The effect of modified atmosphere packaging on the microbiological,physical, chemical and sensory characteristics of broadtail squid (Illex coindetii)

The aim of this work was to evaluate the effect of various atmosphere compositions (20% CO₂/80% N₂ for modified atmosphere packaging (MAP) 1, 50% CO₂/50% N₂ for MAP 2, 70% CO₂/30% N₂ for MAP 3 and vacuum packaging) on the microbial (mesophiles, psychrophiles, Pseudomonas spp., Brochothrix thermosphacta and Enterobacteriaceae), physical, chemical [trimethylamine (TMA) and total volatile basic nitrogen (TVBN)] and sensorial characteristics of broadtail squid (Illex coindetii) stored for 10 days at 2 ± 1 °C. All microbial populations were severely restrained by MAP 3 with the exception of Enterobacteriaceae, which seemed to take advantage of the lack of competitive microflora and had enhanced microbial counts on MAP samples (P < 0.05). Colour attributes were better maintained on MAP‐stored samples. Drip loss was less on vacuum‐packaged squids. MAP 2 was the best atmosphere for the preservation of tissue consistency. TMA and TVBN formation was limited by high CO₂ atmospheres, even though both elevated in all studied conditions. Shelf life based on sensory characteristics was determined to be 10, 8, 6, 6 and 4 days for MAP 3, MAP 2, MAP 1, vacuum and control samples, respectively.     

Effects of vacuum,modified atmospheres and storage temperature on the microbial flora of packaged beef

The flora growing on beef stored in vacuum and 100% CO₂at 2 or 6°C (experiment 1) and in vacuum and different mixtures of CO₂and N₂at −1 or 2°C (experiment 2) was determined in two separate experiments. Both a high concentration of CO₂and a low storage temperature inhibited bacterial growth, especially of the spoilage bacteria pseudomonads andBrochothrix thermosphacta. No packaging conditions gave growth of coliforms. High numbers (log₈5–6) of lactic acid bacteria after storage in vacuum or gas packs, inhibited growth of pseudomonads andB. thermosphactaduring subsequent storage under retail conditions. Samples of the lactic acid bacteria obtained in experiment 2 were identified by genus-specific rRNA probes. Leuconostocs dominated in vacuum and CO₂packs at both temperatures, whereas carnobacteria dominated in N₂at −1°C.     

Effect of muscle,ageing time and modified atmosphere packaging conditions on the colour,oxidative and microbiological stability of packed beef

The objective of this study was to evaluate the influence of two different vacuum ageing times (7 and 14 days) and the impact of the modified atmosphere packaging (MAP) configuration (gas/product ratios: 0.5 and 1 and gas composition: 70% O₂ + 30% CO₂ and 40% O₂ + 30% CO₂ + 30% N₂) on the quality of fresh beef during subsequent storage at 4 °C. For this purpose, three separate experiments were performed. For each experiment, two different muscles (Longissimus dorsi and Biceps femoris) were sampled from four double‐muscled Belgian Blue beef carcasses. Next to colour, also the evolution in microbial load, pH, O₂ and CO₂ in the headspace and lipid oxidation at the meat surface were evaluated. A vacuum ageing for 14 days compared with 7 days resulted in a higher initial microbial load on the day of MAP packaging, which resulted finally in a significantly shorter shelf life. This ageing effect was less pronounced on the colour stability and lipid oxidation of the meat samples. No significant influence of the packaging configuration on any of the analysed parameters (colour, microbial load, pH and lipid oxidation at the meat surface) was observed.     

Effects of three types of modified atmospheric packaging on the physicochemical properties of selected glutinous rice

The effect of modified atmospheric packaging (MAP) on the physicochemical properties of selected glutinous (Thadokkham-8 and Thadokkham-11) rice was studied and compared with a non-glutinous rice (Doongara). The freshly harvested/milled grains were packed in four different MAP conditions viz. control, vacuum, CO₂ and N₂ for 12 months at room temperature (23 ± 1 °C). Gas (N₂ or CO₂) was flushed in aluminum bags at the pressure of 300 kPa for 3 s and subsequently hermetically sealed. Vacuum packaging was done at −100 kPa. Results showed that ageing induced changes in the starch granules were less prominent in vacuum and/or MAP samples using CO₂ or N₂. Surface analysis showed that control storage significantly reduced the percentage of lipids and increased the percentage of proteins on the surface in all selected varieties. N₂ and CO₂ storage of TDK8 and DG slowed down the shift of properties of macromolecules and maintained the surface starch/proteins/lipids ratios during 6 months of storage. Moreover, the grains stored in vacuum maintained the lipids with lower proportion of proteins exposed to the surface after cooking. N₂ and CO₂ induced increase in pasting temperature but significant reduction in final viscosity when compared to control. The findings correlated well with thermal analysis. The in situ Thermal Mechanical Compression Test (TMCT) device cooking and texture analysis revealed that modified storage slightly slowed the ageing induced changes in the cooking quality and stickiness of glutinous rice. Among all storage conditions used vacuum was relatively the best to maintain the quality of the grain.     

