Ultrasonic-microwave synergistic extraction (UMSE) and molecular weight distribution of polysaccharides from Fortunella margarita (Lour.) Swingle

摘要

The objective of this study was to use ultrasonic-microwave synergistic extraction (UMSE) to maximize the yield of polysaccharides from Fortunella margarita (FMPS) and investigate their molecular weight distribution. The results showed the optimum conditions were as follows: ultrasonic power of 131 W, microwave power of 105 W, ratio of water volume to raw material weight of 62 mL/g and extraction time of 120 s. Under these conditions, the yield of polysaccharides could be up to 9.15 +/- 0.13%, which was increased by 405.52%, 128.18% and 76.64% compared to hot water extraction (HWE), ultrasonic-assisted extraction (UAE) and microwave-assisted extraction (MAE), respectively. Furthermore, according to the size-exclusion chromatography connected with multi-angle laser light-scattering and refractive index (SEC-MALLS-RI) system, the molecular weight of FMPS was distributed mainly in the range 1.828 x 10(5)-9.563 x 10(5) g/mol and it accounted for 62.60% of total polysaccharides. The molecular weight and radius of FMPS did not display positive correlation. FMPS were composed of four polysaccharide fractions with different molecular weight. The polysaccharide fractions could be separated according to their molecular structural characteristics. (c) 2015 Elsevier B.V. All rights reserved.