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

Investigation of oxygen packaging to maintain beef color stability and microbiology safety after periods of long-term superchilled storage

This study aimed to develop an appropriate modified atmosphere packaging (MAP) system for displayed beef steaks following long-term superchilled (-1 °C) storage. After superchilled storage for 0, 2, 8, or 16 weeks, beef loins were fabricated into steaks and displayed with 20%, 50%, or 80% O2-MAP under chilled conditions. At each storage point, after display for 0, 3, 7, or 10 days, instrumental color, myoglobin redox forms percentage, lipid oxidation, total viable count (TVC), and total volatile basic nitrogen (TVB-N) were evaluated. Meat color stability decreased, with prolonged storage period and display time. When the storage period was within 8 weeks, under all the above MAP conditions, the display time for the beef steaks was up to 10 days. Considering 80% O2-MAP promoted lipid oxidation, 50% and 80% O2-MAP were not recommended for displaying steaks for more than 10 and 7 days respectively after 16 weeks of storage. However, 20%, 50%, or 80% O2-MAP could maintain 3 days of microbial shelf-life according to TVC and TVB-N results. Additionally, after long-term superchilled storage for 16 weeks, the various O2 concentrations had minimal impact on microbiota succession during the MAP display period. Furthermore, beef steaks packaged under various MAP systems exhibited similar microbial compositions, with the dominant bacteria alternating between Lactobacillus and Carnobacterium. This study provided practical guidance for improving beef color stability after long-term superchilled storage.

Starch/poly (butylene adipate-co-terephthalate) blown films contained the quaternary ammonium salts with different N-alkyl chain lengths as antimicrobials

Antimicrobial biodegradable packaging is in high demand as a one-two punch against microbiological and plastic hazards. Two quaternary ammonium salts (QAS) with different N-alkyl chain lengths were used for starch/poly (butylene adipate-co-terephthalate) (PBAT) blown antimicrobial films. Dioctadecyl dimethyl ammonium chloride (D1821) contributed to a homogeneous film morphology at 5% w/w level, while micro-pores occurred with didodecyl dimethyl ammonium chloride (D1221). Increasing QAS content weakened hydrogen bonding interactions. D1821 promoted the formation of intercalated structure of nano-clays, and improved the strength, thermal stability, barrier, and surface hydrophobicity of the films. Conversely, adding D1221 decreased the mechanical properties, and significantly enhanced the surface hydrophilicity. The films with 3% and 5% w/w D1221 obviously inhibited the growth of both Staphylococcus aureus and Escherichia coli, while those with D1821 cannot show clear zone against the Gram-negative. 5% w/w D1221-loaded film delayed the growth of microorganisms in beef, of which the total viable count was 5.75 lg CFU/g after 21-day chilling storage. Findings supported that QAS had the potential for manufacturing starch/PBAT antimicrobial packaging, but the release kinetics and cytotoxicity still need to be systematically explored before application.

Multispectral and molecular dynamics study on the impact of trans, trans-2,4-decadienal and 4-hydroxy-2-nonenal on myoglobin redox stability

This study investigated the interaction between myoglobin (Mb) and two lipid oxidation products, 4-hydroxy-2-nonenal (HNE) and trans, trans-2,4-decadienal (tt-DDE), at pH 5.6 and 7.4 through the combination of multispectral and molecular dynamics simulations. In this study, tt-DDE was more prone to promote Mb oxidation than HNE by loosening the Mb structure, which is associated with more destroyed secondary and tertiary structures. Furthermore, the pro-oxidation of both lipid products was stronger at pH 5.6 than at pH 7.4. The molecular docking revealed that both tt-DDE and HNE were combined closely with the heme group of Mb. And tt-DDE had hydrogen bonds, hydrophobic interactions, and van der Waals forces with Mb, but HNE only had hydrophobic interactions. In conclusion, it was firstly found that tt-DDE was also shown to have high activity in promoting Mb oxidation as another important aldehyde from lipid oxidation products.

