云南罗非鱼产业发展现状分析及对策

目的探讨葡萄糖酸内酯(GDL)调控对罗非鱼碎肉鱼糜低温酸诱导凝胶特性的影响。方法以罗非鱼(Oreochromis niloticus)碎肉为研究对象，测定不同GDL添加量(0、0.8%、1.6%、2.4%和3.2%)在4 ℃交联24 h后，pH、SDS-PAGE、游离巯基、化学作用力及凝胶特性的变化。结果罗非鱼碎肉在低温酸诱导凝胶形成过程中，随着GDL添加量的提高，肌球蛋白重链(MHC)呈下降趋势，游离巯基呈先下降后上升的趋势；GDL促进了二硫键的形成，但当GDL添加量为0.8%~3.2%时，二硫键含量并无显著性差异(P>0.05)。添加GDL降低了非特异性结合、离子键和氢键含量，提高了疏水相互作用。碎肉鱼糜凝胶的破断强度在2.4% GDL时达到最高，凹陷深度在1.6%~3.2% GDL时达到最高，且无显著性差异(P>0.05)。此外，添加GDL增加了碎肉鱼糜凝胶的持水性和白度。结论罗非鱼碎肉中添加2.4% GDL有利于获得品质较好的鱼糜凝胶制品。

Effects of heating processes on changes in ice crystal formation,water holding capacity,and physical properties of surimi gels during frozen storage

PurposeTilapia minced surimi mediated by glucono-δ-lactone (GDL) were investigated during low-temperature.MethodsThe tilapia (Oreochromis niloticus) minced meat was used as the research object, in order to elucidate the acid induced gelation properties of tilapia minced meat under low-temperature. The addition amount of GDL (0, 0.8%, 1.6%, 2.4%, 3.2%) was added at 4 ℃ for 24 h, then the pH, SDS-PAGE, free sulfhydryl, chemical interactions and gel properties were measured.ResultsDuring the process of low-temperature acid induced gel formation of tilapia minced meat, as the GDL addition amount increased, the intensity of myosin heavy chain (MHC) decreased, while the free sulfhydryl was decreased firstly and then increased. Although GDL contributed to the formation of disulfide bonds, the content of disulfide bond showed no significant difference (P>0.05) when adding 0.8%-3.2% GDL. The content of nonspecific associations, ionic bond and hydrogen bond decreased while hydrophobic interaction increased when GDL was added. The breaking strength of minced meat gels reached the highest when 2.4% GDL was added; the depression depth reached the highest when 1.6%-3.2% GDL was added, and there was no significant difference among them (P>0.05). Meanwhile, the addition of GDL increased the water holding capacity and whiteness of minced meat surimi gels.ConclusionsThe addition of 2.4% GDL to tilapia minced meat was beneficial to obtain good quality surimi gel products.