title: Ultrasound-assisted heating extraction of pectin from grapefruit peel: optimization and comparison with the conventional method.
abstract: The extraction of pectin from grapefruit peel by ultrasound-assisted heating extraction (UAHE) was investigated using response surface methodology and compared with the conventional heating extraction (CHE). The optimized conditions were power intensity of 12.56 W/cm(2), extraction temperature of 66.71°C, and sonication time of 27.95 min. The experimental optimized yield was 27.34%, which was well matched with the predicted value (27.46%). Compared with CHE, UAHE provided higher yield increased by 16.34% at the temperature lowered by 13.3°C and the time shortened by 37.78%. Image studies showed that pectin extracted by UAHE showed better color and more loosen microstructure compared to that extracted by CHE, although Fourier Transform Infrared Analysis indicated insignificant difference in their chemical structures. Furthermore, UAHE pectin possessed lower viscosity, molecular weight and degree of esterification, but higher degree of branching and purity than CHE pectin, indicating that the former was preliminarily modified during the extraction process.
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Wang
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Life Sciences, Yantai University, Yantai, Shandong 264000, PR China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: School of Life Sciences, Yantai University, Yantai, Shandong 264000, PR China.
authors.forename: Zhumao
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Tian
authors.initials: T
authors.lastname: Ding
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Fuli Institute of Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China.
authors.forename: Xingqian
authors.initials: X
authors.lastname: Ye
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Fuli Institute of Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, PR China; Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, Zhejiang 310058, PR China; Zhejiang R & D Center for Food Technology and Equipment, Hangzhou, Zhejiang 310058, PR China. Electronic address: dhliu@zju.edu.cn.
authors.forename: Donghong
authors.initials: D
authors.lastname: Liu
mesh_terms: D032083:Citrus paradisi / Q000033:anatomy & histology / Q000737:chemistry*; D006361:Heating; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature; D014465:Ultrasonics; D014783:Viscosity
chemical_list: D010368:Pectins
keywords: Comparison; Grapefruit peel; Pectin; Response surface methodology; Ultrasound assisted heating extraction