Effects of dietary resveratrol supplementation in cattle on the anti-oxidative capacity and meat quality of beef steaks under high‑oxygen packaging

The effects of dietary resveratrol supplementation on beef quality and antioxidant capacity under high‑oxygen packaging were studied. Twelve cattle were selected and fed a total mixed ration (Control, CON) or supplemented with resveratrol (5 g/cattle/day, RES) for 120 days. The antioxidant capacity and meat quality of beef under high‑oxygen modified atmosphere packaging (HiOx-MAP, 80%O2/20%CO2) and overwrap packaging (OW) were evaluated during storage. Compared to the CON, RES enhanced antioxidant enzyme activity in serum and muscle, and increased the expression of Nrf2 and its downstream target genes (P < 0.05), which decreased the lipid and protein oxidation of steaks during storage (P < 0.05). The RES resulted in a* values increasing throughout storage (P < 0.05) and lower MetMb% than CON steaks (P < 0.05) in HiOx-MAP. The water-holding capacity (WHC) was improved and Warner-Bratzler shear force (WBSF) was reduced (P < 0.05) in RES steaks during storage. Thus dietary resveratrol increased beef antioxidant capacity under HiOx-MAP and improved meat quality, and can be used as a potential method to elevate beef quality and reduce the oxidation under HiOx-MAP.

Non-Destructive Detection of the Freshness of Air-Modified Mutton Based on Near-Infrared Spectroscopy

Monitoring and identifying the freshness levels of meat holds significant importance in the field of food safety as it directly relates to human dietary safety. Traditional packaging methods for lamb meat quality assessment present issues such as cumbersome operations and irreversible damage. This research proposes a quality assessment method for modified atmosphere packaging lamb meat using near-infrared spectroscopy and multi-parameter fusion. Fresh lamb meat quality is taken as the research subject, comparing various physicochemical indicators and near-infrared spectroscopic information under different temperatures (4 °C and 10 °C) and different modified atmosphere packaging combinations. Through precision parameter comparison, rebound and TVB-N values are selected as the modeling parameters. Six spectral preprocessing methods (multi-scatter calibration, MSC; standard normal variate transformation, SNV; normalization; Savitzky-Golay smoothing, SG; Savitzky-Golay 1 derivative, SG-1st; and Savitzky-Golay 2 derivative, SG-2nd), and three feature wavelength selection methods (competitive adaptive reweighted sampling, CARS; successive projections algorithm, SPA; and uninformative variable elimination, UVE) are compared. Partial least squares (PLS) and support vector machine (SVM) are used to construct prediction models for chilled fresh lamb meat quality. The results show that when rebound is used as a parameter, the SG-2nd-SPA-PLSR model has the highest accuracy, with a determination coefficient R²p of 0.94 for the prediction set. When TVB-N is used as a parameter, the MSC-UVE-SVM model has the highest accuracy, with an R²p of 0.95 for the prediction set. In conclusion, the use of near-infrared spectroscopic analysis enables rapid and non-destructive prediction and evaluation of lamb meat freshness, including its textural characteristics and TVB-N content under different modified atmosphere packaging. This study provides a theoretical basis and technical support for further encapsulating the models into portable devices and developing portable near-infrared spectrometers to rapidly determine lamb meat freshness.

Characteristics of key microorganisms and metabolites in irradiated marbled beef

Insights into changes in microorganisms and metabolites in irradiated marbled beef may help elucidate the beneficial effects of irradiation on prolonging the shelf life of meat. In this study, 16S rRNA gene sequencing, ultra-high-performance liquid chromatography-tandem mass spectrometry, and Pearson's correlation analyses were conducted to detect key microorganisms, core metabolites, and potential correlation between the microbiome and metabolome in marbling beef. Microbiome analysis showed that irradiation effectively eradicated the spoilage bacterium Leuconostoc and reduced the proportions of Carnobacterium and Lactobacillus in marbled beef. Additionally, results of metabolomic analysis involving irradiated marbled beef revealed that metabolites with significant differences were mainly organic acids and their derivatives, lipids, and lipid-like molecules, including six core metabolites. Furthermore, a significant correlation between key bacteria and metabolites was observed. Carnobacterium, Lactobacillus, and Leuconostoc affected the accumulation of core metabolites in irradiated marbled beef by influencing amino acid and lipid metabolism. Characterization of the microbiota and metabolites, as well as clarification of their correlation, can contribute to a better understanding of the mechanisms whereby irradiation helps maintain meat quality.

