Modified Atmosphere Technology Research Articles

A Supervisory Control System for Automation of Horizontal Form-Fill-Seal Packaging Plant Based on Modified Atmosphere Technology

Abstract The packaging industry is one of the most important parts of agricultural products processing. A popular method of increasing the shelf life of agricultural products is modified atmosphere packaging (MAP). The main objective of this paper was to increase the adaptability and flexibility of the machines for packaging of different vegetables including lettuces, broccolis, cabbages, cauliflowers, etc. To achieve this goal, a supervisory control and data acquisition (SCADA)-based system was designed and developed for controlling and monitoring of MAP process of fresh vegetables. The system was divided into three physical layers: field devices, remote terminal unit (RTU) and master terminal unit (MTU). For packaging width adjuster system, the R2, maximum error (ME), mean absolute error (MAE) and root mean square error (RMSE) were obtained as 0.999, 8 mm, 2.96 mm and 3.44 mm, respectively. For packaging height adjuster system, the R2, ME, MAE and RMSE were obtained as 0.994, 10 mm, 3.53 mm and 4.57 mm, respectively. The SCADA system can be able to accurately adjust the speed of the conveyor and the temperature of the sealing jaws, based on the desired values. For gas injection unit, the value of 1.66 L/min, 0.557 L/min and 0.667 L/min were recorded for ME, MAE and RMSE, respectively. Four types of trends including temperature, speed, flow and digital parameter trends were designed. In addition to displaying screen alarms, the occurred alarms are stored, automatically as a text file for troubleshooting. Finally, the results showed that the designed system can be reliably used for MAP of various varieties of fresh vegetables.

Design of Control System for Cultural Relics Testing Room Based on STM32

This paper designs a control system for a cultural relic test chamber based on STM32. The system uses the STM32 processor as the underlying main control of oxygen concentration and humidity and uses an industrial all-in-one machine as the bridge to exchange the information between the cloud server and the bottom master controller. The oxygen concentration, humidity and temperature data of the test chamber can be stored on the server in real-time, and the alarm messages are sent through the cloud SMS platform. The results reveal that the oxygen concentration in the test chamber could be adjusted continuously between 0.6% ~ 10% VOL and the relative humidity could be adjusted continuously within 45% ~ 55% RH, and it can keep stable near the set value. The system can meet the requirements of oxygen concentration and humidity for most cultural relics preservation and can also provide a settable constant oxygen concentration and humidity environment for the related research of anoxic treatment and modified atmosphere technology.

Effects of Edible Coating and Modified Atmosphere Technology on the Physiology and Quality of Mangoes after Low-Temperature Transportation at 13 °C in Vibration Mitigation Packaging.

The mango is an important tropical fruit in the world, but it is easily perishable after harvest. In order to investigate the effect of the compound preservation technology on the physiology and quality of mangoes during transportation and storage, mangoes were treated with different packaging and preservation methods. All mangoes were subjected to simulated transportation by a vibration table for 24 h (180 r/min, 13 °C), and stored at 13 °C. The changes in the color, physicochemical characteristics, quality, and antioxidant-related enzymes of the mangoes were measured. The results show that the shelf life of inflatable bag packing (CK) was only 24 d, while the other treatments could be 30 d. The inflatable bag packing with modified atmosphere packaging (MAP) treatment (HPM) had the lowest yellowing degree (12.5%), disease index (34.4%), and mass loss (2.95%), at 30 d. Compared with the CK, the compound treatment containing MAP prolonged the peak respiration of the mangoes by 6 d and suppressed the increase in the total soluble solids and relative conductivity. Meanwhile, the HPM could effectively maintain moisture content, firmness, titratable acid, vitamin C, and the peroxidase and superoxide dismutase content, indicating that the treatment could maintain the better quality and antioxidation ability of mangoes. In summary, the MAP compound treatment better maintained the commercial characteristics of the mangoes, followed by the edible coating compound treatment. The results provide a theoretical reference for mango cushioning packaging and postharvest storage technology.

