ABSTRACT
In this study, hot water treatment (WT), ultrasonic treatment (UT), ultrasonic-sodium hydroxide treatment (UST), ultrasonic-enzyme treatment (UET), and ultrasonic-microwave treatment (UMT) were used to treat sweet potatoes. The structural, physicochemical, and functional properties of the extracted soluble dietary fibres (SDFs) were named WT-SDF, UT-SDF, UST-SDF, UET-SDF, and UMT-SDF, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal properties, and Brunauer-Emmett-Teller (BET) analysis were employed. The structural results indicated that the UST-SDF exhibited the best thermal stability, highest crystallinity, and maximum specific surface area. Moreover, compared to hot water extraction, ultrasonic extraction, or ultrasonic extraction in combination with other methods, enhanced the physicochemical and functional properties of the SDF, including extraction yield, water-holding capacity (WHC), oil-holding capacity (OHC), glucose adsorption capacity (GAC), glucose dialysis retardation index (GDRI), sodium cholate adsorption capacity (SCAC), cholesterol adsorption capacity (CAC), nitrite ion adsorption capacity (NIAC), and antioxidant properties. Specifically, the UST-SDF and UMT-SDF showed better extraction yield, WHC, OHC, GAC, CAC, SCAC, and NIAC values than the other samples. In summary, these results indicate that UST and UMT could be applied as ideal extraction methods for sweet potato SDF and that UST-SDF and UMT-SDF show enormous potential for use in the functional food industry.
ABSTRACT
In this study, the structural characterization, physicochemical properties, antioxidant, hypolipidemic, and hypoglycemic potentials of polysaccharide components (BLP-1, BLP-2, and BLP-3) purified from blueberry leaf polysaccharides (BLP) were investigated. Ion chromatography results showed that BLP-1, BLP-2, and BLP-3 contained rhamnose, arabinose, galactose, glucose, and glucuronic acid. In contrast to BLP-1, BLP-2 and BLP-3 included galacturonic acid. The methylation analysis results indicated that the backbones of BLP-1, BLP-2, and BLP-3 were mainly composed of glycosidic linkages of arabinose, galactose, and glucose, which was consistent with the results of the previously determined monosaccharide composition. The in-vitro antioxidant results showed that BLP-1, BLP-2, and BLP-3 possessed antioxidant activity with the highest scavenging of -OH radicals. Furthermore, BLP-1, BLP-2, and BLP-3 showed high bile acid-binding activity and α-amylase inhibitory activity, suggesting that they have the potentials of hypolipidemic and hypoglycemic. This study provides a reference for the utilization of blueberry leaf resources.