The basics of food preservation and oxygen absorbers
Early civilizations though with limited knowledge and availability of raw materials used to preserve food by salting and sun-drying of foods were used as techniques in the past that persist until today. Spices and pickles are one strong example of preservation. Other food products like dry fish and meat were treated with salt and lime and dry in hot sun, with constant turning and shifting removing the moisture from the food and left hanging on the holders for further drying.
Food preservation is an essential science since time immemorial. However some foods are served fresh without the use of harmful and unwanted food preservatives. Ironically, oxygen is required for the survival of most of the organisms’ i.e. oxidative phosphorylation, but also the growth of microbes which contributes to the spoilage of preserved food and beverages. Thus, the oxygen level is integral in influencing the quality of the stored food product. Other components such as anaerobic microbial growth, variations in moisture levels, light, enzymatic activity and non-oxidative reactions, individually or collectively can deteriorate packaged food-products.
The various effects of oxygen on preserved foods and beverages includes rancidity of unsaturated fats (i.e. ‘off-flavours and toxic end-products), darkening of fresh meat pigments by promoting the growth of aerobic bacteria and fungi, stale odour of soft bakery foods and phenolic browning of fruit/vegetables. Moreover, the deterioration of flavour of beer, loss of vitamin C (ascorbic acid) and acceleration of respiration in fruit and vegetable based foods, with the loss of aroma of beverages (coffee and tea) through oxidation of aroma oils and discoloration of processed foods such as fresh meat, fruit and vegetables has a strong influence on consumer purchasing in the retail food industry. Economic loss due to spoiled food is enormous and often a hidden cost of production, estimated at 1.3 billion tons per year in a study conducted for the FAO.
Further, aerobic bacterial and fungal growth are unwanted in most food products such as breads, with Rhizopusstolonifer, and Mucor spp. being common fungal species, and Bacillus subtilis a common bacteria causing bread spoilage. Thus technological packaging solutions are warranted for the determent of microbial growth and also rancidity of food products without using preservatives.
The shelf-life of packaged foods under chilled or ambient temperatures can be improved with the food product itself being processed, preservatives added or other auxiliary agents used to stabilize against biochemical, microbiological, and enzymatic activity.
The protection against enzymes or microorganisms which can deteriorate or infect respectively, is usually achieved by hermetic sealing in a modified atmospheric packaging (MAP), that usually consists of a high gas-barrier structure that is hermetically closed (i.e. low oxygen transmission rate – OTR); and thus low oxygen environment.
However, residual oxygen is inherent in packed environment, i.e. void-space between food particles and headspace in packaging, and the dissolved and occluded air within food, which may hamper the use of gas flushing or vacuum sealing to create a low oxygen concentration after packaging.
Removal of void-space (space not occupied by food particles) and the dissolved oxygen in food is crucial to provide extended shelf-life of various foods and beverages that may otherwise become deteriorated chiefly through enzymatic, microbiological and biochemical mechanisms. Further, an internal system is required to continually absorb the oxygen that passes through a ‘high oxygen barrier’ such as polymers like PVdC (Polyvinylidene chloride) 10 μm on PET (Polyethylene terephthalate) 60 μm, which commonly displays a combined OTR of 12–18 cc O2/m2/per 24 h at 25 °C.
To overcome the loss due to adverse effects of oxygen on packaged foods, a variety of materials can be used to absorb residual oxygen in the packaging or the oxygen that transmits through the packaging itself. As mentioned, oxygen radicals (i.e. peroxide radicals or singlet oxygen) can react with lipids, whereas anti-oxidants are compounds that nullify the effects of oxygen radicals.
Anti-oxidants include β carotene, butylatedhydroxyanisole, tocopherols, and ascorbic acid can be added to the food mixture to nullify the effects of oxygen degradation on food molecules such as lipids. However, they cannot absorb the oxygen in the void-space of the packaging or between food particles. Oxygen interceptors are compounds found in both the food product and package materials that prevent oxygen from reaching the food product by auto-oxidation.