The microperforated packaging design and evaluation of shelf life of fresh-sliced mushrooms

Fresh mushrooms have a very short shelf life, of 1 – 3 days because of their high respiration rate and lack of cuticles that protect the plant from external factors. In the case of fresh-sliced mushrooms, they will be more susceptible to spoilage reactions due to the increase in respiration rate as a result of a broader surface area. Conventional packaging materials can not meet the requirements for modified atmosphere packaging of fresh-sliced mushrooms. One of the techniques to extend the fresh-cut produce shelf life is the passive modification of modified atmosphere packaging technology. For highly respiring fresh-cut produce such as fresh-sliced mushrooms, the permeability properties of the polymeric materials might not be enough to provide an equilibrium gas concentration in the passive modification of modified atmosphere technology. In this case, the microperforated packaging materials can be used for passive modification of fresh-cut produce. But the microperforation process needs a design for the application of the appropriate number and diameter of microholes to meet the requirements of passive modified atmosphere packaging. For this reason in this research, the design of the microperforation process to be used in passive modified atmosphere packaging was based on the diameter and the number of microholes, and the shelf life of fresh-sliced mushrooms was determined. The samples were stored at 15 °C/80% RH, and pH, color, weight loss, textural, sensorial, and microbial analysis were performed periodically during storage. It was determined that the empirical equation used in this research can be applied to microperforated packaging design for fresh-sliced mushrooms. The shelf life of the fresh-sliced mushrooms packaged with microperforated packaging material was 8 days, while it was less than 7 days (4, 5, or 6 days) when packaged with non-microperforated packaging material. This result shows that the use of microperforated packaging material is effective in extending the shelf life of fresh-sliced mushrooms.

IMPORTANCIA DEL EMPAQUE PARA LA COMERCIALIZACIÓN DE LA CEBOLLA EN RAMA (ALLIUM FISTULOSUM) EN BOYACÁ

Due to the economic potential of the department of Boyacá in relation to the cultivation of Green onions (Allium fistulosum) or junca which is 195,358 tons, corresponding to 67.4% of the total production of the country. The implementation of adequate packaging in order to preserve the vegetable for longer, minimizing transport damages and providing added value by expanding its markets while conserving its organoleptic characteristics, is relevant for the productive sector of the department of Boyacá. The objective of this article is to provide information about current post-harvest processes implemented by producers, evidencing the possible losses of the vegetable caused by the handling observed in the field works carried out in the municipality of Aquitania Boyacá. And also the packaging alternative using modified atmosphere technology and the advantages of its implementation for the sector. The implemented methodology consist of collecting information in primary and secondary bibliographic sources such as scientific articles, web platforms and field visits made directly to the crops in cooperation with the association named Parcela as a source of participant observation. As a result, it was observed a minimal use of package and packaging by producers and their preference for traditional practices that do not allow to generate value to the harvested product, limiting to marketing and sale in storage centers or intermediaries. The packaging technology using modified atmosphere is important for preserving the product. In this way it extends its lifetime, minimizes the loss of quality and conserves its organoleptic characteristics; Likewise, this package reduces damages caused by transportation. these implementations contribute to a considerable improvement in its production chain adding value to the product.

Reducing Atmosphere Packaging Technique for Extending the Shelf-life of Food Products

Food processors generally apply different techniques to extend the shelf-life of food products according to the characteristics of the product. Modified Atmosphere Packaging (MAP) uses different gases in specific combinations to replace the air surrounding the product, which leads to minimize the undesirable oxidation reactions and microbial spoilage growth permitting extending the shelf-life of the product. The property of the Reducing Atmosphere Packaging (RAP) technique is the use of reducing gas like hydrogen besides other gases such as nitrogen, argon and carbon dioxide. The advantage of the presence of a reducing gas in the gaseous combination is the prevention of the oxidation reactions such as the formation of free radicals, the deterioration of vitamins such as C, E and beta-carotene, the deterioration of pigments such as carotenoids and the formation of off-flavors like the rancidity products. The prevention of the latter undesirable reactions aides to protect the freshness notes of the food products by preserving its natural color, taste and aroma, as well as the protection of the nutritional quality. The literature contains a few researches concerning the application of RAP on different food products. This is the first review reporting the potential application of hydrogen in modified atmosphere technology for extending the shelf-life of food products.

