Industrial packaging developments for the global meat market

Sex Does Not Affect the Colour, Shear Stress, and Lipid Oxidation of Pork Meat, but Feed-Added Plant-Derived Extracts, Storage Time and Packaging Type Do

Essential plant oils added to products, packaging or animal feed are used as a method of preserving food quality because they extend the shelf-life of meat due their antioxidant and/or antimicrobial capacity. This action can be achieved with the correct packaging that preserves the meat's quality and safety. This study investigates the effects of plant-derived extracts (PDE) on the meat quality and shelf-life of pork packaged in vacuum or modified atmosphere packaging (MAP). Thirty-six barrows and thirty-six gilts were allocated into three experimental groups: the control, garlic extract (1 kg/ton of feed) and oregano-rosemary oil (2 kg/ton of feed) with the same base-diet. Two packaging were used: vacuum and a commercial MAP (70% O₂, 30% CO₂). The meat fat content, pH, colour, TBARS values and Warner-Bratzler shear stress were investigated. The sex of the animals did not affect any of the studied variables, whereas PDE affected some of the colour variables and the shear stress; both the packaging type and the storage time affected the colour variables, lipid oxidation and shear stress. Vacuum-packed meat was more stable in terms of colour, lipid oxidation and shear stress than MAP-packed meat.

Investigation into the Physicochemical and Textural Properties of an Iron-Rich 3D-Printed Hybrid Food

In the context of dietary transition, blending animal-source protein with plant-source protein offers a promising way to exploit their nutritional complementarity. This study investigates the feasibility of formulating an iron-rich hybrid food product blending plant-source and animal-source protein ingredients for iron-deficient populations. Using a commercial 3D-food printer, two different-shaped products composed mainly of pork and chicken liver and red lentils were designed. After baking at 180 °C with 70% steam, the 3D-printed products were packed under two different modified atmospheres (MAP): O₂-MAP (70% oxygen + 30% carbon dioxide) and N₂-MAP (70% nitrogen + 30% carbon dioxide) and stored at 4 °C. pH, water content, a_w, lipid oxidation, heme iron and non-heme iron contents and textural properties were measured after 0, 7, 14 and 21 days in storage. After 21 days in storage, the 3D-printed hybrid products had an iron content of around 13 mg/100 g, regardless of the product form and packaging method. However, O₂-MAP products showed significant (p < 0.05) time-course changes from day 0 to day 7, i.e., an increase in lipid oxidation, a decrease in heme iron content and an increase in product hardness, gumminess and chewiness. This work opens prospects for developing hybrid food products that upvalue animal by-products.

The Effect of Kosher Determinants of Beef on Its Color, Texture Profile and Sensory Evaluation

Traditional ritual slaughter is an underlying practice in religious Jewish communities and it translates into eating in accordance with core beliefs. This paper aims to comprehensively analyze factors determining the kosher status of beef (sex, slaughter method, and muscle type) and assess their impact on selected quality properties, such as color or texture profile. Sensory evaluation was also performed. The muscles were obtained from 80 carcasses (50% of heifers and 50% of young bulls). The experimental results indicate that each studied kosherness determinant influenced beef quality properties. The process of koshering caused the darkening of beef and lowered the share of color parameters red (a*) and yellow (b*). The influence of the type of slaughter on the values of adhesiveness, gumminess, and chewiness of beef was confirmed; higher values were mostly obtained in the muscles of cattle from kosher slaughter. As to sensory evaluation, the study showed that in the case of muscle type, the sex and slaughter method positively influenced only some of the properties.

