How does modified atmosphere packaging (MAP) extend the shelf life of perishable foods?

Modified atmosphere packaging (MAP) extends the shelf life of perishable foods by altering the gaseous environment within the package to slow down spoilage reactions and inhibit microbial growth. The atmosphere inside the package is modified by adjusting the proportions of gases, typically oxygen, carbon dioxide, and nitrogen, to create an optimal environment for preserving the specific food product. Reducing oxygen levels inhibits the growth of aerobic spoilage microorganisms, which require oxygen to thrive, and slows down oxidative reactions that can lead to rancidity and discoloration. Increasing carbon dioxide levels can further inhibit microbial growth by creating an environment that is unfavorable for many spoilage organisms. Nitrogen acts as a filler gas to prevent package collapse and does not directly contribute to preservation. For example, MAP is commonly used for packaging fresh meat by reducing oxygen levels and increasing carbon dioxide levels to slow down bacterial growth and maintain the meat's red color. The specific gas composition and packaging materials used in MAP are tailored to the specific food product to optimize its shelf life and maintain its quality. MAP extends shelf life by slowing enzymatic browning, reducing moisture loss or gain, and maintaining product texture. It's essential to maintain proper temperature control with MAP to further inhibit microbial growth.