Development of Staphylococcal Toxin and Sensory Deterioration During Storage of Nitrogen and Vacuum Packaged Nitrite-Free Bacon-Like Product

Toxin production by S. aureus was studied in nitrite-free bacon-like product packaged in air permeable film, vacuum packages, and packages flushed with N₂ during storage at 8°C, 12°C or 26°C. Product wrapped in air permeable film deteriorated rapidly at 26°C and was rejected by sensory evaluation prior to staphylococcal enterotoxin detection. Enterotoxin was not detected in vacuum or N₂-flushed packages stored at 26°C. Samples stored at 12°C supported S. aureus growth although enterotoxin was not detected at 12°C or 8°C in any packaging environment. The potential for staphylococcal food poisoning resulting from the production of a nitrite-free bacon-like product was limited under the conditions studied.     

Modified atmosphere influences aflatoxin B1 contamination and quality of peanut (Arachis hypogaea L.) kernels cv. Khon Kaen 84-8

Storage of ‘Khon Kaen 84-8’ peanut kernels in laminated bags (Low density polyethylene (LDPE)/Nylon) (20×30 cm; 120 μm thickness) under different packaging atmospheres had effect on quality, fungal occurrence and aflatoxin B₁ (AFB₁) contamination. During fifteen week storage, peanuts (6.4% moisture content) were kept under different packaging atmospheres with some inoculated (Inoc.) and without (Non-Inoc.) aflatoxin producing fungus Aspergillus flavus. The treatments include; 100% CO₂+Inoc., 100% N₂+Inoc., vacuum + Inoc., Air + Inoc., and Air + Non-Inoc. packed with only ambient air. The storage room conditions were a temperature of 29±2 °C and 70 ± 5% r. h. Mycobiota occurrence, AFB₁ level, moisture content, lipase activity, free fatty acids and rancidity (Thiobarbituric acid; TBA value) were investigated. A total of five major fungi were identified with four storage fungi and one field fungus; Rhizopus stolonifer, Aspergillus niger, A. flavus, Penicillium spp., and Fusarium spp., respectively. Packaging in 100% CO₂+Inoc. significantly repressed the fungal occurrence especially A. niger while all other packaging atmospheres suppressed proliferation of both R. stolonifer and Penicillium spp. The peanuts kept in vacuum + Inoc. package revealed AFB₁ level below detection limit (0.4 μg/kg). Peanut kernels in 100% CO₂+Inoc. packaging atmosphere maintained an acceptable color indicated by L* and a* values, as well as the color change (ΔE) compared to other treatments. Different packaging atmospheres showed variable results in relation to the free fatty acids level with packaging under 100% N₂ revealing the lowest. Subsequently, 100% N₂ packaging atmosphere relatively inhibited rancidity occurrence in peanut kernels during storage. The results of this study portray that 100% CO₂, 100% N₂ and vacuum packaging atmosphere could have a potential to suppress occurrence of mycobiota, maintain peanut kernel quality in relation to color and lipid oxidation, and as well curtail AFB₁ contamination respectively, for fifteen weeks or more given the quality of kernels at the end of storage.     

Influence of hot‐air treatment,superatmospheric O2 and elevated CO2 on bioactive compounds and storage properties of fresh‐cut pomegranate arils

The impact of heat treatment using hot air (HT 45 °C and 55 °C for 1 h) and two active modified atmosphere packaging (MAP) conditions of high oxygen atmosphere (HOA: 80 kPa O₂, 20 kPa N₂) and high CO₂ atmosphere (HCA: 20 kPa CO₂, 80 kPa N₂), individually or combined, on the antioxidant capacity, polyphenols, vitamin C content, total anthocyanins, polyphenoloxydase (PPO) activity and shelf life of fresh‐cut (FC) pomegranate arils stored for 14 days at 4 °C was studied. The results indicate that HT 45 °C along with HOA inhibited PPO activity and prevented loss of antioxidant capacity, vitamin C and phenolic compounds in arils, in comparison with control and HT 55 °C. All treatments reduced the accumulation of anthocyanins, but HCA‐treated arils lost more anthocyanins besides having worse a* colour parameter values. No significant differences in titrable acidity (TA) and total soluble solids (TSS) were observed between treatments. The combination of HOA and HT 45 °C enhanced the benefits of applying each treatment separately and could be useful to improve and extend postharvest life of pomegranate FC arils.     

