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1.
In this work, the combined effects of sodium lactate and modified atmosphere packaging (MAP) in extending the shelf life of a ready‐to‐cook fresh skewer, made up of raw pork chops and semi‐dried vegetable mix (i.e. zucchini, peppers and tomatoes), were investigated. In the first experimental step, a sodium lactate solution was used to dip pork chops at three different concentrations: 20, 40 and 60% w/w. The second part of the work was focused on the use of MAP. In particular, the following MAPs were tested: MA1 (50%O2/30%CO2/20%N2), MA2 (70%O2/30%CO2), MA3 (30%O2/70%CO2) and MA4 (30%O2/30%CO2/40%N2). Finally, the optimal concentration of sodium lactate and the best gas composition were combined. The samples were stored at 4 °C; their microbial and sensory qualities were monitored along the entire observation period. The results indicate that the shelf life of the investigated ready‐to‐cook meal can be extended by approximately 83%, if compared with the control skewer packaged in air. The best preservation strategy is the combination of dipping of meat pieces in 40% sodium lactate solution and packaging under MA1. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

2.
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   

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.
Portions (about 1 kg each) of chicken leg cuts packed in low density polyethylene bags were arranged in masterpack barrier bags injected with two different kinds of modified atmosphere: 80% CO2/20% N2 and 70% CO2/30% N2. All the samples packed in modified atmosphere, as well as the control samples packed in air, were dark stored at 3±1°C. The shelf life of the products was evaluated on the basis of microbiological and sensory criteria. The shelf life of the samples with initial mesophilic and psychotrophic bacteria counts of 5.38 and 5.72 log CFU/g, respectively, and stored under 80% CO2 was extended from 7 to 17 days, considerably longer than the shelf life increase achieved with the samples packed in a modified atmosphere containing 70% CO2, which increased from 10 to 14 days. The odour changes observed during refrigerated storage of all samples followed a uniform pattern, starting with an odour of ‘old chicken meat’ which gradually developed into rancid and, finally, putrid odours. The detection of putrid odours was the basic criterion for rejection of the products and correlated well with the microbiological evaluation data. At the end of the shelf life the appearance of the samples was evaluated as slightly to moderately different from their appearance at the start of the experiment. © 1998 John Wiley & Sons, Ltd.  相似文献   

5.
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   

6.
An investigation was carried out on the microbiological quality of carp fillets linked to slaughtering methods, variation in temperature, storage time and packing as well as recording the main bacterial flora (total aerobic bacteria, Enterobacteria and Pseudomonas sp. and lactic acid bacteria). The results of this study showed the following. (i) The working room temperature (5–18°C) and dipping of the fillets in ice water did not have any influence on the microbiological quality of the carp fillets. However, for industrial purposes it would be more adequate to work at low temperature. (ii) The packaging process (air, vacuum or modified atmosphere) had significant effects on the microbiology of the fillets. (iii) Only those fillets under a modified atmosphere offered a shelf-life of 10 days or more (up to 14 days). (iv) MA packaging with 50% CO2 gave the best results with regard to limiting microbiological growth. (v) Storage of the fillets at a temperature higher than 3°C should be prohibited as well as potential breaks in the cold chain.  相似文献   

7.
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   

8.
A total of 1% nanoclay containing polypropylene (PP)‐nanocomposite and 1% nanoclay plus 5% poly‐beta‐pinene (PβP) containing PP‐active‐nanocomposite materials were produced and tested for packaging of sliced salami. The sliced salami was packaged using both nanofilms and multilayer film of PP/PA/EVOH/PE under vacuum, modified atmosphere packaging under 50% CO2 and 50% N2 and air and stored at 4 °C for 90 days. During storage, headspace gas composition; microbial, physical and chemical analyses; and sensory evaluation were performed. The antimicrobial effect of PβP containing nanomaterial was pronounced under vacuum, and no bacterial growth was observed for 75 days. An a* value decreased notably in all applications during storage and preserved best by the multilayered material under vacuum and high CO2. Thiobarbituric acid reactive substances (TBARS) were 0.63 mg MDA/kg after the processing and gradually increased at all applications during increased storage. TBARS values of all vacuum applications were lower than that of modified atmosphere packaging applications. Rancid taste development was determined by sensory panelists when TBARS values were higher than 0.80 mg MDA/kg on the 90th day. There was no significant moisture loss, and no increase in hardness was determined during the whole storage time. The longest shelf life was 75 days for the sliced salami under vacuum and high CO2 using the multilayer material. PβP containing nanomaterial provided 50 days of shelf life under vacuum, which is commercially considerable. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

