Effect of transglutaminase cross‐linking on debittering of Alaska pollock frame hydrolysate

Abstract

SummaryThe present study aimed to investigate the impact of TGase cross‐linking on the flavour characteristics, particularly focusing on its ability to reduce bitterness in enzymatically digested Alaska Pollock framework (APF) hydrolysates using Protease A ‘Amano’ 2SD (A2SD) and Protease A ‘Amano’ 6SD (A6SD). Electronic tongue results showed that the umami was enhanced, accompanied by a reduction in both bitterness and bitter aftertaste. The contents of glutamic acid (Glu) and nucleotides (AMP, IMP and GMP) exhibited significant differences among all treatment groups (P < 0.05). There was a notable increase in the types and relative concentrations of alcohols, ketones, alkanes and aldehydes in the cross‐linked APF enzymatic hydrolysate. The Fourier transform infrared spectroscopy, ultraviolet spectrum and fluorescence spectrum analyses indicate that TGase cross‐linking leads to a reduction in the exposure of hydrophobic amino acid residues. The surface hydrophobicity of HA2SD‐C and HA6SD‐C exhibited a significantly lower level compared with that of HA2SD and HA6SD. The present study presents an effective approach for mitigating the bitter taste of aquatic hydrolysate, thereby positively contributing to the advancement and utilisation of this valuable resource.