title: Distribution of phosphorus and hydroxypropyl groups within granules of modified sweet potato starches as determined after chemical peeling.
abstract: The distributions of phosphorus and hydroxypropyl groups within granules of cross-linked and hydroxypropylated sweet potato starches were investigated. Chemical surface peeling of starch granules was performed after sieving of native and modified starches into large-size (diameter ≥ 20 μm) and small-size (diameter < 20 μm) fractions. Starch granules were surface gelatinized in a 4M calcium chloride solution at different levels. After the peeling step, the remaining starch granules were analysed for the content of phosphorus and hydroxypropyl groups. The phosphorus level of the parental starch gradually decreased from periphery to core of the granules. The increase in phosphorus content after cross-linking in periphery was higher than that in core. The subsequent hydroxypropylation reaction resulted in lower phosphate levels. Hydroxypropylation resulted in a gradient of hydroxypropyl group concentration from periphery to core. Cross-linking prior to the hydroxypropylation resulted in lower levels of hydroxypropyl groups and less pronounced differences between periphery and core.
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700AA Wageningen, The Netherlands; Jiangnan University, School of Food Science and Technology, 214122 Wuxi, PR China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700AA Wageningen, The Netherlands.
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
authors.affiliation: AVEBE Food Innovation Centre, Veendam, The Netherlands.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Jiangnan University, School of Food Science and Technology, 214122 Wuxi, PR China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
authors.affiliation: AVEBE Food Innovation Centre, Veendam, The Netherlands.
authors.forename: Piet
authors.initials: P
authors.lastname: Buwalda
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, P.O. Box 17, 6700AA Wageningen, The Netherlands. Electronic address: Harry.Gruppen@wur.nl.
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry*; D011198:Solanum tuberosum / Q000378:metabolism*; D013213:Starch / Q000737:chemistry*
chemical_list: D010758:Phosphorus; D002482:Cellulose; D013213:Starch; C008079:hydroxypropylcellulose; D002122:Calcium Chloride
keywords: Cross-linking; Hydroxypropylation; Phosphorus; Starch granule; Substituent distribution; Sweet potato starch