Effect of ultrasound pretreatment on structural, physicochemical, rheological and gelation properties of transglutaminase cross-linked whey protein soluble aggregates

• Published in: Ultrasonics sonochemistry Vol. 74; p. 105553
• Main Authors: Zhang, Tiehua, Zhao, Yanli, Tian, Xiner, Liu, Jing, Ye, Haiqing, Shen, Xue
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2021; Elsevier
• Subjects: Gelation property; High intensity ultrasound; Original; Rheological property; Transglutaminase; Whey protein soluble aggregates; Rheological property; Transglutaminase; High intensity ultrasound; Whey protein soluble aggregates; Gelation property
• ISSN: 1350-4177; 1873-2828; 1873-2828
• DOI: 10.1016/j.ultsonch.2021.105553

[Display omitted] •WPISA was treated by high intensity ultrasound (HUS, ~69 W cm−2).•The treated WPISA solution was incubated with transglutaminase (TGase).•HUS increased the TGase cross-linking degree of WPISA.•HUS facilitated formation of more high molecular weight polymer aggregates.•HUS improved rheological and gelation properties of TGase cross-linked WPISA. A solution (10%, w/v) of whey protein soluble aggregates (WPISA) was pretreated with high-intensity ultrasound (HUS, 20 kHz) for different durations (10–40 min) before incubation with transglutaminase (TGase) to investigate the effect of HUS on the structural, physicochemical, rheological, and gelation properties of TGase cross-linked WPISA. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results showed that HUS increased the amounts of high-molecular-weight polymers/aggregates in WPISA after incubation with TGase. HUS significantly increased (P < 0.05) the degree of TGase-mediated cross-linking in WPISA, as demonstrated by a reduction in free amino group contents. HUS significantly increased (P < 0.05) the particle size, intrinsic fluorescence intensity, and surface hydrophobicity of TGase cross-linked WPISA, but had no significant impact (P > 0.05) on the zeta-potential or total free sulfhydryl group content of TGase cross-linked WPISA. The apparent viscosity and the consistency index of TGase cross-linked WPISA were significantly increased by HUS (P < 0.05), which indicated that HUS facilitated the formation of more high-molecular-weight polymers. HUS significantly increased (P < 0.05) the water holding capacity and gel strength of glucono-δ-lactone (GDL)-induced TGase cross-linked WPISA gels. The results indicated that HUS could be an efficient tool for modifying WPISA to improve its degree of TGase-mediated cross-linking, which would lead to improved rheological and gelation properties.