超声波对罗非鱼糜凝胶特性及挥发性风味物质的影响

Effects of Ultrasonic Treatment on Gel Properties and Volatile Flavor Compounds of Tilapia Surimi

摘要:

为开发高品质低盐鱼糜制品，本论文以罗非鱼为研究对象，考察了超声波时间（0、10、20、30、40 min）对不同盐添加量（低盐1.5 wt.%、高盐3 wt.%）的鱼糜凝胶特性和理化性质的影响，系统分析了质构、持水性、流变性质、水分分布、微观结构及风味。结果表明，与高盐鱼糜相比，超声波对低盐鱼糜的质构及持水性改善作用更为显著，超声时间20 min最适，其硬度、胶粘性、咀嚼性和持水性相较于未处理组分别增加了20.00%、14.24%、18.18%和10.00%，比高盐鱼糜表现出更优的凝胶性能。低盐和高盐鱼糜凝胶的G'值均比未超声处理的高，T22弛豫时间左移。超声处理导致高盐鱼糜凝胶的α-螺旋降低和β-折叠增加。导致低盐鱼糜凝胶的β-转角降低和无规则卷曲增加。挥发性成分分析进一步表明，经超声处理后，鱼糜中氮氧化合物、有机硫化物等的含量有所降低，说明超声处理对改善鱼糜风味具有积极作用。因此，超声处理20 min对鱼糜凝胶特性改善效果最佳，为开发健康型低盐鱼糜制品奠定了理论基础。

Abstract:

To develop high-quality low-salt surimi products, the tilapia was took as the research object, the effects of ultrasonic treatment time (0, 10, 20, 30, and 40 min) on the gel properties and physicochemical properties of surimi with different salt addition levels (low salt: 1.5 wt.%; high salt: 3 wt.%) were investigated, and the texture, water holding capacity, rheological properties, moisture distribution, microstructure, and flavor were systematically analyzed. The results indicated that ultrasonication significantly enhanced the texture and water-holding capacity of low-salt surimi more markedly than that of high-salt surimi, with 20 min being the optimal treatment duration. Under this condition, the hardness, cohesiveness, chewiness and water-holding capacity of low-salt surimi were increased by 20.00%, 14.24%, 18.18% and 10%, respectively compared with the untreated group, exhibiting superior gel properties when compared with high-salt surimi. Both low-salt and high-salt surimi gels exhibited higher G' values than their non-ultrasonic counterparts, at the meantime, T22 relaxation times shifted to the left. Ultrasonication reduced α-helix and increased β-sheet conformation in high-salt surimi gels, while decreasing β-turns and increasing random coiling in low-salt surimi gels. Reduced levels of nitrogen oxides and organic sulphides post-ultrasonication were further revealed by volatile component analysis, indicating its positive effect on flavor improvement. Therefore, the optimal effect of improving the gel properties of surimi was achieved at 20 min of ultrasonic treatment. This research establishes theoretical foundations for the development of healthy low-salt surimi products.