Starch-based composite foam for chicken meat packaging

The development of compostable packages that maintain fresh meat quality, is an important achievement for the poultry industry. The objective of this study was to evaluate the feasibility of using a starch-based composite foam (SCF) in the packaging of fresh chicken meat during refrigerated storage. SCF was prepared using extrusion process. Nisin (2%) was added as antimicrobial agent (SCFN). Commercial expanded polystyrene (EPS) was used as control. Physical characterization, antimicrobial analysis and storage of fresh chicken meat were carried out. No differences were observed in SEM images between SFC and SCFN samples. Water uptake of SCF were higher than SCFN (p < 0.05). SCFN exhibited higher Young´s modulus and flexural strength (p < 0.05), and antimicrobial effect against foodborne pathogens. During the storage of chicken meat, the starch-based composite foam showed a higher capacity to retain liquid than EPS. The color of chicken meat had slight variations at day 4 compared with the raw meat. Nisin did not retard lipid oxidation of chicken meat, however, the aerobic plate count was lower. Therefore, the starch-based composite foam is suitable for fresh meat storage, being improved with the incorporation of nisin as antimicrobial agent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05538-6.

Transcriptomic analysis of the response of Photobacterium phosphoreum and Photobacterium carnosum to co-contaminants on chicken meat

This study investigated the impact of Brochothrix (B.) thermosphacta and Pseudomonas (Ps.) fragi on the transcriptomes of Photobacterium (P.) phosphoreum and P. carnosum on chicken meat under modified atmosphere (MA) and air atmosphere (AA). P. phosphoreum TMW2.2103 responded to MA with a reduced transcript number related to cell division and an enhanced number related to oxidative stress. Concomitantly, the analysis revealed upregulation of fermentation and downregulation of respiration. It predicts enhanced substrate competition in presence of co-contaminants/MA. In contrast, the strain upregulated the respiration in AA, supposably due to improved substrate accessibility in this situation. For P. carnosum TMW2.2149 the respiration was downregulated, and the pyruvate metabolism upregulated under MA. MA/co-contaminant resulted in multiple upregulated metabolic routes. Conversely, AA/co-contaminant resulted only in minor regulations, showing inability to cope with fast growing competitors. Observations reveal different strategies of photobacteria to react to co-contaminants on meat.

Polar lipid characterization and description of Chryseobacterium capnotolerans sp. nov., isolated from high CO2-containing atmosphere and emended descriptions of the genus Chryseobacterium, and the species C. balustinum, C. daecheongense, C. formosense, C. gleum, C. indologenes, C. joostei, C. scophthalmum and C. ureilyticum

Modified atmosphere (MA) packaging plays an important role in improving food quality and safety. By using different gas mixtures and packaging materials the shelf life of fresh produce can significantly be increased. A Gram-negative-staining, rod-shaped, orange-pigmented strain DH-B6T, has been isolated from MA packed raw pork sausage (20% CO2, 80% O2). The strain produced biofilms and showed growth at high CO2 levels of up to 40%. Complete 16S rRNA gene and whole-genome sequences revealed that strain DH-B6T belongs to the genus Chryseobacterium , being closely related to strain Chryseobacterium indologenes DSM 16777T (98.4%), followed by Chryseobacterium gleum NCTC11432T (98.3%) and Chryseobacterium lactis KC1864T (98.2%). Average nucleotide identity value between DH-B6T and C. indologenes DSM 16777T was 81.1% and digital DNA–DNA hybridisation was 24.9%, respectively. The DNA G+C content was 35.51 mol%. Chemotaxonomical analysis revealed the presence of the rare glycine lipid cytolipin, the serine-glycine lipid flavolipin and the sulfonolipid sulfobacin A, as well as phosphatidylethanolamine, monohexosyldiacylglycerol and ornithine lipid, including the hydroxylated forms. Major fatty acids were iC15 : 0 (50.7%) and iC17 : 1 cis 9 (28.7%), followed by iC15 : 0 2-OH (7.0%) and iC17 : 0 3-OH (6.2%). The isolated strain contained MK-6 as the only respiratory quinone and flexirubin-like pigments were detected as the major pigments. Based on the phenotypic, chemotaxonomic and phylogenetic characteristics, the strain DH-B6T (=DSM 110542T=LMG 31915T) represents a novel species of the genus Chryseobacterium , for which the name Chryseobacterium capnotolerans sp. nov. is proposed. Emended descriptions of the genus Chryseobacterium and eight species of this genus based on polar lipid characterisation are also proposed.

