Use of image analysis to evaluate the shelf life of bakery products

The effects of polypropylene thermo-welding (PPTH) and lacquered acrylic (PPAL) films were tested on a bakery product (muffins) up to 12 weeks. Chemical and physical parameters such as lipid oxidation, loss of weight, water activity, dry matter and moisture were monitored in both packaging solutions, the sensory profile method and image analysis measurements were performed during the 12 weeks of storage. The end of shelf life was established according to the final occurrence of the muffins discolouration. After defining the most important sensory parameters, a panel of twelve judges investigated sensory changes. The use of different kinds of analysis, allows obtaining complementary results, which help draw general conclusions on the quality loss. The results showed that muffins packaged in both films had the same shelf life. Moreover, the analysis of different quality indexes allows a most effective and significant discrimination for the specific product. The moisture of products and all other related parameters, seems to be the most influencing the quality changes. A not expensive, not destructive and a fast technique as image analysis can be easily used to estimate the quality and the ageing of these bakery products.