Green biomass serves as an eco-friendly, plant-derived substitute for conventional protein sources. Leaf protein concentrate (LPC) not only acts as a viable alternative to animal-derived proteins but also contains essential vitamins and bioactive compounds providing nutraceutical advantages. The extraction technique plays a critical role in maximizing LPC yield. In this study, green juice derived from the wet pressing of green triticale biomass was divided into two aliquots, each subjected to distinct processing techniques for LPC isolation. One portion underwent direct thermal coagulation via microwave irradiation, followed by vacuum filtration, yielding green LPC (MW-GLPC) and its brown juice (GJ-BJ). The other was first centrifuged to remove large photosynthetic complexes, producing yellow juice that was subsequently thermally coagulated and vacuum filtered to obtain yellow LPC (YLPC) and its brown juice (YJ-BJ).The crude protein content in the MW-GLPC fraction (38.44 g 100 g−1 DW) was higher than the raw green juice (16.38 g 100 g−1 DW). YLPC fraction, obtained by incorporating a centrifugation step into the process, resulted in a significantly increase in crude protein (67.22 g 100 g−1 DW). For fractions of brown juice (BJ), the crude protein content differed depending on the processing technique, with GJ-BJ exhibiting 0.73 g 100 g−1 FW and YJ-BJ displaying 1.06 g 100 g−1 FW. Size exclusion chromatography (SEC) indicated that BJ primarily contained oligopeptides ranging from 200 to 3000 Da.Phytochemical assessments demonstrated that YLPC exhibits the highest concentration of some beneficial bioactive compounds, such as luteolin (27.2 μg g−1), and isovitexin (111.6 μg g−1). These findings are consistent with results obtained from the Drosophila melanogaster model under high-sugar conditions designed to simulate high-sugar-induced stress. Flies supplemented with a concentration of 20% YLPC demonstrated a 10.52% increase in viability relative to the control group, thereby indicating the beneficial potential of YLPC in high-sugar containing environments.