Green Extraction of Antioxidant Fractions from Humulus lupulus Varieties and Microparticle Production via Spray-Drying

The formulation of polymeric microparticles to encapsulate bioactive compounds from two hop varieties (Nugget and Perle) using sequential green extraction processes was performed. The technologies used were ultrasound-assisted extraction (UAE) and pressurized hot water (PHW) extraction. Liquid phases were analyzed for total phenolic content (similar to 2%), antioxidant activity (IC50, DPPH: 3.68 (Nugget); 4.46 (Perle) g/L, TEAC (similar to 4-5%), FRAP (similar to 2-3%), and reducing power (similar to 4%)), protein content (similar to 1%), oligosaccharide content (similar to 45%), and for structural features. The fractions obtained from UAE were selected to continue with the drying process, achieving the maximum yield at 120 C-degrees (Perle) and 130 C-degrees (Nugget) (similar to 77%). Based on these results, the formulation of polymeric microparticles using mannitol as the carrier was performed with these fractions. The production yield (similar to 65%), particle size distribution (Perle: 250-750 mu m and Nugget: similar to 100 mu m), and rheological features (30-70 mPa s at 0.1 s(-1)) were the parameters evaluated. The UAE extracts from hop samples processed using a sustainable aqueous treatment allowed the formulation of microparticles with a suitable yield, and morphological and viscosity properties adequate for potential food and non-food applications.