Drying ,Chilling, Freezing ,Sterilisation, Pasteurisation are some of the methods which we have heard many a times as methods of food preservation.Food industries are heavily dependent upon these but there is a major drawback in these methods which are ignored most of the times and that is “loss of essential nutrients and organoleptic properties” There comes in the picture 2 methods- Controlled Atmospheric Packaging (CAP) and Modified Atmospheric Packaging (MAP) which are currently gaining much importance. These methods allows the preservation of least processed foods without the addition of any chemical preservative and stabilisers. CAP and MAP are used alongwith drying,chilling,freezing etc so as to increase the efficiency of food preservation. Since it does not imply any heat treatment and low temperature treatment hence there is no loss of nutrients and organoleptic properties are also retained. Let’s get in touch with the Difference Between CAP and MAP.
In both CAP and MAP, the principle is to store the products under high Carbon dioxide content (other gases like nitrogen and ethylene are also added alongwith it) and low oxygen content .The addition and removal of gases is such that atmospheric composition of fruits, vegetables and their products is different from that of air. In both of these processes there is controlled rate of respiration to preserve the natural colour , flavour and taste and aroma.
MODIFIED ATMOSPHERE PACKAGING (MAP)
- It is defined as enclosure of food in a package in which the atmosphere inside the package is modified or altered to provide an optimum atmosphere for increasing shelf life and maintaining food quality.
- Generally used alongwith other operations like chilling.
- Other benefits of MAP include maintainence of high RH, reduction in water loss, improved hygiene by reducing contamination during handling.
- Modified of air can be done by 2 methods-active modification and passive modification.Active modification (also called gas flushing ) involoves displacing the air with controlled ,desired mixture of gases while passive modification occurs as a consequence of food’s respiration and metabolism of microorganisms present inside it.
Related Read: MAP in Detail
CONTROLLED ATMOSPHERE PACKAGING (CAP)
- It is a storage method in which the concentartions of oxygen,carbon dioxide and nitrogen is altered and temperature and humidity of product’s atmosphere is regulated.
- Some Carbon dioxide release agents ,oxygen scavenger and ethylene absorbers are classified as CAP.
Related Read: CAP in Detail
Although CAP and MAP have same working principle, the difference comes in the degree of control.
Difference Between CAP and MAP
Advantages of MAP and CAP
- Retardation of Senescence
- Some physiological disorders like chilling injury is prevented.
- Post harvest diseases and decay is prevented.
- Shelf life is increased
- Nutritional qualities retained.
- No addition of chemical preservatives.
Disadvantages of MAP and CAP
- Internal browning
- Sometimes, increased concentration of carbon dioxide leads to anaerobic respiration thus leading to off flavour development.
- Irregular ripening of bananas and tomatoes.
Food packaging, principles and practice by Gordon L. Robertson