ABSTRACT
Shelf life is the time required for a food to become unacceptable from a sensory, nutritional, microbiological, or safety perspective. Provided the mechanism that causes a food product to spoil is known and can be manipulated, shelf life of a food product can be extended. Food systems are available in three forms: processed, minimally processed, and fresh. For processed food systems, shelf life is extended by using various techniques such as thermal processing (e.g., retort and aseptic processing), freeze-drying, cryogenic freezing (e.g., individual quick frozen technique, IQF), and nonthermal processing (e.g., high-pressure processing). Food industries have commercially adapted these technologies to extend the shelf life of high-acid liquid foods (e.g., aseptic or high pressure), low-acid liquid foods with or without particulates (e.g., retorting), dehydrated foods (e.g., freeze-drying), fruits and vegetables cuts (e.g., IQF), and meat (e.g., refrigeration or freezing). These food preservation techniques control microbial growth by the virtue of “processing.” Therefore, the primary factor extending the shelf life is “process”; however, “packaging” further aids in preservation. It is to be noted that these processed foods need to be coupled with an excellent package with high barrier properties to prevent any microbial growth. Usually barrier properties of interest are related to water vapor and oxygen (O2) transmission. Due to the absence of such barrier properties, moisture and O2 levels in the package can be enhanced and thus can favor microbial growth.
