Modified Atmosphere Research Articles

Effects of Foliar Nutrition on Onion Seed Storage under Modified Atmosphere Packages

Modified atmosphere packaging (MAP) and controlled atmosphere storage techniques to reduce the oxygen around the food are largely used for the preservation of fresh produce. There have been great technological advances in this area of preservation, particularly as it refers to improving the quality and shelf-stability of highly perishable food products, such as produce. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on onion seeds storage under modified atmosphere packages. Germination percent of seeds decreased in 5°C than storage in room temperature. Germination percent of seeds was gradually decreased with increasing the storage period. Packaging treatments had a significant effect on germination percent of seeds. All the packaging treatments had the higher germination percent than the paper package (control). The highest germination percent after 12 months of storage was recorded for the treatment with non perforated polypropylene in room temperature and polyethylene and non perforated polypropylene in 5°C. Catalase activity decreased with the prolongation of storage period. The non perforated polypropylene package had the highest catalase activity. The treatment with non perforated polypropylene had the highest catalase activity after 12 months of storage in both room and 5°C temperatures. Peroxidase activity of seeds was gradually decreased with increasing the storage period. The highest peroxidase activity after 12 months of storage was recorded in non perforated polypropylene in both storage temperatures.

THE ASSESSMENT OF APPLE SHELF LIFE AFTER STORAGE AT MODIFIED ATMOSPHERE

THE ASSESSMENT OF APPLE SHELF LIFE AFTER STORAGE AT MODIFIED ATMOSPHERE

Effects of aw at packaging time and atmosphere composition on aroma profile, biogenic amine content and microbiological features of dry fermented sausages

The aim was to evaluate the effects of different water contents (corresponding to aw 0.940, 0.914, 0.895 and 0.875) of sausages at different times on the characteristics of typical Italian dry fermented sausages packaged under two different modified atmospheres (MAP) (100%N2 or 30%CO2/70%N2). During ripening and storage, samples were analyzed to evaluate pH and aw changes, microbial population, biogenic amine (BA) accumulation and aroma profile.The results showed that during storage under MAP several microbiological and enzymatic activities proceeded, leading to changes in aroma profile. In particular, higher hexanal concentrations in samples at lower aw and significant amounts of acetone, 2-butanone, ethanol and 2-butanol in samples at aw>0.900 were detected. Moreover, data showed modifications in BA content, such as higher accumulation in samples at aw>0.900 in MAP with 100%N2. This behavior depends, in first instance, on the aw of the sausages when packaged.

Development and evaluation of Modified Atmosphere (MA) packages<br>employing lamination technique for Royal Delicious apple

Modified atmosphere (MA) packages were prepared for Royal Delicious apple with an aim to achieve the optimum storage atmosphere within the packages in minimum possible time. Apples were harvested at their commercial maturity and respirtion rate of the fruits was measured at temperatures between 0 ? 25°C. On the basis of preliminary investigations, air composition with 3% O2 and 3% CO2 was found appropriate for MA packaging of apple. The MA package was finalized with a size of 24 cm x 19 cm for 1 kg fill-weight of apples. As the gas transmission rates of individual polymeric films could not match the gas transmission requirements of MAP, judicious combinations of the films were made to bring gas transmission characteristics close to the required values. The equilibrium concentrations of O2 and CO2 were established within 36-72 h under different storage temperatures. The mathematical model, developed applying enzymatic kinetics based respiration equation coupled with the Arrhenius model, effectively predicted the equilibrium time and the levels of O2 and CO2 at equilibrium. MA packages were evaluated through assessment of different quality parameters of apple during storage and were found to increase its shelf life by 125-210% that of unpacked fruits at different storage temperatures.

