坛紫菜蛋白质提取工艺优化及其特性分析

为了开展坛紫菜高值化加工利用，以坛紫菜为原料、蛋白质提取率为评价指标，通过考察提取溶剂、超声时间和功率、料液比、pH等单因素实验、正交试验设计优化超声波提取工艺，对其等电点、乳化性、起泡性等基础特性进行分析，并进行抗氧化活性测定。结果表明，在超声全程时间50 min、超声功率1350 W条件下，坛紫菜蛋白质提取率为60.98%±1.01%。同时通过对所提取的坛紫菜蛋白质特性分析结果显示，坛紫菜蛋白质的等电点为4.5，在等电点附近，坛紫菜蛋白质有较好的泡沫稳定性，可达80.84%±2.95%；抗氧化测定结果显示，坛紫菜蛋白质在5~50 mg/mL范围内具有较强的抗氧化活性，浓度为50 mg/mL时，总抗氧化能力为2.89±0.09 U/mL，ABTS+自由基清除能力相当于0.83±0.08 mmol/L Trolox，DPPH清除率在10 mg/mL时达到68.04%±0.73%。该研究可以为坛紫菜资源的开发利用提供一定的理论依据和技术支持。

Optimization of Extraction Process and Properties of Protein from Porphyra haitanensis

The protein extraction rate from Porphyra haitanensis was investigated as index to carry out high-value processing and utilization of Porphyra haitanensis. The supersonic wave extraction techniques of protein from Porphyra haitanensis were studied by single factor experiments and orthogonal method. Extraction solvent, ultrasonic time and wave power, solid-liquid ratio and pH were investigated, and the Porphyra haitanensis protein was analyzed for its spectral properties such as equielectric point, emulsification, foaming, and antioxidant activities. The optimum extraction conditions of Porphyra haitanensis protein were as follows: Ultrasonic wave power 1350 W, working time 50 min. Under these conditions, the extraction ratio of Porphyra haitanensis protein was 60.98%±1.01%. The results showed that the isoelectric point (pI) of Porphyra haitanensis protein was 4.5. At the isoelectric point, Porphyra haitanensis protein had better foam stability, reaching 80.84%±2.95%. Porphyra haitanensis protein extract exhibited an excellent antioxidant ability within 5~50 mg/mL. When the concentration was 50 mg/mL, the total antioxidant capacity was 2.89±0.09 U/mL and the scavenging capacity of ABTS+ radical was equivalent to 0.83±0.08 mmol/L Trolox, and the scavenging capacity of DPPH radical was 68.04%±0.73% at 10 mg/mL. This study can provide theoretical basis and technical support for the exploitation and utilization of Porphyra haitanensis resources.