Polyvinyl Chloride Overwrap Research Articles

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.

Effects of Pyruvate on Lipid Oxidation and Ground Beef Color

Our overall objective was to better understand the effects of added pyruvate on enhanced beef color stability. The 2 possible mechanisms assessed were the role of pyruvate in lipid oxidation and direct interaction between pyruvate and beef myoglobin. Microsomes were incubated with pyruvate at pH 5.6, 25 °C, and lipid oxidation was measured hourly for 3 h. Bovine oxymyoglobin at pH 5.6 was incubated with pyruvate and used to quantify both redox stability (metmyoglobin formation) and pyruvate-myoglobin adduction using mass spectrometry analysis. Surface color and lipid oxidation were measured on ground beef patties stored for 6 d in polyvinyl chloride over-wrap (PVC) or high oxygen. Addition of pyruvate to microsomes decreased lipid oxidation compared with controls (P < 0.05). Conversely, no effect on myoglobin was observed (no changes in redox stability and no peaks corresponding to pyruvate were observed; P > 0.05). However, pyruvate increased color stability and decreased lipid oxidation of ground beef patties packaged in PVC and high oxygen. Pyruvate decreased nitric oxide metmyoglobin-reducing capacity and oxygen consumption of patties compared with controls (P < 0.05). This research suggests that pyruvate may improve beef color stability primarily through its antioxidant effect on lipids. Discoloration of meat often results in significant revenue loss. This study suggests that pyruvate can improve the color stability of patties packaged in high oxygen and PVC primarily through its antioxidant effect on lipids.

National Meat Case Study 2004: Product labeling information, branding, and packaging trends

Fresh meat retail cases in 104 supermarkets across 5 regions of the United States were audited for the use of packaging types and materials, branding, and cooking/nutritional information. Frequency means were separated for species of beef, ground beef, pork, chicken, turkey, lamb, and veal. Traditional polyvinyl chloride overwrap was used on 47.0% of packages in the fresh meat case nationwide and was the most frequent packaging type for beef, ground beef, pork, lamb, and veal. The use of modified atmosphere packaging was greatest (P < 0.001) in ground beef (33.2%) and turkey (45.1%) products. The 3 most common tray colors in the fresh meat retail case on a national level were white (39.6%), yellow (22.4%), and black (11.5%). Foam trays were used in 72.6% of all packages in the retail meat case. In 2004, 60.2% of all packages were case-ready. Chicken (94.8%) and turkey (95.6%) products utilized case-ready packaging systems more (P < 0.001) than any other species. On a national level, 50.1% of all products carried a national brand, 12.2% carried a store brand, and the remaining 37.7% of products in the fresh meat case in 2004 were not branded. Chicken was most (P < 0.001) likely to carry a natural brand label. Labels with cooking instructions were found most (P < 0.001) on pork (37.3%) and turkey products (48.1%). Chicken (20.4%) and turkey products (20.7%) were most (P < 0.001) likely to have the cooking instructions printed on the packaging material compared with all other species. Labels with nutritional information were most (P < 0.001) likely to be found on turkey products (55.7%) in the fresh meat case compared with any other species. On the national level, 6.1% of all packages reported in the fresh meat case in 2004 were value-added.

Effects of Packaging Systems on the Natural Microflora and Acceptability of Chicken Breast Meat

The effect of 3 packaging systems on the spoilage microflora, objective color, and sensory characteristics of fresh commercial broiler chicken breast meat was investigated. Fresh skinless and boneless chicken broiler breasts were purchased from a local poultry processing plant and packaged in either (1) a conventional Styrofoam tray with polyvinyl chloride overwrap and absorbent pad, (2) a Styrofoam tray with polyvinyl chloride overwrap minus absorbent pad, or (3) a Fresh-R-Pax (FRP) container equipped with an absorbent liner-gel system. All packages were heat sealed and stored at 1.2 +/- 1 degrees C for 8 d. At each sampling period (0, 2, 4, 6, and 8 d), packages from each treatment were analyzed for Pseudomonas spp., psychrotrophic organisms, objective color, and sensory characteristics. In general, Pseudomonas spp. and psychrotrophic counts increased as storage time increased for all packaging systems. Color and overall appearance were similar (P >0.05) for all packaging systems. Although not significant, the off-odor scores for breast meat packaged in FRP were higher (P >0.05) after 6 and 8 d when compared with the breast meat packaged in a Styrofoam tray with polyvinyl chloride overwrap with or without an absorbent pad. Although the absorbent pad did not control microbial growth, it maintained aesthetic appeal by absorbing all visible moisture released from the meat during storage.