Combination effects of postharvest treatments and modified atmosphere packaging on shelf life and quality of Iranian pomegranate fruit cv. Sheshi-kab

The main objective of this study was to assess the effectiveness of individual application and combination effect of different postharvest treatments in both unpacked and modified atmosphere (MA) packed on reducing the occurrence of chilling injury, decay and subsequently on extending shelf life and quality improvement of pomegranate fruit during long-term cold storage. Treatments were hot water (50°C) for 3 minutes, salicylic acid (1 or 2 mMol/l) or calcium chloride (1 or 2%) for 3 minutes at 20°C or combinations of both chemicals with hot water (HW). No packed and MA packed also were studied before fruit stored at 5°C and 80% RH. Combining hot water and chemical treatments with MAP had greater effect on control of fruit decay, reduction of chilling injury and also to extend fruit shelf life than individual application of each treatment. Shelf life roughly doubled in fruit that treated with a combination of HW and salicylic acid (1 mMol/l) and packed in PE bags compared to the control fruit with no packaging. Treatments had no significant effect on total soluble solid (TSS) and sensory assessments of arils. Overall, combination of HW, salicylic acid and MAP could be used to improve fruit quality, to reduce decay and to extend pomegranate shelf life during prolonged cold storage.

Simulation of Gas and Water Vapor Exchange in Perforated-film Modified Atmosphere Packaging under Dynamic Storage Conditions

Simulation of Gas and Water Vapor Exchange in Perforated-film Modified Atmosphere Packaging under Dynamic Storage Conditions

Colour Changes in Jaggery Cubes under Modified Atmosphere Packaging in Plastic Film Packages

Jaggery cubes made from sugarcane (variety: CoJ64) was stored under modified atmosphere packaging (70% N2+30% CO2), at ambient conditions in low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthlate (PET), and laminated aluminum film packages for a period of 210 days, to enhance the shelf life and to evaluate the effect of modified atmosphere packaging (MAP) on moisture content, phenols, color, reducing sugars, and texture of jaggery. MAP resulted in colour changes in the original yellowish red colour of jaggery under different plastic films. Instead of conventional CIELAB colour space system utilizing only L*, a* and b* values, the colour changes were analyzed as per L*C*h* colour space system using lightness, chroma and hue angle values, to evaluate the final hue (colour). On 210th day of storage, the samples kept in all the films were dark, but the intensity of darkness was least for PET film. The best retention of colour was observed for PET film under MAP. Further, the sensory and visual analysis of jaggery samples during entire storage period was in line with the results obtained from L*C*h* colour space diagram.

The Physiological and Quality Change of Mushroom Agaricus bisporus Stored in Modified Atmosphere Packaging with Various Sizes of Silicone Gum Film Window

The Physiological and Quality Change of Mushroom Agaricus bisporus Stored in Modified Atmosphere Packaging with Various Sizes of Silicone Gum Film Window

Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions.

Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and −1°C. Sensory analysis of cooked samples revealed a shelf life of 13–15 days for air-packaged fillets during storage at 1°C and 20 days at −1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g−1. In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (<log 8 CFU g−1) after 23 days of storage at both 1°C and −1°C. However, modified atmosphere (MA) packaging negatively affected color characteristics of the fillets soon after packaging (day 6). Color is an important indicator of tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at −1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study.

Atmosfera modificada e controle de etileno para bananas 'Prata-Anã' cultivadas na Amazônia Setentrional Brasileira

O presente trabalho teve por objetivo avaliar o efeito da atmosfera modificada (AM) pelo uso de embalagem plástica de polietileno de baixa densidade (PEBD), do vácuo e da adsorção de etileno, visando à manutenção da qualidade das bananas 'Prata-Anã' produzidas em Roraima. As análises foram realizadas em intervalos de 5 dias após a colheita, até 35 dias de armazenamento refrigerado (AR). Verificou-se que os frutos submetidos a embalagem de PEBD apresentaram as menores perdas de massa fresca quando comparados aos demais. Da mesma forma, os frutos embalados na presença do adsorvedor de etileno obtiveram a melhor manutenção na coloração da casca, atraso temporal, do pico climatérico, assim como o retardamento na degradação do amido, os menores incrementos de sólidos solúveis e acidez titulável, as menores concentrações de etileno nos interiores das embalagens e atraso temporal e a diminuição da atividade enzimática. Isso, possivelmente, proporcionou os maiores teores de pectina total e solúvel ao final do período experimental. A combinação do uso da embalagem de PEBD com o sachê de permanganato de potássio (KMnO4) resultou no retardamento do processo de maturação dos frutos de banana 'Prata-Anã', quando armazenada a 12 ºC. Pode-se atribuir esse efeito benéfico à presença do sachê na adsorção de etileno e, consequentemente, na ação do etileno no amadurecimento dos frutos, retardando a senescência das bananas 'Prata-Anã'.

