Unaided efficient transglutaminase cross-linking of whey proteins strongly impacts the formation and structure of protein alginate particles

•Microbial transglutaminase (MTG) cross-linked >70% β-lactoglobulin (β-Lg) at pH 8.5.•Initial MTG catalyzed isopeptide bond formation caused partial unfolding of β-Lg.•>75% of whey protein cross-linked, forming hetero-polymers containing β-Lg.•50% less alginate is needed to form particles with cross-linked than with native β-Lg.•Cross-linked β-Lg and alginate formed suspendable hydrophobically driven particles.