Storage of soybean seeds: Packaging and modified atmosphere technology

ABSTRACT The characteristics of materials used in packages for seed storage may have a negative influence in the deterioration process, causing future problems during the period of storage and in emergence in the field. In this study, the objective was to evaluate the physiological quality of soybean seeds, stored in different packages with and without the addition of CO2 (modified atmosphere), for different periods of storage and in uncontrolled environmental conditions. In order to carry out the experiment, a completely randomized design was used in a split-plot scheme, with three types of packages (permeable, hermetic package inside the permeable package and hermetic package inside the permeable package with CO2 injection) in the main plot and six storage periods (zero, 45, 90, 135, 180 and 225 days) in the subplot, with four repetitions, totaling 72 experimental units. In hermetic packages multi-layer paper was used with or without CO2 injection, stored them for 225 days and performed an assessment at regular intervals of 45 days. At each period, the seeds were submitted to tests for moisture content, germination, seedling emergence, accelerated aging and electrical conductivity. The hermetic package, with and without CO2 injection, decreases the speed of deterioration of soybean seeds. The hermetic package allows a higher physiological quality of soybeans compared to the permeable package, with a storage period of up to 180 days under uncontrolled environmental conditions. The addition of CO2 inside the hermetic packages favors the maintenance of the physiological quality of soybean seeds in storage.

Passive modified atmosphere affects the quality of minimally processed escarole

This study aimed to evaluate the quality changes of the minimally processed escarole under passive modified atmosphere, packaged in different flexible plastic packages, which included polyvinyl chloride (PVC) stretch film, low-density polyethylene (LDPE) bag, polypropylene (PP) bag, and bi-oriented polypropylene (BOPP) bag, during storage for 20 days at 0°C and 90%–95% RH. The atmosphere of 16% O2and 3% CO2 formed in the PVC overwrap package provided the lowest browning index and the best conservation of ascorbic acid, chlorophyll, and carotenoids. During the experiment, no differences in phenolic compounds and polyphenol oxidase activity among the treatments were observed, while the activity of peroxidase showed peaks in different analysis days. Weight loss of all samples did not exceeded 1%. The minimally processed escarole showed sensitivity to high CO2 concentrations. Thus, a simple PVC stretch film provided the best visual and nutritional preservation of the minimally processed escarole. Practical applications Escarole is one of the most consumed leafy vegetable as a minimally processed product, however, there is no information about its quality changes associated with the package. This produce is widely commercialized in the same package of other leafy vegetables. This research has focused on application of passive modified atmosphere technology for quality preservation of escarole during storage, in order to indicate the most adequate package for its quality and nutritional conservation. The results implied that the quality of minimally processed escarole is better-maintained using PVC stretch film, which is quite different from the usual plastic bags used for minimally processed leafy vegetables. This information is quite interesting at processer and market levels in order to standardize the packaging of this product and prolong its visual and nutritional quality.

Modified Atmosphere Packaging (MAP) and the Effect of Chemical Preservative to Enhance Shelf Life of Khoa (Heat Desiccated Milk Product)

Khoa is an indigenous heat desiccated milk product having very poor shelf life. At ambient condition, shelf-life of Khoa is normally only 2 days. The aim of present study was to determine the effect of benzoic acid as preservative as well as modified atmosphere packaging (MAP) technology to enhance shelf life of Khoa at 27 ± 2 °C and 65% RH. During storage, analysis of chemical, sensory as well as microbiological characteristics were taken into consideration to mark distinguishable changes between the package of modified atmosphere technology (MAP) and ordinary packed Khoa (with and without preservative) samples. The results indicated a significant decrease of moisture content, pH and sensory scores and increase in titratable acidity, standard plate count and yeast and mould count during storage, irrespective of the type of packaging conditions. However, the rate of changes in characteristics of product packed in modified atmosphere was found to be slow. The storage study indicated that the Khoa packed in ordinary packaging, with and without preservative, was acceptable for 8 and 4 days, respectively, whereas for modified atmosphere packed samples, it was consumable up to 12 and 8 days respectively.

