Chitosan/NaCl microparticles used as sodium reduction strategy: studies on the physicochemical characteristics and optimization of preparation conditions

Abstract

Previous research suggested that chitosan microparticles were highly potent saltiness enhancer in food industry. In the present study, we attempted to investigate the preliminary production of chitosan/sodium chloride microparticles with maltodextrin as excipient by utilizing a lab-scale spray drying process. At first, chitin was isolated from shrimp shells and then underwent heat-alkali treatment to obtain purified chitosan, and the chitosan aqueous solutions were prepared subsequently. Acetic acid and lactic acid solutions were used to dissolve chitosan at concentrations of 0.5 and 1% (w/v), respectively. The effects of concentration of chitosan and the type of acid used for dissolving chitosan on the yields and the characteristics of product were evaluated. The impact of the excipient content was also assessed. The yields of microparticles were ranged in 39.7- 57.7%, resulted in pale yellow dried powder. Morphology study of microparticles showed spherical shape, with particle sizes ranged in 2.3-9.7 μm. The particles revealed acceptable dissolution rates in artificial saliva, however failed to confer comparable saltiness perception to NaCl in solution system. In contrast, they provided significant salty tastes on the dry food model, and demonstrated 21-45% of sodium reduction potencies without causing significant impairment in saltiness. Therefore, the prepared chitosan/NaCl microparticles may be a promising alternative of saltiness enhancers in the food industry.