Utilization of spray-dried raspberry powder as a natural additive to improve oxidative stability, microbial quality and overcome the perception of discoloration in vacuum-packed ground beef during chilled storage

The present study was conducted to determine the effects of spray-dried raspberry powder (SDRP) (CONTROL, 1.0%, 2.0%, and 3.0%) as a natural antioxidant, antimicrobial, and colorant on physicochemical properties, lipid oxidation, discoloration, and microbial quality of vacuum-packed (VP) ground beef during chilled storage at 2 ± 0.5 °C for 18 days. By incorporating SDRP into VP ground beef pH, lipid oxidation (TBARS), lightness, and hue angle (h°) values decreased (P < .01), while redness (a*) and chroma (C*) values improved (P < .01). SDRP treatments had higher redness, more stable color, and lower pH and TBARS values during storage in a dose-dependent manner (P < .05), demonstrating that SDRP had a preventive effect on lipid oxidation and discoloration. The combination of vacuum packaging with SDRP generally resulted in lower bacterial growth during storage. These results demonstrated that 2% or 3% SDRP treatment has promising potential as an effective strategy to achieve oxidative and microbial stability and overcome discoloration in VP fresh meats.

Comparison of physiochemical attributes, microbial community, and flavor profile of beef aged at different temperatures

Beef aging for tenderness and flavor development may be accelerated by elevated temperature. However, little to no research has been undertaken that determines how this affects other important meat quality characteristics and microbial community. This study aims to decrease aging time by increasing temperature. Beef were aged and vacuum packaged at 10 and 15°C, and the effects of increased temperature on meat physiochemical attributes, microbial community, and flavor profile were monitored. The shear force decreased with aging in all temperature and showed the higher rate at elevated temperatures compare to 4°C. The beef aged at elevated temperatures (10 or 15°C) for 5 days showed equivalent shear force value to the beef aged at 4°C for 10 days (p  >  0.05), however, the final tenderness was not affected by the elevated temperature. The beef aged at elevated temperatures showed a significantly higher cooking loss and less color stability compared to 4°C (p  <  0.05). The total volatile basic nitrogen and aerobic plate count increased (p  <  0.05) faster at elevated temperatures compare to 4°C. Carnobacterium, Lactobacillus and Hafnia-Obesumbacterium were the dominant genus in the beef samples aged at 4, 10, and 15°C, respectively. In addition, the contents of isobutyraldehyde, 3-methylbutyraldehyde, 2-methylbutyraldehyde, and 3-methylbutanol were higher than aged at 4°C (p  <  0.05). Therefore, these results suggest that application of elevated aged temperatures could shorten required aging time prior while not adversely affecting meat quality. In turn, this will result in additional cost savings for meat processors.

Effect of Lipids in Yak Muscle under Different Feeding Systems on Meat Quality Based on Untargeted Lipidomics

Simple Summary

With the development of living standards, consumers are paying more and more attention to meat quality and flavor. When consumers choose meat, they directly pay attention to meat quality and flavor, so the meat quality and flavor directly decide meat price and sales volume. Better meat quality and flavor are the crucial factors that increase the additional value of meat. Because of its special nutritional value and taste, yak meat is popular with consumers. The intramuscular lipids can greatly affect the meat quality and flavor, but there is no report on the effect of lipids in yak muscle on the meat quality and flavor. In this study, we studied the characterization of lipids in yak muscle under different feeding systems and further explored the key lipids affecting yak meat quality and flavor. This study can provide new insight into the improvement of yak meat quality and flavor.

Abstract

The effect of lipids on yak meat quality and volatile flavor compounds in yak meat under graze feeding (GF) and stall feeding (SF) was explored using untargeted lipidomics based on liquid chromatography–mass spectrometry (LC-MS) in this study. First, the volatile flavor compounds in longissimus dorsi (LD) of SF and GF yaks were detected by gas chromatography–mass spectrometry (GC-MS). In total 49 and 39 volatile flavor substances were detected in the LD of GF and SF yaks, respectively. The contents of pelargonic aldehyde, 3-hydroxy-2-butanone and 1-octen-3-ol in the LD of both GF and SF yaks were the highest among all detected volatile flavor compounds, and the leading volatile flavor substances in yak LD were aldehydes, alcohols and ketones. In total, 596 lipids were simultaneously identified in the LD of SF and GF yaks, and the leading lipids in the LD of both GF and SF yaks were sphingolipids (SPs), glycerolipids (GLs) and glycerophospholipids (GPs). Seventy-five significantly different lipids (SDLs) between GF and SF yaks were identified in the LD. The high content of TG(16:1/18:1/18:1), TG(16:0/17:1/18:1) and TG(16:0/16:1/18:1), PE(18:0/22:4) and PC(18:2/18:0) can improve the a* (redness) and tenderness of yak muscle. The changes in volatile flavor compounds in yak muscle were mainly caused by TG(18:1/18:1/18:2), TG(18:0/18:1/18:1), TG(16:0/17:1/18:1), TG(16:0/16:1/18:1), PC(18:2/18:0), TG(16:1/18:1/18:1), PI(18:0/20:4), TG(16:1/16:1-/18:1) and TG(17:0/18:1/18:1). The above results provide a theoretical basis for improving yak meat quality from the perspective of intramuscular lipids.