9.
The effects of vacuum or modified atmosphere packaging conditions on the ripening dynamics of kimchi and sensory preference were investigated to determine the potential of initial atmospheric flushing as a method for improving quality at consumption. In all the packaging treatments (control of air, vacuumizing, CO2 flushing and N2 flushing), the partial pressures of O2 and N2 remained at nearly constant initial levels; therefore, the increases of package pressures were dominantly caused by the increases in the CO2 partial pressures as a result of kimchi fermentation. The CO2 production from kimchi was greater in the vacuumed and CO2‐flushed packages. The initial vacuumed treatment helped to maintain relatively lower pressure during extended storage, and the pressure of the CO2‐flushed package could have been reduced as a result of the high solubility of CO2 in the aqueous product. Initial CO2 flushing also provided the packaged product with a pleasant cool flavour at the properly ripened state.  相似文献   

10.
Radiofrequency magnetron sputtering deposition at low temperature (150°C) was used to deposit bioactive glass coatings onto titanium substrates. Three different working atmospheres were used: Ar 100%, Ar + 7%O2, and Ar + 20%O2. The preliminary adhesion tests (pull-out) produced excellent adhesion values (~75 MPa) for the as-deposited bio-glass films. Bioactivity tests in simulated body fluid were carried out for 30 days. SEM–EDS, XRD and FTIR measurements were performed. The tests clearly showed strong bioactive features for all the prepared films. The best biomineralization capability, expressed by the thickest chemically grown carbonated hydroxyapatite layer, was obtained for the bio-glass coating sputtered in a reactive atmosphere with 7% O2.  相似文献   

11.
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   

12.
Apatite layer was formed on polyethyleneterephthalate (PET) substrate by the following biomimetic process. The PET substrate was placed on granular particles of a CaO, SiO2-based glass in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma to form apatite nuclei on their surfaces. The apatite nuclei was then grown into a continuous layer by subsequently soaking the substrate in SBF under air or CO2 atmosphere in which CO2 partial pressure in the ambient was adjusted to 14.8 kPa to increase the content of carbonate ion to a level nearly equal to that of blood plasma. The increase in the content of carbonate ions in SBF changed the Ca/P atomic ratio of the apatite from 1.51 to 1.63, content of CO3 2- ions from 2.64 to 4.56 wt %, and lattice constants a from 94.32 to 94.23 nm and c from 68.70 to 68.83 nm, respectively. The Ca/P ratio and lattice constants of the apatite formed in SBF under CO2 atmosphere were approximately identical to those of bone apatite, i.e. Ca/P atomic ratio 1.65, content of CO3 2- ion 5.80 wt % and lattice constants a 94.20 and c 68.80 nm. This indicates that an apatite with composition and structure nearly identical to those of bone apatite can be produced in SBF by adjusting its ion concentrations including the content of carbonate ions to be equal to those of blood plasma.  相似文献   

13.
Fully matured fresh guava fruits (Lucknow‐49) were precooled at 10 °C for 1 h and pretreated with 500‐ppm benomyl for 5 min. The fruits were packed in 25‐µm and 50‐µm LDPE bags with active modified atmosphere packaging of 3% O2 + 5% CO2, 6% O2 + 5% CO2 and 9% O2 + 5% CO2 gas concentrations and stored at 5 ± 1 °C and 10 ± 1 °C temperatures as well as non‐packaged as control. The shelf life of guava could be increased up to 42 days by packaging in 50‐µm LDPE bags with a gas concentration of 9% O2 + 5% CO2 and stored at 10 °C without much change in physical, biochemical and sensory characteristics. Physico‐chemical changes viz., PLW, pulp to peel ratio, firmness, TSS, total sugar, ascorbic acid and titratable acidity were observed minimum for fruits packed in 50‐µm LDPE bags at 3% O2 + 5% CO2 gas concentration at 5 °C storage temperature, but sensory score decreased drastically after 21 days of storage. Chilling injury was observed for the fruits packed at 5 °C storage temperature after 21 days of storage, and it was severe in 25‐µm LDPE bag at later stage. Control fruits over‐ripened with the highest weight loss (12.47%) on 6 days of storage and discarded from the storage. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

