Optimization of glycosylation process of tilapia myofibrillar protein

Abstract

Objective: This study aimed to improve the emulsifying and processing properties of tilapia myofibrillar protein. Methods: The tilapia muscle fibrin (TMP) was modified with galactose oligosaccharide (GOS). The effects of TMP/GOS concentrations, pH values, temperature, time and other technological conditions on the grafting degree, solubility, emulsifying activity and emulsifying stability of TMP-GOS conjugation were investigated. The preparation process of TMP-GOS conjugate was optimized using emulsion stability as response surface. The functional properties of TMP-GOS conjugation were analyzed and verified by endogenous fluorescence spectroscopy, surface hydrophobicity, Fourier infrared spectroscopy and peakering emulsion microscopy. Results: The optimal process conditions were as follows: tilapia myofibrillar protein/ galactooligosaccharides (mTMP∶mGOS=1∶1) mass concentration is 27.34 mg/mL, pH value is 11.2, temperature is 79.9 ℃, time is 4.09 h. The emulsifying stability, emulsifying activity and solubility of glycosylated TMP were (90.30±1.44) min, (4.70±0.03) m2/g and (66.09±0.52) %. Compared with before modification, they increased by 112.97%, 62.07% and 129.39% respectively. The glycosylation grafting degree of TMP was 34.17%; The protein hydrolysis degree was large, and the protein structure was expanded; The surface hydrophobicity index decreased by 55.68%. Conclusion: Galactose oligosaccharide can significantly modify the structural properties of TMP and improve the emulsification activity and the solubility of TMP.

Keywords

• tilapia
• myofibrillar protein
• galactooligosaccharides
• glycosylation
• emulsification characteristics
• protein structure