USO DE REVESTIMENTO COMESTÍVEL PARA EXTENSÃO DA VIDA ÚTIL DA GOIABA ‘PEDRO SATO’

A goiaba possui intensa atividade metabólica, requerendo o uso de tecnologias pós-colheita para extensão de sua vida útil e manutenção da qualidade. Como é fruto que se consome com a casca, a aplicação de revestimento comestível é uma tecnologia de modificação da atmosfera passível de ser implementada. Objetivou-se, com esse trabalho, avaliar índices de qualidade pós-colheita de goiaba ‘Pedro Sato’, tais como vitamina C, licopeno, β-caroteno, glicose, frutose, sacarose, etc., submetida a três diferentes revestimentos comestíveis (à base de amido de mandioca, alginato de sódio ou carboximetilcelulose) e armazenamento refrigerado à 10 oC. Independentemente do tratamento aplicado, as goiabas ‘Pedro Sato’ alcançaram maiores teores de vitamina C após o armazenamento prolongado de 22 dias. Por outro lado, o uso de revestimentos comestíveis à base de amido e alginato foram eficientes em retardar o amadurecimento das goiabas ‘Pedro Sato’ armazenadas por quatro dias sob refrigeração, seguidos de três dias em temperatura ambiente. As goiabas revestidas com amido de mandioca apresentaram os maiores teores de licopeno (ação antioxidante) e de β–caroteno (precursor da vitamina A no organismo humano), nos períodos de armazenamento mais prolongados, podendo-se recomendar este revestimento comestível para o armazenamento desse fruto, para que se obtenha maior retenção de importantes atributos de sua qualidade.

Modified Atmosphere Systems and Shelf Life Extension of Fish and Fishery Products.

This review aims at summarizing the findings of studies published over the past 15 years on the application of modified atmosphere (MA) systems for shelf life extension of fish and fishery products. This review highlights the importance of CO2 in the preservation of seafood products, and underscores the benefits of combining MA technology with product storage in the superchilled temperature range. It is generally accepted that MA technology cannot improve product quality and should not be utilized as a substitute for good sanitation and strict temperature control. Benefits derived from application of MA, however, can significantly impact preservation of product quality and it subsequent shelf-life. For this reason, this review is the first of its kind to propose detailed handling and quality guidelines for fresh fish to realize the maximum benefit of MA technology.

Main Technical Differences in the Processing of Broilers: A Comparison between Slaughterhouses in Brazil and UK

Rapid technological advances in chicken processing in plants around the world have meant that different techniques are being employed regarding the slaughter’s flow process. This paper aimed to compare and contrast systems and practices in two large slaughterhouses—one in UK and the other in Brazil. Annotated observations were made during inspection visits to chicken slaughterhouses in the two countries between 2014 and 2016. Whilst there were similarities in the two systems, there are also clear differences. The Brazilian case is evidently adapted for a more tropical condition, rather than the temperate one in UK. The handling practices of birds used during transportation, waiting, stunning as well as pre-cooling differ in techniques employed and consequently likely their efficiencies. In UK, the practices are more geared towards water and energy saving. The difference in market conditions and the length of the respective supply chains also determine the type of primary packaging used in final products. Both countries adhere to similar rulings applied to slaughterhouses. However, in the Brazilian case, it tended to comply with mainly external market demands. In conclusion, managers in the Brazilian poultry system could consider looking into adopting some of the practices used in UK, such as cage/crate dimension which reduce bird’s lesions and bruises; the use of stunning by modified atmosphere and pre-cooling for resource efficiency reasons and improvement in animal welfare. Finally, when distances between sites of production and consumption are great such as in Brazil, the use of modified atmosphere technology could be also further explored to ensure better quality of the final product.

Rachis browning in tablegrapes

Rachis browning is considered the second most important postharvest problem of tablegrapes. The primary problem, control of decay, was extensively studied in recent years, often with minor attention to rachis browning. To the consumer, a green rachis is an indication of freshness, and hence, a brown rachis can be a major cause of consumer rejection and eventually fruit waste. The significant advantage of the sulfur dioxide technology in its various forms of application is that it can prevent both decay and reduce rachis browning. Such an advantage is partly why alternative control measures, which may be significant for control of decay, did not develop further. Understanding rachis browning starts with a description of methods to measure it. Dehydration is considered the primary cause of browning, and therefore, packaging and other technologies which decrease dehydration are discussed. Controlled and modified atmosphere technologies may have opposing effects on rachis browning, making it important to be familiar with the wider picture. It is also important to realise the effect of various other treatments in which rachis browning was measured, because it can hint on what has, and has not, a potential to reduce it. The effect of plant-growth regulators is discussed with special emphasis on the potential role of ethylene in enhancing rachis browning and ethylene antagonists in reducing it. It is suggested that controlling rachis browning may require dedicated treatments based on physiological and molecular mechanism of browning in combination to control of decay.