Oxygen absorbers/or Oxygen scavengers (interchangeable name herein used) are materials usually contained within a satchel that is added to MAP to remove the oxygen from void space around the food particles. They react with oxygen and moisture; via oxidation of a salt such as iron carbonate. The present review focuses on characteristics and applications of oxygen absorbers/scavengers in the food industry.
Demand for oxygen absorber post covid
The packaging scenario and requirements are changing rapidly across the globe, especially with the pandemic in question. Packaging with enhanced functionality, by way of using new technologies, new materials, and trackability like smart packaging, has enormous potential not only to create value but also to disrupt traditional business models. Nowadays, smart packaging and functional food demand is increasing exponentially mainly due to rising population, rising consumer concern regarding food safety, increasing consumption of packaged food products, growing demand for fresh fruits & vegetables, increasing disposable income level, high use of the products in the automotive & personal care sector, and rising demand for corrosion control packaging.
Sayed Murtuza Ali, from O2ZERO deliberated that, since the lockdown in covid-19, a lot of packaged food will become a majority part of people’s diet, though there are a lot of restriction in travel and moving around, food industry will see an exciting 50% boom in next few years to come. Even if the vaccine does come in, the impact of covid will remain worldwide including India.
“Demand will be there for higher shelf-life and storage life all together. Oxygen absorbers will play prime role in increasing shelf-life, stability and along the freshness of the products in the process food industry. So the consumption of oxygen absorbers will increase to give better shelf-life to the products”, he added on.
Ms. Persis Pathre, Business Head – Strategic Sales for Food and Pharma, Sorbead, India, explained that the pandemic has certainly brought a change in humans from a variety of aspects say purchasing behavior or consuming habits. “There has been a huge demand across the world for packaged foods and it has grown in many folds. This has led to the need of increasing the shelf life of packed foods. In turn, there is a strong need for oxygen absorber to keep the packaged food to its best quality”, said Pathre.
“In fact the concept of using oxygen absorber (oxysorb) was backed up by Sorbead India with significant Technical expertise, she further added.
Murtuza also explicated that even if the vaccine does come in, the impact of covid will remain worldwide including India. Oxygen absorbers will play prime role in increasing shelf-life, stability and along the freshness of the products in the process food industry. So the consumption of oxygen absorbers will increase to give better shelf-life to the products.
“After Covid-19, we have seen a drastic shift in the buying patterns from consumers.There has been a major rise in the demand for packaged food products, and with many food outlets still closed, people are inclined to buy packaged foods” said Vivek Patel of Oxymist Absorbers.
Vivek added on that, “Oxygen absorbers have remained an ideal choice for the preservation of food and pharmaceutical products to reduce food wastage in developed nations and increased food security in developing countries. With the packaged food, the demand for Oxygen absorbers has also increased noticeably”.
History of oxygen absorbers/scavengers
Earlier in the 20th century, a number of chemicals were incorporated into food products to absorb residual oxygen, including ascorbic acid and glucose oxidase/catalase. During the 1960s dithionite, calcium hydroxide, activated carbon, and water were incorporated into a system and used in Japan for oxygen scavenging properties which was also patented.
By the 1970s, the use of plastic packaging varying in oxygen permeability started to be widely used. Concerns regarding the oxidation by residual oxygen and also the oxygen which transmits through the packaging material lead to the development of chemical means of oxygen removal by using packets or sachets within the package, which saw the beginnings of new category of packaging called active packaging, including oxygen absorbers.
How oxygen absorbers work
To obtain the maximum removal of oxygen from the inner packaging environment, it is essential to understand the appropriate usage of oxygen absorbers. For food products packaged in high barrier packaging and under hermetic seals the recommended initial oxygen level in the headspace is calculated and also the oxygen between food particles and absorbed onto and absorbed into the food. The dissolved oxygen in food, void space and also oxygen that can permeate through the film must all be considered in determining the amount of ferrous iron to be used in the oxygen absorber.
This will then determine the correct sized oxygen absorber to be used. As 20.9 % of atmospheric air is oxygen, and there is 478 ml (cc) of headspace ‘void’, and estimated residual oxygen between the food particles, then approximately 100 cc oxygen absorber would be recommended.
