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1.
The objective of this study was to evaluate the effects of different modified atmosphere packaging (MAP) systems applied during ageing and retail display on the quality of beef longissimus dorsi. The quality of the steaks was measured by sensory analysis, thiobarbituric acid‐reactive substances (TBARS), myofibrillar fragmentation index (MFI), protein oxidation, weight loss, cooking loss and vitamin E content. The study included 11 different packaging systems investigated in two separate trials, using O2, CO2, N2 gas and vacuum in combination or alone during ageing and retail display. In some systems, loins were sliced into steaks before packaging, and in other systems, loins were vacuum packed and aged for 14–18 days, and thereafter were sliced and repacked in different atmospheres. Systems including high O2 MAP resulted in a large increase in warmed‐over flavour and in TBARS as well as a decrease in juiciness, tenderness and vitamin E content, compared to anaerobic systems. Also, MFI was lower in high O2 MAP steaks, and an increase in protein oxidation was seen, suggesting that the decrease in meat tenderness was due to reduced proteolysis and/or protein oxidation. In addition, the cooked steaks of high O2 MAP looked well done, although the internal temperature was only 62°C, indicating premature browning. Ageing of steaks in N2 did not affect any measured parameter compared to vacuum thermoforming packed muscle. Steaks stored in vacuum skin pack for 20 days were less tender than steaks stored in 100% N2 for 18 days followed by 2 days in atmospheric air. In conclusion, packaging in high O2 concentrations compromises several aspects of meat quality. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

2.
Beef steaks from Gluteus medius, Longissimus dorsi, Psoas major and ground beef from Triceps brachii were packed in master packages containing expanded polystyrene trays overwrapped with polyvinyl chloride film under an anoxic atmosphere containing 0.2% CO, 60.0% CO2 and 39.8% N2 (T1) or 0.2% CO/99.8% CO2 plus oxygen scavengers. After 28 days of storage at 1 and 4°C, the meat quality was evaluated. The visual and instrumental colour of the beef steaks and ground beef were similar to that of fresh meat. Pathogenic bacteria were not detected, and psychrotrophic bacterial counts were lower than 7.5 log CFU/g. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

3.
Steaks from gluteus medius m. (GM) and longissimus dorsi m. (LD) were packaged in atmospheres containing two low levels of CO (0.2 and 0.4%) in combination with 21% O2 or without oxygen. The other components of the modified atmosphere packaging systems were carbon dioxide (30%) and nitrogen (balance). Steaks were evaluated on 0, 7, 14 and 21 days of storage at about 2oC to investigate the effects of the gas mixtures on the microflora, instrumental (CIE L*a*b*) and visual colour and odour. The preservation of colour and odour of GM and LD steaks packaged under low carbon monoxide was best achieved using anoxic mixtures containing 0.2% CO and 30% CO2. Steaks packaged without oxygen retained a desirable colour and practically did not present a visible discoloration or perceptive off‐odour along the entire storage time. Colour stabilization with 0.2% CO and 30% CO2, without O2, following storage up to 21 days at 2°C did not increase microbial risk of products. The increase in CO from 0.2 to 0.4% had a negative effect on the colour of LD steaks which was regarded as ‘artificial’ by some panellists. The higher stability achieved in this study using 0.2% CO may result from increased stability of the colour from Bos indicus × Bos Taurus cross. Discoloration and off‐odour were evident in the GM and LD steaks packaged aerobically after 14 days of storage when the counts of deteriorant bacteria achieved approximately 6.5 to 9.7 log CFU/g. Highest bacteriostatic effect could be obtained if the volume of injected CO2 was sufficient to saturate the meat and keep in balance around the product during storage. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