14.
A pinhole in a packaging system for kimchi, a Korean lactic acid fermented vegetable, was found to actively modify the headspace gas and improve the quality of the product. The effect of the presence of a pinhole on the headspace atmosphere and microbial flora was investigated in the packaging system and a prototype of this active packaging system was fabricated and tested for its effectiveness in improving quality. The incorporated pinhole eliminated pressure build-up in the package by allowing restricted flow of gas to the atmosphere. O2 and N2 gases in the headspace were flushed out by CO2 gas produced continuously from lactic acid fermentation and this modified atmosphere enhanced the growth of lactic acid bacteria. In particular, the growth of Leuconostoc species, heterofermentative lactic acid bacteria, was promoted by the pinhole. The increased amount of heterofermentative lactic acid bacteria led to a higher accumulation of CO2 in the package and this provided the kimchi with a stronger cool carbonic taste and a desirable flavour. An elaborate design of the pinhole incorporating microporous film and a gas adsorvent could be adopted to improve the kimchi packaging system by preventing leakage of fermentative aroma and possible contamination from outside atmosphere. © 1997 John Wiley & Sons, Ltd.  相似文献   

15.
There has been increasing demand for various fresh‐cut tropical fruits. However, their short shelf‐life has limited the market increase of this product. Quality changes (firmness, colour, total soluble solids (TSS), titratable acidity (TA), sensory quality and microbial safety) of fresh‐cut mangoes, pineapples, melons and mixes of these fruits were evaluated. Chemical treatments to reduce browning, firmness loss and decay of fresh‐cut tropical fruits were investigated. The most effective agents for fresh‐cut mangoes, pineapples and melons were 0.1m ascorbic acid, 0.2m ascorbic acid and 0.2m ascorbic acid + 0.2m calcium chloride, respectively. Fresh‐cut tropical fruits were packaged in various rigid containers (PET, OPS and OPLA). Gas composition in the package headspace and time to reach steady‐state condition varied among fresh‐cut packaging systems and affected their quality and shelf‐life. The effects of package permeability of O2 and CO2 on quality and shelf‐life of the fresh‐cut products are discussed. Extended shelf‐life was observed in fresh‐cut mangoes, pineapples and mixes packaged in PET due to reduced O2 and elevated CO2 atmosphere. A modified atmosphere of 6% O2 and 14% CO2 achieved in PET extended the shelf‐life of fresh‐cut pineapples from 6 to 13 days. Accumulation of CO2 may impart an off‐odour of fresh‐cut fruits. The results suggested that the shelf‐life of fresh‐cut fruits could be extended by using proper rigid containers. Suitable mixes to create optimal equilibrium modified atmosphere had a potential to extend shelf‐life of short shelf‐life fresh‐cut tropical fruits. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

16.
Pieces of pre‐rigor filleted Atlantic salmon were modified atmosphere (MA)‐packaged (60% CO2 and 40% N2) in eight different ways according to tray sizes (ml), gas/product ratios (g/p ratios), number of fillet layers and capacities of the CO2 emitters being used (based on the fish weight or on the surface area of the fish). All the samples were stored at 2°C for 21 days. Gas measurement showed that the CO2 emitter based on fish weight developed too much CO2, and the emitters based on surface area developed too less during storage. Samples with the lowest CO2 level in the headspace (emitter based on surface area), and also probably the lowest amount of absorbed CO2, had the highest bacterial growth after 17 days of storage for some of the samples. Both the pH and the bacterial growth were similar between the top layer and the bottom layer within the packages of more than one layer in each tray. This indicates that the CO2 was also available for the bottom layers. The liquid loss was similar for the trays with the different emitter types, but it differed between the tray sizes. A model based on the weight and surface area of the fish, and g/p ratio and capacity (ml) of the tray was made in order to more precisely calculate an optimal amount of the CO2 emitter ingredients because of a predefined CO2 level in the headspace. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