Review: On-farm and processing factors affecting bovine carcass and meat quality

This paper reviews the current state of knowledge on beef carcass and meat quality, with particular emphasis on on-farm and processing factors associated with its high and inconsistent variability. The diversity of livestock systems comes from the diversity of breeds (dairy or beef), ages and gender (bulls, steers, heifers, cull cows) used to produce either mainly beef or beef and milk. In addition, there are factors linked to farming practices (including diet, especially grazing) which significantly influence the sensory, nutritional, technological and extrinsic (such as image) quality attributes of meat. These can become factors of positive differentiation when controlled by the application and certification of technical specifications. Finally, preslaughter (such as stress), slaughter (such as the chilling and hanging method of carcasses) and postslaughter (such as ageing, packaging and cooking) conditions have a strong influence on the microbiological, sensory, technological and image quality attributes of beef. In this review, potential synergisms or antagonisms between the different quality attributes are highlighted. For example, finishing cattle on grass, compared to indoor fattening on a high concentrate diet, has the advantage of producing leaner meat with a higher proportion of omega-3 fatty acids while exhibiting superior oxidative stability, but with the consequence of a darker meat colour and lower productivity, as well as higher seasonality and land surface requirements. Moreover, the control of on-farm factors is often guided by productivity (growth rate, feed conversion ratio) and carcass quality attributes (weight, conformation and fatness). Genetic selection has often been oriented in this direction, without taking other quality attributes into account. Finally, the interactions between all these factors (and especially between on-farm and slaughter or processing factors) are not considered in the quality grading schemes in European countries. This means that positive efforts at farm level may be mitigated or even eliminated by poor slaughtering or processing conditions. All these considerations explain why between-animal variability in quality can be high, even when animals come from the same farming system. The ability to predict the sensory and nutritional properties of meat according to production factors has become a major objective of the supply chain.

A study on shelf life of prepackaged retail-ready Korean native black pork belly and shoulder butt slices during refrigerated display

OBJECTIVE

In most retail centers, primal pork cuts for sale are usually prepared into retail-ready slices and overwrapped with air-permeable plastic film. Also, meat of Korean native black pig (KNP) is reputed for its superior quality, however, its shelf life during retail display has not been studied. Thus, the objective of this study was to evaluate shelf life of prepackaged retail-ready KNP belly and shoulder butt slices during refrigerated display.

METHODS

Bellies and shoulder butt obtained at 24 h post-mortem from finishing KNP were used. Each belly or shoulder butt was manually cut into 1.5 cm-thick slices. The slices in each cut type were randomly taken and placed on white foam tray (2 slices/tray) overwrapped with polyvinyl chloride film. The retail-ready packages were then placed in a retail display cabinet at 4°C. Shelf life and sensory quality of the samples were evaluated on day 1, 3, 6, 9, 12, and 15 of display.

RESULTS

The shoulder butt reached the upper limit (20 mg/100 g) of volatile basic nitrogen for fresh meat after 9 days while, the belly remained within this limit throughout the display time (15 days). Both the cuts reached a thiobarbituric acid reactive substances level of above 0.5 mg malondialdehyde/kg after 9 days. The a* (redness) values remained unchanged during first 9 days in both cuts (p>0.05). After 9 days, off-flavor was not found in either cut, but higher off-flavor intensity was found in shoulder butt after 12 days. The shoulder butt was unacceptable for overall eating quality after 12 days while, belly still was acceptable after 12 days.

CONCLUSION

The belly showed a longer shelf life compared to the shoulder butt, and a shelf life of 9 and 12 days is recommended for the prepackaged retail-ready KNP shoulder butt and belly slices, respectively.