Effects of polyvinyl chloride overwrap film, high-oxygen modified atmosphere packaging, or ultra-low-oxygen modified atmosphere packaging on bone marrow discoloration in beef humerus, rib, thoracic vertebra, and scapula1

Meat retailers have reported bone marrow discoloration to be a problem, especially in modified atmosphere packages (MAP). Therefore, it is important to determine the prevalence and cause(s) of bone marrow discoloration in different beef bones and packaging systems. Thirty-six beef humeri, ribs, scapulas, and thoracic vertebrae from USDA Select and Choice carcasses were obtained from a commercial abattoir, cut into 2.54-cm-thick sections at 4 d postmortem, and packaged into 1 of 3 systems: 1) polyvinyl chloride film (PVC) overwrap; 2) high-oxygen (80% O2, 20% CO2) MAP; and 3) ultra-low-oxygen (70% N2, 30% CO2) MAP. Instrumental reflectance and visual color scores were taken on d 0, 2, and 4, and on d 0 to 4 of display, respectively. Bone marrow was extracted from humeri, ribs, and thoracic vertebrae for analysis but not from scapulas. Ribs, scapulas, and thoracic vertebrae packaged in PVC and high-oxygen MAP developed undesirable gray or black discoloration. In ultra-low-oxygen MAP, mean visual color scores were acceptable throughout the entire display period. Discoloration (darkening) was more extensive for ribs, scapulas, and thoracic vertebrae than for humeri, especially for bones packaged in PVC and high-oxygen MAP. Humeri had lower (P < 0.05) a* values (larger positive a* values indicate a redder color) than the other bones. The a* values for ribs, scapulas, and thoracic vertebrae decreased (P < 0.05) over time. Chroma showed that bone marrow discolored during display, but graying was dramatically less for all bones packaged in ultra-low-oxygen MAP and for humeri in PVC and high-oxygen MAP. Humeri marrow had lower (P < 0.05) 2-thiobarbituric acid reactive substances (TBARS) than did ribs and thoracic vertebrae marrow. Ultra-low-oxygen MAP resulted in the least amount of change in TBARS from d 0 to 4, whereas thoracic vertebrae marrow had greater (P < 0.05) TBARS values at d 4 of display than at d 0 in PVC and high-oxygen MAP. Humeri marrow had dramatically less total Fe and hemoglobin than did that of ribs and thoracic vertebrae for all packaging systems. Myoglobin was undetectable in humeri marrow. The much larger amounts of Fe and hemoglobin in ribs and thoracic vertebrae likely contribute to marrow discoloration. Bone marrow discoloration was distinct in ribs, scapulas, and thoracic vertebrae packaged in PVC or high-oxygen MAP. Bones packaged in ultra-low-oxygen MAP had minimal discoloration.

Evaluation of topical antioxidants and packaging materials to decrease the incidence of bone discoloration in pork retail cuts (2004)

Color characteristics were evaluated on 48 pork backbones. After 6 d postmortem, six 1- inch-thick sections of lumbar vertebrae were cut from each backbone. Lumbar vertebrae were treated with different concentrations of ascorbic acid, with combination treatments of ascorbic acid and natural antioxidants, or left untreated. Bones were packaged in one of three systems: high-oxygen modifiedatmosphere packaging (MAP), ultra-lowoxygen MAP, or polyvinyl chloride (PVC) overwrap trays. Bones were visually evaluated by a trained panel on d 0, 1, 2, 3, 4, 5, and 8. Lightness (L*) was also measured on d 0, 2, and 8 of display. After 8 d of display, antioxidant- treated bones packaged in highoxygen MAP were more desirable than those in PVC overwrap trays. Bones packaged in ultra-low-oxygen MAP became less desirable over 8 d of display. Solutions of 1.875% and 2.50% ascorbic acid yielded the most desirable color after 8 d for bones in high-oxygen MAP and in PVC overwrap trays. Bones treated with 1.875% or 2.50% ascorbic acid tended to have lighter color (higher L*) on d 8 for high-oxygen MAP and PVC overwrap trays, whereas an overall difference was not observed for lightness for bones packaged in ultra-low-oxygen MAP.; Swine Day, 2004, Kansas State University, Manhattan, KS, 2004

Color stability of semitendinosus, semimembranosus, and biceps femoris steaks packaged in a high-oxygen modified atmosphere.

