Eco-friendly extraction carrageenan from seaweed using a ball mill: celite effect during filtration and ion addition on carrageenan physicochemical properties

Abstract

The aim of this study was to evaluate the extraction method of carrageenan using a new eco-friendly process, namely a ball mill, to produce good carrageenan characteristics and to assess the physicochemical properties. The variables evaluated included the seaweed : water ratio and celite concentration. Results showed that seaweed : water ratio and celite concentration affected yield, gel strength, sulfate content, and viscosity. Optimum conditions occurred at 14:1 w/v seaweed : water ratio and 4% celite concentration, which resulted in 68.89% carrageenan yield, 161.34 g/cm2 gel strength, 15.53% sulfate content, 5.4 cP viscosity, 45.32°C melting point, 30.50°C gel point, 5.56% water content, 25.10% ash content, pH 8.75, and 57% purity. Fourier Transform Infrared (FTIR) proves that the type of carrageenan is kappa-carrageenan. The addition of celite has been shown to simplify the filtration process, and the ball mill method effectively achieves high results quickly. However, the physicochemical properties obtained were inferior to those of the alkali method, especially in gel strength. The gel strength, viscosity, melting point, and gel point of carrageenan are significantly affected by ion variations (K+ and Ca2+).