燕麦β-葡聚糖对低盐羊肉肉糜凝胶特性的影响

Effect of Oatβ-Glucan on Gel Properties of Low-Salt Mutton Mince

将燕麦β-葡聚糖(oatβ-glucan,OG)作为替代物加入羊肉肉糜中等量替代食盐,采用5个不同OG替代量0%、0.4%、0.8%、1.2%、1.6%,即对应肉糜中的盐含量为2.0%、1.6%、1.2%、0.8%、0.4%。通过对复合肉糜凝胶的蒸煮损失率、保水性、水分分布及含量、色泽、凝胶强度、质构、肌原纤维蛋白二级结构以及扫描电镜进行测定分析筛选出相对合适的OG替代添加量。结果表明:随着OG替代量的增加,复合肉糜凝胶的蒸煮损失率先下降后逐渐升高,保水性则先升高后逐渐降低;当添加1.6%OG时,凝胶的持水能力显著下降(P<0.05),而低场核磁共振分析表明高含量的OG会使凝胶中的弱结合水与自由水向不易流动水转移;凝胶色泽亮度L^(*)和白度逐渐增加(P<0.05),凝胶横切面呈现明显的白色;凝胶的破裂力与破裂距离在0.4%OG替代量时达到较好效果,改善了凝胶强度,而较高替代量的OG则对凝胶强度不利;凝胶硬度、内聚性、咀嚼性以及恢复性在OG替代量达到0.8%时显著降低(P<0.05),而凝胶弹性虽呈现与其他指标相同趋势但不同OG替代量之间差异并不显著(P>0.05);在微观结构的观察中,凝胶在较高OG替代量(>0.8%)时,肌原纤维蛋白二级结构接近对照组(P>0.05),扫描电镜图显示其结构更加松散,孔隙增多。通过相关性与主成分分析判断出在0.4%OG替代量下肉糜凝胶特性综合得分要优于其他实验组,在维持羊肉肉糜凝胶品质的同时保证了食盐摄入量的进一步减少。

Oatβ-glucan(OG)was used to replace salt in mutton mince at levels of 0%,0.4%,0.8%,1.2%and 1.6%.To determine the appropriate level of OG replacement,the cooking loss,water-holding capacity(WHC),water distribution and content,color,gel strength,texture,secondary structure of myofibrillar protein,scanning electron micrograph(SEM)of mince samples with 2.0%salt,0.4%OG+1.6%salt,0.8%OG+1.2%salt,1.2%OG+0.8%salt and 1.6%OG+0.4%salt were measured.The results showed that with increasing level of OG replacement,the cooking loss of mutton mince gels decreased first and then increased gradually,while the WHC showed the opposite trend.A significant decrease in the WHC was observed when 1.6%OG was added(P<0.05).Low-field nuclear magnetic resonance(NMR)analysis indicated that high levels of OG replacement caused the transformation of weakly bound and free water into immobilized water in the gels.The brightness(L^(*))and whiteness of the gels increased gradually(P<0.05),and the transverse cross-section showed an obvious white color.The rupture force and rupture distance of the gel with 0.4%OG replacement were good,indicating improved gel strength.High levels of OG replacement were unfavorable to the gel strength.The gel hardness,cohesiveness,chewiness and resilience significantly decreased at a substitution level of 0.8%(P<0.05),and the gel elasticity showed a similar trend but with no significant difference between them(P>0.05).The secondary structure of myofibrillar protein in the gel with high levels of OG replacement(>0.8%)was similar to that in the control(P>0.05),and the SEM image showed more loose structure with increased porosity.Through correlation analysis and principal component analysis(PCA),it was found that the synthetic score of the gel with 0.4%OG was higher than that of the other groups,which could ensure further reduction of salt intake while maintaining the gel quality of mutton mince.