PECAN (CARYA ILLINOINENSIS) NUTSHELL AS AN EASILY ACCESSIBLE MATERIAL FOR FOOD APPLICATIONS

Introduction: Pecan nut processing results in the production of high amount of shells (40 to 50% by weight ), an industrial byproduct reddish in color, that may represent an alternative and sustainable source of compounds at high antioxidant capacity.1 We explored in this study the potential use of pecan nutshell (PNS) and its extracts for food applications. Material & Methods: PNS was ground by means of a blade mill through a 250 micron sieve. PNS extract was prepared by treatment of PNS with ethanol-water= 6/4 v/v. Polyethylene (PE) and polylactic acid (PLA) films containing PNS extract were prepared by extrusion. DPPH, FRAP, aging of oil samples, mushroom tyrosinase and apple browning inhibition assays were performed as described.2,3 Results: PNS exhibited efficient antioxidant activity in both the DPPH (EC50<0.1 mg/mL) and FRAP (>0.3 Trolox equivalents) assays. A significant DDPH reduction was observed also with PLA and PE films containing 3% PNS extract. PNS significantly reduced iron-induced lipid peroxidation in cod liver oil-water emulsions. PNS extract efficiently inhibited dopa oxidation mediated by mushroom tyrosinase in a dose-dependent manner, with an IC50 value <0.05 mg/mL, and was also able to significantly delay the onset of browning in apple smoothies. Conclusion: These preliminary results open new perspectives in the exploitation of PNS as an easily accessible and low cost material for use in active packaging and food preservation.