Active Packaging and Intelligent Packaging for Fruits and Vegetables

Active packaging of Fruits and Vegetables

Table of Contents

1. Introduction

2. Active Packaging

2.1 Oxygen Control

2.2. Ethylene Control

2.3. Moisture Control

2.4. Antimicrobial Packaging

3. Intelligent Packaging

4. Conclusion

5. References

1. Introduction

 Feeding of exponentially increasing world population meanwhile meeting the food safety regulations are challenging the food industries. Packaging is an essential step for food processing that can contribute to quality, safety, shelf-life, convenience and economic viability of foods. There are escalating demands of longer shelf-life and better quality retention for foods because of economic globalization. Technologies for packaging are therefore evolving in response to market needs. Shipping fresh produce, such as fruits and vegetables over long distance and maintain

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 The traditional role of packaging is a container for foods, which can improve efficiency of transportation on processing lines, prevent foods from damaging, and maintain food quality and safety to consumers (Ozdemir & Floros 2004). Packaging is a barrier that exists between foods and external environment to protect foods from oxygen, moisture, light, volatiles, physical, chemical, as well as biological hazards contamination. Perish produces may experience shipment delay or temperature abuse during transportation causing food spoilage or over ripening, which will lead to economical lost. However, not as inert traditional packaging, active packaging is defined as a system that aims to enhance the function of packaging by interacting with food and/or environment (Lim, 2011). Furthermore, intelligent packaging system came into sight that can help monitor the conditions and quality of products through specific indicators, such as freshness indicators and radio frequency identification tags (Siddiqui et al. 2018).

The challenges of fruits and vegetables packaging mainly are based on their post-harvest metabolism: respiration, ripening and senescence; the metabolism can only be slow down but cannot be stopped (Siddiqui et al. 2018). Respiration rates of fruits and vegetables is influenced by many factors such as species, temperature, component of atmosphere and humidity (Gross et al. 2004). Other than these, fresh cut products have higher respiration rates because of stress generated from mechanical cutting (Kader & Saltveit 2003). Therefore, the design of packaging for fruits and vegetables should focus on building a suitable gas atmosphere for respective product, such as optimum oxygen and carbon dioxide level in the headspace gas of packaging (Siddiqui et al. 2018). In general, oxygen level of in packaging of fruits and vegetables should be in the range from 0.5% to 5% to maintain aerobic respiration (Kader et al. 1989). Reduced oxygen level in the packaging has been proved to effectively slow down product ripening (Siddiqui et al. 2018). However, too low oxygen level can lead to anaerobic respiration, which result in off-flavors and deterioration of products (Siddiqui et al. 2018). Besides reduced oxygen level, increase of carbon dioxide concentrations can slow down the respiration rate although carbon dioxide tolerance levels are different from foods types. For example, the carbon dioxide tolerance levels for tomatoes and grapes are about 2% while the level in melons and berries can be high up to 15% (Siddiqui et al. 2018). Unlike other food products, fresh produces, such as fruits and vegetables, requires gas permeable or perforated packaging materials allowing gas exchange to retain quality. Due to natural respiration of fruits and vegetables, the atmosphere inside packaging will gradually has elevated carbon dioxide level and decreased oxygen level, which is challenging to retain quality of products (Siddiqui et al. 2018). In order to extend shelf-life of fruits and vegetables, in-packaging atmosphere cooperating with packaging materials with different permeability have to work together to reach optimum gas atmosphere for packaging (Siddiqui et al. 2018). Equilibrium MAP is introduced to take both of gas transferal through film and respiration rates of fruits and vegetables into consideration so that optimum gas atmosphere can be achieved (Siddiqui et al. 2018).

Microbial loads are another important factor that can affect shelf-life of fruits and vegetables (Siddiqui et al. 2018). Although the microorganisms may not affect human health, it could cause rapid decay in fresh produces if they are not correctly stored or handled (Siddiqui et al. 2018). Preventing fresh produces from further contamination at packaging level is as important as decontamination step before packaging. Both of MAP and antimicrobial packaging are able to contribute in delaying growth of microorganisms so that to ensure food quality and safety (Siddiqui et al. 2018). 

This review is going to investigate different active packaging methods in fruits and vegetables: oxygen control, ethylene control, moisture control, and use of antimicrobial agent in packaging. Intelligent packaging, mainly freshness indicators, is also mentioned in this assignment. 

