Removal of Natural Deep Eutectic Solvents on Heavy Metals in Porphyra haitanensis and Its Effects on Its Quality

Natural deep eutectic solvents(NADESs)are green solvents. In this paper,28 kinds of NADESs of 2 types were prepared,and this manuscript aimed to study the removal of Pb,Cd,Cr,As,Cu from Porphyra haitanensis(P. haitanensis)by using NADESs and to optimize the removal conditions. At the same time,it explored the impact on the quality of P. haitanensis during removal. Results showed that the removals were significantly improved by NADESs compared with control where the removal rates of Pb,Cd,Cr,As and Cu were 17.40%~87.54%,57.54%~100.00%,9.80%~48.59%,21.32%~78.24% and 11.68%~79.73%,respectively. The optimal condition was 10% water content(v/v)and solid-liquid ratio of 1∶20. In addition,the addition of 20%(v/v)natural surfactant arabic gum(AG,1%)could further increase the heavy metals removal rates of NADESs. During the removal of heavy metals,NADESs of different substrates had different effects on the quality of P. haitanensis. Compared with the control,the soluble protein content in P. haitanensis significantly decreased after elution(P<0.01),and there was no significant change in polysaccharides and fats. NADESs would not affect the sensory quality of P. haitanensis,and the main impact on the texture was the reduction of elasticity. Therefore,for the first time,a green and effective method for removing heavy metals from P. haitanensis was established in this study,which enriched the application of NADESs in food and provided new ideas for the removal of heavy metal in algae food.