Vacuum Packaging Can Extend Fresh Color Characteristics of Beef Steaks during Simulated Display Conditions

Packaging technology is evolving, and the objectives of this study were to evaluate instrumental surface color, expert color evaluation, and lipid oxidation (TBARS) on beef longissimus lumborum steaks packaged in vacuum-ready packaging (VRF) or polyvinyl chloride (PVC) overwrap packaging. Paired strip loins (Institutional Meat Purchasing Specifications # 180) were cut into 2.54-cm-thick steaks and assigned randomly to one of two packaging treatments, VRF or PVC. Steaks packaged in VRF were lighter in color (p < 0.05) as the display period increased, whereas steaks packaged in PVC became darker (p < 0.05). Redness (a*) values were greater (p < 0.05) for PVC steaks until day 5, whereas VRF steaks had a greater (p < 0.05) surface redness from day 10 to 35 of the display period. Calculated spectral values of red to brown were greater (p < 0.05) for steaks in VRF than PVC. In addition, expert color evaluators confirmed VRF steaks were less brown and less discolored (p < 0.05) from day 5 to 35 of the display. Nonetheless, lipid oxidation was greater (p < 0.05) for PVC steaks from day 10 through day 35 of the display. Results from this study suggest that the use of vacuum packaging for beef steaks is plausible for maintaining surface color characteristics during extended display periods.

Effects of high-oxygen, carbon monoxide modified atmospheres and vacuum packaging on quality of Longissimus thoracis et lumborum steaks from Nellore cows during ageing

Nellore (Bos indicus) cows play an important role in Brazilian beef production. Here, we investigated whether modified atmosphere packaging (MAP) technology could contribute to improving the quality of Nellore cow steaks. To verify this, steaks obtained from Longissimus thoracis et lumborum (LTL) were stored at 2 °C for 28 days using different packaging systems, with one being vacuum and the others being three MAP systems: 75% O₂/25% CO₂ (75%O₂-MAP), 60% CO₂/0.2% CO/39.8% N₂ and 40% CO₂/0.4% CO/59.6% N₂ (0.2%CO-MAP and 0.4%CO-MAP, respectively). Steaks packaged using the CO-MAP showed improved color stability of fresh meat. In turn, the 75%O₂-MAP drastically affected the oxidative stability related to proteins and lipids compared to both anaerobic environments (CO-MAP and vacuum). The CO-MAP increased tenderization and ultrastructural changes when compared to the aerobic MAP without affecting pH, collagen or cooking loss, which were influenced by the storage time. In conclusion, MAP technology may improve the quality and appearance of fresh meat originating from Nellore cows, being a promising alternative for the Brazilian beef industry.

Effects of spraying lactic acid and peroxyacetic acid on the quality and microbial community dynamics of vacuum skin-packaged chilled beef during storage

A long shelf life for fresh meat products is very important both to processors, retailers and consumers. In this work, the effect of repeat acid spraying on the shelf life of vacuum skin-packaged (VSP) chilled beef, as well as the quality and microbial community dynamics was evaluated. Carcasses were sprayed with 300 ppm peroxyacetic acid (PA) or 3% lactic acid (LA) three times during the chilling process, or one more time of LA spray before packaging (LLA). Quality, sensory attributes and microbial load of VSP beef during 32 days of storage at 4 °C were evaluated. The results showed that quality and sensory scores decreased over time for all treatments, but LLA treated samples were still above the rejection threshold at the end of the storage period. Moreover, the total volatile basic nitrogen value and the total viable counts were 15.0 mg/100 g and 7.2 log CFU/g for the control group, while acid treated groups remained below these two values until the end of the storage period. In particular LLA treated beef steaks exhibited the best preservation potential even at the end of storage. This is attributed to the reduction of Proteobacteria in LLA beef steaks shown by the bacterial diversity analysis via high-throughput sequencing, as well as the lower counts of B. thermosphacta and Enterobacteriaceae during storage. This indicates that LLA treatment has the potential to achieve a shelf life extension of VSP steaks without impacting on quality.

