Components of Modified Atmosphere Packaging

1. Packaging equipment

With the rapid development of the retail market, the needs of consumers of meat products are changing. Consumers pay more and more attention to the added value of products. According to a survey, only 43% of shoppers know what specific type of meat products they will buy. , which means 57% of purchasing decisions are made in-store. The factors that affect the purchase decision are: product price unit price, total price; and the importance of price factors is declining. In addition, the three factors of nutrient content, meat preparation knowledge, and cooking preparation time are showing an upward trend. It is mainly reflected in 4 trends: health, enjoyment, convenience/utility, and ethics. So, how does packaging affect consumers' purchasing decisions?

Packaging Printing: Full-sided printing, with see-through windows, high-gloss appearance.

Packaging form: "Serve-to-table" packaging: attracts consumers with its beautiful, reclosable, easy-to-open and beautiful appearance; multi-functional packaging; multi-packs: only open the edible portion required, and the rest will remain fresh; Packaging for special groups: the elderly, children, people with allergies, diabetics.

Packaging materials: bio-explainable, compostable; improved functional properties (gas barrier, non-breathing, UV resistance, etc.); paper-like materials.

At present, the MAP market can be divided into thermoforming stretch film packaging, tray packaging, and chamber vacuum packaging.

Thermoforming stretch film packaging: the packaging box is made on the equipment; suitable for mass production; simple packaging shape, standard packaging materials; low cost of raw materials; no pollution during film storage; easy film storage, low cost; low labor cost.

Tray packaging: a wide range of output designs; a variety of mold possibilities; complex packaging shapes; a variety of packaging material possibilities; small investment. Compared with thermoforming stretch film packaging, the advantages are: possibility of special-shaped packaging, convenient mold replacement, automatic tray supply, possibility of multiple packaging materials, assembly line design, PP, CPET materials are superior to stretch film packaging equipment.

2. Packaging gas

Microorganisms are ubiquitous around us, and during the processing of meat products, microbial spoilage has already started. Therefore, the testimony processing chain must maintain good hygienic conditions. The way in which microorganisms contaminate food and cause spoilage depends on the type of microorganisms and the ingredients themselves. The types of microorganisms can be divided into: anaerobic and aerobic; the main factors affecting the growth of microorganisms: water activity, pH value, temperature, CO2.

As an important gas in the field of modified atmosphere packaging technology, CO2 has the following functions: reducing the pH value of the surface of cooked meat products and juice; easily soluble in water (1.57 g/kg at 100 kPa, 20 ℃); soluble in fat; inhibiting the growth of microorganisms (25% content can inhibit the growth of aerobic bacteria). However, as the temperature increases, the dissolution of CO2 in water and fat intensifies, and there is a possibility of packaging collapse.

N2: Colorless, odorless inert gas; low water solubility (0.018 g/kg at 100 kPa, 20 °C); mainly used to replace O2 and prevent packaging from collapsing.

Gas is used for food, i.e. it is handled as food. So how do you choose a gas?

1. When choosing a gas or gas composition, the properties of the gas and its interaction with food ingredients, such as the solubility of the gas in the food, should be considered;

2. These gases can be pre-mixed or stored in high pressure bottles or in liquid form in insulated tanks for later mixing on packaging machines;

3. The selected gas should comply with "food grade" regulations, such as EC Directive 96/77/EC applicable in the European Union and FDA guidelines applicable in the United States.

Different ways of supplying food grade gas:

1. Cylinder gas: elemental gas; premixed according to specifications; cylinders specially used in the food industry are required.

2. Liquid gas cylinders: limited to elemental gases (for medium to high volumes).

3. Bulk liquid gas: It needs to be applied after heating and gasification of liquid gas (for higher capacity)

3. Packaging materials

Semi-rigid material/hard material: APET tray, PP tray, PVC tray, HIPS tray, roll film. Amorphous polyethylene terephthalate (APET) as a prefabricated box material with the following characteristics: clean peel, no residue on the tray; high oxygen and moisture barrier; printed or unprinted ; Color can be selected. In addition, it is worth mentioning the application of anti-fog technology and easy peel technology.

Anti-fog technology: The anti-fog component is embedded in the center of the heat sealing layer, and the anti-fog effect occurs when the component continues to migrate to the surface of the film, preventing the product from fading and drying.

Easy-peeling technology: separate the heat-sealing layer from the peeling layer to achieve complete heat-sealing of the heat-sealing layer, and the easy-peeling force is not affected by the heat-sealing temperature or machine conditions.

4. Application and prospect of modified atmosphere packaging

At present, MAP is mostly multi-layer high-barrier cover film (P modified atmosphere ET or OPA/PE/EVOH/PE) and multi-layer high-barrier tray (APET or PP or EPS//PE/EVOH/PE). The typical MAP is Beef uses 80% O2/20% CO2, and processed meat is mainly N2. Through these means, it can achieve extended shelf life (1 to 4 weeks for processed meat, 4 to 10 days for beef), bright color (red meat), and prevention of juice leakage. (Requires an absorbent pad), but still has the following disadvantages:

1. The contents of the bag will be transferred

2. Flat display, need additional transportation, storage and display space

3. Shorter shelf life than vacuum packaging

4. Expensive (multi-layer high barrier)

5. Not environmentally friendly and cannot be recycled (multi-layer)

The future MAP cover film and tray will be transformed from multi-layer PP and multi-layer APET to single-layer APET tray. This change enables environmentally friendly recycling with high reliable seal integrity, adjustable opening force, high chemical barrier properties, and reduced raw material costs and environmental taxes.