Advanced Packaging Systems: MAP, CAP, Vacuum Packaging, Active & Intelligent Packaging

Definition and mechanism of active packaging systems:

• Maintaining a static modified gas composition is the characteristic function of passive Modified Atmosphere Packaging (MAP).
• Active packaging is defined as a packaging system that incorporates deliberate active additives (such as oxygen scavengers, ethylene absorbers, carbon dioxide emitters, moisture absorbers, or antimicrobial agents) directly into or onto the packaging film material to actively interact with the packaged food and internal atmosphere to extend shelf life.
• Rapid random gaseous fluctuation is detrimental and uncontrolled.
• Active packaging is designed to prevent spoilage rather than cause contamination.

Principles of Controlled Atmosphere Storage (CAS):

• Standard cold storage controls only temperature and relative humidity, leaving atmospheric gas proportions at normal ambient levels ($21\%\ O_2$, $0.04\%\ CO_2$).
• Frozen storage relies on sub-zero temperatures (below $-18^\circ\text{C}$) to depress chemical and microbial activity.
• Lyophilization is freeze-drying under vacuum sublimation.
• Controlled Atmosphere Storage (CAS) actively controls and maintains an artificial gaseous environment, specifically elevating carbon dioxide ($CO_2$, typically $1\text{--}5\%$) and depressing oxygen ($O_2$, typically $1\text{--}3\%$) alongside low temperature to suppress post-harvest fruit respiration and ethylene biosynthesis.