Effectiveness of bacterial cellulose in controlling purge accumulation and improving physicochemical, microbiological, and sensorial properties of vacuum-packaged beef

The application of bacterial cellulose (BC) as a wrapping material for vacuum-packaged beef was studied and compared against unwrapped beef for up to 3 weeks. The impact of BC wrap on the weight loss, purge accumulation, and drip loss were assessed along with low-field nuclear magnetic resonance, physicochemical, microbiological, and sensorial evaluations. The BC wrap significantly (P < 0.05) reduced purge accumulation in vacuum packages which was confirmed by an increased swelling ratio and scanning electron microscopy images. Colorimetric measurements showed significantly (P < 0.05) increased redness and yellowness values in wrapped samples compared to unwrapped samples. BC wrap did not affect pH, tenderness, and odor of meat, but significantly (P < 0.05) increased lipid oxidation, and numbers of lactic acid bacteria and Brochothrix thermosphacta counts. This study shows that BC wrap has potential as a purge absorbent in vacuum packaged meat. PRACTICAL APPLICATION: Bacteria cellulose has good water holding capacity that can be utilized to absorb purge exudate from beef. It helps to improve the appearance and consequently consumer acceptance of vacuum packed beef.

The Effect of Different Packaging Systems on the Shelf Life of Refrigerated Ground Beef

Abstract: The aim of this study was to investigate the effects of different packaging systems on the shelf life of refrigerated ground beef. The ground beef samples were packaged as follows: AA (100% ambient air), 90O2:10CO2 (90% O2 and 10% CO2), 80O2:20CO2 (80% O2 and 20% CO2), 70O2:30CO2 (70% O2 and 30% CO2), 60O2:40CO2 (60% O2 and 40% CO2), 50O2:50CO2 (50% O2 and 50% CO2), 100O2 (100% O2), and VP (vacuum packaging). All treatments were analyzed daily for O2 and CO2 levels, pH, filtration time, total volatile basic nitrogen (TVB-N), aerobic mesophilic heterotrophic bacteria (AMHB), and aerobic psychrotrophic heterotrophic bacteria (APHB) over 20 days at 2 °C. All MAP systems had a decrease of O2 and an increase of CO2 levels during storage period (p < 0.05). Overall, the MAP systems were similarly able to decrease the pH and retard the increase of TVB-N and filtration time over the storage period (p > 0.05). Moreover, the MAP systems increased the lag phase and/or the generation time of both AMHB and APHB, extending the shelf life by 3 (90O2:10CO2), 4 (70O2:30CO2 and 100O2), and 5 days (80O2:20CO2, 60O2:40CO2, 50O2:50CO2, and VP). All MAP systems were equally effective in retarding physicochemical degradation; however, 80O2:20CO2, 60O2:40CO2, 50O2:50CO2, and VP were the most effective in impairing bacterial growth and extending the shelf life of ground beef stored under refrigeration.

Preliminary investigation of the use of Raman spectroscopy to predict beef spoilage in different types of packaging

In this study, pH, meat color analysis, microbial counts and Raman spectroscopic data were obtained from beef steaks stored at 4 °C for up to 21 days using two different packaging methods: vacuum (VP) and modified atmosphere packaging (MAP). Models using partial least square regression (PLSR), indicated that Raman spectroscopy was able to predict total viable counts (TVC) and lactic acid bacteria (LAB) measured at 21d post mortem (TVC in VP: R²_cv = 0.99, RMSEP = 0.61; TVC in MAP: R²_cv = 0.90, RMSEP = 0.38; LAB in VP: R²_cv = 0.99, RMSEP = 0.54; LAB in MAP: R²_cv = 0.75, RMSEP = 0.60). The results of this study demonstrate that Raman spectroscopy may have potential for the rapid determination of meat spoilage.