Flavor, Texture, Color, and Hexanal and TBA Values of Frozen Cooked Beef Packaged in Modified Atmosphere

Cooked beef loin slices were packaged with (1) vacuum, (2) 80% N₂ and 20% CO₂ gas mixture, or (3) air and stored at -20°C for 11 wk. Modified packaging of cooked beef improved flavor and odor. After storage and reheating, flavor and aroma of samples in vacuum and N₂/CO₂ packages were more meaty, less warmed-over, less cardboardy, and less oxidized and had lower TBA, less hexanal, and less pentanal than those in air-containing packages. Textural properties of beef were unaffected by packaging treatments. Vacuum-packaged beef slices had higher HunterLab a values than those in N₂/CO₂ and air packages.     

Colour of hot paprika from the La Vera and Murcia regions packaged in different atmospheres during storage

This study compared the behaviour of hot paprika (Capsicum annuum L.) samples from the district of La Vera and the region of Murcia packaged in five different conditions during storage. The following five different packaging conditions were used in this study: modified atmosphere packaging with three different conditions (100% N₂; 50% N₂ and 50% CO₂; and 100% CO₂), vacuum packaging and traditional packaging (product packaging system without modifying the atmosphere). After the samples were packaged, they were stored for 8 months at room temperature (normal storage conditions). The following parameters were used to indicate the quality of the samples: Aw, ASTA colour, CIE_L*a*b* colour parameters, and the composition of red and yellow compounds. The results indicate that the modified atmosphere packaging and vacuum packaging exerted a protective effect on the paprika quality characteristics regardless of the paprika origin. However, no clear differences were detected between the effect of vacuum packaging and the different modified atmosphere packaging conditions.     

The effect of modified atmospheres on the saw-toothed grain beetle Oryzaephilus surinamensis (L.)(Coleoptera: Silvanidae) and the quality of semi-dried dates

The saw-toothed grain beetle Oryzaephilus surinamensis plays a major role in reducing the quality and volume of dried fruits. The aim of this study was to evaluate the effect of modified atmospheres (MAs) enriched in CO₂ or N₂ at 25 °C and 35 °C on the adult and larval stages of O. surinamensis and dried date quality. The tested MAs containing 20%, 30%, 40%, and 50% CO₂ and the MAs containing 97% and 98% N₂, with different exposure periods were performed in the laboratory at 25 °C or 35 °C ± 2 °C, 65% ± 5% r.h and photoperiod of 16 Light:8 Dark. The adults and larvae were found to be more susceptible to CO₂ or N₂ at 35 °C than those at 25 °C. Both adults and larvae reached 100% mortality after 4–6 days exposure to 20%–50% CO₂ at 25 °C and 3–5 days exposure to the same concentrations at 35 °C. The mortality reached 100% after 2–3 days when adults were exposed to 97% or 98% N₂ at 35 °C, but the larvae reached the complete mortality after 5 and 4 days exposure to 97% and 98% N₂, respectively, at 35 °C. The adult stage was more susceptible than the larval stage to MAs enriched in CO₂ or N₂. Also, the results showed that an MA containing 50% CO₂ and another containing 98% N₂ led to increased total carbohydrates, protein, fat, and ash in treated dates compared to control dates. MAs at high temperatures may be recommended to control O. surinamensis populations in dried date stores due to the advantage of a short duration treatment capable of killing larvae and adult stages of this insect, with positive effects on dried fruit quality.     

Microbiological,physical and chemical characteristics of freshwater prawns (Macrobrachium rosenbergii) in modified‐atmosphere packaging

This study evaluated the influence of packaging atmosphere (air versus 50% N₂/50% CO₂) on microbiological (mesophiles, psychrotrophs), physical (gas measurement) and chemical (pH, total volatile basic nitrogen [TVB‐N], NH₃, H₂S and biogenic amines) parameters in freshwater prawns during storage at 0 ± 1 °C for 240 h. To select the most appropriate packaging, 21 batches of each treatment were analysed. Both the packaging permeability and the combination of gases affected the shelf life, but the modified‐atmosphere packaging (MAP) was more efficient than air packaging, increasing the shelf life by 40 h. The parameters of pH and TVB‐N showed no statistical difference between the two atmosphere conditions all along the storage period. The biogenic amine agmatine showed potential for use as a quality indicator due to the increased concentration during storage. In further studies, this amine can be applied as an indicator for public health issue.     

