fat) with chitosan (1% w/w) or without chitosan (control) were individually packaged either in vacuum (VP), aerobic packaging (AP), carbon monoxide modified atmosphere packaging (LO-OX; 0.4% CO+19.6% CO2+80% N2), or high-oxygen modified atmosphere packaging (HI-OX; 80% O2+20% CO2), and stored for 0, 1, or 3days at 1°C. At the conclusion of storage, raw surface redness was evaluated, patties were cooked to internal end-point temperatures of either 66°C or 71°C, and internal cooked color was measured. The incorporation of chitosan increased (P<0.05) the interior redness of patties stored in AP, VP, and LO-OX, but not in HI-OX. The results of the present study suggest that the incorporation of 1% chitosan minimizes premature browning in ground beef patties stored under AP, VP, and LO-OX.

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% O(2)+20% CO(2)), carbon monoxide MAP (CO; 0.4% CO+19.6% CO(2)+80% N(2)), 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% O 2 + 20% CO 2), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO 2 + 80% N 2), 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.

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% O 2 + 20% CO 2), or carbon monoxide MAP (CO; 0.4% CO + 19.6% CO 2 + 80% N 2), 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.

Spoilage and Safety Characteristics of Ground Beef Packaged in Traditional and Modified Atmosphere Packages

Two separate studies, one with pathogen-inoculated product and one with noninoculated product, were conducted to determine the safety and spoilage characteristics of modified atmosphere packaging (MAP) and traditional packaging of ground beef patties. Ground beef patties were allotted to five packaging treatments (i) control (foam tray with film overwrap; traditional), (ii) high-oxygen MAP (80% O2, 20% CO2), (iii) high-oxygen MAP with added rosemary extract, (iv) low-oxygen carbon monoxide MAP (0.4% CO, 30% CO2, 69.6% N2), and (v) low-oxygen carbon monoxide MAP with added rosemary extract. Beef patties were evaluated for changes over time (0, 1, 3, 5, 7, 14, and 21 days) during lighted display. Results indicated low-oxygen carbon monoxide gas flush had a stabilizing effect on meat color after the formation of carboxymyoglobin and was effective for preventing the development of surface discoloration. Consumers indicated that beef patties packaged in atmospheres containing carbon monoxide were more likely to smell fresh at 7, 14, and 21 days of display, but the majority would probably not consume these products after 14 days of display because of their odor. MAP suppressed the growth of psychrophilic aerobic bacteria when compared with control packages. Generally, control packages had significantly higher total aerobic bacteria and Lactobacillus counts than did modified atmosphere packages. In the inoculated ground beef (approximately 105 CFU/g) in MAP, Escherichia coli O157 populations ranged from 4.51 to 4.73 log CFU/g with no differences among the various packages, but the total E. coli O157:H7 in the ground beef in the control packages was significantly higher at 5.61 log CFU/g after 21 days of storage. On days 14 and 21, the total Salmonella in the ground beef in control packages was at 5.29 and 5.27 log CFU/g, respectively, which was significantly higher than counts in the modified atmosphere packages (3.99 to 4.31 log CFU/g on day 14 and 3.76 to 4.02 log CFU/g on day 21). Data from these studies indicate that MAP suppresses pathogen growth compared with controls and that spoilage characteristics developed in MAP packages.

EFFECT OF CARBON MONOXIDE AND HIGH OXYGEN MODIFIED ATMOSPHERE PACKAGING (MAP) ON QUALITY CHARACTERISTICS OF BEEF STRIP STEAKS

ABSTRACT Carbon monoxide (CO), recently approved as a modified atmosphere packaging (MAP) gas, has the potential to extend color shelf life in case‐ready beef. The objective was to determine how CO versus traditional high oxygen MAP treatments affect beef quality. Strip loins were enhanced with a commercial phosphate–salt solution. Steaks were cut, packaged in atmospheres containing either 0.4% CO/30% CO2/69.6% N2 (HiOx) or 80% O2/20% CO2 (HiOx), aged in the dark for 12 and 26 days, and placed in a lighted retail display case. Steaks were visually evaluated by trained panelists using a 7‐point color scale and a 5‐point surface sheen scale. On days 14 and 28, packages were opened, and steaks were cooked for consumer evaluation. Cooked steaks were cut through for internal cooked color evaluation. Results indicate that CO had no effect on flavor or acceptability and minimal effects on other characteristics, such as color, sheen and purge loss. If the CO environment provides microbiological stability through 28 days, it can be expected that the raw product appearance will not differ from steaks in traditional HiOx packaging. PRACTICAL APPLICATIONSTo prevent surface browning, which occurs over time due to high oxygen environments, carbon monoxide (CO) can be used in modified atmosphere packaged (MAP) fresh beef because it binds very strongly to the meat pigment myoglobin, allowing it to maintain its bright red color and extending its shelf life. Strip loin steaks were packaged in high oxygen MAP or high oxygen plus CO packaging then evaluated by a panel of 100 consumers after 14 and 28 days of storage. CO had some effect on raw color, surface sheen and interior cooked color compared to the high oxygen atmosphere when steaks were evaluated after 14 days. CO had no effect on flavor or acceptability and only minimal effects on other characteristics. Use of this recently approved MAP gas can extend the color shelf life of beef.

Comparison of Color and Thiobarbituric Acid Values of Cooked Hamburger Patties after Storage of Fresh Beef Chubs in Modified Atmospheres

ABSTRACT: Cooked meat color is an important quality attribute for consumers. This study compared color and thiobarbituric acid (TBA) values of cooked ground beef (internal temperatures of 49 to 79 °C), after storage of raw product in atmospheres of 0.4% carbon monoxide (CO), 80% oxygen, or vacuum at 2 °C for 7 to 21 d. Premature browning, observed as a brown cooked color at internal temperatures as low as 49 °C, was found in patties made from meat stored in 80% oxygen. At all cooking temperatures, samples stored in high oxygen had less internal red color, higher myoglobin denaturation values, and were more rancid with higher TBA values than CO or vacuum‐packaged ground beef. Raw ground beef held in 0.4% CO modified‐atmosphere packaging (MAP) remained bright red throughout the 21‐d storage period. Premature browning and high TBA values in cooked patties were avoided by use of this packaging system. However, internal patty color remained somewhat red even at the highest internal cooking temperature of 79 °C. The persistent pink color observed in CO‐treated patties cooked to 79°C internal temperature was likely due to development of heat‐denatured CO‐hemochrome, rather than the presence of undenatured CO myoglobin. The problems of PMB and high TBA values of cooked patties were also avoided by vacuum packaging. However, the development of dark purple color associated with vacuum packaging of raw beef limits the use of this packaging method for products in retail display. Keywords: beef, packaging, carbon monoxide, oxygen