4.
Changes in biochemical indices, microbial growth, headspace and sensory quality of mussels which had been packaged in two modified atmospheres [Modified atmosphere packaging (MAP) 1: 60% CO2/20% N2/20% O2 and MAP 2: 60% CO2/40% N2] and under vacuum (VP) were studied for 14 days. The results showed better quality retention and greater shelf life of mussels packaged under MAP 1 as compared to MAP 2 and VP samples. Increase in total volatile basic nitrogen followed the order: MAP 1 < MAP 2, VP < air (control) samples while increase in trimethylamine nitrogen followed the order: MAP 1 < air < MAP 2 < VP. The 2‐thiobarbituric acid (TBA) values of MAP 1 and air samples were significantly higher (p < 0.05) than the TBA values of VP and MAP 2 samples. MAP 1 showed a greater (p < 0.05) inhibition effect on total viable count of mussel samples than all other packaging conditions. Based primarily on odour scores, the MAP 1 samples remained acceptable up to ca. 10–11 days, the MAP 2 and VP up to ca. 7–8 days while the air‐packaged samples up to ca. 5–6 days of storage. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

5.
The effects of different modified atmosphere packaging (MAP) on microbial quality, oxidation and colour of meatballs were investigated. Meatballs were prepared in our laboratory and packaged in vacuum or in different gases: combinations of O2 (0, 2, 21%) and CO2 (0, 33, 66, 100%) with N2 as balance gas. Total microbial count, thiobarbituric acid reactive substances and colour were determined during storage at 3°C for 3 weeks. Total microbial count remained unchanged at around 6.3 LogCFU/g in vacuum and 100% CO2 packages after 7 days, and slightly increased afterwards. The microbial count was higher in other packages and increased to 7.6 LogCFU/g after 21 days storage. Oxidation was inhibited by reduced O2 and increased CO2 in the packages. Packages with low O2 maintained colour (a‐values) to a greater extent than the packages with higher O2 levels. MAP containing 1–3%O2 with 33%CO2 inhibited microbial growth, oxidation and colour change in meatballs. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
The impact of different packaging methods [vacuum, modified atmosphere packaging (MAP) (60% CO2 and 40% N2) and MAP + CO2 emitter] on the quality of fresh reindeer meat (M. semimembranosus) stored at 4°C for 21 days was investigated. Colour and odour of the meat, drip loss, pH, microbial content, antioxidant capacity and cooking loss were measured. The MAP + CO2 emitter resulted in prolonged microbial shelf life compared with vacuum and MAP without CO2 emitter as lower level of total viable counts was detected after 13 and 17 days. Samples stored with CO2 emitter also had lower drip loss. Samples stored in vacuum had significant lower L*‐value, higher a*‐value and lower intensity of freshness (odour and colour) compared with those stored in MAP and MAP with CO2 emitter. However, MAP with a gas‐to‐product volume ratio of 1 : 1 seems to be too low in quality preserving. Increased partial pressure by adding a CO2 emitter improved bacterial inhibition compared with vacuum and traditional MAP. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

7.
The focus on sustainability and circular economy is leading to a need for development of new food packaging concepts, including recyclable materials that ideally consist of a single material in a monolayer system. This research was focused on the possibility of replacing complex multilayered material [amorphous polyethylene terephthalate/polyethylene (APET/PE)] with simple recyclable mono material [high-density polyethylene (HDPE)] for packaging of chicken fillets in modified atmosphere packaging (CO2/N2: 60%/40%). Bacterial growth measured as total viable count (TVC), lactic acid bacteria and Enterobacteriaceae, Brochothrix thermosphacta and Escherichia coli for chicken fillets packed in HDPE mono materials was compared with chicken fillets packed in APET/PE. TVC increased during the storage period (24 days) with high level of TVC count (7 log10 CFU/g) recorded at Days 19–20 of storage in both HDPE and APET/PE material. No significant differences were recorded in off-odour between chicken stored in APET/PE compared with HDPE in CO2/N2 atmosphere during the storage period (samples were regarded as acceptable on the 24th day of storage). The drip loss increased in all samples during storage, and no significant differences between samples stored in different materials were recorded. Significant differences in bacterial growth were recorded between samples with different gas volume to product volume (G/P) ratio (Day 17), implying that higher G/P ratio is resulting in lower TVC count. The lowest G/P ratio caused the highest drip loss, whereas addition of CO2 emitter reduced the drip loss to some extent. This research is very encouraging as it provides new insight into the use of monolayer materials as well as the importance of design for recycling in circular economy.  相似文献   

