不同聚合度菊粉对鱼糜抗冻性的影响

Effect of inulin with different degree of polymerizationon freezing resistance of surimi

以鲢为原料,研究短链菊粉(聚合度2~6)、长链菊粉(聚合度23~46)和天然菊粉(聚合度10~23)的添加对鱼糜冻藏过程中蛋白质冷冻变性和凝胶品质劣化的影响,并通过偏最小二乘回归分析揭示蛋白质生化指标和凝胶性能之间的关系。结果显示,不同聚合度菊粉对鱼糜均具有冷冻保护效果,短链菊粉的效果最强,能够显著抑制盐溶蛋白含量、Ca^2+-ATPase活性、总巯基和活性巯基含量的下降和表面疏水性的上升(P<0.05),且蛋白质二级结构、SDS-PAGE图、凝胶品质(持水性、凝胶强度及质构)与新鲜鱼糜最为接近,可替代商业抗冻剂,天然菊粉的效果次之,长链菊粉效果最弱。预测回归系数表明影响鱼糜凝胶品质的蛋白质生化指标由强到弱依次为盐溶蛋白含量、蛋白质二级结构、表面疏水性、总巯基和活性巯基含量,可以作为评价鱼糜冷冻变性的主要指标,而Ca^2+-ATPase活性对鱼糜凝胶品质的影响较小。

Freezing is a common processing method used in the production of surimi.In order to prevent quality deterioration during freezing storage,commercial cryoprotectant(4%sucrose and 4%sorbitol)is added,which introduces excessive sweetness and calorie and limits partial consumers.With low sweetness,rich probiotic function and reasonable structure,inulin is a potential cryoprotectant.Therefore,it is essential to conduct a systematic research on the freezing resistance of inulin with different degree of polymerization for surimi.The purpose of the study was to investigate the effects of inulin with different degrees of polymerization on protein denaturation and quality deterioration of surimi,and to reveal the relationship between protein biochemical properties and gel properties.In this study,frozen silver carp surimi was prepared by adding short chain inulin(degree of polymerization 2-6),natural inulin(degree of polymerization 10-23)and long chain inulin(degree of polymerization 23-46).The protein biochemical and gel’s indicators were measured during frozen storage.Furthermore partial least squares regression analysis(PLSR)was performed to analyze the relationship between protein and gel’s indicators.Results showed that,all of the inulin had anti-freezing effect on surimi.Short chain inulin had the best effect among these,and could significantly inhibit the decrease of the salt-soluble protein content,Ca^2+-ATPase activity,sulfhydryl content and the increase of surface hydrophobicity(P<0.05).Meanwhile,secondary structure,sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and gel properties(water holding capacity,gel strength and texture)of sample added with short chain inulin was the closest to those of fresh surimi.In addition,salt-soluble protein content,secondary structure,surface hydrophobicity and sulfhydryl content had sequentially decreased influence on gel qualities,which could be used as main indexes indirectly evaluating gel quality of frozen surimi.But Ca^2+-ATPase activity exerted little influence.This study provided a reference for the freezing denaturation of surimi and the development of new cryoprotectant.