2. Active packaging in Fruits and Vegetables

2.1 Oxygen control

Generally, oxygen can cause off-flavour, colour change, oxidative degradation, loss of nutrients, and accelerate spoilage in fruits and vegetables, which can greatly affect consumers’ purchasing at retail level. Oxygen absorbers can be introduced to extend the shelf life of fruits and vegetables by removing amount of oxygen from void atmosphere in packaging and inhibiting growth of aerobic microorganisms. Use of oxygen absorber, are considered as one of active modified atmosphere packaging (MAP). Active MAP generally consists of gas-scavenging or gas flushing to reach suitable environment within the package (Charles et al. 2003). Oxygen absorbers can be used to effectively reduce O₂ partial pressure inside package and also available for absorbing O₂ permeated from external environment (Charles et al. 2003). Oxygen sensitive products, such as lettuce and potato requires atmosphere of less than 1% oxygen to slow browning caused by polyphenol oxidation (Charles et al. 2003). Example of oxygen absorber includes enzymes (glucose oxidase), any metal that can react with oxygen (iron, zinc, etc.), and ascorbic acid based scavengers (Vitamin C).

One common oxygen absorber is iron carbonate, which is usually contained in a sachet adding to MAP (Cichello 2015). Iron carbonate is a salt that can react with oxygen and moisture through oxidation so that the oxygen can be removed from atmosphere of headspace. Although the iron-based oxygen absorber is usually used in dry packaged products, Charles et al. (2003) successfully extended shelf-life of tomatoes by implementing iron-based oxygen absorbers in packaging with tomatoes Furthermore, Emenhiser et al. (1999) conducted experiment on use of oxygen absorbers in vacuum sealed dried sweet potato chips with films made by high barrier polypropylene and nylon laminate, respectively. Both of high-barrier polypropylene and nylon laminate films act as an oxygen barrier; only permeate low level of oxygen. Researchers concluded that the combination use of oxygen absorbers and high barrier polypropylene film can effectively retain B-carotene at highest level over 210 days (Emenhiser et al. 1999). In addition, Tarr & Clingeleffer (2005) assessed the life cycle stages of Tribolium castaneum (red flour beetle) in a sealed bag of sultana raisins with or without use of oxygen absorbers. The sealed bag with oxygen absorbers caused 100% of mortality rate of red flour beetles with no eggs or pupae in all sections with different temperature and time. In contrast, eggs and pupae were found in sealed bag without oxygen absorbers storing at 22.5C for 20 days as well as 30C for 9 days although the adult red flour beetles all died (Tarr & Clingeleffer 2005). Other than this, Tarr & Clingeleffer (2005) compared the color change on sultana raisins stored at different temperature and period with and without using oxygen absorbers in sealed bag. Researchers found that the combination of low temperature storage (15C) and oxygen absorbers are able to maintain color of the fruit for at least 45 days. However, the significant negative color changes were found in the fruits without oxygen absorbers at higher temperature and longer time (30C for 9 days and 22.5C for 20days) (Tarr & Clingeleffer 2005).

However, oxygen scavenger could cause problems when the oxygen level inside package of fruits and vegetables becomes lower than the tolerance limit, which may result in anaerobic conditions and causes malodorous compounds and growth of anaerobic microorganisms (Charles et al. 2003). Therefore, it is necessary to take absorber activity into consideration in order to reach longer shelf life and better quality of fruits and vegetables (Charles et al. 2003).

2.2 Ethylene Control

 Ethylene is a natural hormone produced by fruits and vegetables that can stimulate growth and accelerate respiration of fruits and vegetables (Ozdemir & Floros 2004). The hormone plays many essential roles in growth of fruits and vegetables, such as flowering, color and volatiles development (Coles et al. 2003). However, exposure to ethylene on other hands could be undesirable; ethylene can reduce the shelf-life of fruits and vegetables, particularly for climacteric fruits. Vegetables in comparison are not that sensitive to ethylene (Vermeiren et al. 2003). Therefore, ethylene should be removed from the package.

Ethylene scavengers can be applied in filming, sachet, paper bags and cardboard boxes; they usually consists of potassium permanganate, activated carbon, and mineral substrates (Coles et al. 2003). Potassium permanganate is able to react with ethylene forming acetate ethanol so that ethylene can be removed while carbon-based ethylene scavengers absorb ethylene in the atmosphere and then break them down (Coles et al. 2003).

