Exploring the Potential of Water-Soluble Squid Ink Melanin: Stability, Free Radical Scavenging, and Cd<sup>2+</sup> Adsorption Abilities
Shuji Liu,
Xianwei Liu,
Xueqin Zhang,
Yongchang Su,
Xiao’e Chen,
Shuilin Cai,
Dengyuan Liao,
Nan Pan,
Jie Su,
Xiaoting Chen,
Meitian Xiao,
Zhiyu Liu
Affiliations
Shuji Liu
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Xianwei Liu
College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
Xueqin Zhang
College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
Yongchang Su
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Xiao’e Chen
College of Food and Pharmacy, Zhejiang Ocean University, Joint Key Laboratory of Aquatic Products Processing Technology of Zhejiang Province, Zhoushan 316022, China
Shuilin Cai
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Dengyuan Liao
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Nan Pan
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Jie Su
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Xiaoting Chen
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Meitian Xiao
College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
Zhiyu Liu
Fisheries Research Institute of Fujian, National Research and Development Center for Marine Fish Processing (Xiamen), Key Laboratory of Cultivation and High-Value Utilization of Marine Organisms in Fujian Province, Xiamen 361013, China
Squid ink melanin can be efficiently extracted from the byproduct ink sac generated during squid processing. As a natural food colorant, it possesses inherent antioxidant properties and the capability to adsorb heavy metals. This study aims to investigate the solubility of water-soluble squid ink melanin (WSSM) obtained from the ink sac, as well as its stability under various conditions including temperature, pH, salt, sugar, potassium sorbate, metal ions, sodium benzoate, sodium sulfite (reducing agent), and hydrogen peroxide (oxidizing agent). Moreover, it explores the scavenging effects of WSSM on free radicals and cadmium ions. The findings suggest that WSSM’s stability is insignificantly affected by high temperature, sucrose, and salt. However, acidity, sodium benzoate, potassium sorbate, sodium sulfite (Na2SO3), and hydrogen peroxide (H2O2) significantly influence its stability. Most metal ions do not impact the stability of WSSM, except for Fe2+, Fe3+, Al3+, and Cu2+, which result in the precipitation of WSSM. Additionally, WSSM exhibits remarkable antioxidant activity with IC50 values of 0.91, 0.56, and 0.52 mg/mL for scavenging superoxide anion radicals (O2−·), hydroxyl radicals (·OH), and DPPH radicals, respectively. It also demonstrates the ability to adsorb the heavy metal Cd2+, with the adsorption rate gradually increasing with a higher temperature and larger amounts of WSSM added. Infrared spectroscopy analysis reveals the weakening of characteristic peaks (-COOH and -OH) during the process of Cd2+ adsorption by WSSM, while SEM confirms surface roughening and structural damage after Cd2+ adsorption. This study provides valuable insights for the utilization of squid melanin products as natural antioxidants and heavy metal adsorbents in the food industry.