Comportamiento de frutos de tomatillo (Physalis ixocarpa Brot.) con cáliz y sin cáliz en atmósfera modificada

The behavior of untouched (with calyx) and removed husk (without calyx) “tomatillo” husk tomato fruit (Physalis ixocarpa Brot.) was evaluated in postharvest, for four weeks, at 20 °C, in modified atmosphere technology (MAP), with plastic films brands Bol Rol® (BR; 25 cm × 38 cm, 16.8 mm thick) and Ziploc® (ZP; 27 cm × 28 cm, 52.2 mm thick). The removal of calyx caused a reduction in the rate of O2 consumption, loss of water and loss of firmness; for that reason, the removal of husk was considered to be a beneficial practice. There was no significant effect in the total soluble solids contents, nor the acidity, sugars or color attributes, which was also considered to be beneficial since the parameters that define the quality of the fruit were not altered. By using plastic bags, the O2 concentration was reduced and the CO2 concentration increased in the fruit environment. The Ziploc® bags allowed higher values of firmness; thus, they were considered better than the Bol Rol® ones to implement MAP. The removal husk reduced the risk of fermentative metabolism and for a 20 °C condition it is recommended handling tomatillo, husk tomato with removed husk for 13 days in modified atmosphere.

Modified Atmosphere Technology in Seed Health Management: Laboratory and Field Assay of Carbon Dioxide Against Storage Fungi in Paddy

Modified Atmosphere Technology in Seed Health Management: Laboratory and Field Assay of Carbon Dioxide Against Storage Fungi in Paddy

Effects of innovative packaging materials on apricot fruits (cv Tom Cot®)

Introduction . Innovation in the management of perishability/freshness is an essential theme of the future fruit sector, not only for commercial and distribution systems but also for production. Plastic films with modified atmospheres represent a postharvest technology that can be used to store stone fruits, such as apricots, that have a short shelf life when maintained in a normal atmosphere under cold conditions. The aim of our work was to evaluate the effect of several packaging materials on the postharvest quality of apricot fruits stored for 21 days by considering the most important qualitative traits. Materials and methods . Modified atmosphere technology with different packaging materials was used to store apricot fruits cv. Tom Cot® at (+1 ± 0.5) °C and 90–95% relative humidity (RH). Different passive modified atmosphere packaging (MAP) conditions were developed because of the interaction between fruit respiration and the different oxygen and carbon dioxide barriers of the films. The effects of MAP were evaluated on the postharvest quality of the fruits by monitoring the headspace gas composition, weight loss, fruit flesh firmness (FFF), total soluble solids content (TSS), titratable acidity (TA) and skin colour. Results and discussion . Changes in packaging headspace gas composition were observed for all films used, but only multilayer films and biodegradable film maintained the MAP conditions until the end of storage. Wrapped fruits lost less weight than fruits maintained under normal conditions; in particular, multilayer films maintained the highest FFF values after 21 days. The biodegradable film exhibited good performance in terms of maintaining the CO2 and O2 equilibrium inside the baskets by balancing the fruits’ respiration and the film’s permeability. Traditional plastic materials, such as multilayer films, and more sustainable films, such as the biodegradable film used in our study, can be successfully employed to store apricot fruits cv. Tom Cot® for up to 21 days in passive MAP conditions.

Development of antimicrobial films for microbiological control of packaged salad

The aim of the present work was to characterize the antimicrobial efficiency of films consisting of PP/EVOH structures with oregano essential oil and citral. Both substances are known for their antimicrobial activity based on their interaction with the cell membrane. The films developed were used to pack minimally processed salads, combining modified atmosphere technology to extend shelf-life and active packaging technology to reduce possible microbiological risks. The antimicrobial activity of the films against the pathogenic microorganisms Escherichia coli, Salmonella enterica and Listeria monocytogenes and natural microflora was investigated “in vitro” and also on the food itself. The effect of release of the antimicrobial agent on the sensory characteristics of the salad was also studied. The results showed that antimicrobial activity reduced spoilage flora on the salad as well as inhibited the growth of pathogens in contaminated salads. This effect was greater against Gram-negative bacteria. Sensory studies showed that the package that was most effective and most accepted by customers was the one containing 5% oregano essential oil.