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 Patricia et al. (2002) impregnated plastic films (PVA) into ethylene scavengers agent to test their effects on apple storage. Compared to the apples wrapped in regular PVA, the study demonstrated that the apples coated with treated PVA film have longer shelf-life. In addition, Abe and Watada (1991) conducted a study about effects of ethylene scavenger sachets containing charcoal and palladium chloride on fresh cut kiwifruit, bananas, spinach, and broccoli. After packaging the fruits at 20C for two days, the researchers found that the kiwifruits and bananas with ethylene scavenger were firmer than the controls, which indicated that the removal of ethylene can retain quality of kiwifruits and bananas. They also found that spinach leaves had less chlorophyll less under effect of ethylene scavengers but not in broccolis. However, Esturk et al. (2014) demonstrated that broccolis covered by LDPE films with ethylene scavenger (zeolites) can maintain high quality in terms of total soluble solids, total phenolic content, mass loss, chlorophyll loss and stem hardening at 4C for 20 days, whereas, the broccolis wrapped in only LDPE films were susceptible to anaerobic fermentation after 5 days storage because of less than 1% of oxygen concentration (Esturk et al 2014). The ethylene contents in samples with ethylene scavengers were limited to 0.33ppm, which was greatly different from 61.8 ppm of ethylene in samples without ethylene scavengers (Esturk et al 2014).

Much studies indicated that the positive effect of ethylene scavengers in many fruits and vegetables. However, active packaging system involves ethylene scavengers cannot success until the capacity, absorption rate of the scavengers, film permeability of ethylene as well as ethylene tolerance of different fruits and vegetables have been deeply studied.

2.3 Moisture control

Fresh fruits and vegetables usually have high water activities so the recommended packaging conditions are about 85%-95% of relative humidity. Low humidity level causes shriveling of produces while too high humidity level leads to undesirable microbial growth (Ben-Yehoshua & Rodov, 2003). Humidity absorbers are designed for reducing humidity level in the packages to a proper level in order to extend shelf-life of fresh fruits and vegetables (Rux et al. 2016). There are many available humidity absorbers, such as sorbitol, sodium chloride, potassium chloride, and bentonite (Rux et al. 2016). Sodium chloride, potassium chloride, sorbitol are considered as fast humidity absorbers while bentonite has relatively slower absorption rate than the salts and sorbitol.

Deliquescent salts, for example, NaCl, can absorb moisture rapidly when relative humidity in the gas atmosphere over than 75% (Rux et al. 2016). However, this process is reversible, which means that when the humidity level lower than 75%, humidity absorbers would release water vapor (Rux et al. 2016). Therefore, deliquescent salts act as humidity regulator that could be able to buffer the fluctuation of humidity level in the package (Rux et al. 2016). Shirazi and Cameron (1992) stored red-ripe tomatoes in LDPE film package with 20g of NaCl absorbers at 20C and tested the shelf-life of tomatoes comparing to controls without NaCl absorbers. The results showed the shelf-life of tomatoes with NaCl absorbers were 10-12 days longer than the controls. Mahajan et al. (2008) tested combination use of CaCl₂ (20%), sorbitol (25%) and bentonite (55%) on mushrooms (Agaricus bisporous). In the test, researchers prepared 250g of mushroom samples with and without different amount of mixed desiccants covered by PVC film and stored at 10C for five days (Mahajan et al. 2008). Mahajan et al. (2008) concluded that use of 5g of mixed desiccant in 250 g of mushroom had greatest overall appearance through sensory evaluation.

In packages of fresh fruits and vegetables, condensation could form if relative humidity is high or leakage happened on products, which lead to formation of water droplet on the covering film and products. Antifog film can solve this problem by absorbing water molecule and forming a thin invisible film instead of water droplets (Isaka & Ohta 1989). Antifog film is made of hydrophilic materials, which have high affinity to water. Use of antifog film can prevent condensation in fruits and vegetables packaging with no influence on humidity level, but the consumers can get products with better out looking. 

Proper amount of humidity absorbers can prolong shelf-life for specific fruits or vegetables. However, there are many factors should be taken into consideration before choosing moisture absorbers, such as species, water vapor permeability of packaging materials, storage condition of produces, absorption capacity of absorbers and initial humidity level (Coles et al. 2003).

