According to The Institute of Food Science and Technology, The shelf life of a food product is defined as “the period of time during which the food product will remain safe; be certain to retain its desired sensory, chemical, physical, microbiological, and functional characteristics; where appropriate, comply with any label declaration of nutrition data, when stored under the recommended conditions.”
Shelf life Analysis helps in determining the length of time that a food product may be stored without becoming unfit for use, consumption, or sale. Such analysis helps in ascertaining the time till which a food product is safe to be consumed and can be stored without any microbial growth or toxins; its quality has not deteriorated or its nutrient content has not significantly lessened in any way.
Several factors bring about the deterioration or loss of the original quality of a food product. These factors can be intrinsic(inherent to the nature of the food itself) or extrinsic (external conditions facing food. These factors are determined by different quality parameters: organoleptic, nutritional, hygienic, physical, chemical, or microbiological.
The intrinsic factors are those that correspond to the formulation of the food. In the food industry, it is imperative that the manufacturer has the following knowledge about its products; such as Raw materials, Composition and Formulation of the product (additives used), Water activity, Total acidity, and pH value, Potential Redox, Available oxygen, etc.
The extrinsic factors those that are present in the process, packaging and storage of the product; like Exposure to sunlight, Temperature, Humidity, Damage to packaging, Distribution, and places of sale, etc.
Although pathogens are usually monitored during Shelf life studies, a suitable food safety program is the best way to ensure the safety of the food product.
There are generally two types of Shelf Life testing; Accelerated Shelf Life Testing and Real-Time Shelf Life Testing.
Under Accelerated Shelf Life Testing, the food product is conditioned and stored at an elevated temperature and/or humidity and the quality changes of the product are evaluated at a specific sampling rate. It can be 2 or 4 times faster than the real-time shelf-life study.
While under Real-Time Shelf Life Testing, food products are stored understated or selected conditions for longer than the expected shelf life and check at regular intervals to see when spoilage begins.
In both the shelf life testing processes; organoleptic, Physico-chemical and microbiological evaluations are recommended.