Effect of superchilled storage on shelf life and quality characteristics of M. longissimus lumborum from Chinese Yellow cattle

The effect of superchilled storage (SC, -4 °C) on shelf life and quality characteristics of M. longissimus lumborum from Chinese Yellow cattle compared with traditional chilling (TC, 2 °C) and frozen storage (-18 °C) was studied. The shelf life of beef steaks held at -4 °C extended to 12 weeks based on the total volatile basic nitrogen (TVB-N) value, which was 2.4 times longer than steaks stored at 2 °C. As the storage time increased, SC samples showed a lower increase of the total aerobic count (TAC), pH and thiobarbituric acid reactive substances (TBARS) values compared to TC samples. Further, L^⁎ and a^⁎ values of SC samples changed more slowly than that of TC samples. Beef steaks held frozen had a longer shelf life than SC steaks, however, the shear force of frozen steaks remained above 55 N throughout the storage time indicative of toughness. Consequently, SC offers an effective approach for maintaining better shelf life and quality of beef steaks.

Effect of different short-term high ambient temperature on chicken meat quality and ultra-structure

Objective

This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure.

Methods

Chickens were randomly divided into 7 groups to receive different HS treatments: i) 36°C for 1 h, ii) 36°C for 2 h, iii) 38°C for 1 h, iv) 38°C for 2 h, v) 40°C for 1 h, vi) 40°C for 2 h, and vii) un-stressed control group (25°C). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed.

Results

HS temperatures had significant effects on breast meat temperature, lightness (L*), redness (a*), cooking loss and protein solubility (p<0.05). The HS at 36°C increased L*_{24 h} value (p<0.01) and increased the cooking loss (p<0.05), but decreased a*_{24 h} value (p<0.05). However, as the temperature increased to 38°C and 40°C, all the values of L*_{24 h}, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p> 0.05). Only the ultimate pH_{24 h} at 40°C decreased compared to the control group (p<0.01). The pH in 36°C group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group 40°C was much better than those in 36°C with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection.

Conclusion

HS at higher temperature (above 38°C) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from 36°C. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

Proteomic analysis to investigate color changes of chilled beef longissimus steaks held under carbon monoxide and high oxygen packaging

This study investigated the proteome basis for color stability variations in beef steaks packaged under two modified atmosphere packaging (MAP) methods: HiOx-MAP (80% O₂/20% CO₂) and CO-MAP (0.4% CO/30% CO₂/69.6% N₂) during 15 days of storage. The color stability, pH, and sarcoplasmic proteome analysis of steaks were evaluated on days 0, 5, 10 and 15 of storage. Proteomic results revealed that the differential expression of the sarcoplasmic proteome during storage contributed to the variations in meat color stability between the two MAP methods. Compared with HiOx-MAP steaks, some glycolytic and energy metabolic enzymes important in NADH regeneration and antioxidant processes, antioxidant peroxiredoxins (thioredoxin-dependent peroxide reductase, peroxiredoxin-2, peroxiredoxin-6) and protein DJ-1 were more abundant in CO-MAP steaks. The over-expression of these proteins could induce CO-MAP steaks to maintain high levels of metmyoglobin reducing activity and oxygen consumption rate, resulting in CO-MAP steaks exhibiting better color stability than HiOx-MAP steaks during storage.

Microbial community dynamics analysis by high-throughput sequencing in chilled beef longissimus steaks packaged under modified atmospheres

The microbial community dynamics were investigated in this study to understand the spoilage of beef steaks packaged in both modified atmosphere packaging (MAP): 80%O₂-MAP (80% O₂/20% CO₂) and CO-MAP (0.4% CO/30% CO₂/69.6% N₂). Steaks were stored at 2 °C for 20 days. Meat physicochemical changes and microbial counts were monitored, and the microbial communities were evaluated by high throughput-sequencing. The microbial diversity for both MAP decreased over time and it was more complex in CO-MAP steaks than that in 80%O₂-MAP steaks. B. thermosphacta and Pseudomonas spp. were dominant bacteria of 80%O₂-MAP steaks but Pseudomonas spp. gradually outcompeted the former from day 10. Leuconostoc, Lactobacillus, Lactococcus, Vagococcus and Serratia dominated alternately in CO-MAP steaks during storage, and Lactococcus eventually became the most common bacteria. Predicted metagenomes indicated a higher microbial amino acid and lipid metabolism level in 80%O₂-MAP compared with CO-MAP at day 20, which may contribute to the dramatic physicochemical deterioration of 80%O₂-MAP steaks.

