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.

Mechanical, Barrier and Thermal Properties of Amylose-Argan Proteins-Based Bioplastics in the Presence of Transglutaminase

“…The plasticizer used to prepare the AM-based films, creating new hydrogen bonds, filled the free volume among the polysaccharide molecules making the surface homogenous. The blended films showed a less smooth and less homogeneous surface, probably due to the presence of the oil fraction in APs, as reported also by Mirpoor et al [ 19 ], both in the presence and absence of mTGase ( Figure 4 B,C). The cross-sections of blended films ( Figure 4 B,C) showed irregularities and cracks that visibly increased in APs100-based films ( Figure 4 D,E).…”

“…The optical properties are crucial to developing products, such as for food packaging, able to attract the interest of consumers. As reported, AM100-based films possess an opacity value of 1.84 ± 0.34 A 600nm /mm, similar to the commercial petrol-based plastic LDPE (low-density polyethylene) (opacity value = 1.44 ± 0.04 A 600nm /mm) [ 19 ]. The addition of APs notably increases the opacity of the films already, with a content of 15% ( w/w ).…”

“…The film color becomes darker proportionally with the increase of APs content ( Figure 3 ). It reaches the highest value, for APs100-based films, of 5.55 ± 0.18 A 600nm /mm that, nevertheless, is lower than the opacity value of commercial MaterBi ® (61.92 ± 3.55 A 600nm /mm) [ 19 ]. The presence of mTGase reduces film opacity: probably, crosslinking reactions induce the formation of a more ordered structure of film matrices, increasing light transmission and changing the refractive index.…”

“…The choice to develop a blended biomaterial derives from the effort to reduce the cost of production, avoid the loss of carbon storage potential, utilize an inexpensive byproduct as a resource that otherwise would be destined for disposal, and improve the bioplastic properties. Recent research has focused on the recovery of waste material from oil seed processing of plants such as hemp, cardoon, cottonseed, sunflower, and argan [ 17 , 18 , 19 ]. These crops are grown all over the world, mainly for oil extraction, which produces a waste around 50% of the original seed weight.…”

“…Recently, Mirpoor et al used argan seed proteins (APs) derived from APC to produce protein-based bioplastics by the casting method and using glycerol as a plasticizer. They showed satisfying mechanical, barrier, and hydrophilicity features, and they were successfully tested as wound dressings [ 19 ]. Here, APs were chosen to test the performance of a blended bioplastic with AM, because they represent a waste to be recovered, that does not subtract soil from food cultivations, and that has the potential to improve the properties of the final product.…”