2.4 Antimicrobial Packaging

 Growth of undesirable microorganisms on fruits and vegetables are important factors affecting products’ short life, which could result in spoilage and pose threats to food safety. Antimicrobial packaging can effectively reduce microbial contamination and therefore extend shelf life of products. Antimicrobial packaging requires use of antimicrobial agents; there are two types of antimicrobial agents: volatile and non-volatile (Siddiqui et al. 2018). Non-volatile agents has to contact with packaging material and surface of products constantly, for example, organic acids, enzymes, bacteriophages and polysacchrides (Siddiqui et al. 2018). In contrast, volatile agents can be easily spread in the atmosphere with no direct contact with products, such as ethanol, essential oils, and sulfur dioxide (Siddiqui et al. 2018). Non-volatile antimicrobial packaging is usually used in vacuum-packed products while volatile antimicrobial packaging is suitable to bag-packed products (Siddiqui et al. 2018). Antimicrobial packaging can present in varies form such as sachets with volatile antimicrobial agents, packaging films and food coatings (Siddiqui et al. 2018). Surveys showed that consumers preferred antimicrobial agent derived from natural sources more over synthetic ones (Burt 2004 & Lee 2005).

 Seo et al. (2012) tested effect of allyl isothiocyanate as volatile antimicrobial agent against E.coli on spinach leaves. Allyl isothiocyanate is extracted from mustard essential oil and encapsulated in the beads containing in sachets (              Seo et al. 2012). In 5 days, the antimicrobial sachets is able to inactivate 5.7 log of E.coli at 25C and 2.6 log of E.coli at 4C (Seo et al. 2012). It had to mention that lower temperature can affect volatile ability of antimicrobial agents. In addition, Murriel-Galet et al. (2012) integrated oregano essential oil and citral within PP film and tested the antimicrobial efficiency on salads against Escherichia coli, Salmonella enterica and Listeria monocytogenes. Researchers proved that the film containing 5% oregano essential oil had the most effects on preventing the growth of pathogens in salads. Besides, the salad covering with 5% oregano essential oil is most accepted in the sensory study. Furthermore, Fernández et al. (2010) conducted an experiment on antimicrobial effect of absorbent pads on fresh cut melon at 4C for 10 days; the absorbent pads consisted of cellulose fibers with 1% of silver nitrate nanoparticles adsorbed. The researchers found that the melon with presence of adsorbent pads had total counts of 3 log CFU/g lower than the melons with no adsorbent pads (Fernández et al. 2010). Besides that, the researchers also demonstrated that the melons with adsorbent pads have higher sugar content and juicer appearance compared to the control (Fernández et al. 2010).

  Due to the health and safety concern, consumers nowadays prefer using ingredients and materials that are derived from natural source in food production (Burt 2004). Therefore, there is an increasing trend of using essential oils as antimicrobial agents. However, essential oils generally contain strong sensory attributes, which could negatively affect flavor of products (Antunes and Cavaco 2010). Sensory evaluation have to be taken into consideration while using the technology of antimicrobial packaging.

3. Intelligent Packaging

Intelligent packaging refers to the packaging methods that can monitor the status and quality of foods, but doesn’t have effects to modify in-package environment or extend shelf life (Yam 2012). Intelligent packaging is able to communicate with stakeholders and act as support tool for them by providing information of changes of internal and external environment and conditions of products (Kerry et al. 2006). Common intelligent packaging involves indicators, data carriers and sensors (Ghaani et al. 2016). Indicators can pass the quality information to consumers, such as warning consumers if the produces had expired or if the produces exposed to any potential hazards or extreme environments (Ghaani et al. 2016). Quality changes of products can be visually presented on the indicators (Ghaani et al. 2016). The rate of change on the indicators should depend on the rate of change on the deterioration of products. Data carriers are usually used for tracing purpose and storage management, for example, radio frequency identification tags (Ghaani et al. 2016). Sensors are designed for quantifying corresponding analytes rapidly (Ghaani et al. 2016). This section is going to focus on the freshness indicator, which is commonly used for fruits and vegetables.

