Cashew apple bagasse; Enzyme-assisted extraction; Phenolic compounds; Antioxidant activity; Cosmetic.
Cashew apple bagasse (Anacardium occidentale L.) is an agroindustry by-product with a composition rich in cellulose, hemicellulose, and lignin. In addition, cashew residue (CR) to being an important source of phenolic compounds, which opens up possibilities for the generation of value-added products. In this context, the present work aimed to obtain an extract rich in phenolic compounds from CR, using enzyme-assisted extraction as a sustainable method for cosmetic application. The CR was subjected to liquid hot water (LHW) and steam explosion (SE) pretreatments, and characterized by FTIR, DRX, and lignocellulosic composition. Then, enzyme-assisted extraction (EAE) of pre-treated CR was evaluated using a cellulolytic cocktail. The effects of enzyme load, solids load, and incubation time were investigated and optimized using a rotational central composite design (RCCD) 23. The extracts obtained were evaluated for their phenolic composition, in vitro antioxidant activity, cellular antioxidant activity, sugar content, and cytotoxicity. The results showed that the pretreatments modified the structure of the residue, removing crystalline fractions, and making the material more accessible to enzymes. In addition, the pretreatment by LHW associated with the enzymatic cocktail favored the greater release of phenolics from the lignocellulosic biomass (75,13 ± 3,5 mg GAE/L) and higher antioxidant activities, corresponding to 72.81 ± 0.9% for the kidnapping of the radical DPPH and 241.04 ± 1.7 μM EQ Trolox/L for the kidnapping of the radical ABTS. The experimental design demonstrated that a longer incubation time (80 h) and solid load (8% and 10%) contributed to the increase in the content of phenolic compounds, obtaining, in the best condition, a phenolic concentration of 150.38 ± 10.0 mg GAE/L. Additionally, cashew extract showed antioxidant activity, evaluated by different mechanisms, with iron chelation ability, DPPH and ABTS radical scavenging presenting linear correlation with the concentration of solids. The extracts also showed cellular antioxidant activity, corresponding to 36.03 ± 2.4% of inhibition of Reactive Oxygen Species (ROS) for the extract obtained with 8% solids. These results are important indicators of a possible anti-aging application, opening perspectives for future formulations. Furthermore, the extract proved to be non-toxic, with cell viability greater than 95% in MRC-5 fibroblast cell line. Therefore, enzyme-assisted extraction of phenolic compounds from CR proved to be viable and practicable, given the applicability of the method that meets the sustainability requirements. From a marketing point of view, this research contributes to the development of more efficient products and processes, environmentally sustainable, and optimize the use of resources to obtain bioactive substances for the development of new cosmetic products.