Pecan (Carya illinoinensis (Wagenh.) K. Koch) Nut Shell as an Accessible Polyphenol Source for Active Packaging and Food Colorant Stabilization

Abstract

Herein, the antioxidant and food stabilizing properties of a pecan nut shell (PNS) hydroalcoholic extract (PNSE) are reported. Chemical degradation of PNSE demonstrated the presence of condensed tannins as the main phenolic components. PNSE showed remarkable antioxidant properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (EC 50 = 0.004 mg/mL). PNSE was initially tested as an inhibitor of mushroom tyrosinase, exhibiting a quite low IC 50 value (0.055 mg/mL) against the enzyme diphenolase activity, suggesting its use in enzymatic browning inhibition. The anthocyanin stabilization properties were evaluated under accelerated aging conditions of both pure pigments and commercial fruit juices, and PNSE was found to be effective at concentrations (0.05 mg/mL) at which well-known stabilizers such as chlorogenic and ferulic acids proved to fail. PNSE also performed well in the stabilization of spray-dried anthocyanins for use as a food colorant, increasing the half-life of blackberry anthocyanins up to 20%. In order to explore the possibility of using PNSE as a functional additive for active packaging, polylactic acid (PLA) films containing PNSE were prepared by solvent casting, and no substantial alteration of the mechanical properties was found on addition of the extract up to 10% w/w. The films showed remarkable antioxidant properties (DDPH reduction >60% with a 3% w/w loading, at a dose of 1 mg/mL in the DPPH solution) and delayed the onset of browning of apple smoothies (ca. 30% inhibition with a 10% w/w loading). These results highlight the exploitation of PNS as a low-cost polyphenol source for food industry applications.

Condensed Tannins, a Viable Solution To Meet the Need for Sustainable and Effective Multifunctionality in Food Packaging: Structure, Sources, and Properties

“…Given the widespread occurrence and the growing global interest toward green production processes, in the last years the possibility to recover these compounds from low-cost, largely available, and sustainable sources, such as agri-food byproducts, has been intensively investigated. − One of the richest sources (up to 25% w/w, of dry matter) of CT is undoubtedly grape pomace, especially grape seeds, ,,,, followed by walnut and peanut skin, , canola hull, pecan nut and cocoa shell, ,, bean seed coat, buckwheat hull, and apple peel . Recently, the possibility to exploit exhausted woods from tannin extraction as a source of high-molecular-weight CT has also been reported …”

Eat Tasty and Healthy: Role of Polyphenols in Functional Foods

“…Betacyanins (red-violet) and betaxanthins (yellow-orange), from beets are also powerful antioxidants, which can be used as natural colorants in the food industry [97]. Furthermore, pecan nut shell has been already studied as a food colorant for active packaging for color stabilization [98].…”

A tunable deep eutectic solvent-based processing for valorization of chestnut wood fiber as a source of ellagic acid and lignin

“…Agri-food industry is responsible for the generation of up to 140 billion tons per year of organic wastes/by-products [1][2][3][4] which can be considered as a largely available, low-cost source of value-added compounds such as polyphenols, including mainly flavonoids and phenolic acids [5][6][7][8][9][10][11]. These latter are well-known for their health beneficial effects [6,12], ascribed in part to their efficient antioxidant properties [13] that have also recently prompted their use as additives for implementation of functional materials.…”