Predominant enterobacteria on modified-atmosphere packaged meat and poultry

Enterobacteria on modified-atmosphere (MA) packaged meat (n = 54) and poultry (n = 32) products were enumerated, and 899 isolates were picked and ribotyped. For identification, 16S rRNA genes of representative strains were sequenced and analyzed. Altogether 54 (60%) of the samples contained enterobacteria >104 CFU/g. In 34% of the poultry samples, enterobacteria counts were >106 CFU/g suggesting that enterobacteria may contribute to spoilage of MA packaged poultry. The enterobacteria identified were predominantly Hafnia spp. (40%) and Serratia spp. (42%) with Hafnia alvei, Hafnia paralvei, Serratia fonticola, Serratia grimesii, Serratia liquefaciens, Serratia proteamaculans, and Serratia quinivorans being the species identified. In addition, 6% of the isolates were identified as Rahnella spp., 3% as Yersinia spp., and 1% as Buttiauxella spp. Percentage distributions of the predominant genera in different products showed that 89% of the Serratia spp. were from products packaged under a high-O2 MA containing CO2 (25–35%), whereas most (76%) isolates of Hafnia originated from anaerobically packaged red meat and poultry. These findings suggest that the gas mixture used for MA packaging influence the selection of enterobacteria growing on meat and poultry.

Aplicações de tecnologias pós-colheita para bananas 'Prata-Anã' produzidas em Roraima

Neste trabalho objetivou-se manter a qualidade e aumentar o tempo de prateleira durante a pós-colheita de bananas 'Prata-Anã' e se avaliou a eficiência do armazenamento refrigerado (AR) e da atmosfera modificada (AM) pelo uso de embalagens plásticas de polietileno de baixa densidade (PEBD), do vácuo e da utilização de sachê adsorvedor de etileno. Os tratamentos foram: T1: Controle (sem embalagem, sistema de adsorção de etileno e sem vácuo); T2: Embalagem de polietileno de baixa densidade (PEBD); T3: PEBD + adsorvedor de etileno; T4: PEBD + vácuo e T5: PEBD + adsorvedor de etileno + vácuo. As análises foram realizadas em intervalos de 5 dias após a colheita, até 35 dias de AR. Verificou-se que os frutos submetidos à embalagem de PEBD apresentaram as menores áreas de lesão na casca, as menores concentrações de etileno, os menores incrementos de acidez titulável (AT) e comportamento normal/manutenção dos valores de pH o que, possivelmente, proporcionou os maiores teores de açúcares totais e redutores ao final do período experimental; concluiu-se,então, que a combinação do uso da embalagem de PEBD com os sachês adsorvedores de etileno resultou no retardamento do processo de maturação dos frutos de banana 'Prata-Anã' proporcionando, comercialmente, a extensão da vida útil dos frutos em até 30 dias após a colheita.

Study on High-Oxygen Modified Atmosphere Packaging for Chilled Fresh Pork

Modified atmosphere packaging (MAP) is used CO2, O2, N2and other protective gas which have different effects to extend the preservation period. 2% salt and 0.3% lactic acid preservative-treated chilled fresh pork are placed controlled group, 45%, 55%, 65%, 75%, 85% of six different concentrations of oxygen with modified atmosphere packaging to test TVB-N and pH changes during storage. The results show that their fresh-keeping are followed by 75%&gt; 65%&gt; 55%&gt; 85%&gt; 45%&gt; CK, and 75% group has the best fresh-keeping effect, and if we continued to increase the oxygen concentration, the fresh-keeping had been worse.

