Characteristics of edible films enriched with fruit by-products and their application on cookies

Edible coatings and films provide an environmentally-conscious alternative to plastic food packaging options. This study investigated physico-chemical, morphological and thermal properties of edible coatings and films based on chitosan and gum arabic (GA) enriched with grape seed extract (GSE). Their influence on the quality and shelf-life of whole grain cookies with grape and aronia (chokeberry) pomace (GAP) was also investigated. The addition of 0.1% GSE to the film formulations significantly increased thickness and resistance to water vapor, while reducing water solubility, visible light transmission, and rotational force. Moreover, the addition of GSE influenced the film color (turning it dark, reddish, and yellowish) and microstructure as shown by thermal, scanning electron microscopy and Fourier transform-infrared analysis. The addition of GSE led to an increase in the total phenolic content. Thus, edible coating led to lower formation of peroxides in cookies during storage. Cookies with edible coatings were harder and tougher but with much better sensory properties than control during six months of storage. Both, an accelerated shelf-life test and a direct shelf-life method confirmed that the GAP cookies with edible film were safe and of acceptable quality after six months of storage. The results of this study showed that GA and chitosan edible film enhanced with GSE had a positive impact on cookie shelf–life.