Shelf life and moisture transfer predictions in a composite food product: impact of preservation techniques.

摘要

Three techniques to prevent moisture transfer in a multidomain food system constituted by a cookie in contact with a moist filling were investigated: reducing the water activity difference between components, reducing the effective moisture diffusivity of the cereal-based component, and applying an edible moisture barrier at the interface between components. Shelf-life of the food product was extended by 6 days by decreasing the water activity of the moist filling in contact from 0.99 to 0.64 (cookie aw being 0.23, 20 degrees C). Decreasing effective moisture diffusivity from 1.56 to 0.99*10-11 m2/s by the addition of 2.35 g of fat in the formulation of the cookie was limited by technological and organoleptic considerations and allowed an extension of shelf-life of 2 more days. From a technical and nutritional point of view, the application of a sprayed edible barrier at the surface of the cookie was the more effective solution increasing shelf life of almost 8 days for only 1.7 g of fat per cookie.