Effect of modified atmosphere and vacuum packaging on microbial,chemical and sensory quality indicators of fresh,filleted Sardina pilchardus at 3 °C

The self‐life, quality and safety of refrigerated sardine fillets (Sardina pilchardus) were determined at 3 °C in atmospheric air, vacuum and modified atmosphere (50% CO₂/50% N₂) packaging conditions. Microbiological, physico‐chemical and sensory parameters were utilised as quality indicators. The microbial flora of sardine comprised—according to order of occurrence—Shewanella putrefaciens, pseudomonads, Brochothrix thermosphacta, lactic acid bacteria and, finally, Enterobacteriaceae. Bacteria grew most quickly in sardines stored in air, followed by those in vacuum packaging, and the lowest counts were found in modified atmosphere packaging. The concentrations of moisture, ash, protein, fat and polyunsaturated fatty acids were not affected during the storage period compared to the pH values and the concentrations of lactate and ammonia that showed significant differences. Copyright © 2007 Society of Chemical Industry     

Role of Acetaldehyde Production in the Removal of Astringency from Persimmon Fruits under Various Modified Atmospheres

Astringency of persimmons was removed by enclosing the fruits in polyethylene bags under vacuum or by replacing air with N₂ or CO₂. Acetaldehyde produced by the fruit under these conditions accumulated at different rates. The rate of the deastringency process was directly proportional to the level of acetaldehyde accumulation. Thus, the fruit held at 20°C in CO₂ was the first to lose its astringency, but showed internal browning after 1 wk. Fruits under vacuum or N₂, where less volatiles accumulated, maintained their high quality and firmness for 2 wk at 20°C or 3 months at ? 1°C. However, fruit held under vacuum began to show internal browning when acetaldehyde accumulated above a certain level.     

Combined Application of Antibrowning,Heat Treatment and Modified‐Atmosphere Packaging to Extend the Shelf Life of Fresh‐Cut Lotus Root

This work aimed to determine the effects of different concentrations of antibrowning treatments (that is, distilled water [DW], 1% ascorbic acid [AA], 0.5% chamomile [CM], and 1% AA + 0.5% CM) and heat‐treatment (55 °C for 45 s) combined with packaging under 4 different modified‐atmosphere gas compositions (that is, air, vacuum, 100% CO₂, 50% CO₂/50% N₂) on the quality and microbiological characteristics of fresh‐cut lotus root. The quality characteristics (that is, color, weight loss, texture, pH, polyphenoloxidase activity, and total phenolic content) of the AA + CM‐dipped sample in 100% CO₂ packaging were maintained significantly better than those of the other samples (P < 0.05). The microbiological counts observed in the DW‐dipped sample during storage were higher than those of the AA, CM, and AA + CM samples, and heat‐treatment retarded the microbiological deterioration of fresh‐cut lotus root. Therefore, the results revealed that dipping in an antibrowning treatment (AA + CM), and 100% CO₂ MAP with heat treatment effectively extend the shelf life of fresh‐cut lotus root to 21 d at 5 °C.     

Pretreating Callosobruchus maculatus (F.) eggs in mung bean with modified atmosphere conditions influence its adult emergence and survival

Cowpea bruchid (Callosobruchus maculatus Fab.) is a cosmopolitan pest that causes economic losses to legumes during storage. The present study determined the post-effects of exposing the C. maculatus eggs in mung bean to modified atmosphere (MA) conditions on the emergence and development of adults at ambient conditions (28 ± 3 °C and 65 ± 5% RH). The 24 h old C. maculatus eggs on mung bean kernel were packed with 500 g of mung bean in nylon/linear low-density polyethylene (nylon/LLDPE) bags (12.5 × 30 cm; 80 μm thick) and sealed with air (control), 100% CO₂, 100% N₂, and vacuum for 48 h. The very low O₂ conditions in the MA package had significantly caused longer onset and developmental duration of egg to adult emergence and significantly reduced the adult emergence percentage of C. maculatus, especially those in the vacuum treatment. This was due to low pressure that disrupted the structure of the eggs as indicated by the scanning electron microscopy (SEM). In addition, the MA conditions shortened the adult emergence duration, longevity, and mortality duration. The number of females was also reduced by the low O₂ conditions, particularly in those treated with vacuum. Eggs pretreated with the MA conditions probably affected the biomolecules of the eggs that in turn have affected the growth and development of the insect, with the order of effectivity highest in vacuum followed by 100% N₂ then 100% CO₂.     

