Vacuum packaging (WU) is a common method for packaging refrigerated products, such as raw red meat, dried meat and cheese.
Like the CSG, the VU method increases the shelf life of food by removing oxygen and, consequently, suppressing the growth of spoilage aerobic microorganisms and reducing the rate of oxidative damage .
To maintain the vacuum around the foodstuffs requires materials with very low oxygen permeability. Although the necessary protection from O2 for AS depends on the type of food product being packaged, usually 02 penetration rate is required less than 15 cm3 / m-2 • day-1 • ATM-1. In addition, the materials should be used with low vapor permeability. Typical materials for VU consist of laminated (multilayer) or obtained co-extrusion films such as OPP / EVOH / PE, PA / PE, PET / PE, OPP / PVDC / PE, GGG / PVDC / OPP and PVC / EVOH / PVC [22 ].
Packaging in vacuum-film on the substrate
Packing in a vacuum-formed film on a substrate (VFP) is a method that was developed to overcome some of the shortcomings of traditional vacuum packaging and the CGS . The principle of the WWF is based on the use of a highly elastic plastic laminate, which neatly fits onto the food product, taking the shape corresponding to the contours of the product and forming the so-called “second skin”. This emphasizes the natural shape, color and texture of the product, and since no mechanical pressure is applied when exposed to vacuum, soft or fragile products are not destroyed or deformed. Success in the UK market received sliced boiled and cured meat, pies / pies and fish products (for example, seasoned pepper and mackerel), sliced into the WWF. In contrast to VP, WWF and CSG, after opening the package, it is easy to separate pre-cut meat slices. With DFT, the appearance of the product is improved, and the shell without wrinkles prevents product movement, allowing the product to be positioned vertically in the display case. In addition, since the upper and lower films are connected tightly from the edge of the package to the edge of the product, the maximum solidity of the package and the restriction of juice are achieved. Finally, compared to the packings in the CSG, the WWF saves space in household refrigerators and is ideal for freezing, as the “second skin” prevents the formation of ice crystals on the product surface, thereby eliminating cold burn and dehydration .
Active packaging is packaging with the inclusion of certain additives in the packaging film or inside the packaging to increase the shelf life of food products [10,14,18].
Such additives or improvers freshness can absorb 02, S02 and / or ethylene; releasing preservatives, ethanol, or SOA, to absorb the moisture and / or flavors and odors (see. Table. 6.6). Some improvers freshness, which is claimed to increase
6.6 Table. Some examples of active packaging
|Devices||active packaging system||Real and potential applications|
Metal / acid
Metal (e.g., platinum) catalyst
Ascorbate / Metal salt
|Bread, cakes, steamed rice, cookies, pizza, pasta, cheese, cured meats and fish, coffee, snacks, dried foods and drinks|
absorbers / and
iron / calcium oxide hydroxide
Železistyj carbonate / Halogen metal
Calcium oxide / activated carbon
Ascorbate / sodium bicarbonate
|Coffee, fresh meat and fish, nuts, and other snacks and biscuits|
The activated clay / zeolite
|Fruits, vegetables and other horticultural products|
Extracts of spices and herbs
BHA / BHT antioxidants
Vitamin E is an antioxidant
|Cereals, meat, fish, bread, cheese, snacks, fruit and vegetables|
|1. Encapsulated ethanol||The basis for pizza, cakes, bread, biscuits, fish and bakery products|
|Fish, meat, poultry, snacks, cereals, dried foods, sandwiches, fruit and vegetables|
taste / odor
A layer of PVA
Activated clays and minerals
Glandular salt / ascorbate
Activated charcoal / clay / zeolite
|Fruit juices, fried snacks, fish, cereals, poultry, dairy products and fruit|
The shelf life of food products (many of them are chilled) must be approved for use with food products [10,18].
Active packaging is a growing and promising area of food technology, which is evolving thanks to advances in packaging technology, materials science, biotechnology and the emergence of new demands from consumers. This technology can largely contribute to maintaining a wide range of stable, ambient-temperature and chilled foods. The challenge is to increase the shelf life of food while maintaining their nutritional properties and ensuring microbiological safety . The use of active packaging is becoming increasingly popular and in the future there will be many more new possibilities for using this technology .
In addition to the systems for active packaging, listed in Table. 6.6, developed or is developing many other systems using combinations of various ceramics, enzymes, chemicals and materials to control the gaseous environment inside the package. Among them are photosensitive dyes, which indirectly absorb 02, and antibacterial packaging films and materials. One of the most interesting developments is perhaps in the combination of packaging technology and enzymology — so that packaging can actually change the chemical composition of the packaged liquid products . For example, in California firm PharmaCal Ltd. packages with immobilized enzymes that can remove lactose and cholesterol from milk have been developed (Fig. 6.2).
In the coming years, the packaging of refrigerated foods will likely affect the factors listed below.
Across Europe, work in the field of packaging will increasingly hinder legislation in packaging waste. The need to satisfy
Fig. 6.2. Removal of cholesterol in the package using immobilized enzyme
Recycling requirements lead to quick solutions to packaging problems that may not be in the long-term interest. Legislation requires more and more packaging to be recyclable, but in some cases this may not lead to the most environmentally friendly solutions. Moreover, additional requirements for minimizing packaging may conflict with the requirement of suitability of packaging for processing, since the lightest materials may not be the easiest to process. Finally, in the future, packaging waste legislation is likely to lead to higher requirements for their recycling, and it may be that the goal is to reuse it .
The new packaging, due to consumer requests
Growing attention to consumer needs gives the packaging industry an opportunity to upgrade. Consumers respond well to innovations that improve the functional qualities and packaging design, for example, funds that facilitate opening and re-closing, bottles that facilitate filling, tools that make visible attempts to open packaging, time-temperature indicators, labels and indicators of dish readiness when using microwave Packaging is increasingly seen as a strategic marketing tool. The retail supply system is becoming more flexible and customer-oriented, and in terms of packaging, this means that there is a demand for ever smaller quantities of packages of uniform quality delivered on tight schedules. To meet the demand, there is a wide variety of packaging formats, and this diversity is likely to be increase in the future. For example, freshly frozen soups can be bought packaged in bottles, plastic thermoformed boxes, laminated cardboard bags and flexible bags, with each type of packaging having different technical and marketing advantages. Consumers have responded well to food packaging for fast food, and this trend will undoubtedly continue in the future - for example, this applies to fruits, vegetables and salads ready to eat or warm up in a microwaveable  package.
New materials and technology
Under the influence of environmental and economic considerations, new lightweight packaging materials are being developed worldwide. Examples include the introduction of improved plastics using metallocene catalysts and corrugated paper and cardboard materials with micro corrugations. Research and development in the field of edible and biodegradable packaging continues to expand; methods are also being developed to reduce the cost of packaging recycling. In the future, other strategic developments will continue to expand in areas such as barcode labeling, active and intelligent packaging, and digital printing [2,16,19].
In the field of new materials, the invention of progressive catalytic technologies (for example, metallocene technologies) has allowed the development of new plastpolymers, many of which make it possible to obtain better-quality thin packaging materials that can be specially created in accordance with the requirements of a particular application. Among the noted technical advantages of metallocene plastpolymers are increased rigidity, transparency and gloss, excellent durability (including puncture resistance, during heat sealing and gluing at high temperature), the possibility of achieving low mass and reducing thickness, which previously were not available in traditional plastpolymers [ 2,16].
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