Study on the extraction of low-potassium Kappa-Carrageenan by ethanol inhibition

Abstract

Objective: In order to control the potassium ion content in Carrageenan, this project used alcohol inhibition method instead of potassium ion solution to extract Carrageenan. Methods: The volume fraction of ethanol in the processes of alkali treatment, alkali residual cleaning, and precipitation of carrageenan after filtration during the extraction were optimized for controlling K+ concentration. Results: The concentration of ethanol to inhibit the dissolution of Carrageenan was 60% in the process of alkali treatment and cleaning residual alkali, and the ratio of 60% ethanol solution to glue solution was 5∶1 in the process of Carrageenan precipitation. By using this process, the yield of Carrageenan was （28.76±1.38）%, and the Carrageenan of potassium ion was 0.63%, which was significantly lower than that of potassium ion extracted from traditional Carrageenan （16.26%）. In addition, the gel strength was significantly lower than that of Carrageenan extracted by traditional methods. And there was no significant difference in viscosity, hardness, elasticity, chewiness, and recovery between the two methods. Conclusion: K+ concentration and gel strength of Kappa-carrageenan extracted by ethanol inhibition were significantly lower than traditional technology.

Keywords

• kappa carrageenan
• ethanol
• inhibition
• potassium ion content