Ultrasound-Assisted Extraction and Microencapsulation of Bioactive Compounds from Black Sugarcane Rind for Functional Food Applications

Abstract

This study explored the valorization of black sugarcane (BSC) rind, a by-product of the sugar industry, by producing functional ingredients through ultrasonic-assisted extraction (UAE) and microencapsulation. The UAE process was optimized using a Box-Behnken Design (BBD) and response surface methodology (RSM) to maximize total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (measured by DPPH and FRAP assays). To achieve the study objectives, extraction process was conducted using varying conditions, including ethanol concentration (45–55%), temperature (55–65 °C), and extraction time (20–40 min). The optimal conditions (65 °C, 20 min, 50% ethanol) resulted in high yields of bioactive compounds and antioxidant activity. The extracted bioactive compounds were subsequently encapsulated by spray drying with gum arabic (GA), maltodextrin (MD), and their combination as wall materials. GA-based microcapsules exhibited superior antioxidant activity, spherical morphology, and enhanced stability, as confirmed by thermogravimetric analysis and scanning electron microscopy. This research highlights the potential of BSC rind as a sustainable source of high-value functional ingredients, promoting waste valorization and a circular economy. By converting agricultural waste into innovative functional food ingredients, these findings offer economic and environmental benefits, particularly for the sugar industry and resource-limited regions.