Valorization of sugar beet molasses powder by microwave and ultrasound-assisted extractions of bioactive compounds: An optimization study

Sugar beet molasses is one of the most important by-products of the sugar industry. The present study investigates the optimization of microwave-assisted (MAE) and ultrasound-assisted (UAE) extraction conditions of sugar beet molasses powder in terms of total phenolic content (TPC), total flavonoid content (TFC), free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). A three factor, and three level Box-Behnken design was used to optimize microwave power, extraction time, and methanol concentration conditions for MAE and ultrasound amplitude, extraction time, and methanol concentration for UAE. The optimal MAE parameters were a microwave power of 420 W, an extraction time of 70 s, and a methanol concentration of 30%. For UAE, an amplitude level of 90%, an extraction time of 300 s, and a methanol concentration of 46% were determined as optimal conditions.