In today\u27s overcrowded world with declining food supplies and the constant struggle against waste accumulation, scientists are increasingly trying to discover new ways to solve these problems. Like many industries, the food industry generates, disposes and accumulates waste thus creating an environmental and economic problem. In this study the one of the green extraction technologies, ultrasound-assisted extraction (UAE), for isolation of bioactive compounds from cocoa bean shell (CBS), a by-product in the chocolate production, was applied. Different temperature (40, 60, 80 °C), extraction time (30, 60, 90 minutes), liquid/solid ratio (10, 30, 50 mL/g) and ultrasound power (30, 50, 70 %) were used to obtain the cocoa bean shell extracts. Six active compounds were detected in the extracts by high performance liquid chromatography with a diode array detector as follows: theobromine (2.077-5.916 mg/g), gallic acid (0.110-1.407 mg/g), caffeine (0.276-0.785 mg/g), catechin
(0.033-0.457 mg/g), while the highest obtained concentrations for epicatechin and caffeic acid were 0.100 and 0.527 mg/g of CBS. The highest total phenolic content (TPC) and % scavenging activity measured were 132.897 mgGAE/gextr. and 86.377%. From all investigated parameters, liquid/solid ratio had the greatest influence on the concentrations of obtained compounds. Study proved how UAE is an efficient method for the extraction of bioactive compounds from food by-product - CBS. It should also be emphasized that such application could find the purpose at the industrial level for the discarded waste that still contains valuable compounds, while the enriched extracts could be further used as raw material in other processes
