Physicochemical properties of tilapia (Oreochromis niloticus) actomyosin subjected to high intensity ultrasound in low NaCl concentrations |
| |
Institution: | School of Food Technology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand |
| |
Abstract: | Effects of high intensity ultrasound (HIU) on physicochemical properties of tilapia (Oreochromis niloticus) actomyosin in low NaCl concentrations were investigated. The protein content extracted in low NaCl concentrations (0.1–0.3 M NaCl) increased with increasing HIU intensity up to 20.62 W/cm2 (p < 0.05). The effect of HIU on actomyosin extractability in high NaCl concentrations (0.6 and 1.2 M NaCl) was less obvious. Ca2+-ATPase activity and total sulfhydryl (SH) group content decreased in both 0.2 and 0.6 M NaCl. HIU showed more pronounced effect on oxidation of the SH groups in 0.6 M NaCl, while the reactive SH content at 0.2 M NaCl increased after a prolonged exposure to HIU, suggesting conformational changes induced by HIU. Surface hydrophobicity of actomyosin in 0.6 M NaCl increased with increasing ultrasonic intensity and exposure time to a higher degree than that in 0.2 M NaCl. A greater absolute value of the zeta potential of actomyosin subjected to HIU were also observed. The HIU treatments decreased the turbidity of actomyosin incubated at 40 and 60 °C. A drastic increase in the solubility of myosin heavy chain (MHC) and actin with 0.2 M NaCl were evident when HIU treatments were applied, but degradation of MHC occurred in both 0.2 and 0.6 M NaCl. Based on particle size and microstructure, actomyosin in 0.6 M NaCl underwent more disruption by HIU than that in 0.2 M NaCl. HIU induced protein unfolding and protein dissociation, enabling better extraction in a lower NaCl concentration. |
| |
Keywords: | NaCl Actomyosin High intensity ultrasound Physicochemical properties |
本文献已被 ScienceDirect 等数据库收录! |
|