In addition, as mentioned, the potential oxygen transmission must also be calculated, and adsorbed oxygen on food particles, which is normally calculated by expert consultants in their field and thus a larger oxygen absorber would be required as a function of dissolved oxygen, shelf-life, and packaging film transmission rate.
When the whole world runs on science and it is a trial and effect method we have proved our way through it. The oxygen absorbers are basically, design to preserve your product because Food items and consumer goods suffer from spoilage, microorganism growth, change in colour, reduced nutrition, rancidity, lowered quality due to oxygen in the packaging.
According to Pathre, Oxygen is a well-known source of degradation in many types of foods. When foods are packaged, oxygen that is trapped in the container headspace during the filling process or that enters the package from the outer atmosphere during shelf storage can cause adverse effects, most critically degrading the taste and fragrance of the product.
She further went on to explain the technology of oxygen absorber is a very interesting manner; The iron absorbs 99% of the oxygen that’s present when placed in a sealed environment, like a jar or bag. The remaining atmospheric gases are completely inert and don’t lead to food degradation through the oxidization process.
When the packets are removed from their sealed container, they immediately start absorbing O2, which reacts to with the iron powder, forming iron oxide through a catalyst. Oxygen will be removed (if you’ve used the correct quantity of packets), and the chemical reaction will stop.This keeps food from going rancid, and also keeping bugs and insects out.
Murtuza explained that food items and consumer goods suffer from spoilage, microorganism growth, change in colour, reduced nutrition, rancidity, lowered quality due to oxygen in the packaging. Using Modified Atmospheric Packaging techniques (MAP) like gas flushing and vacuum, oxygen gas is removed for packaging prior to hermetic sealing. However, these methods are not successful in removing residual oxygen levels or to achieved the desired (Below 0.5% oxygen level) in packaging.
Another problem with these methods is the oxygen gas from outside environment seeps into the packaging due to poor Oxygen barrier in poly-based packaging material. This is known as Oxygen Transmission. Modified Atmospheric Packaging techniques do not resolve this problem complete.
He explicated that O2Zero oxygen absorber sachet or packets have been designed as a single solution to oxygen gas problems from packaging. O2Zero oxygen sachet or packets permanently absorb oxygen from void space of packaging upto 0.01%. Even under harsh conditions O2Zero oxygen absorber Sachet or packet effectively reduce oxygen to increase the shelf-life of food products. Food Products that are sensitive to oxygen can be protected using O2Zero.
A whole range of the composition of the bottled food is prone to oxidation and hydrolysis. In order to stop hydrolysis and oxidation, we need to remove the oxygen gas from the packing, which is the atmospheric oxygen in the packing, that are prone to hydrolysis and oxidations are longer functional basically means the hydrolysis and oxidation process will be arrested when used to preserve the vital minerals, Vitamin E is the most vulnerable to oxidation which changes colour and taste of it. Hydrolysis is when moisture increases the products water molecules enter the products whereby it goes a change chemically and bring about changes in the state property. In layman words it is the bacteria growth or fungal growth so Vitamin becomes rancid because of this.
According to vivek, the main ingredient of Oxygen absorbers is IRON powder. When Iron reacts with Oxygen (AIR), it getsoxidized, thereby reducing the oxygen concentration.
Fe (Iron) +O2 (Oxygen) → Fe2O3 (Rusting of Iron)
Oxygen absorber brings down the concentration of Oxygen to 0.1% or less interior of a sealed package.Without oxygen, food products are protected from mold, and products high in oils and fats are safe from rancidity. No Oxidation means Nutritional values are also maintained for a longer time, he said.
AGELESS Oxymist absorbers absorb oxygen in a sealed packaging to create a deoxidized environment. This way, it is possible to protect and preserve foods’ nutritional values.
It is more effective than conventional vacuum and gas replacement packaging to preserve nutritional value of food product. It also provides a simple and effective way to Maintain Flavour, Color, Fragrance, and Nutrition of freshly prepared food as well as dramatically extends shelf life.
Vivek Patel then added on that using AGELESS is extremely easy and can be a great asset when used with a number of food and pharmaceutical products as well as many more.
