Du, Xiaojing, Wang, Li, Huang, Xin, Jing, Huijuan, Ye, Xin, Gao, Wei, Bai, Xinpeng, and Wang, Hongxin
This research evaluated the effects of enzymatic-chemical extraction (EC-SDF), subcritical water extraction (SW-SDF), and ultrasonic-chemical extraction (UC-SDF) processes on the yield, chemical composition, structural characterization, flow behavior, physicochemical, and functional properties of soluble dietary fiber (SDF) from defatted coconut flour (DCF). The optimum conditions of these three extraction methods were evaluated by response surface methodology. Compared with EC-SDF and UC-SDF, SW-SDF had the maximum yield (13.99 ± 0.12 g/100g). The structural results indicated that SW-SDF and UC-SDF possessed more complex and porous structures than EC-SDF and DCF. Moreover, they showed smaller molecular weight, stronger gelling property, higher thermal stability, and lower crystallinity. A monosaccharide composition analysis indicated that the major sugars in EC-SDF, UC-SDF and UC-SDF were mannose and galactose. Notably, the SW-SDF demonstrated the highest water and oil holding capacity, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, and nitrite ion adsorption capacities. The above results suggest the defatted coconut flour to be a potential functional food and a possible source of cheap natural dietary fiber. • Soluble dietary fiber was recovered from the defatted coconut flour. • Three different methods were used to extract soluble dietary fiber. • The composition, structure and properties of the extracts were compared. • Subcritical water extraction method had the highest physicochemical properties. • The defatted coconut flour has great potential for the application in functional food industry. [ABSTRACT FROM AUTHOR]