Coating with chitosan containing lauric acid (C12:0) significantly extends the shelf-life of aerobically - Packaged beef steaks during refrigerated storage

The present research aimed at investigating the application potential of a newly developed chitosan/lauric acid edible coating in preservation of fresh beef under refrigerated storage and aerobic packaging conditions. The 2-cm thick steaks were coated with 2% chitosan (CHI), 1 mM lauric acid in 2% chitosan (CHI/1 mM LA) or 3 mM lauric acid in 2% chitosan (CHI/3 mM LA), and over-wrapped in permeable film. Non-coated samples were used as a control (CON). Results showed that the inhibitory effects against the spoilage bacteria growth, volatile basic nitrogen formation and lipid oxidation of the chitosan coating was increased with the incorporation of lauric acid (p˂0.05). More importantly, the incorporation of lauric acid almost completely protected the meat samples against the discoloration after 21 days of storage. The coating with chitosan or chitosan/lauric acid completely inhibited the formation of bacterial spoilage-derived volatile compounds. Overall, coating of chitosan containing 1-3 mM lauric acid could be a promising method in preservation of fresh beef to improve safety and quality under aerobic packaging condition.

Sphingomonas aliaeris sp. nov., a new species isolated from pork steak packed under modified atmosphere

Species belonging to the genus Sphingomonas have been isolated from environments such as soil, water and plant tissues. Many strains are known for their capability of degrading aromatic molecules and producing extracellular polymers. A Gram-stain-negative, strictly aerobic, motile, red-pigmented, oxidase-negative, catalase-positive, rod-shaped strain, designated DH-S5^T, has been isolated from pork steak packed under CO₂-enriched modified atmosphere. Cell diameters were 1.5×0.9 µm. Growth optima were at 30 °C and at pH 6.0. Phylogenetic analyses based on both complete 16S rRNA gene sequence and whole-genome sequence data revealed that strain DH-S5^T belongs to the genus Sphingomonas, being closely related to Sphingomonas alpina DSM 22537^T (97.4 % gene sequence similarity), followed by Sphingomonas qilianensis X1^T (97.4 %) and Sphingomonas hylomeconis GZJT-2^T (97.3 %). The DNA G+C content was 64.4 mol%. The digital DNA-DNA hybridization value between the isolate strain and S. alpina DSM 22537^T was 21.0 % with an average nucleotide identity value of 77.03 %. Strain DH-S5^T contained Q-10 as the ubiquinone and major fatty acids were C_18 : 1 cis 11 (39.3 %) and C_16 : 1 cis 9 (12.5 %), as well as C_16 : 0 (12.1 %) and C_14 : 0 2-OH (11.4 %). As for polar lipids, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, dimethylphosphatidylethanolamine and sphingoglycolipid could be detected, alongside traces of monomethylphosphatidylethanolamine. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain DH-S5^T (=DSM 110829^T=LMG 31606^T) is classified as a representative of the genus Sphingomonas, for which the name Sphingomonas aliaeris sp. nov. is proposed.

Influence of the packaging atmosphere and presence of co-contaminants on the growth of photobacteria on chicken meat

Fresh meat is commonly packaged in modified atmosphere to decelerate spoilage processes. The applied gas mixture affects the growth of spoilage organisms and selectively shapes the spoilage community. In this study, we investigated the impact of O₂ and CO₂ on the growth of Photobacterium (P.) phosphoreum and P. carnosum strains in situ on chicken meat by packaging under different modified atmospheres (air, 70% O₂/30% CO₂, 70% N₂/30% CO₂, 100% N₂). Combination of 70% O₂ and 30% CO₂ resulted in significant growth reduction of the analyzed strains, suggesting inhibitory effects of both gases in combination. In contrast, 30% CO₂ alone had only a minor effect and photobacteria are supposed to have a growth advantage over other meat spoilers in this atmosphere. Additionally, single growth of the strains in the different atmospheres was compared when challenged with the presence of Pseudomonas (Ps.) fragi or Brochothrix (B.) thermosphacta as prominent co-contaminants in different ratios (10:1, 1:1, 1:10). Presence of co-contaminants resulted in increased cell numbers of P. carnosum TMW2.2149 but reduced or unchanged cell numbers of P. phosphoreum TMW2.2103 in most packaging atmospheres. The initial ratio of photobacteria and co-contaminants defined the relative abundance during storage but did not change the type of the interaction. Our results suggest either a commensalistic (P. carnosum) or competitive interaction (P. phosphoreum) of photobacteria and co-contaminants on modified atmosphere packaged chicken, respectively. Furthermore, in a mix comprising seven prominent spoilers, strains of both Photobacterium species prevailed as a constant part of the spoilage microbiome during 7 days of refrigerated storage on chicken meat packaged under O₂/CO₂ atmosphere.

