Argan (Argania spinosa L.) Seed Oil Cake as a Potential Source of Protein-Based Film Matrix for Pharmaco-Cosmetic Applications

Abstract

Various different agri-food biomasses might be turned into renewable sources for producing biodegradable and edible plastics, potentially attractive for food, agricultural and cosmeceutical sectors. In this regard, different seeds utilized for edible and non-edible oil extraction give rise to high amounts of organic by-products, known as seed oil cakes (SOCs), potentially able to become protein-rich resources useful for the manufacturing of biodegradable films. This study reports the potential of SOC derived from Argania spinosa (argan), a well-known plant containing valuable non-refined oil suitable for food or cosmetic use, to be a promising valuable source for production of a protein-based matrix of biomaterials to be used in the pharmaco-cosmetic sector. Thus, glycerol-plasticized films were prepared by casting and drying using different amounts of argan seed protein concentrate, in the presence of increasing glycerol concentrations, and characterized for their morphological, mechanical, barrier, and hydrophilicity properties. In addition, their antioxidant activity and effects on cell viability and wound healing were investigated. The hydrophobic nature of the argan protein-based films, and their satisfying physicochemical and biological properties, suggest a biorefinery approach for the recycling of argan SOC as valuable raw material for manufacturing new products to be used in the cosmeceutical and food industries.

Keywords: argan seed oil; biomaterials; cosmeceutical sector; food coating; protein-based film; seed oil cake.

Figure 1

SDS-PAGE (12%) profile of different amounts of argan seed protein concentrate (ASPC).

Figure 2

Zeta potential and particle size detected during titration of argan seed protein concentrate. Further experimental details are given in the text.

Figure 3

Films obtained at pH 12 using 600 mg argan seed protein concentrate in the presence of different concentrations of glycerol (GLY). No manipulable films (X).

Figure 4

SEM images of argan seed protein concentrate (ASPC)-based films prepared by using 600 mg ASPC in the presence of 50% GLY. Film surfaces (A,B) and cross-sections (C,D) were observed at different magnifications: (A) 1000×; (B) 50,000×, (C) 1000×, and (D) 10,000×. Further experimental details are given in the text.

Figure 5

Thickness and mechanical properties of argan seed protein concentrate (ASPC)-based films prepared with film-forming solutions containing the indicated ASPC amounts and glycerol (GLY) concentrations. Different small letters (a–h) indicate significant differences among the values reported (p < 0.05). Further experimental details are described in the text.

Figure 6

Effects of different concentrations (A, 0.1 mg/mL; B, 1.0 mg/mL; C, 5.0 mg/mL) of argan seed protein concentrate (ASPC)-based films present in the Dulbecco’s modified Eagle’s medium (DMEM) on the viability of immortalized human dermal fibroblast (HDF-hTERT) assayed directly. The absorbance evaluation was carried out after 72 h of treatment. Further experimental details are given in the text.

Figure 7

Representative micrograph images of the time course (a, at time 0; b, after 6 h; c, after 12 h; d, after 24 h; e, after 48 h) of the scratch assays of the immortalized human dermal fibroblast (HDF-hTERT), treated in the absence (A) or presence (B) of 0.1 mg/mL of ASPC-based film, immediately after the scratches.