Freshness indicators of fruits and vegetables are designed based on pH change of headspace gas. Spoilage of fresh fruits and vegetables lead to increase in pH over time because of loss of total volatile acids Anthon et al. 2011). The dye in the indicators will change color by sensing pH increase simply. Kuswandi, et al. (2013) developed a simple and cost efficient ripeness indicator for strawberries based on using methyl red. Methyl red were absorbed onto bacterial cellulose membrane and able to interact with volatile acids changing color from yellow to red-purple as the pH increases over time (Kuswandi, et al. 2013). Mixed-dye-based indicators contain more colors and are more sensitive to pH change. By using the freshness indicator, packaging can effectively communicate the freshness condition of product with consumers. Compared to use of best before date, freshness indicator is more sensitive with less error. It is an easy and real time checking of food quality providing convenience to consumers.

Figure 1.Freshness indicator used on packaging of fruits(from internet)

 Ripeness indicators a type of freshness indicators, but the ripeness indicators are more applicable in fruits packaging. There are many different ripeness indicators. Ethylene is a good component that could be sensed by ripeness indicators for climacteric fruits, such as apples and guavas. For example, Figure 2 showed a ripeness indicator designed by Ripe-Sense™. The sensor label on the packaging can indicate the ripeness of guavas by sensing the aroma components released by the guavas at different ripening stage. Red color indicates that the guavas are still very crisp while yellow color means that the guavas are very juicy.  Consumers can use the indicators as reference for purchasing and consuming.

Figure 2. Ripeness indicator on packaging of guava (from internet)

 Although produces with freshness indicators are rarely seen on the markets, the function is really useful at consumers’ level. The future of intelligent packaging is bright as the technology got developed. Freshness indicators are very good examples that could offer convenience and guide consumers to take food in at peak stage regarding qualities.

4. Conclusion

 Packaging of perish fruits and vegetables should provide the protection, ensure safety, and retain quality of produces. Active packaging is a great method to achieve these requirements by interacting with produces and manipulating headspace atmosphere inside package through use of oxygen absorbers, ethylene absorbers, moisture absorbers as well as using antimicrobial agents. Other than active packaging, intelligent packaging, particularly freshness indicator, can communicate the condition and quality of produces with consumers. The combination use of both intelligent packaging and active packaging can effectively extend shelf life and provide high quality produces at consumer ends.

