Heat-set gelation of milk- and fermentation-derived β-lactoglobulin variants
Zheng Pan, Remco Kornet, Sheelagh Hewitt, Alan Welman, Jeremy P. Hill, Marcel Wubbolts, Stephen C. Mitchell, Warren C. McNabb, Aiqian Ye, Alejandra Acevedo-Fani, Skelte G. Anema
Abstract
Milk-derived β-lactoglobulin (mβ-LG) and fermentation-derived β-lactoglobulin (fβ-LG) may slightly differ in their amino acid sequences. This study aims to investigate the heat-set gelling behaviour of mβ-LG (variants A, B, and C) and fβ-LG A variants. Differential scanning calorimetry indicated similar denaturation temperatures for mβ-LG A and fβ-LG A (∼75 °C), with mβ-LG C highest (∼81 °C) and mβ-LG B intermediate (∼78 °C). All fβ-LG A formed translucent gels with a fine-stranded structure, whereas mβ-LG A, B, and C formed opaque gels with a coarse particulate structure. fβ-LG A exhibited delayed gelation onset and lower gel stiffness compared to mβ-LG A. Among mβ-LG's, mβ-LG A showed the highest gel stiffness, followed by mβ-LG B and then mβ-LG C. Rheological analysis showed that fβ-LG A gels were more elastic and ductile compared to mβ-LG A gels, indicated by smaller tan δ values and delayed increases in energy dissipation ratio at higher strain amplitude; mβ-LG B and mβ-LG C gels were less elastic but more ductile compared to mβ-LG A gels. The more elastic and ductile nature of fβ-LG A gels indicates their potential for applications requiring these specific textural properties. By selecting mβ-LG variants from milk and/or utilizing precision fermentation to engineer additional differences, it is possible to tailor the gelation characteristics of β-LG to meet specific functional requirements. • Heat-induced gels from milk-derived and fermentation-derived β-lactoglobulin variants were compared. • Milk-derived β-lactoglobulin produced opaque gels, whereas fermentation-derived β-lactoglobulin produced translucent gels. • The gel stiffness was in the order of milk-derived β-lactoglobulin A > B C > fermentation-derived β-lactoglobulin A. • Gels from the fermentation-derived β-lactoglobulin were more elastic and ductile than those from milk-derived β-lactoglobulin.