Use of oxygen absorbers in Mithai and namkeen packaging
The implementation of oxygen absorbers extends to a wide variety of food types including mithai and namkeen. And implementation of oxygen reduces lipid oxidation and the development of oxidative rancid odours, which were strongly correlated. Moreover, in more moist based foods, oxygen absorbers have been shown to decrease spoilage organisms such as Penicillium commune, P. roqueforti.
Moreover, the use of an oxygen absorber that also emits alcohol has been shown to be highly effective and a good alternative to chemical preservatives such as calcium propionate (282) or potassium sorbate (E202). When combined with an ethanol emitter, the oxygen absorber significantly decreased the growth of yeasts, moulds and Bacillus cereus, and inhibited lipid peroxidation and rancid odours.
Moreover, oxygen absorbers reduce microorganism growth in mithai and namkeens. Thus oxygen absorbers appear highly relevant for the preservative free preservation of mithai and snacks via inhibition of food spoilage bacteria and fungi.
The oxygen absorbers have to be designed in ubiquitous application. The two main strategies, the two dictomy of snack food industry would be oily or non-oily. So oily food will have certain amount of oil on it as it has been fried, so if oil is introduced in the food the chance of oxidation will be extremely high, the product will not maintain its freshness and shelf-life and nutrients will diminish over a period of time.
Murtuza elaborated that it is important to understand that O2ZERO is of heavier oxygen absorber, higher strength oxygen absorber then what is available in the market now. Second dichotomy is of a product which is already stable in the market the oxygen absorbers give supportive strength to the product inside the package the oily product will require higher strength oxygen absorbers and non-oily ones will require relatively lower strength oxy absorbers. But it will be in the same chemical formula the product is the same it will be in a 2 or 3 different sizes.
While Indian sweets and namkeens and snack foods is an integral part to start a day for every Indian across the globe, it becomes imperative to keep the products fresh and maintain its authentic taste. Hence people like us who hold expertise in giving the correct dosage calculation come in picture, evaluated Parthe.
She gave out a few points that are very important to take into consideration while selecting the right oxygen absorber:
• Packaging configuration and dimensions
• Shelf life to be claimed
• Nature of product
• Ingredients of the product
She also said that it is utmost necessary to consider two things first look for the oxygen absorbers which can soak up oxygen up to 3 times its weight.
Secondly, to have options to customize the sachet/volume of oxygen absorber because you might be working keeping in mind the requirements of the ultimate consumer who are very dynamic? “So, why not stop at Sorbead India where both the above suggestions are being fulfilled! Hope your search ends here, she said proudly.
Murtaza believes that for using oxygen absorber packaging for mithai and namkeen simplicity is the answer. The simplicity of use of O2ZERO in packaging makes it easy to implement without the need of major changes to the process or facility. It’s compact and sleek design allows it to be easily placed or included into any packaging enclosures.
O2ZERO sachet can be easily inserted into all type of boxes, bags, pouches, bottles, cans, bulk bags, drums, plastic containers or rigid packaging etc. It can be easily integrated into primary or secondary packaging component.
For sweets, one does not need those harmful food Preservatives when you have ageless Oxygen absorbers – and can achieve the shelf life of up to 4 times with appropriate packaging and the right size of Ageless Oxygen absorbers, explainedPatel. And added on that for Namkeens, we can achieve the shelf life of even 3- 6 months.
The stakeholders
It becomes necessary to be Progressive & provide uniqueness to the consumer. So, oxygen absorbers are economically & environment friendly.
Unlike others, Sorbead, India are experts in making qualitative oxygen absorbers that reduce the oxygen content down to 0.10℅which makes us stand strong and capture a big market share.
Their core expertise, apart from unique oxygen absorber has been on dosage calculations. We at Sorbead India, have our very significant and strong presence throughout the Food and Pharma Industry since last 30 years, said Persis Pathre.
She added that their technical team in action has efficiently provided dosage calculations to major clients and their oxygen absorber sachets are specially designed so as to absorb the moisture in a packed environment bringing down the oxygen level to 0.1% and the Sachets are a three layer arrangement comprising of PET/PAPER/PE and comes in varied sizes like Oxysorb 20 cc, 50 cc, 100 cc, 200 cc, 500 cc, 1500 cc, 3000 cc. The material inside the sachets is Iron powder, Natural Zeolite, Salt & water.
