https://www.maximizemarketresearch.com/market-report/global-coffee-roaster-market/108834/

A coffee roasting machine is called a coffee roaster. During the roasting process, the physiochemical characteristics of green coffee beans are converted into roasted coffee products. By enabling green coffee beans to expand and change in color, flavor, smell, and density, roasting is what gives coffee its unique flavor. Although they lack flavor, unroasted beans have the same acids, protein, and caffeine as roasted beans. The Maillard process and other chemical reactions require heat.