Valorization of Yak (Bos grunniens) Bones as Sources of Functional Ingredients

Yak (Bos grunniens) bone, is an underutilized biowaste that is generated as a major byproduct from yak slaughtering process. More commonly, yak bones are either made into primary processing products like whole bone powder or simply disposed, which may not only cause resources waste but also produce pressure on the sensitive and frail environment in cold plateau areas. The aim of this study was to valorize yak bone biowastes to functional ingredients while simultaneously reduce the adverse impact of yak bone biowastes discharge on plateau fragile ecological environment. Sequential purification of yak bone collagen hydrolysates was achieved by ultrafiltration, size exclusion chromatography (SEC), semi-preparative reverse phase high-performance liquid chromatography (RP-HPLC) and HPLC coupled to electrospray ionization tandem mass spectrometry (ESI-MS/MS). The bioactivity of the peptides on MC3T3-E1 osteoblast proliferation was evaluated in vitro by MTT method. Furthermore, the most potent peptide was selected and its underlying molecular mechanism was investigated through molecular docking simulation using the software of Discovery Studio 2018. 35 novel peptides were identified by mass spectrometry analysis, of which 9 were chemically synthesized and evaluated for the osteoblast proliferation-promoting activity. At a concentration of 0.05 mg/mL, peptide GPAGPPGPIGNV displayed the highest osteoblast proliferation-promoting activity with an increase of 42.7% in cell growth. Molecular docking study revealed that the main interactions of GPAGPPGPIGNV with epidermal growth factor receptor were the van der waals and hydrogen bonding. These results suggest that yak bones-derived peptides could be potentially used as osteogenic ingredients in functional foods. This work provides a feasible strategy for valorization of yak bone biowastes and sustainable development of animal husbandry industry in Qinghai-Tibetan Plateau. Graphic This work provides a feasible strategy for valorization of yak bone biowastes and sustainable development of animal husbandry industry in Qinghai-Tibetan Plateau. [GRAPHICS] .