Glycosylated peptides isolated from cheese whey have antifreezing activity

Authors: FOMICH, MADISON - University Of Tennessee; YUAN, YUAN - University Of Tennessee; SMITH, MICHOLAS - Oak Ridge National Laboratory; Krishnan, Hari; DIA, VERMONT - University Of Tennessee; WANG, TONG - University Of Tennessee

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2024
Publication Date: 1/7/2025
Citation: Fomich, M., Yuan, Y., Smith, M., Krishnan, H.B., Dia, V., Wang, T. 2025. Glycosylated peptides isolated from cheese whey have antifreezing activity. ACS Food Science and Technology. 469. https://doi.org/10.1016/j.foodchem.2024.142530.
DOI: https://doi.org/10.1016/j.foodchem.2024.142530

Interpretive Summary: Ice recrystallization is a phenomenon that can compromise the quality of frozen foods over time. Investigating key characteristics of ice recrystallization inhibitors could pave the way for new agents that prevent damage to frozen foods. While natural antifreeze proteins are potent inhibitors, their scarcity poses a challenge. In our study, we explored the presence of ice recrystallization inhibitors in agricultural byproducts, including those from the dairy industry. We successfully isolated glycomacropeptide concentrate from cheese whey byproduct and demonstrated its ice recrystallization inhibition (IRI) activity. Our findings suggest that glycomacropeptide concentrate may serve as an effective cryoprotective agent in acidic and low-salt food applications. Moreover, recrystallization inhibition active peptides can be extracted in substantial quantities from cheese whey byproduct. Overall, our research has the potential to enhance frozen food quality and benefit the food industry.

Technical Abstract: The glycomacropeptide (GMP) present in the cheese whey byproduct can be an excellent antifreezing agent due to its unique molecular structure. The objective of this study was to concentrate this peptide and investigate its ice recrystallization inhibition (IRI) ability. Heat denaturation of the non-GMP proteins and preparative liquid chromatography were used to create fraction 1 (F1) and fraction 2 (F2) and these were tested using the splat assay and a modified sucrose sandwich assay to investigate their IRI activity. Both F1 and F2 showed moderate IRI activity, but this activity was strongest under low salt and low pH conditions as indicated by the regression trends. F1 demonstrated an ice shaping ability similar to that of antifreeze glycoproteins. Molecular dynamic simulations of GMP, de-glycosylated GMP, and alpha-lactalbumin were performed and confirmed substantial differences of GMP when compared to the others in its high degree of conformational diversity and flexibility, as shown by the combination of radius of gyration, solvent accessible surface area, secondary structure, and hydrogen-bonding measurements together. Thus, GMP was shown for the first time as an effective IRI agent and its concentrate can be feasibly obtained from dairy processing byproduct.