Modified atmosphere packaging as a means to alleviate package expansion of Korean fermented red pepper paste

Summary Korean fermented red pepper paste was packaged under a modified atmosphere (MA) of 30% CO₂/70% N₂ and 100% CO₂. A plain air package was also prepared as a control for comparison. The MA conditions were applied with a high gas barrier film and subsequently with a gas permeable film. Throughout the storage period at 13 °C, package volume, headspace gas composition, microbial flora, surface colour, pH and acidity were measured. An MA of 100% CO₂ suppressed the growth of aerobic bacteria and yeasts, and reduced the CO₂ production from the paste without any adverse effect on product quality, and thus alleviated the volume expansion of flexible packages stored at 13 °C. However, the reduced volume expansion for the package of high‐barrier film was not sufficient in prolonged storage. An MA package of 100% CO₂ using plastic film of appropriate gas permeability could be stored at 13 °C for 150 days without volume expansion or any adverse quality changes, and was also tolerant to temperature abuse conditions at 25 °C.     

Shelf-life of a Greek whey cheese under modified atmosphere packaging

“Anthotryros” cheese was packaged under vacuum (VP) or modified atmosphere (MAP) and stored at 4 or 12 °C. MAP mixtures were 30%/70% CO₂/N₂ (M1) or 70%/30% CO₂/N₂ (M2), while VP was taken as the control sample. Microbiological results showed that M1 and M2 delayed microbial growth compared with VP samples. Of the two modified atmospheres, gas mixture M1 was the most effective for inhibition of growth of mesophilic bacteria. Based primarily on sensory evaluation, the use of both MAP conditions extended the shelf-life of fresh Anthotyros cheese stored at 4 °C by ca. 10 days (M1) or 20 days (M2) compared with VP, and by ca. 2 days (M1) and 4 days (M2) at 12 °C, with cheese maintaining good sensory characteristics.     

Development of Botulinal Toxin and Sensory Deterioration During Storage of Vacuum and Modified Atmosphere Packaged Fish Fillets

Toxin production by C. botulinum type E was studied in cod, whiting, and flounder filets packaged in air-permeable film, vacuum packages and packages flushed with N₂ or CO₂ during storage at 8°, 12° or 26°C. Cod and whiting filets were flushed with CO₂ and stored continuously at 4°C or cycled between 4° or 8° and 26°C. Cod and whiting fillets were flushed with gas mixtures and stored at 8°C or 26°C. Flounder deteriorated rapidly and was rejected by sensory evaluation prior to toxin detection during vacuum or modified atmosphere storage at 12°C and 8°C but after toxin detection at 26°C. Toxin was present either prior to or simultaneously with sensory rejection of cod and whiting fillets for all vacuum or modified atmosphere treatments and temperature regimens.     

Microbiological,physicochemical and sensory characteristics of Cameros cheese packaged under modified atmospheres

This study evaluated the shelf-life quality of Cameros cheeses packaged under modified atmospheres. Five different modified atmosphere conditions were studied (carbon dioxide/nitrogen mixtures and vacuum). Control cheeses were packaged in air. The product stored at 3–4°C was evaluated periodically to investigate its sensory quality, microbiological condition and physicochemical characteristics. Weight loss and pH evolution were similar in vacuum and air packaging. Cheeses packaged in 100% CO₂showed the greatest weight losses and lower pH values. CO₂reduced proteolysis and lipolysis during storage in all conditions studied. Fat acidity and NPN/TN values were slightly higher in vacuum than in CO₂, but lower than in air. Modified atmosphere packaging presented an extended shelf life. Those containing CO₂reduced the growth rate of mesophiles, psychrotrophs, Enterobacteriaceae and coliforms, which was lower when the CO₂concentration increased. The lowest microbial counts were at 100% CO₂while vacuum conditions presented microbial counts only slightly lower than the controls. Salmonella spp.,Staphylococcus aureus and Listeria spp. were not found in any of the samples. Faecal coliforms, moulds and yeasts were not detected under CO₂atmospheres or in vacuum. After 7 days of storage, the sensory characteristics of the control cheeses were unacceptable in all the parameters studied. However, the overall score for cheeses stored in 40% and 50% CO₂did not change substantially, retaining a reasonable acceptability until the end of the storage period. The 100% CO₂atmosphere had a very negative effect on sensory quality. With regard to Cameros cheese, packaging in 50%CO₂/50%N₂and 40%CO₂/60%N₂are the most effective for extending shelf life and retaining good sensory characteristics.