ORIGINAL PAPER Exploitation of Polyphenolic Extracts from Grape Marc as Natural Antioxidants by Encapsulation in Lipid-Based Nanodelivery Systems Mariarenata Sessa & Alessandro A. Casazza & Patrizia Perego & Rong Tsao & Giovanna Ferrari & Francesco Donsì Received: 7 March 2012 / Accepted: 5 June 2012 # Springer Science+Business Media, LLC 2012 Abstract Phenolic compounds were extracted from grape marc by means of high pressure and temperature extraction. In order to increase their dispersability in the aqueous phase, the polyphenolic extracts were encapsulated at a final con- centration of 0.1 % (w/w) in nanoemulsion-based delivery systems, which were formulated with natural ingredients, using either a liquid (sunflower oil) or a solid (palm oil) lipid phase, as well as the combination of a hydrophilic and hydro- phobic emulsifier, and were produced by high-pressure ho- mogenization. The delivery systems were characterized in terms of physicochemical stability under accelerated ageing (storage at 4 °C, 30 °C, and 55 °C for 14 days), by recording the evolution of the mean droplet size, the creaming index as well as the UV–vis absorption spectra of the encapsulated polyphenols. The antioxidant activity of the encapsulated extracts was measured with two different chemical assays (FRAP and ORAC) and a cellular antioxidant assay. Sunflower oil-based nanoemulsions resulted to be the most physically and chemically stable, with no significant variation of the mean droplet size and no degradation of the encapsu- lated compounds under the different conditions tested. The FRAP and ORAC assays showed that the antioxidant com- pounds, when encapsulated, are as available as unencapsu- lated polyphenols in scavenging the peroxyl radicals (ORAC), but are less available in reducing the ferric tripyridyltriazine complexes (FRAP). Remarkably, the cellular antioxidant ac- tivity was significantly higher for the encapsulated grape marc polyphenols than for the unencapsulated ones, suggesting the fundamental role of the nanoemulsions in favoring the deliv- ery through the biological membranes. Keywords Grape marc polyphenols . Nanoemulsion . Delivery system . Physicochemical stability . Cellular antioxidant activity Introduction The growing demand for processed crop products has sig- nificantly increased the amount of waste produced during food processing. This has consequently led to the search for possible waste recovery solutions. In the wine industry, large amounts of grape marc are produced, with every 100 kg of grape-vine producing approximately 20–25 kg of grape waste. Grape marc has had a significant impact on the environment due to the high phenols content consider- ably increasing both the chemical and biochemical oxygen demands (Spigno and De Faveri 2007), thus making its disposal a serious environmental problem. This by-product has been used as animal feed (Vaccarino et al. 1992), organ- ic fertilizer (Ferrer et al. 2001), as well as in harvesting yeast Francesco Donsì and Rong Tsao contributed equally. M. Sessa : G. Ferrari : F. Donsì (*) Department of Industrial Engineering, University of Salerno, 84084 Fisciano, Italy e-mail: fdonsi@unisa.it A. A. Casazza : P. Perego Department of Chemical and Process Engineering “G. B. Bonino”, University of Genoa, 16145 Genoa, Italy R. Tsao Guelph Food Research Centre, Agriculture and Agri-Food Canada, N1G 5C9 Guelph, Ontario, Canada G. Ferrari ProdAl, Competence Center on Agro-Food Productions, University of Salerno, 84084 Fisciano, Italy Food Bioprocess Technol DOI 10.1007/s11947-012-0911-9