[目的]采用超声法制备酪蛋白酸钠-大豆油预乳化液,将其作为猪背脂替代品加工低脂法兰克福香肠。[方法]研究不同超声预乳化液替代比例(25%、50%、75%和100%)下,法兰克福香肠的化学组成、色泽(亮度、红度、黄度)、质构特性(硬度、咀嚼性、弹性、内聚性、回复性)、保水保油性(蒸煮损失、加压损失)、水分子分布状态和微观结构。[结果]随着超声预乳化液替代比例的增加,水分含量增加,脂肪含量和能量减少(P〈0.05),各组之间的灰分含量差异不显著(P>0.05),蛋白质含量变化不大;L*值显著增大,a*值显著减小(P〈0.05);弹性、内聚性和回复性随着替代比例的增加而增大,替代比例达到50%以上时,弹性值与对照组差异不显著(P>0.05),替代比例达到25%以上时,内聚性显著高于对照组(P〈0.05),替代比例高于50%时,回复性显著高于对照组(P〈0.05),硬度和咀嚼性随着替代比例的增加而减小,但均高于对照组,质构特性提高;蒸煮损失和加压损失增加,但均低于对照组(P〈0.05),保水保油性改善。随着替代比例的增加,T23从57.22 ms增至64.57 ms,pT23减小而pT24增加,但与对照组比,各处理组的可移动水含量高,自由水含量低。扫描电镜结果表明,100%超声替代组香肠中的乳化球体积小,填充均匀。[结论]超声处理可以减小预乳化液滴的体积并提高蛋白质分子对水油的吸附和保持能力,从而有效改善低脂香肠的食用品质。
[Objective]Pre-emulsified sodium caseinate-soybean oil emulsion prepared with pulsed ultrasound was used to replace pork back fat in frankfurter-style sausages.[Method]Effect of ultrasound pre-emulsified emulsion with different substitution rates(25%, 50%, 75%, and 100%) on the chemical composition, color parameters(L*, a*, b*), textural properties(hardness, chewiness, springiness, cohesiveness, resilience), water- and fat-binding(WFB) capacity(cooking loss, expressing loss), water distribution and microstructure of frankfurters was performed in this study. [Result]With the increasing of substitution rate, the moisture of frankfurters became larger, fat content and energy value became smaller(P〈0.05). There was no significant difference among frankfurters in ash and protein content(P〉0.05). L* value increased and a* value decreased significantly(P〈0.05) with the increasing of substitution rate. Both of hardness and chewiness decreased as substitution rate increased but significantly higher than the control(P〉0.05). Springiness, cohesiveness and resilience significantly increased with the increasing of substitution rate(P〈0.05). Sausages formulated with pre-emulsions(75%, 100% replacer) had similar(P〉0.05) springiness but higher resilience with the control(P〈0.05). Compared with the control, sausages with the substitution rate of 50%, 75% and 100% had higher cohesiveness(P〈0.05). Cooking loss and expressing loss significantly increased with the increasing of substitution rate but lower than the control(P〈0.05). T23 relaxation time increased from 57.22 ms to 64.57 ms, immobile water increased and bulk water decreased. Frankfurters formulated with ultrasound emulsion had homogeneous fine three-dimensional network textural property with smaller emulsion droplet. [Conclusion]Ultrasound treatment can produce much smaller pre-emulsified emulsion droplets than conventional homogenization. Good water and fat absorption and binding capa