QUALITY CHANGES IN FRESH-CUT CAPSICUM (CAPSICUM ANNUUM) SHREDS UNDER MODIFIED ATMOSPHERES DURING SIMULATED RETAIL AND HOME STORAGE

ABSTRACT Capsicum shreds were stored under modified atmosphere packaging in differentially perforated and nonperforated packages at 5 and 15C. Chlorophyll was largely maintained at both storage temperatures in perforated packages having two macroperforations. Maintenance of chlorophyll in nonperforated packages was not considered to be beneficial in view of anaerobic environment at 15C, which affected other qualitative constituents adversely. While the ascorbic acid deteriorated at a faster rate in nonperforated packages at both temperatures, it was better retained in all perforated packages. A decrease in storage temperature to 5C resulted in rapid oxidation of phenolic content, while it was hampered in nonperforated packages. Because all the objectively assessed qualitative characteristics could not be maintained under a single gas condition, subjectively evaluated sensory ratings could point out that in-pack atmosphere under two perforations could be used for a storage period of 5 days under simulated storage environment. PRACTICAL APPLICATIONS Minimally processed capsicum has high rates of respiration and due to non-utilization of standardized packaging has a shorter shelf life at the retail shelves and, thereafter, at the consumer level. This research has focused on application of modified atmosphere technology under simulated storage environment at the retailer and then at the customer level for minimally processed capsicum shreds. The results of the study have implied that a shelf life of 5 days from processing to consumption along with maintenance of various physicochemical constituents can be attained using the perforated packaging instead of the conventional nonperforated packages being used commercially. These results have potential application at the level of processer and retailer engaged in the postharvest chain of capsicum processing. Utilization of the results of this research is likely to aid them to standardize the packaging of capsicum shreds and maintain its better shelf life and various physicochemical constituents.

Modified and controlled atmosphere storage of subtropical crops

Purpose of the review: This article addresses the use of modified atmosphere (MA) and controlled atmosphere (CA) storage for the preservation and maintenance of the postharvest quality of subtropical fruits. There have been great technological advances, especially in improving the quality and shelf-life of fresh-cut produce. Thus, this review focuses on MA and CA technologies that are either commercially available or under investigation. Recent findings: Under MA and CA conditions, the respiration rate of the fruit is decreased and, as a direct effect, the consumption of respiration substrates such as organic acids and sugars is retarded, and the growth of micro-organisms is suppressed. Therefore, MA and CA are helpful in maintaining the quality of many subtropical fruits. Limitations: When using these technologies, careful attention must be paid to the survival and growth of pathogenic organisms in the enclosed conditions due to high relative humidity, particularly at warm non-chilling temperatures. Directions for future research: More research is needed on the microbiological safety of fresh-cut subtropical fruits and the effect of antimicrobial films on various intact and fresh-cut subtropical commodities. Interaction between various gas concentrations, both MA and CA, the development of pathogenic micro-organisms and finding better film types for different species and cultivars of subtropical fruits also merit further research.

Efeito da atmosfera modificada e da refrigeração na conservação pós-colheita de manga espada vermelha

Este trabalho visou avaliar o comportamento pós-colheita da variedade de manga Espada Vermelha em refrigeração e o potencial da tecnologia de atmosfera modificada na conservação pós-colheita. A atmosfera modificada foi conseguida através do uso de PVC (6µm), PEBD (25µm), PEBD (25µm) com sachê absorvedor de etileno de permanganato de potássio, filme de permeabilidade seletiva aditivado com absorvedor de etileno (Conservax) e controle (sem filme plástico). Os frutos foram mantidos a 12°C e 90% UR. A avaliação da qualidade foi feita semanalmente logo após a saída dos frutos da refrigeração e após a sua permanência por 4 dias, em temperatura ambiente. Foram feitas determinações de perda de peso individual dos frutos, evolução da cor da casca e da polpa, taxa de firmeza dos frutos, ocorrência de manchas deteriorativas, pH da polpa, teores de sólidos solúveis (°Brix), porcentagem de acidez (% de ácido cítrico) e cálculo da relação °Brix/acidez. PEBD+sachê influenciou positivamente a manutenção da qualidade e o Conservax prejudicou a maturação dos frutos de manga.