Carbon Monoxide in Meat and Fish Packaging: Advantages and Limits

Due to increased demands for greater expectation in relation to quality, convenience, safety and extended shelf-life, combined with growing demand from retailers for cost-effective extensions of fresh muscle foods’ shelf-life, the food packaging industry quickly developed to meet these expectations. During the last few decades, modified atmosphere packaging (MAP) of foods has been a promising area of research, but much remains to be known regarding the use of unconventional gases such carbon monoxide (CO). The use of CO for meat and seafood packaging is not allowed in most countries due to the potential toxic effect, and its use is controversial in some countries. The commercial application of CO in food packaging was not then considered feasible because of possible environmental hazards for workers. CO has previously been reported to mask muscle foods’ spoilage, and this was the primary concern raised for the prohibition, as this may mislead consumers. This review was undertaken to present the most comprehensive and current overview of the widely-available, scattered information about the use of CO in the preservation of muscle foods. The advantages of CO and its industrial limits are presented and discussed. The most recent literature on the consumer safety issues related to the use of CO and consumer acceptance of CO especially in meat packaging systems were also discussed. Recommendations and future prospects were addressed for food industries, consumers and regulators on what would be a “best practice” in the use of CO in food packaging. All this promotes high ethical standards in commercial communications by means of effective regulation, for the benefit of consumers and businesses in the world, and this implies that industrialized countries and members of their regulatory agencies must develop a coherent and robust systems of regulation and control that can respond effectively to new challenges.

The combined effects of superchilling and packaging on the shelf life of lamb

The aim of this study was to evaluate the effect of superchilled storage at -1° on the shelf life of lamb slices packaged in an O₂ enriched (40% O₂/30% CO₂/30% Ar) or in an anaerobic atmosphere (vacuum skin packaging). Physicochemical, microbial and sensory analyses were performed. The effect of superchilled storage on lamb stability differed depending on the atmosphere surrounding the product. Superchilled (-1°C) slices of lamb showed lower microbial counts than those refrigerated at 4°C in both packaging conditions. Moreover, meat stored at -1°C had a higher colour stability under vacuum. Superchilled storage combined with an O₂ enriched atmosphere increased the rate of lipid oxidation, which reduced the shelf life reached by refrigerating at 4°C. Vacuum skin packaging strongly inhibited lipid oxidation independently of storage temperature. Thus, superchilled storage extended the shelf life at least twice compared to storage at 4°C under anaerobic conditions while it was disadvantageous when an O₂ enriched atmosphere was used.

Effect of reduction of oxygen concentration in modified atmosphere packaging on bovine M. longissimus lumborum and M. gluteus medius quality traits

This paper reports the impact of modified atmosphere gas compositions with different concentrations of CO₂/O₂/N₂ on physicochemical traits of beef steaks from M. longissimus lumborum and M. gluteus medius. Samples were stored at +2°C for 12days. The gas compositions were as follows: (i) 50% O₂/20% CO₂/30% N₂ (MAP1), (ii) 65% O₂/20% CO₂/15% N₂ (MAP2) and (iii) 80% O₂/20% CO₂ (MAP3). Packaging atmosphere did not affect CIEL*a*b* colour coordinates, which were affected by storage time and by muscle type. Lipid oxidation in M. longissimus lumborum was affected by packaging treatment; however packaging treatment×storage time interaction affected lipid oxidation significantly. Results showed that reduction of oxygen from the commercially used 80% to 50% does not negatively impact colour properties and state of myoglobin, but significantly lowers oxidative deterioration of M. longissimus lumborum at the end of storage.

Cross-linked alginate/chitosan polyelectrolytes as carrier of active compound and beef color stabilizer

The aim of this work was to develop polyelectrolyte material suitable for active beef steaks coatings, by complexation of chitosan (CH) and sodium alginate (ALG) in a broad range of alginate/chitosan ratios (R). The rheological analysis confirmed significant effect of polymers ratios on the physical properties of sodium alginate-chitosan (ACH) hydrosols. The shear thinning non-Newtonian nature, thixotropic behavior and gel-like structure of solutions were displayed. Obtained complexes possess DPPH radical scavenging activity corresponding to 5.33, 17.06 and 41.41μMTrolox/ml for 0ppm, 500ppm and 1000pmm of sodium erythorbate dose, respectively. Application of ACH hydrosols enriched with 1000ppm of sodium erythorbate enhanced redness and color stability of beef steaks during storage (∆E after 2-weeks of storage=1.44±0.08) compared to uncovered beef (∆E after 2-weeks of storage=3.53±0.13). The limited solubility in range of 0%-54.56% as well as favorable wetting properties (contact angle between 45°-66°) of polyelectrolyte ACH films were obtained.