8.
The effectiveness of modified atmosphere packaging (MAP) was evaluated for a combination prepared food (Korean braised green peppers with dry anchovies). From a preliminary storage test of the ready‐to‐eat dish at 10°C, the aerobic bacterial count on the green peppers was selected as a primary quality index. The effect of MAP with different CO2 concentrations on the product quality at 10°C was also studied. MAP with a CO2 concentration of ≥30% extended the lag time and/or reduced the growth rate of bacteria. Finally, the effect of different storage temperatures (5, 10, 15 or 20°C) on the shelf life of the product was investigated. Mathematical modelling of bacterial growth curves under stretch‐wrap air packaging and MAP with 60% CO2/40% N2 showed that MAP increased the hypothetical minimum temperature in the square root model that describes the temperature dependence of the lag time and growth rate. MAP conditions of 60% CO2/40% N2 extended the shelf life at 10°C by 130% (to 18.4 days) relative to that achieved with stretch‐wrap air packaging (7.9 days) based on the time taken to reach the quality limit of an aerobic bacterial count of 105 CFU/g. The relative extension of shelf life achieved with MAP was greater at lower temperatures. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

9.
Freshly slaughtered meat was packed in modified atmosphere packs (MAP) containing 5%, 15%, 25%, 35%, 45% and 55% O2 along with 20% CO2 in each package and stored for 8 days at 4°C. The samples were evaluated on the 8th day in terms of TVBN total volatile base nitrogen (TVBN) value, thiobarbituric acid reactive substances (TBARs) value, colour acceptability score, overall acceptability score and total microbial count. The result indicated better effects for 45% and 55% O2‐containing MAP; however, the TBARs value of 45% O2 atmosphere was significantly lower, without having significant differences in other evaluation criteria, than in the 55% O2 package; hence 45% O2 and 20% CO2 gas mixture were selected as the most appropriate gas composition for fresh pork packaging. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

10.
The effect of different modified atmospheres (100% N2, 100% CO2, 70% N2/30% CO2, 50% N2/50% CO2, and air) on the quality preservation of powdered infant formula was investigated by a storage test at 30°C. Metal can packages of 400 g per unit were stored for 493 days with periodic measurements of package gas composition and product quality attributes, which included peroxide value (POV), pH, titratable acidity, bifidobacteria count, hydroxymethylfurfural content, surface colour, and solubility. In the air package, POV as an oxidative quality index increased highly along with oxygen concentration decrease, reaching a maximum of 58.7 meq/kg lipid at 350 days. Compared with the air package, POV increase of the product was significantly lower, with all the O2‐excluded modified atmosphere packages showing a maximum of 28.5 to 29.3 meq/kg at 350 days. Packages of high CO2 concentration experienced a pH decrease and an acidity increase of the stored product caused by dissolution of CO2. The count of bifidobacteria in the product was maintained higher after 119 days in the package of 100% CO2 than in the other packages. Hydroxymethylfurfural content showed a slight increase after an initial period of slight decrease, with little difference among the package treatments. There were no significant changes in product solubility and surface colour during storage. Considering that the high CO2 atmosphere helps the survival of bifidobacteria and protects the product from oxidation without negative effects on the other quality attributes, it is suggested for use in packaging of powdered infant formula.  相似文献   

