The biomass components have received significant attention in the last decades due to their high application potential, as is the case of bioactive peptides. They are usually obtained through biological, chemical, and hydrothermal releasing processes from protein matrices. Among them, processes developed sustainably using protein sources have received greater acceptance in the last years. In addition, hydrothermal processes, such as the application of subcritical water, have been studied because they are more sustainable and ecologically favorable, resulting in improved processes. This chapter describes the sources and nature of protein resources and non-conventional processes like hydrolysis with subcritical water for protein extraction and fractionation and its advantages over conventional processes. A summary of relevant articles in the area, the evaluation of recent investigation findings, and the hydrothermal process perspectives for obtaining bioactive peptides in the food industry are also provided.