Characterization of yeast protein isolates extracted via high‐pressure homogenization and pH shift: A promising protein source enriched with essential amino acids and branched‐chain amino acids

Abstract

AbstractIn the global food industry, plant‐based protein isolates are gaining prominence as an alternative to animal‐based counterparts. However, their nutritional value often falters due to insufficient essential amino acids. To address this issue, our study introduces a sustainable protein isolate derived from yeast cells, achieved through high‐pressure homogenization (HPH) and alkali pH‐shifting treatment. Subjected to HPH pressures ranging from 60 to 120 MPa and 1 to 10 cycles, higher pressure and cycle numbers resulted in enhanced disruption of yeast cells. Combining HPH with alkali pH‐shifting treatment significantly augmented protein extraction. Four cycles of HPH at 100 MPa yielded the optimized protein content, resulting in a yeast protein isolate (YPI) with 75.3 g protein per 100 g powder, including 30.0 g of essential amino acids and 18.4 g of branched‐chain amino acids per 100 g protein. YPI exhibited superior water and oil‐holding capacities compared to pea protein isolate, whey protein isolate (WPI), and soy protein isolate. Although YPI exhibited lower emulsifying ability than WPI, it excelled in stabilizing protein‐stabilized emulsions. For foaming, YPI outperformed others in both foaming ability and stabilizing protein‐based foam. In conclusion, YPI surpasses numerous plant‐based protein alternatives in essential amino acids and branched‐chain amino acids contents, positioning it as an excellent candidate for widespread utilization as a sustainable protein source in the food industry, owing to its exceptional nutritional advantages, as well as emulsifying and foaming properties.Practical ApplicationThis study introduces a sustainable protein isolate derived from yeast cells. YPI exhibited considerable promise as a protein source. Nutritionally, YPI notably surpassed plant‐based protein isolates in EAA and BCAA contents. Functionally, YPI demonstrated superior water‐holding and oil‐holding capacities, as well as an effective emulsion and foam stabilizer.