动态高压微射流对乌贼墨黑色素物理性质及微观结构的影响

Effects of Dynamic High Pressure Microfluidization on Physical Properties and Microstructure of Sepia Melanin

为改善乌贼墨黑色素在食品中的应用性能,以虎斑乌贼(Sepia pharaonis)墨囊为原材料,采用碱性蛋白酶酶解制备乌贼墨黑色素,研究不同动态高压微射流(DHPM)(0、40、80、120、160、200 MPa)均质对其物理性质的影响,并采用红外光谱、扫描电子显微镜分析其微观结构。结果表明,DHPM处理使乌贼墨黑色素聚集体解聚,浊度增加、平均粒径减小,粒度分布更加集中和细微化,同时改善了其在去离子水和生理盐水中的溶解性;在压力作用下表现为粘度、空间色度值均有所增大;差示扫描量热法(DSC)分析表明,乌贼墨黑色素在120 MPa下热变性温度为90.70℃,焓变值为0.45 J·g-1,且该压力下其贮藏稳定性最好;红外光谱分析表明,在特定压力处理范围内,DHPM处理使乌贼墨黑色素分子间形成了较强的氢键;扫描电镜观察发现样品颗粒在120 MPa处理后颗粒尺寸最小。因此,DHPM改性技术改善了乌贼墨黑色素的物理性质和微观结构,为其在食品工业中的应用提供了理论依据。

In order to improve the application performance of Sepia melanin in food, the Sepia pharaonis ink sac was used as raw material to prepare melanin by alkali-protease hydrolyzation, and the effects of homogenization of different dynamic high pressure microfluidization(DHPM)(0、40、80、120、160、200 MPa) on its physical properties. The microstructure was analyzed by infrared spectroscopy(IR) and scanning electron microscopy(SEM). The results indicated that DHPM treatment depolymerized sepia melanin aggregates, increased turbidity, reduced average particle size, made it more concentrated and finer distribution, and improved solubility in deionized water and physiological saline. Apparent viscosity and spatial chromaticity values increased under the pressure. DSC analysis showed that the thermal denaturation temperature was 90.70℃, and the enthalpy change value was 0.45 J·g-1 at 120 MPa. At the same time, the storage stability was the best under this pressure. Infrared spectroscopy analysis showed that DHPM treatment formed a strong hydrogen bond between the melanin molecules in a specific range. Scanning electron microscopy revealed that the sample particles was the smallest after treatment of 120 MPa. Therefore, DHPM modification technology improved the physical properties and microstructure of Sepia pharaonis melanin and provided a theoretical basis for its application in the food industry.