即食鱼胶产品的杀菌工艺

Sterilization technology of ready-to-eat isinglass

摘要:

为了改进鱼胶的热杀菌工艺，减少鱼胶杀菌后品质的劣化。实验以美国红鱼鱼胶为对象，确定了在F (杀菌强度)为4.5 min时不同杀菌温度下的杀菌工艺，通过物性分析、低场核磁分析和红外色谱分析等方法，研究了不同杀菌温度对鱼胶质构、色泽、胶原蛋白含量、水分分布以及二级结构的影响。结果显示，为达到F=4.5 min，在110、115、121和1和125 ℃下，鱼胶产品分别需要杀菌56.44、15.85、3.46和0.92 min，杀菌后的鱼胶产品均能达到商业无菌状态。在110~125 ℃，杀菌后的鱼胶能保持一定的蛋白结构。随着杀菌温度的升高，鱼胶的亮度L^*值和b^*值分别由59.78和17.80逐渐下降至49.65和11.25，a^*值无显著变化；鱼胶的硬度和剪切力显著上升、黏性下降，经125 ℃杀菌后分别为37.02 g和34.24 g·s，黏性为-2.82 g；样品的胶原蛋白含量上升、析出减少，110和125 ℃杀菌后鱼胶中胶原蛋白的含量分别为7.62%和14.92%，溶液中胶原蛋白浓度分别为3.33和0.15 mg/mL。110 ℃杀菌后鱼胶内水分的自由度最高，鱼胶内自由水的比例随杀菌温度的升高而下降。研究表明，即食鱼胶在较高的温度下杀菌后亮度降低，但维持了更好的质构以及更高的胶原蛋白含量，保持了较好的品质。本研究对于促进鱼胶的加工利用，提高杀菌即食水产品的品质具有重要的实践意义。

关键词:眼斑拟石首鱼;鱼胶;即食;杀菌温度;胶原蛋白;品质

Abstract:

Isinglass is one of the traditional fish products in China, with unique flavor and taste. However, shortcomings such as soft taste and loss of nutrients after sterilization, limit its commercial development. In order to improve the heat sterilization process and reduce the deterioration of the quality of Sciaenops ocellatus isinglass after sterilization, the corresponding sterilization process at different sterilization temperature with F=4.5 min was investigated. Through the analysis of physical property, low-field nuclear magnetic and infrared chromatography, the effects of different sterilization temperature on the texture, color, collagen content, water distribution and protein structure of isinglass were investigated. The results showed that the isinglass products needed to be sterilized for 56.44, 15.85, 3.46 and 0.92 min at 110, 115, 121 and 125 ℃, respectively, to reach the F=4.5 min, and corresponding products could reach the commercial sterile state. In the range of 110 to 125 ℃, the brightness L^* value and b^* value decreased gradually from 59.78 to 49.65 and 17.80 to 11.25, while a^* value didn’t change notably (P>0.05), with the increase of the sterilization temperature. In addition, FTIR confirmed the triple helical structure of the collagens. The significant improvement of hardness and shear force of isinglass and the reduction of viscosity were also observed (P<0.05). After being sterilized at 125 ℃, hardness and shear force values were 37.02 g and 34.2 g·s, respectively, the viscosity was –2.82 g. Meanwhile, the collagen content of the sample rose from 7.60% to 14.92% and the collagen concentration in the solution declined from 3.33 mg/mL to 0.15 mg/mL. After being sterilized at 110 ℃, the degree of freedom of water in the isinglass was the highest, the proportion of free water in the isinglass gradually decreased with the increase of the sterilization temperature. Therefore, under the sterilization condition of higher temperature, the brightness of the isinglass was reduced, but the quality was improved with better texture and higher content of collagen. This study has important practical significance for promoting the processing and utilization of isinglass and improving the quality of sterilized ready-to-eat aquatic products.

Key words:Sciaenops ocellatus;isinglass;ready to eat;sterilization temperature;collagen;quality