Monitoring Thermal and Non-Thermal Treatments during Processing of Muscle Foods: A Comprehensive Review of Recent Technological Advances

Muscle food products play a vital role in human nutrition due to their sensory quality and high nutritional value. One well-known challenge of such products is the high perishability and limited shelf life unless suitable preservation or processing techniques are applied. Thermal processing is one of the well-established treatments that has been most commonly used in order to prepare food and ensure its safety. However, the application of inappropriate or severe thermal treatments may lead to undesirable changes in the sensory and nutritional quality of heat-processed products, and especially so for foods that are sensitive to thermal treatments, such as fish and meat and their products. In recent years, novel thermal treatments (e.g., ohmic heating, microwave) and non-thermal processing (e.g., high pressure, cold plasma) have emerged and proved to cause less damage to the quality of treated products than do conventional techniques. Several traditional assessment approaches have been extensively applied in order to evaluate and monitor changes in quality resulting from the use of thermal and non-thermal processing methods. Recent advances, nonetheless, have shown tremendous potential of various emerging analytical methods. Among these, spectroscopic techniques have received considerable attention due to many favorable features compared to conventional analysis methods. This review paper will provide an updated overview of both processing (thermal and non-thermal) and analytical techniques (traditional methods and spectroscopic ones). The opportunities and limitations will be discussed and possible directions for future research studies and applications will be suggested.

Plant-Derived Extracts Feed-Addition and Packaging Type Influence Consumer Sensory Perception of Pork

This paper investigates whether the combination of the addition of extracts derived from plants (plants derived extracts, PDE) to pork feedstuff and the meat conservation conditions (packaging and time exposure) affect consumers' perception of pork quality, studied by means of visual appraisal, purchase intention and a home test. The three PDE groups were control, garlic extract and blended oil composed by carvacrol, timol, cynamic aldehide and eugenol extracts. Meat was packed in film, vacuum or modified atmosphere (MAP) packaging. A visual test was designed comprising a four-day storage step followed by a four-day exposure step in a refrigerated island display case. All studied effects influenced visual appraisal scores, being time exposure and packaging effects more noticeable than PDE or pig-sex effects. Meat from MAP scored higher than the rest. Scores decreased as exposure time increased, but this evolution was less perceptible in vacuum packaging and was faster for meat from the garlic group. Only gender affected the visual appraisal scores, with women scoring higher than men. Neither PDE addition nor pig sex affected to purchase intention whereas both exposure time and packaging type did. A maximum of 2 days of exposure would be recommended. In the home-test, meat from male pigs obtained higher scores than meat from female pigs, and none of the consumer-related effects influenced the given scores.

