Diluted Thermopressurized Phosphoric Acid: A Gentle Proton Donor for Polysaccharide Acid Depolymerization and (Bio)processing

Abstract

Phosphorus is a very important element for several metabolic pathways in all living organisms as exemplified by DNA, RNA, glucose and fructose-P, and adenosine triphosphate (ATP). The whole metabolism of phosphate in any living organism involves the catalysis carried out by many enzymes, such as kinases, pyrophosphorylases, isomerases, and phosphatases. Symptoms of hypophosphatemia include neurological dysfunction and disruption of muscle and blood cells and could be caused by malnutrition, failure to absorb phosphate, and metabolic syndromes. Phosphoric acid is widely used as an acidifying agent in a variety of pharmaceutical formulations as an acidulant, flavor, and synergistic antioxidant and sequestering. At the laboratorial and industrial territories, due to safety precautions, phosphoric acid may be considered a valid acid alternative for stronger and risky acids such as sulfuric, hydrochloric, and nitric acids. Furthermore, phosphoric acid, among the mineral acids, is less corrosive for steel and all goods made therefrom. Taking into account all these favorable arguments, the applied research at our laboratory (LQBB) is focused, with success, in the utilization of much diluted and moderately thermopressurized phosphoric acid (o-PA) in the pretreatment of polysaccharides for many biotechnological, as oligosaccharides production, important prebiotics for the human gastrointestinal tract.