High-quality alginates form strong gels and provide thick aqueous solutions. The purification methods offered by us all reduce the number of known contaminants in alginate, namely polyphenols, endotoxins, and proteins. An increase in the viscosity of the alginate solution was observed after alginate purification. Sodium alginate is the main alginate form. We provide production and purification of not only sodium alginate, but also alginic acid and calcium, ammonium and potassium salts, and propylene glycol alginate. Calcium alginate and alginic acid are obtained in the process of preparing calcium alginate from sodium alginate. Other salts are made by neutralizing moist alginic acid with a suitable base (usually ammonium hydroxide or potassium carbonate). The versatility and biocompatibility of alginates have led to the use of alginates as viscosity modifiers and stabilizers in food, cosmetic, and high-value medical applications, including wound dressings, drug delivery systems, and, more recently, tissues for regenerative therapy packages.

Fig. 1 Schematic presentation of alginate affinity purification (AAP). (A Chaudhari S, et al., 2015)