Microbial changes under packaging conditions during transport and comparison between sampling methods of beef

This study was performed to evaluate the microbial and temperature changes of boxed beef during transport and distribution under vacuum and modified atmosphere packaging (MAP), and to compare between excision and swab sampling for 15 days. The top round and striploin (quality grade 1) from Hanwoo steers at 2 days post-slaughter were obtained from a local meat processing plants and chilled at 4 ± 2°C in a cold room. The boxes were transported under refrigeration (4 ± 2°C) to the laboratory within half an hour. Vacuum and MAP packs were subsequently taken out from cool boxes, and microbiological examinations were carried out at 0, 6, 12, and 24 h of storage time. MAP was more effective than vacuum packaging for the inhibition of total aerobic, lactic acid bacteria and Pseudomonas (p < 0.05). Microbial loads of swab methods were slightly lower than those of excision ones (p < 0.05). The results of this study could be utilized by meat consumers in future studies as well as by manufacturers to determine the ideal storage conditions for cool boxed meat, thus ensuring reduced economic losses due to spoilage.

Changes in the colour and sensory properties of beef frozen after seven days of ageing in a modified atmosphere

The aim of the study was to evaluate the colour, sensory properties and shear force values of meat from ten young bulls produced by crossing Polish Black-and-White Holstein-Friesian cows with Belgian White Blue bulls. The quality of the longissimus lumborum (LL) muscle was determined after seven-day ageing under various modified atmosphere (MA) conditions (vacuum – group B; 40% CO2 + 60% N2 – group C; 30% CO2 + 70% Ar – group D) followed by freezing and frozen storage. The process of seven- day ageing in MA composed of 40% CO2 + 60% N2 significantly increased the colour lightness of the beef samples. Eight-month frozen storage increased colour lightness in the meat samples aged in MA composed of 30% CO2 + 70% Ar. Meat samples aged under various MA conditions had a higher contribution of redness (a*) and yellowness (b*) than non-aged beef. Meat samples frozen after ageing in MA containing Ar had less redness than the samples from other groups. After frozen storage, meat samples from all groups had less redness and yellowness. Ageing and frozen storage had no significant effect on the juiciness of the beef. The beef aged in vacuum conditions was the most tender, both before and after frozen storage. Ageing had no significant influence on the shear force of meat samples evaluated before freezing. Meat samples aged in MA composed of 30% CO2 + 70% Ar evaluated after frozen storage had lower average shear force values than beef that had not been aged prior to freezing.

Effect of Various Packaging Methods on Small-Scale Hanwoo (Korean Native Cattle) during Refrigerated Storage

The objective of this study was to investigate comparison of physicochemical, microbiological, and sensory characteristics of Hanwoo eye of round by various packaging methods [wrapped packaging (WP), modified atmosphere packaging (MAP), vacuum packaging (VP) with three different vacuum films, and vacuum skin packaging (VSP)] at a small scale. Packaged Hanwoo beef samples were stored in refrigerated conditions (4±1°C) for 28 days. Packaged beef was sampled on days 0, 7, 14, 21, and 28. Physicochemical [pH, surface color, thiobarbituric acid reactive substances (TBARS), and volatile basic nitrogen (VBN) values], microbiological, and sensory analysis of packaged beef samples were performed. VP and VSP samples showed low TBARS and VBN values, and pH and surface color did not change substantially during the 28-day period. For VSP, total viable bacteria, psychrotrophic bacteria, lactic acid bacteria, and coliform counts were lower than those for other packaging systems. Salmonella spp. and Escherichia coli O157:H7 were not detected in any packaged beef samples. A sensory analysis showed that the scores for appearance, flavor, color, and overall acceptability did not change significantly until day 7. In total, VSP was effective with respect to significantly higher a* values, physicochemical stability, and microbial safety in Hanwoo packaging (p<0.05).

