title: Characterization of natural low-methoxyl pectin from sunflower head extracted by sodium citrate and purified by ultrafiltration.
abstract: Sunflower head pectin was extracted by 0.6% (w/v) sodium citrate under 85°C, 3.5h with a solid to liquid ratio of 1:40, giving the maximum uronic acid yield of 16.90% (w/w). The extract was purified by an ultrafiltration membrane with the molecular weight cut-off of 8000 Da and dried by spray-drying to obtain SFHP(A) powders with particle diameters of 2-5 μm. In comparison to the SFHP(B) extracted by ammonium oxalate and isolated by alcohol, SFHP(A) had a close DM (22.56%) but a considerably lower DAm (3.42%). HPSEC-MALLS analysis suggested that SFHP(A) has undergo a deeper degradation resulting in smaller Mw and Mn. HPAEC-PAD showed that SFHP(A) contains more neutral sugars since the degraded RG fragments have been retained during ultrafiltration. Finally, pectin aggregation in aqueous was investigated by FEG-SEM, which reveals that pectin network structure is constructed by microfilaments via coiling, intertwining and crosslinking.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 214122 Wuxi, China. Electronic address: 545580559@qq.com.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Kang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 214122 Wuxi, China; School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China. Electronic address: huaxiao@jiangnan.edu.cn.
authors.forename: Xiao
authors.initials: X
authors.lastname: Hua
authors.affiliation: School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China. Electronic address: yrj@jiangnan.edu.cn.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Yang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 214122 Wuxi, China. Electronic address: 794089406@qq.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 214122 Wuxi, China; School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China. Electronic address: 569981644@qq.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
mesh_terms: D002951:Citrates / Q000737:chemistry*; D006368:Helianthus / Q000737:chemistry* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010368:Pectins / Q000737:chemistry*; D000077559:Sodium Citrate; D014462:Ultrafiltration
chemical_list: D002951:Citrates; D000077559:Sodium Citrate; D010368:Pectins
keywords: Image investigation; Sodium citrate extraction; Structural parameters; Sunflower head pectin; Ultrafiltration