17.
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   

18.
The increase of warm-room gas is thought to cause the rise of atmosphere temperature, which is called the warm-room effect. Therefore, the decomposition treatment of carbon dioxide (CO2) gas is an important research subject in order to solve the global environmental problem. In this study, a high-energy plasma process was used to decompose CO2 gas as a warm-room gas, and the decomposition mechanism was clarified by varying the plasma operation conditions. The possibility of transforming of the CO2 gas to various resources was also discussed. Firstly, the performance test of the gas tunnel-type plasma jet used for decomposition of CO2 was conducted, and decomposition characteristics of CO2 gas by the gas tunnel-type plasma jet was determined under various conditions. The decomposition ratio of CO2 was about 30%, when the power input was P=8 kW, and the CO2 content in argon was 10%. Secondly, the improvement of operating conditions of the plasma jet was discussed in order to enhance its performance.  相似文献   

19.
The objective of this study was to evaluate the influence of package materials on the preservation of cold‐stored ‘Kumagai’ guavas. The treatments were: PO2, co‐extruded polyolephinic film with gas injection (5% O2/5% CO2/N2); PO3, co‐extruded polyolephinic film with gas injection (5% O2/5% CO2/N2); LDPE, linear low density polyethylene film; LDPE‐gas, linear low density polyethylene film with gas injection (3% O2/8% CO2/N2); PVC, polyvinylchloride stretch film; PO1, co‐extruded polyolephinic film and control: non‐packaged guavas. Guavas were stored at 10 ± 1°C/80–90% RH for 21 days, and then transferred to room temperature. Gas composition within the package headspace was analysed during storage and the physical and chemical characteristics of the guavas were evaluated daily during ripening. The modified atmosphere provided by PO1 film was insufficient to promote the benefit of senescence control. Although PVC provided an atmosphere close to that recommended, it did not preserve the colour and pulp firmness. PO2, PO3, LDPE and LDPE‐gas retarded the senescence process of the guavas during 21 days at 10°C plus 2 days at room temperature, but harmed the normal ripening of guavas in some aspects. This can be explained by reduced O2 and elevated CO2 levels within these four packages. None of the packages influenced the titratable acidity and the soluble solids, but they did harm ascorbic acid synthesis. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

20.
Broccoli (Brassica oleracea L. var. Italica) florets were packaged in low‐density polyethylene (LDPE) bags with or without ethylene adsorber under passive modified atmosphere and then stored at 4°C for 20 days. LDPE films with (8% Tazetut® masterbatch, M2) or without ethylene adsorber (M1) were tested. The effects of modified atmosphere packaging treatments on gas concentrations (O2, CO2 and ethylene) in the headspace, the mass loss, colour, texture, pH, total soluble solids, chlorophyll content, total phenolic content and sensory quality of packaged broccoli were determined by comparing with unpackaged (control) florets. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by mass loss, chlorophyll degradation and stem hardening. Also, it was found unacceptable by sensory panel after 5 days. Conversely, in those florets packaged under modified atmosphere packaging, especially for LDPE with ethylene adsorber (M2), all changes related with loss of quality were significantly reduced and delayed with time. Additionally, total soluble solids and total phenolic content remained almost unchanged during the whole period. Ethylene concentration was determined as 61.8 ppm in M1 and 0.33 ppm in M2, respectively, at the end of the storage. Thus, broccoli packaged with M2 films had prolonged storability up to 20 days with high quality attributes, this period being only 5 days in unpackaged control broccoli. Oxygen concentration decreased below 1% after 5 days of storage in M1, and the shelf life of broccoli in these bags was limited to 5 days because of risk for anaerobic fermentation. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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