Novel porous films based on xanthan gum (XG), poly(vinyl alcohol) (PVA), and red grape pomace (RGP), as entrapped natural antioxidant agent, were prepared by freeze/thawing, a versatile and non-destructive method. The stability of XG/PVA films was dependent on the crystalline zones created by PVA under freeze/thawing treatment. After three cryogenic cycles, the introduction of RGP into the 3D polymer matrix plays a major role by hindering the access of water into the cavities already formed during the first and second cryogenic cycles. By contrast, XG/PVA-based cryogels with enhanced mechanical strength were obtained when the number of freeze/thawing cycles increased from three to seven, while pores stability was improved by entrapment of RGP. The remarkable antioxidant and antimicrobial activity of XG/PVA/RGP cryogel films compared to the XG/PVA films, indicates the potential application of these systems in food packaging.
Keywords: Antioxidant properties; Red grape pomace; Xanthan gum.
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