“…7 also reveals that over-dosing surfactants resulted in apparent changes in the peak vibration for some functional groups, such as amide CN stretching vibration at 1233 cm −1 and CH stretching groups at 2960 cm −1 in CH 3 structure, which indicates that the excessive amphoteric functional groups of surfactants might also combined and adsorbed with other complex substances such as humic substances, soluble tyrosine aromatic protein, soluble microbial metabolites (protein-like compounds), etc. and thus destroy chemical properties and/or decrease the alginate purity of the ALE extraction (Kavitha et al, 2016;LaSarre and Federle, 2013;Macakova, 2007;Nikpay et al, 2017). Anyway, the improvement of the ALE extraction enhanced by over-dosing surfactants could reduce the economic value of biopolymers for future applications.…”