Turmeric extract-loaded-oil-in-water emulsion containing soy polysaccharide: Physical properties, bioactive abilities, stability, and in vitro gastrointestinal digestion
Sunsanee Udomrati, Thidarat Pantoa, Possathorn Pongpaew, Jutamat Klinsoda, Phichamon Noisuwan, Doungjai Thirathumthavorn
Abstract
Turmeric ( Curcuma longa L . ) extract containing 23 % curcuminoid was produced using ethanol extraction. The turmeric extract was encapsulated in an oil-in-water (O/W) emulsion containing soy polysaccharide (EMsp) with soy polysaccharide (SP) concentrations of 5–35 % (w/w). The curcuminoid as the main bioactive compound of the turmeric extract was selected as the monitoring target of this investigation. As the SP concentration increased: (1) the emulsion stability improved during storage at room temperature for 7 and 14 days, resulting in reduced coalescence and inhibited creaming; (2) the curcuminoid encapsulation efficiency was enhanced, resulting in increased antioxidant activity, anti-α amylase activity, and anti-pathogenic bacteria activity ( Staphylococcus aureus and Escherichia coli ); and (3) curcuminoid deterioration was delayed during storage. For in vitro gastrointestinal digestion, the increase in SP concentration retarded curcuminoid loss in all digestion phases (oral, gastric, and intestinal) and increased lipid digestibility as complete digestion. The EMsp sample containing 35 % SP produced the highest potential improvement for emulsion and curcuminoid stability during storage and digestion compared to the other SP concentrations. EMsp showed promise as an attractive alternative emulsion system to develop and design a bioactive compound delivery system for functional foods.