Effect of O2[sbnd]CO2 enriched atmospheres on microbiological growth and volatile metabolite production in packaged cooked peeled gray shrimp (Crangon crangon)

This study evaluated the effect of modified atmospheres (MAs) with different O2 concentrations on microbial growth and volatile metabolite production in gray shrimp (Crangon crangon) during storage at 4°C. Eight MAs were evaluated in total. Four of the MAs evaluated were without CO2: 0/0/100, 0/10/90, 0/30/70, 0/50/50 (% CO2/O2/N2) whilst the other four MAs all contained 50% CO2: 50/0/50, 50/10/40, 50/30/20, 50/50/0 (% CO2/O2/N2). Volatile spoilage metabolites were identified by thermal desorption GC-MS and quantified during storage by selective ion flow tube mass spectrometry (SIFT-MS). In comparison to microbial growth observed with an atmosphere of 100% N2, microbial growth was stimulated by the addition of O2 in the MAP in the absence of CO2. Under these conditions the total psychrotrophic counts exceeded 7 log cfug−1 after just 3days of storage. However, in the presence of 50% CO2 the total psychrotrophic count exceeded 7 log cfug−1 after 5days of storage. The combination of 50% CO2 and 50% O2 significantly inhibited microbial growth. For this MA condition, a diminishing effect on the production of metabolites was also observed, especially for amines and sulfur compounds, which constituted the major fraction of components causing the offensive odor.

Effects of chilled storage on quality of vacuum packed meagre fillets

The aim of this study was to experimentally assess several quality indices of meagre Argyrosomus regius (Asso, 1801) fillets packed in air (AP) and vacuum (VP) stored chilled (+4°C) for up to 13days. Considering our experimental data on concentration of bacterial counts, shelf-life is estimated at ca. 6days for AP fillets and an additional 3–5days for VP meagre fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA-N) did not reach the regulated limits (25–35mg/100g chilled fish). The models implemented in the software Seafood Spoilage and Safety Predictor predicted a relatively shorter shelf-life of 4.8–6.9days for fish stored in air at +4°C when compared to AP and VP fillets. Empirical data and the models implemented in the software were used to predict the shelf-life of fillets if packaged under different modified atmospheres (MAP). Chilled, MAP fillets are likely to have a longer shelf-life than AP or VP samples if equilibrium CO2 concentration is substantially high.

Dynamics of gas levels inside packages containing minimally processed Pera orange

The purpose of this study was to evaluate the changes in concentrations of O2 and CO2 inside packages of minimally processed Pera orange. Previously selected oranges that were washed, sanitized, and chilled were peeled using hydrothermal treatment (immersion of fruits in water at 50 °C for 8 minutes). The peeled oranges were then packed in five different plastic packages under passive and active modified atmosphere (5% O2 + 10% CO2 + 85% N2). The fruits were stored at 6 °C and 12 °C. The package headspace gas composition was evaluated for twelve days at 6 °C and nine days at 12 °C. The polypropylene film (32 µm) promoted modified atmosphere similar to that initially injected (5% O2 + 10% CO2 + 85% N2) at 6 °C and 12 °C. With regard to the atmosphere modification system, the injection of a gas mixture anticipated achieving an equilibrium atmosphere inside the packages at 12 °C. At 6 °C, the gas composition inside the packages was kept close to that of the injection, but the equilibrium was not verified.

Irradiation in combined treatments and food safety

Irradiation combined with other processes can contribute to insuring food safety to consumers and controlling severe losses during transportation and commercialisation. We have demonstrated that using in synergy with other treatments; a lower dose could be used to eliminate pathogenic bacteria and permit a better protection of the sensorial quality and to prolong the shelf life of foods. Results indicated that some bacteria are more sensitive to irradiation under modified atmosphere (MAP) and the presence of active compound can increase the bacterial radiosensitivity by more than 4 times under air and by more than 10 times under MAP. Mild heat treatment or addition of natural antimicrobial compounds before irradiation treatment has also permitted an increase of Bacillus cereus radiosensitization. An increase of the bacterial radiosensitization of 1.5 and 1.56 was respectively observed. The effectiveness of the use of edible coating containing natural antimicrobial compounds, modified atmosphere packaging (MAP) or mild treatment before irradiation treatment was demonstrated in order to inactivate Listeria monocytogenes, Salmonella typhimurium, Escherichia coli and Bacillus cereus growth or B. cereus spore germination, to increase the bacterial sensitivity to irradiation, to reduce the water loss and to extend the shelf life of the food when stored at 4 °C. Also, the use of edible coating previously crosslinked by irradiation have permitted a better control of the active compounds release. Studies of combined treatments were used in ready to eat vegetables, fruits and meat products.

