Valorization of Blueberry By-Products (Vaccinium spp.): Antioxidants by Pressurized Liquid Extraction (PLE) and Kinetics Models

Abstract

Blueberry by-products are rich in bioactive compounds with antioxidant properties, such as phenolic compounds and anthocyanins. Pressurized liquid extraction (PLE) is an alternative to traditional methods in the obtention of bioactive compounds and can adjust pressure and temperature conditions to regulate the solubility of target compounds in the solvent. In this context, this study aimed to evaluate different solvents in the extraction of the compounds, antioxidants from the blueberry by-products obtained by using the PLE technique and evaluating Weibull and power-law models in the kinetics for extraction yield, total phenolic content (TPC), and monomeric anthocyanin content (MAC). Extract yields of 31.33 to 48.98% (m/m) were obtained. The highest yield was obtained using ethylene glycol 20% (v/v). The extracts present TPC between 3541.62 and 4116.62 mg GAE/100g dr, the propylene glycol 20% (v/v) presented the highest content. The extracts present a MAC between 801.06 and 1036.65 mg C3CE/100g dr, the methanol presented the highest content. The best antioxidant activity was demonstrated by the extract obtained using propylene glycol 20% (v/v) as a solvent, with IC50 of the 0.11 mg/mL, justified by the higher content of extracted phenolic compounds. All extracts presented good antioxidant activity, and the PLE technique can be used to obtain biocomposites blueberry by-products.