Characterization of transglutaminase-crosslinked black bean-whey dual protein complexes for constructing oleogel-based emulsions and application in low-fat salad dressings

Black bean -whey dual protein cross-linked complex (T-B-W) prepared by transglutaminase. • The structure change and crosslinking mechanism of T-B-W was explored. • Oleogel-based emulsion (OTE) prepared by T-B-W demonstrated enhanced stability. • OTE serve as fat substitutes used in low-fat salad dressing. This study developed novel protein complexes (T-B-W) by transglutaminase (TGase)-mediated cross-linking of black bean protein isolate (BBPI) and whey protein isolate (WPI). Based on this, oleogel-based emulsions (OGEs) as fat substitutes in low-fat salad dressings were developed. Optimal cross-linking conditions were identified as 20 U/g TGase, a BBPI:WPI ratio of 4:1 ( w /w) and incubated at 40 °C for 4 h. These conditions produced T-B-W with higher molecular weight, dense fibrous structures and the surface hydrophobicity decreased by 32.75%. The formed emulsions with T-B-W have smaller and more uniform droplets, with enhanced emulsion stability and improved rheological strength. Importantly, salad dressings formulated with 100% fat replacement using T-B-W-stabilized OGEs exhibited rheological and textural characteristics comparable to commercial full-fat products. This study elucidates the mechanism by which TGase-induced BBPI–WPI complexes function and demonstrates their potential for use in developing healthier and higher-quality food fat substitutes. Download: Download high-res image (118KB) Download: Download full-size image