11.
An evaluation of the suitability of commercially available biopolymers on the shelf‐life of fresh salmon fillet was done. The comparison included two different types of biomaterials, poly lactic acid (PLA)‐based and starch‐based materials, and two traditional materials, amorphous polyethylene terephthalate/polyethylene (APET/PE) and high‐density polyethylene (HDPE). Fresh salmon fillets were stored at 4°C in modified atmosphere (60% CO2 and 40% N2) for 5, 7, 9 and 14 days. The biomaterials have been briefly evaluated with respect to composition and mechanical properties. The effect of different packaging materials on bacterial growth, off‐odour, pH and colour was investigated. The traditional materials (APET/PE and HDPE trays) offered the best protection regarding the bacterial growth. A relatively high level (log 6 CFU/g) of total viable counts was detected after 9 days and 14 days for fillets stored in biomaterials and traditional materials, respectively. The level of lactic acid bacteria and H2S producing bacteria followed almost the same pattern. Storage in traditional materials resulted in higher intensity of freshness (fresh odour) compared with the samples stored in biomaterials; after 14 days, the salmon stored in starch‐based pouches was regarded as having lower intensity of freshness compared with APET/PE trays and PLA‐based pouches. The opposite result was obtained regarding the colour of the salmon, where the biomaterials resulted in higher intensity of fresh colour compared with the traditional materials although the surface of the salmon at the end of the experiment was dry and unpleasant. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

12.
Modified atmosphere packaging (MAP) storage has become a useful technique for extending the shelf life of fruit and vegetables. However, the success of MAP depends on many factors, including types of fresh products, storage conditions, and the characteristics of the packaging films. To achieve the optimal gas composition in the package headspace and improve the postharvest quality of fresh produce, the packaging film with appropriate barrier properties needs to be selected. This study aimed to predict the film thickness by applying produce respiration rate and package film permeability data measured in given product weight and storage conditions. An available film (eg, 25‐μm‐thick low‐density polyethylene) was used to pack fresh produce, and the respiration rate of fresh produce and in‐package O2 and CO2 concentrations at steady state were measured. Permeability of the film was calculated based on mass balance, and the thickness of the film could be predicted if the recommended target O2 and CO2 concentration was obtained from the literature. To validate the predicted thickness value, an experiment was conducted by packaging fresh table grapes in bags of the predicted thickness. The effect of packaging with different film thicknesses on the quality of the fruit was determined. The results showed good agreement between the predicted and the experimental in‐bag O2 and CO2 concentrations, and the MAP with predicted thickness (90 μm) film was more effective in maintaining postharvest quality of grapes during low‐temperature storage than the thinner films (30 and 60 μm) and the control.  相似文献   

13.
The quality of honey peach fruit stored at 2°C in modified atmosphere packages was studied. Three different thickness low‐density polyethylene (LDPE) films were used as packaging films. Honey peach fruits of ‘chaoyang’ were packaged in LDPE bags 15, 25 and 40µm thick and control (air). The respiration rate, O2 and CO2 concentrations in the packages, flesh colour, total soluble solid (TSS), titratable acidity (TA), flesh firmness (FF) and membrane integrity of the fruits were monitored. Compared to the control, MAP treatments inhibited the climacteric peak, avoided the increase of flesh colour, decreased the development of softness and retarded the reduction of TTS, TA and membrane integrity. Significant differences in the quality of the fruits were found between the three packages and the control (p ≤ 0.05). After 20 days at 2°C within the LDPE25 bags, a steady‐state atmosphere of 5% CO2 + 4% O2 was reached. Honey peaches stored in these bags showed the best quality at the end of the storage. Copyright copy; 2006 John Wiley & Sons, Ltd.  相似文献   

14.
Pita bread has a shelf-life of only a few hours, mainly due to its large surface to volume ratio. Hardening, caused by staling and drying, is the main factor affecting shelf-life. Extension of shelf-life by packaging pita in a high barrier laminate under modified atmosphere (MAP) of 99% CO2 or 73% CO2 with 27% N2 was studied. A shelf-life of 14 days, as determined by microbial spoilage, was obtained for MAP pita bread. Staling, as determined by means of a penetrometer, was delayed in MAP pita. Organoleptic hedonic comparisons of MAP pita, against frozen defrosted pita from the same batch, gave almost identical results. Shelf-life was terminated by the appearance of microorganisms on bread.  相似文献   