The objectives of this study were to evaluate visual and chemical attributes of beefsteaks from various USDA quality grades and muscles packaged in high-oxygen (80% O2/20% CO2) modified-atmosphere packaging (MAP). A total of nine carcasses were selected to represent Select (n = 3), low Choice (n = 3), and high Choice (n = 3) USDA quality grades. The semimembranosus (SM), semitendinosus (ST), and biceps femoris (BF) muscles were removed from each carcass and allotted to two packaging types (MAP or polyvinyl chloride over-wrap) and were displayed for up to 10 d, with evaluation on d 1, 3, 5, 7, and 10. Fifty-four steaks were evaluated on each day by a five-member trained panel for visual color (lean color and discoloration) and were also analyzed with a Minolta Chroma Meter CR-310 for L* and a* values (lightness and redness, respectively). Chemical properties measured included percentage of metmyoglobin formation and fat content. Visual color scores did not differ (P > 0.05) at d 1 and 3 with respect to all quality grades, but decreased after d 3, with a greater reduction (P < 0.05) in high Choice steaks for both lean color and discoloration. The low Choice steaks packaged in MAP displayedhigher (P < 0.05) lean color scores and less (P < 0.05) discoloration at d 7 and 10 than did Select and high Choice steaks. Redness (a*) values also decreased (P < 0.05) after d 3, whereas (lightness) L* values declined (P < 0.05) from d 1 to 5. The high Choice steaks had higher (P < 0.05) metmyoglobin content than low Choice and Select steaks, but packaging had no effect (P > 0.05) on metmyoglobin content. Muscle type did affect metmyoglobin content; however, the metmyoglobin content of the SM was greatest (P < 0.05), followed by the BF, with the ST having the lowest (P < 0.05) metmyoglobin formation. Results indicate that low Choice steaks react the best in MAP, and the ST maintained greater storage characteristics regardless of quality grade or packaging.

Effects of Antioxidants in Polyethylene Film on Fresh Beef Color

ABSTRACT: BHA, BHT, rosemary extract, and α‐tocopherol were incorporated into low‐density polyethylene (LDPE) at the 0.1% level and thermoformed into 25‐mm‐dia, 0.25‐mm‐thick discs, which were exposed to the surface of fresh beef and held in contact with a polyvinyl chloride (PVC) overwrap. On d 0, the control treatment with only the PVC overwrap had greater “a” (redness) values, probably due to greater transmission of oxygen to the meat surface. However, by d 7, the control with only the PVC overwrap had lower redness values than any of the other treatments. By d 8 and 9, the meat packaged with the BHA‐impregnated film had higher “a” (redness) values than any of the other film treatments

Microbiological and Sensory Evaluation of Fresh Fish Packaged in Carbon Dioxide for Retail Outlets in the Midwest

Fresh fish obtained from a commercial packaging plant were evaluated for microbial content and sensory changes during 3 weeks of storage. Fish were packaged in (a) nylon-Surlyn bags and backflushed with approximately 80% CO2, (b) in nylon-Surlyn bags with no alternation of gaseous environment, or (c) over-wrapped with polyvinyl chloride film. After packaging, fish were stored at 1°C. Two types of fish (ocean perch and sea trout) were analyzed. The data indicate that fish packaged in the nylon-Surlyn bag with CO2 had the smallest increase in microbial numbers followed by the fish packaged without CO2. An increase in the bacterial lag phase was observed for the fish packaged in CO2 when compared with fish packaged without CO2 or over-wrapped. The fish packaged in CO2 maintained a lower pH during storage compared with fish packaged without CO2. The highest microbial load was found in fish packaged with the polyvinyl chloride over-wrap.