Gelation properties of acidified skim milk concentrates produced by bipolar membrane electrodialysis prior to ultrafiltration

Electrodialysis with bipolar membranes (EDBM) provides a method for milk acidification, with potential for improving pH stability and modifying the gelation properties of milk concentrates compared to conventional acidification using citric acid (CA). Simultaneously slowly acidifying and removing cations, EDBM maintains a distinct mineral profile that enhances ultrafiltration (UF) performance, reduces membrane fouling, and improves the properties of milk protein concentrates. EDBM-treated UF concentrates showed different gelation properties after rennet-, acid-, and heat-induced gelation compared to CA acidified concentrates. At pH 5.7, rennet-induced gels from EDBM-treated milk were stronger and more deformable, whereas CA-acidified milk yielded more brittle and heterogeneous gels. At pH 6.1, acid-induced gels from CA acidified concentrates showed an earlier gelling point than EDBM concentrates, while at pH 5.7, the opposite is observed. Similarly, heat-induced gels from EDBM-treated milk display higher shear moduli (G'). EDBM is a promising alternative to traditional acidification, helping to modulate the texture and functionality of milk concentrates.