Quality of Gamma Ray-irradiated Iceberg Lettuce and Treatments to Minimize Irradiation-induced Disorders

Irradiation of Iceberg lettuce was recently approved by the U.S. Food and Drug Administration (FDA) to enhance microbial safety and to extend shelf life at doses up to 4 kGy. However, the radiation tolerance of whole head lettuce is unclear. The present study was conducted to investigate the effects of gamma irradiation on the quality of Iceberg lettuce and explore means to reduce irradiation-induced disorders. Irradiation (0.5 and 1.0 kGy) induced symptoms similar to russet spotting and other discolorations (pink ribs, rusty brown, and vein browning) in both external and internal leaves during post-irradiation storage in air at 4 °C. Irradiation in the absence of oxygen or pretreatment with 1 ppm 1-methylcyclopropene had little effect on the irradiation-induced tissue discoloration. However, low oxygen atmosphere when maintained during the entire 14-day storage almost eliminated the disorders. Compared with non-treated control, irradiation created significantly lower headspace O2 and higher CO2 levels in the packages, indicating that irradiation promoted respiration. Our results suggest that modified atmosphere (MA) packaging could be used to mitigate irradiation-induced disorders in Iceberg lettuce.

Susceptibility of different life stages of Indian meal moth Plodia interpunctella (Hübner) and almond moth Ephestia cautella (Walker) (Lepidoptera: Pyralidae) to modified atmospheres enriched with carbon dioxide

The susceptibility of the different life stages of the Indian meal moth Plodia interpunctella and almond moth Ephestia (Cadra) cautella to different modified atmospheres (MAs) containing various concentrations of carbon dioxide (CO2) was studied as an alternative to methyl bromide fumigation at 27 °C and 60 ± 5% relative humidity (r.h.). The MAs tested were 40%, 60% and 80% CO2 in air at different exposure times. Results showed that five days were adequate to kill all eggs and pupae of the two moths under all tested MAs. Exposure time needed to be extended to 6 and 7 days at 80% CO2 to obtain complete mortality of larva of E. cautella and P. interpunctella, respectively. The order of sensitivity of P. interpunctella to MAs was: egg = pupa > larva, while for E. cautella it was: pupa > egg > larva. Generally, eggs and pupae of P. interpunctella were more sensitive to MAs than those of E. cautella but the larvae of the latter were more sensitive.

Volatile organic compounds as biomarkers of the freshness of poultry meat packaged in a modified atmosphere

The volatile organic compounds (VOCs) in the packing of chicken meat in a modified atmosphere was qualitatively and quantitatively evaluated. The total number of 72 samples of chicken hindquarters were stored under two different modified atmospheres (70% O&lt;sub&gt;2&lt;/sub&gt;, 30% CO&lt;sub&gt;2&lt;/sub&gt;, and 70% argon, 30% CO&lt;sub&gt;2&lt;/sub&gt;) for 20 days. Analyses were performed on Days 0, 4, 8, 12, 16, and 20. VOCs in the headspace samples were detected and quantified by gas chromatography/mass spectrometry (GC/MS) every fourth day of storage. Pentamethylheptane, dimethylsulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl tetrasulphide, hydrogen sulphide and ammonia were detected. Pentamethylheptane and ammonia had similar values for both modified atmospheres (MA). The other compounds were found only in argon MA from the Day 16 of storage with a subsequent increase of values. The measured values for dimethylsulphide were 10.7 and 13.8 mg/l, for dimethyl disulphide they were 1.9 and 10.7 mg/l, dimethyl trisulphide levels were 15.7&amp;nbsp;and 19.3 mg/l and dimethyl tetrasulphide levels were 93.2 and 418.3 mg/l for Day 16 and 20. The hydrogen sulphide level was detected from 80 to 370 mg/l after the 8&lt;sup&gt;th&lt;/sup&gt; day of storage. We showed that the argon MA is less suitable for packaging raw chicken parts than the oxygen MA in view of the increased amount of microflora and unpleasant odour as assessed by sensory analysis. Oxygen prolonged the shelf life by about four days in comparison with argon. Sensory evaluation was similar for both atmospheres after air exhaustion. The argon MA did not extend the shelf life as compared to the oxygen MA. &amp;nbsp;