Packaging Containers for Shelf-life Extension in Fruits and Vegetables

 Packaging Materials and Containers for Shelf-life Extension in Fruits and Vegetables

Packaging:

         Packaging materials or food packing materials are defined as the means or system by which fresh produce or processed product will reach from the production centre to the ultimate consumer in safe and sound condition at an affordable price.

Packaging containers:

            Packaging containers or packaging materials are the convenient containers used for packaging of fresh produce viz., fruit, vegetables, flowers etc., from the production centre till it reaches the consumer place.

Relevant information:

            Packaging fresh fruit and vegetables are one of the most important steps in the long and complicated journey from grower to consumer. Packaging is one of the essential elements required for protection and to extend the shelf life of food products. However, it is required not only for food preservation and protection but also for the safe transportation of products during storage and handling. Increasing exports and developing export market needs have also affected the packaging trend. Packaging requires to contain foods, protect foods from environmental factors, for convenience in handling, storage and marketing and to communicate information to consumers about the food inside the package. Therefore, it has an active role in retaining the safety and quality of foods throughout the supply chain. The use of properly designed containers for transporting and marketing horticultural produce can significantly reduce their losses and maintain their freshness and quality for a longer period.

Qualities of ideal packaging materials/ containers:

1. They must be non-toxic and compatible with specific foods.

2. Sanitary protection

3. Moisture and fat protection i.e., compatible with the food product.

4. They should not affect the flavour of the product inside the packet.

5. Stable performance over a large range of temperatures.

6. Adequate compulsive strength and sufficient impact and puncture strength.

7. The sufficient thickness of cushioning materials with good ventilation.

8. Protection of the content from oxygen, moisture and light.

9. Easy in the opening.

10. Low cost and availability.

11. Reseal and disposal easiness.

12. Size, shape and weight limitations.

13. Protection of the content from adulteration.

Functions of food packaging materials/ containers:

1.      1. To assemble the produce into convenient units for handling.

2.     2. A properly designed produce container should contain, protect and identify the produce satisfying everyone from grower to consumer.

Hermetic and non-hermetic containers:

            Hermetic containers are those containers, which are absolutely impermeable to gases and vapours throughout their entire use.

Example- rigid metal, cans, glass bottles etc.

            Non-hermetic containers are those containers, which prevent the entry of microorganisms only.

Classification of packaging containers:

    A. Based on the quantity of produce

i.   Consumer/ retail package- This group deals with less quantity of produce.

ii.  Transport/ bulk pack- This group deals with large quantities of produce.

  B. Based on the materials used

i. i. Moisture-resistant materials- polythene films, polyester films, polyvinyl films, aluminium foils, laminations, cellulose films, rubber hydrochloride, cellulose acetate, glass containers etc.

               Ø  Restrict the movement of moisture into and out of the container.

       Ø  Have more life spans compared to the moisture-susceptible containers 

ii.  Moisture susceptible materials- wood materials, cellulose and paper products.

Example- are wood pallets, pallets bins, wire-bound crates, wooden crates and lugs, wooden baskets and hampers, pulp containers, paper bags and mesh bags.

Ø  Generally, allow the entry or exit of both moisture and air into and out of the containers.

Ø  They are damaged after a certain time.

Ø  They have poor shelf life compared to moisture-resistant packaging containers.

iii.  MAPs (Modified Atmospheric Packaging)-The shelf life of perishable foods such as fruit and vegetables are limited in the presence of normal air by two principal factors-

1.      Chemical effect of atmospheric oxygen and

2.      Growth of aerobic spoilage microorganism.

            These factors either individually or in association with one another bring about changes in the odour, flavour, colour and texture leading to an overall deterioration in the product quality. MAP is the replacement of air in the package with a single gas or mixture of gases. The proportion of each component is fixed when the mixture is introduced. The normal composition of air is 21% O₂, 78% N₂ and less than 0.1% CO₂. Modification of the atmosphere within the package by reducing oxygen content while increasing the carbon dioxide content and/or nitrogen content has been shown to significantly extend the shelf life of perishable fruit and vegetables. The concentration of O₂ is from 3-5%, whereas, the CO₂ is maintained at 5-10%.

Advantages of MAPs:

1. Increased shelf life of the perishable product.

2. Reduction in retail waste.

3. Improved presentation-clear view of the product and all-round visibility.

4. Hygienic packaging.

5. Easily stackable pack- free from product drop and odour.

6. Easy separation of sliced products.

7. Little or no chemical preservatives.

8. Increased distribution area and reduce transportation costs.

Disadvantages of MAPs:

1. Huge capital investment in gas packaging materials, packaging types of machinery, analytical instrument and gas.

2. Increase package volume as a result of adding gases to the container, which might affect the transportation cost.

3. Potential growth of food-borne pathogens due to fluctuating temperature in retail units.

4. Benefits of MAP are lost once the package is opened or leaks.