15.
The profile of major biogenic amines was investigated in Indian mackerel packed in modified atmosphere for up to 12 days at 5 ± 1°C. Beheaded and gutted Indian mackerel was packed under different carbon dioxide compositions to study the effects on biogenic amines formation. The treatments were control air (C), vacuum packaging (VP), 30% CO2/65% N2/5% O2 (M30C), 60% CO2/35% N2/5% O2 (M60C), 80% CO2/15% N2/5% O2 (M80C) and 100% CO2 (M100C). Each amine responded differently to different CO2 levels. After 12 days of storage, concentrations of histamine were reduced by 6.4%, 8.5%, 70.3%, 78.8% and 90.2% in fish packed under VP, M30C, M60C, M80C and M100C, respectively as compared with control air. Changes in putrescine and cadaverine showed a similar pattern. Gas mix of M30C and VP stimulated the formation of tyramine reaching 203 and 172 ppm, respectively. Higher composition of CO2 had a significant inhibitory effect on tyramine concentration (p < 0.05). There were parallel increases of putrescine and spermidine in C, VP and M30C. No significant effect of CO2 was observed on spermine (p > 0.05). After 9 days of storage, more than 300 ppm of histamine was detected in mackerel packed in VP and M30C; therefore, these atmospheres pose a histamine intoxication risk. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

16.
Seafood is a highly perishable food, which has a relative short shelf‐life. Modified atmosphere packaging (MAP) is a system that offers a way of extending the shelf‐life of seafood products, maintaining quality and inhibiting bacterial growth. The objective of this research was to study and determine the optimal conditions for packaging scallops in a modified atmosphere system, which includes CO2/O2/N2 mixture, headspace:food ratio and storage temperature, utilizing an integrated mathematical model for MAP systems with its respective experimental validation. For validation purposes, two experiments were conducted, using gas mixtures of: (a) 45% CO2/10% O2/45% N2; and (b) 60% CO2/10% O2/30% N2. In addition, two experiments, at 6°C and 20°C, were conducted to obtain the shelf‐life model, utilizing the following gas mixtures: 30% CO2/10% O2/60% N2; 45% CO2/10% O2/45% N2; 60% CO2/10% O2/30% N2; and 75% CO2/10% O2/15% N2. Gas mixtures with CO2 concentrations between 30% and 70% and different headspace:food ratios were tested during simulations. The optimal conditions for scallop storage were a 60% CO2/10% O2/30% N2 gas mixture and a headspace:food ratio of 2:1. With these conditions, a simulated shelf‐life of 21 days was obtained. Optimal conditions consider maximum shelf‐life, an adequate film collapse criterion, and time to reach the pseudo‐equilibrium condition. The predictive mathematical model, coupled with experimental studies for specific products, can be efficiently utilized to evaluate packaging alternatives (size, material and selected thickness) for different temperatures and initial gas concentration scenarios of MAP products. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

17.
The influence of various modified atmosphere packaging (MAP) (21/0.05, 4/8 and 60/20% O2/% CO2) on fresh strawberry qualities [pH, acidity, °Brix, colour ( L, a ) and texture profile analyses] was investigated and compared during storage. Among the gas combinations used, pH of fresh strawberry was 3.281 at 1 day, and increased to 3.561 for air [21/0.05% (O2/CO2)], 3.53 for low (4/8) and 3.538 high (60/20) at 12 days. At the end of the storage, °Brix had evolved from the initial 7.07 to 5.47, 5.65 and 5.62 for 21% O2; 4% O2 and 60% O2, respectively. Storage in 60% O2 or 4% O2 delayed the decrease of °Brix, titratable acidity and increased pH compared with 21% O2. At the end of the storage, the strawberry L values had slightly decreased. Initial values of the firmness were 1067 gf and reduced to 501 gf (21% O2); 613 gf (4% O2) and 575 gf (60% O2) at 12 days storage. Higher O2 resulted in better springiness and chewiness than those treated with 4% O2 and 21% CO2, but did not significantly affect resilience. These results show that the use of various MAP gas compositions, including high oxygen, could be a good alternative to maintain fresh strawberry qualities for at least 12 days. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