Development of antioxidant food packaging materials containing eugenol for extending display life of fresh beef

In this study, clove essential oil (CL) or eugenol (EU) containing cellulose acetate (CA) or acrylic component/hydrophobically modified starch (AC/S) coatings on corona treated oriented polypropylene film (OPP) were designed and investigated for their possible applications as antioxidant packaging materials for fresh meat. The antioxidant properties of the coatings were investigated by Vapour Phase-DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The CA coatings containing CL or EU showed 43-92% and 43-94% inhibition against DPPH free radicals through the vapour phase, respectively, whereas AC/S/CL and AC/S/EU coatings resulted in DPPH inhibition of 21-65% and 25-84%, respectively. AC/S/EU and CA/EU coatings on OPP containing from 0.32 ± 0.03 to 6.40 ± 0.14 g/m² of EU were used to prepare packaging for fresh beef (Longissimus thoracis). After 14 days, the lipid oxidation in beef steaks kept in control and antioxidant packages was 3.33 and 1.00-1.22 mg of malondialdehyde per kilogram of meat, respectively. Moreover, red colour of beef in antioxidant packages was retained.

Synthesis and characterization of novel bactericidal Cu/HPMC BNCs using chemical reduction method for food packaging

In this research copper nanoparticles (Cu NPs) were incorporated in the biodegradable hydroxypropyl methylcellulose (HPMC) matrix using the simple and low cost chemical reduction method for application as food packaging material. The properties of Cu/HPMC bionanocomposites (BNCs) were studied as a function of the CuSO4 concentration. Surface morphology of the film was investigated by scanning electron microscopy. Mechanical analysis and water vapor barrier properties of HPMC/Cu nanocomposites were analyzed. It was observed that mechanical and water vapor barrier properties of the films were improved by the concentration of CuSO4. The antibacterial activity of HPMC/Cu thin films were evaluated based on the diameter of inhibition zone in a disk diffusion test against Gram positive bacteria, ie, Streptococus A., S. epidermidis, S.aureus , B.cereus and Gram negative bacteria, ie, E. coli, E. faecalis, Salmonella, P. aeruginosa using Mueller Hinton agar at different concentration of CuSO4. The results revealed a greater bactericidal effectiveness for nanocomposite films containing 5 % of CuSO4. Packages prepared from HPMC/Cu nanocomposite films were used for meat packaging. The films were filled with meat and then stored at 4 °C. Microbial stability of the meat was evaluated after 3, 7, 10 and 15 days of storage. The results showed that microbial growth rate significantly reduced as a result of using this nanocomposite packaging material.

High throughput headspace GC-MS quantitative method to measure the amount of carbon monoxide in treated tuna fish

A robust and dependable headspace HS-GC-MS method has been developed for the determination of carbon monoxide (CO) treated tuna fish. The performance of the method has been evaluated by analyzing spiked and blank samples. The proposed method uses a programmed temperature vaporizing (PTV) injector to implement the HS injection and overcome the negative effects on the column of water contained in the sample. The level of CO could be easily detected in the treated samples, its amount differing markedly from that detected in the untreated samples. Proper oven temperature programming prevented any deterioration of chromatographic performance caused by the accumulation of water, carbon dioxide and other low molecular weight hydrocarbons in the column during serial analyses. The introduction of PTV injection and the restoring of GC column, by oven temperature programming, were crucial for obtaining the required robustness. This procedure assures the run-to-run repeatability necessary for high throughput applications. The method affords linear calibration curves ranging from 50 to 2500 ng/g of CO content in tuna sample.

Preservation technologies for fresh meat - a review

Fresh meat is a highly perishable product due to its biological composition. Many interrelated factors influence the shelf life and freshness of meat such as holding temperature, atmospheric oxygen (O(2)), endogenous enzymes, moisture, light and most importantly, micro-organisms. With the increased demand for high quality, convenience, safety, fresh appearance and an extended shelf life in fresh meat products, alternative non-thermal preservation technologies such as high hydrostatic pressure, superchilling, natural biopreservatives and active packaging have been proposed and investigated. Whilst some of these technologies are efficient at inactivating the micro-organisms most commonly related to food-borne diseases, they are not effective against spores. To increase their efficacy against vegetative cells, a combination of several preservation technologies under the so-called hurdle concept has also been investigated. The objective of this review is to describe current methods and developing technologies for preserving fresh meat. The benefits of some new technologies and their industrial limitations is presented and discussed.