Influence of Water Sorption Phenomena on the Shelf Life of Third Generation Snacks

Abstract

The shelf life of third generation snacks (pellets) was estimated through the measurement of physicochemical parameters. Samples were provided by a snack manufacturing industry and were placed in three different types of packaging: high density polyethylene (HDPE); polypropylene/kraft paper; and polypropylene/HDPE. The samples were tested under different conditions of temperature and relative humidity. Water activity (aw) at 25 and 40°C and moisture gain (89% relative humidity, 25°C) were analyzed for 60 days. The polypropylene + HDPE packaging showed the best properties for sample preservation, allowing for a shelf life of 1 month under extreme conditions of humidity. Therefore, it is possible to extend the shelf life of the pellets studied by using proper packaging materials to limit phenomena of water sorption. Practical Applications For most food companies, to know the shelf life of their products is fundamental to avoid economic losses due to undesirable changes on them. However, shelf life determination of food products is a complex process that involves a series of microbiological, physicochemical and sensory parameters. Although the kinetic studies of the behavior of those parameters contribute to preserve the quality of the product during long periods of time, they are usually expensive and time consuming. The practical application of the method used in this research is that it represents an alternative to shelf life prediction of snack products without using expensive or complicated equipment or chemical reactants.