Evaluation of shelf life of bakery products by image analisysis

Plastic fi lms today are widespread and involved in different roles. Just one of these will see them used directly in contact with foods as primary packaging. Producers try to reach the most suitable kind for all purposes, working on different mixtures, new coupled, density, thickness, and expecially on water vapour transmission (WVT) and oxygen permeability (OP): the two most important properties for fresh bakery products. The appearance of baked products is an important quality attribute, correlating with product fl avour and infl uencing the visual perceptions of consumers and hence potential purchases of the product. Consumers look at the quality as major factor for selecting a product and among the main characteristics related to it they considered texture, taste and surface colour. Two different plastic fi lms, polypropylene (PP) and lacquered acrylic (LA) fi lms having two main differences, cost and oxygen permeability were tested on a typical bakery product: a “muffi n” having an ordinary shelf-life of 7 weeks. The aim of this study was to understand the main changes caused in the external appearance of a muffi n, comparing image and chemical analysis between samples packed differently. Muffi ns were tested for 12 weeks or rather. Image analysis and chemical analysis as lipid oxidation, loss of weight, water activity and dry matter, were carried out on both samples. Muffi ns packaged in the two polymeric fi lms used showed the same chemical attitude. As one of the main goals of this research we could suggest to the muffi n’s producer to use the cheapest polimeric fi lm, looking at the economical benefi t.