Techniques of salted jellyfish dealumination by optimized ultrasonic-assisted methodology

In order to study the technological conditions of salted jellyfish dealumination by ultrasonic-assisted method, residual aluminum content is detected by ICP-MS through experiment with salted jellyfish as raw material. First, a study is made of the impact of multiple preservative solution concentration, ultrasonic power, ultrasonic frequency and ultrasonic time on the dealumination effect of salted jellyfish by single factor experiment. And then, based on analyzing Box-Behnken central composite design and Response Surface, an optimization is made of multiple preservative solution dealuminating process as well as ultrasonic-assisted dealuminating technology respectively. The experimental results show that the optimizing conditions without ultrasonic assisted treatment go as follows: raw material-to-water ratio is 1∶7 (g/mL); soaking time, 4 h ; water changing number, 3 times and the jellyfish lowest residual aluminum content (wet base)is 126.4 mg/kg. Thus it can be seen that the soaking time has the most significant effect upon salted jellyfish dealumination; the factors affecting salted jellyfish dealumination by ultrasonic assisted treatment are: ultrasonic time > ultrasonic power > ultrasonic frequency > multiple preservative solution concentration. Among them, the optimum ultrasonic conditions are: ultrasonic frequency is 28 kHz, ultrasonic power 272.61 W, concentration(V acetic acid∶m calcium propionate=1∶2), 0.68% and ultrasonic time 35.06 min. Thus, the jellyfish aluminum residue(wet base) can be reduced to 124.46 mg/kg, and the maximum removal rate of aluminum can be up to 85.3%. Actual dealumination obtained from the validation test is 82.1%. Compared with the theoretical prediction values, the relative error rate from the experimental results is 3.2%. This study also indicates that the removal rate of aluminum is stable with hours reduced from 12 to 1.75 and process efficiency improved by 6.9 times. Therefore, application of ultrasonic technology to jellyfish industry will provide theoretical references for highly-efficient development of low aluminum salted jellyfish products.