18.
The ratio of Coupling Rate Constant: Deamination Rale Constant (k2, k1) for a considerable number of magenta, yellow and cyan developer soluble colour couplers has been determined by competition between deamination and coupling. The determinations were made in a medium approximating to the colour developer using 5-diethylamino-2-aminotoluene as the developing agent. pK measurements showed that all the colour couplers were fully ionised in this medium. The photographic data have been shown to fit the empirical equation, γ = A log t + B where γ = Contrast, t = Time of Development in minutes, A = Activity Constant and B = Inducticn Constant, k2, k1 and A values have been shown to be related by the equations, A=3.55 e–5.05×102(K1/K2) for oxidation by K3Fe(CN)6 A=3.55 e–5.05×102(K1/K2) for oxidation by AgCl.

These equations show that the photographic activity of a colour coupler is related to its rate of coupling with oxidised developer and increases with increase in k2/k1. Further they also show that there is a limiting value for A of 3·55. The results also show a broad indication that log k2/k1, is proportional to the pK of the colour couplers. This indicates that electron releasing substituents would increase the coupling rate and hence the activity of the colour coupler.

Of 21 colour couplers studied approximately one-third did not obey the above equations. Experiments have shown that the anomalies arise from azomethine dye destruction in the film due to attack by (a) Na2SO3, and NH2OH under alkaline conditions and (b) excess pyrazolone colour coupler in the case of magenta colour couplers.  相似文献   

19.
We developed a multi‐functional agar‐based biofilm for fresh produce packaging by modulating its CO2 absorption and water vapour absorption functions. The film was prepared from solutions containing agar as a matrix and a water vapour absorbent, glycerol as a plasticizer, and sodium carbonate (SC) and/or sodium glycinate (SG) as a CO2 absorbent. The optical, mechanical, and CO2 and water vapour absorption properties of SC, SG, and SC/SG films were investigated. Multi‐functional films tended to show poor mechanical properties, with a hard texture and an opaque and yellowish colour. The three films had different CO2 absorption capacities and coefficients, with SC film showing the highest absorption, followed by SC/SG and SG films. The water absorption coefficients were much higher than those of CO2, with the opposite dependence on the absorbent compound. The multi‐functional benefits of the developed film were shown by using the film for modified atmosphere packaging (MAP) of shiitake mushrooms as an insert label. A tailored MAP design for shiitake mushrooms was produced based on mass transfer mathematical models. The package attached with SC film label was capable of generating the desired internal atmosphere and thus showed the best quality preservation in terms of colour, firmness, flavour score, and bacterial growth after 5‐day storage. A tailored MAP system with our multi‐functional film can provide an optimal modified atmosphere for CO2‐sensitive fresh commodities, preserve their quality, and extend their shelf life. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

20.
The main objective of the present work was to determine whether a single agropolymer [wheat gluten (WG)] could fit the modified atmosphere packaging (MAP) requirements of a range of six different fresh produce in key terms of oxygen permeation (PeO2) and CO2/O2 permselectivity (S) values. The required properties for optimal packaging of fresh fruits and vegetables were first evaluated using the Tailorpack MAP modelling software (UMR IATE, Montpellier, France) with packaging dimensions and respiratory and optimal atmosphere data as input parameters. Then, the modelled values obtained were compared with the properties of a range of WG composite films: monolayer self‐supported or multilayer at microscale or nanoscale, cast or thermoplasticised, with different formulations (percentage of plasticisers or nanofillers). The experimental gas transfer properties that could be covered by these materials ranged from 0.05 × 10?10 to 2.00 × 10?10 mol/m2 s Pa for PeO2 and up to 18.0 for S. These ranges are much larger than conventional plastics that exhibit PeO2 from 0.10 × 10?10 to 0.20 × 10?10 mol/m2 s Pa and S up to 4.5. It was demonstrated from a food‐requirements‐driven (Tailorpack modelling) and a multiscale film structuring (WG‐based composites) approaches, that transfer properties of WG‐based films would fit the requirements of the six selected fruits and vegetables better than conventional plastics. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

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