5. References

• Abe, K., & Watada, A. E. (1991). Ethylene absorbent to maintain quality of lightly processed fruits and vegetables. Journal of food science, 56(6), 1589-1592.
• Anthon, G. E., LeStrange, M., & Barrett, D. M. (2011). Changes in pH, acids, sugars and other quality parameters during extended vine holding of ripe processing tomatoes. Journal of the Science of Food and Agriculture, 91(7), 1175-1181.
• Antunes, M. D. C., & Cavaco, A. M. (2010). The use of essential oils for postharvest decay control. A review. Flavour and fragrance journal, 25(5), 351-366.
• Ben-Yehoshua, S. and V. Rodov. 2003.Transpiration and water stress. In: J.A. Bartz and Brecht. J.K. (Eds.). Postharvest Physiology and Pathology of Vegetables. 2nd ed., Marcel Dekker, Inc., NY. Pp. 111-159.
• Burt, S. (2004). Essential oils: Their antibacterial properties and potential applications in foods – a review. International Journal of Food Microbiology, 94, 223-253.
• Charles, F., Sanchez, J., & Gontard, N. (2003). Active modified atmosphere packaging of fresh fruits and vegetables: modeling with tomatoes and oxygen absorber. Journal of Food Science, 68(5), 1736-1742.
• Cichello, S. A. (2015). Oxygen absorbers in food preservation: a review. Journal of food science and technology, 52(4), 1889-1895.
• Coles, R., McDowell, D., & Kirwan, M. J. (2003). Food packaging technology (Vol. 5). CRC Press.
• Emenhiser C,Watkins RH, Simunovic N, Solomons N, Bulux J, Barrows J, Schwartz SJ (1999) Packaging preservation of β-Carotene in sweet potato flakes using flexible film and an oxygen absorber. J Food Qual 22(1):63–73
• Esturk, O., Ayhan, Z., & Gokkurt, T. (2014). Production and application of active packaging film with ethylene adsorber to increase the shelf life of broccoli (Brassica oleracea L. var. Italica). Packaging technology and science, 27(3), 179-191.
• Fernández, A., Picouet, P., & Lloret, E. (2010). Cellulose-silver nanoparticle hybrid materials to control spoilage-related microflora in absorbent pads located in trays of fresh-cut melon. International Journal of Food Microbiology, 142(1-2), 222-228.
• Ghaani, M., Cozzolino, C. A., Castelli, G., & Farris, S. (2016). An overview of the intelligent packaging technologies in the food sector. Trends in Food Science & Technology, 51, 1-11.
• Gross, K. C.; Wang, C. Y., Saltveit, M. E., Eds.; The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks; United States Department of Agriculture: Beltsville, MD, 2004.
• Isaka, T., & Ohta, S. (1989). U.S. Patent No. 4,876,146. Washington, DC: U.S. Patent and Trademark Office.
• Kader, A. A. Saltveit, M. E. Respiration and Gas Exchange. In Postharvest Plant Physiology and Pathology of Vegetables Bartz, J. A., Brecht, J. K., Eds.; Marcel Dekker Inc.: New York, 2003b; pp 7–29.
• Kader, A. A., Zagory, D., Kerbel, E. L., & Wang, C. Y. (1989). Modified atmosphere packaging of fruits and vegetables. Critical Reviews in Food Science & Nutrition, 28(1), 1-30.
• Kerry, J. P., O’Grady, M. N., & Hogan, S. A. (2006). Past, current and potential uti- lisation of active and intelligent packaging systems for meat and muscle-based products: a review. Meat Science, 74, 113e130.
• Kuswandi, B., Kinanti, D. P., Jayus Abdullah, A., & Heng, L. Y. (2013). Simple and Low-Cost Freshness Indicator for Strawberries Packaging. Acta Manil., 61, 147-159.
• Kuswandi, B., Maryska, C., Abdullah, A., & Heng, L. Y. (2013). Real time on-package freshness indicator for guavas packaging. Journal of Food Measurement and Characterization, 7(1), 29-39.
• Lee, D. S. (2005). Packaging containing natural antimicrobial or antioxidative agents. In J. H. Han (Ed.), Innovations in food packaging (pp. 108-122). San Diego: Elsevier Academic Press.
• Lim, L-T. (2011). Active and intelligent packaging materials. In M. Moo-Young (Ed.), Comprehensive biotechnology 2nd edition (pp. 629-644). San Diego: Elsevier Academic Press.
• Mahajan, P. V., Rodrigues, F. A., Motel, A., & Leonhard, A. (2008). Development of a moisture absorber for packaging of fresh mushrooms (Agaricus bisporous). Postharvest Biology and Technology, 48(3), 408-414.Shirazi, A., & Cameron, A. C. (1992). Controlling relative humidity in modified atmosphere packages of tomato fruit. HortScience, 27(4), 336-339.
• Muriel-Galet, V., Cerisuelo, J. P., López-Carballo, G., Lara, M., Gavara, R., & Hernández-Muñoz, P. (2012). Development of antimicrobial films for microbiological control of packaged salad. International Journal of Food Microbiology, 157(2), 195-201.
• Ozdemir, M., & Floros, J. D. (2004). Active food packaging technologies. Critical reviews in food science and nutrition, 44(3), 185-193.
• Ponce, P., Carbonari, G. L., & Lugão, A. B. (2002). Active packaging using ethylene absorber to extend shelf-life.
• Rux, G., Mahajan, P. V., Linke, M., Pant, A., Sängerlaub, S., Caleb, O. J., & Geyer, M. (2016). Humidity-regulating trays: moisture absorption kinetics and applications for fresh produce packaging. Food and bioprocess technology, 9(4), 709-716.
• Seo, H. S., Bang, J., Kim, H., Beuchat, L. R., Cho, S. Y., & Ryu, J. H. (2012). Development of an antimicrobial sachet containing encapsulated allyl isothiocyanate to inactivate Escherichia coli O157: H7 on spinach leaves. International journal of food microbiology, 159(2), 136-143.
• Siddiqui M.W., Rahman M.S., Wani A.A. (2018). Innovative Packaging of Fruits and Vegetables: Strategies for Safety and Quality Maintenance. Florida, US : CRC Press
• Tarr, C. R., & Clingeleffer, P. R. (2005). Use of an oxygen absorber for disinfestation of consumer packages of dried vine fruit and its effect on fruit colour. Journal of Stored Products Research, 41(1), 77-89.
• Vermeiren, L., Heirlings, L., Devlieghere, F., & Debevere, J. (2003). Oxygen, ethylene and other scavengers. Novel food packaging techniques, 22-49.