On the other hand O2ZERO has worked with Haldiram and Bikano with their oxygen absorbers giving anin-depth experience and knowledge which is well formulated working with the top brands and also with MAP packaging. O2Zero has supplied oxygen absorbers to Food industry, Pharmaceuticals and Nutraceutical companies.
“The oxygen absorbers manufactured at our end are 300% more absorbing power than the others in the market with life of two years inside the packing, and Oxygen absorbers are from Europe, UK and now this same product is available in India also” stated Murtuza.
He said, “We are enjoying catering to a lot of our clients like processing industry, the quality of the product is so high that you will require half the quantity what you will be using of the other brands.
We are using food grade to match all the standards. People are lowering the quality in India for certain benefits but we have kept our standards high and uniform application in all the required industries”.
O2ZERO has an incredible capacity to
remove for oxygen molecule without affecting the packaged item itself. O2ZERO does not release any harmful gasses or produce any harmful reaction.
All components of O2ZERO oxygen absorber sachets are non-hazardous and non-toxic, they are acceptable to be used in food & pharmaceutical products for direct contact. In fact, O2ZERO has been registered with the US FDA for use with Food & Pharmaceutical products.
This system of oxygen removal is a much safer healthier option to increase shelf-life and storage life of food & pharmaceutical products without the need of adding unhealthy preservatives.
“The O2ZERO oxygen absorber that we supply complies with all EU labelling, food and packaging regulation. For the reference of our U.S.A customer, we have also obtained the Certificate of Drug Master File (DMF) with the U.S Food and Drug Administration for our O2ZERO products” humbly stated Murtuza.
India is still a cost-conscious market rather than quality. Most of the Oxygen absorbers available are imported from China and Taiwan. But we have (Ageless Brand), which is World’snumber one Oxygen absorbers. These were Invented, Patented, and Manufactured by Mitsubishi Gas Chemicals, Japan, clarified Vivek.
The main difference is the handling time (Air exposure time) and Oxymist absorbers can be kept them for up to 3 hours in the open air as compared to 30 min from Chinese Grades, The Quality of raw materials, ingredients & technology makes it the global leader in the Oxygen absorbers industry. Oxymist absorbers comes with US FDA, EU FDA, FSSC ( Food safety system certifications ISO 22000 Non-Toxic and 100% Food safe.
Conclusions
The use of active packaging is an important development in preserving and enhancing the shelf life of packaged food materials. Up to date technology has not only improved the methods of food preservation but has also developed into new fields of food preservation which were previously seen as impractical.
However, the real benefits are perceived by the consumer as an end user of the food. The increased number of preservative free foods available in supermarkets, with longer shelf-life, adds to the perception of a ‘fresh food’ shopping experience.
Further, supermarkets and retails have a vested interest in increasing the shelf-life of food products naturally as consumers are becoming increasing aware of the harmful effects of some chemical preservatives. Moreover, the use of oxygen absorbers to extend the shelf-life of food decreases the land fill space (i.e. less food wastage), both of which need to be considered in the long run.
Food security is also an important issue in the third world and developing nations, where an oxygen absorber and packaging cost but a few cents, but would ensure food security all year round, especially storing foods for use during drought.
Similarly achieving environmental and sustainability advantages is a continuous challenge in food preservation both for the manufacturers and end users.
Improved oxygen absorber systems in combination with moisture removal and active packaging technology help to reduce food product loss at the supermarket, as well as to enhance the recyclability and elimination of environmentally unfriendly materials which can now be recycled, especially for food manufacturers and processors.
Newer agents that can preserve packaged food not only from oxidative degradation but other forms of degradation are continually being developed, but oxygen absorbers remain an integral, well established and utilized global food preservation system with high barrier packaging.
Oxygen absorbers have an important role in the removal of dissolved oxygen, preserving the colour, texture and aroma of different food products, and importantly inhibition of food spoilage microbes. … Ferrous iron oxides are the most reliable and commonly used oxygen absorbers within the food industry.