title: Effects of granule size of cross-linked and hydroxypropylated sweet potato starches on their physicochemical properties.
abstract: Sweet potato starch was modified by cross-linking, hydroxypropylation, and combined cross-linking and hydroxypropylation, and the starches were subsequently sieved to obtain differently sized granule fractions. The effects of granule size of native and modified sweet potato starch fractions and all fractions were investigated with respect to their physicochemical properties. The large-size granule fraction (27-30 μm) showed a 16-20% higher chemical phosphorylation and a 4-7% higher hydroxypropylation than the small-size granule fraction (14-16 μm). The large-size granule fractions of native and modified sweet potato starches showed lower transition temperatures (0.7-3.1 °C for peak temperature of gelatinization) and lower enthalpy changes (0.6-1.9 J/g) during gelatinization than the small-size granule fractions, making the sweet potato starch different from cereal starches. The large-size granule fraction of native starch showed a higher paste viscosity (78-244 cP) than the corresponding small-size granule fraction. In addition, cross-linking and hydroxypropylation affected the paste viscosity of the large-size granule fraction significantly more than that of the small-size granule fraction when compared to the corresponding parental starch fractions. The large-size granule fraction of native and dual-modified starches showed a lower syneresis after freeze-thaw treatments than the small-size granule fractions. The difference in swelling power between large- and small-size granule fractions was not significant. In general, the large-size granule fraction of sweet potato starch was more susceptible for cross-linking and hydroxypropylation and the physicochemical properties were changed to a higher extent compared to the corresponding small-size granule fraction.
authors.affiliation: †Laboratory of Food Chemistry, Wageningen University, Post Office Box 17, 6700 AA Wageningen, Netherlands.|‡School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Zhao
authors.affiliation: §AVEBE Food Innovation Centre, 9640 AA Veendam, Netherlands.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: ‡School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
authors.affiliation: §AVEBE Food Innovation Centre, 9640 AA Veendam, Netherlands.
authors.forename: Piet
authors.initials: P
authors.lastname: Buwalda
authors.affiliation: †Laboratory of Food Chemistry, Wageningen University, Post Office Box 17, 6700 AA Wageningen, Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: Gruppen
authors.affiliation: †Laboratory of Food Chemistry, Wageningen University, Post Office Box 17, 6700 AA Wageningen, Netherlands.
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
mesh_terms: D027723:Ipomoea batatas / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D014783:Viscosity
chemical_list: D010936:Plant Extracts; D013213:Starch
keywords: cross-linking; hydroxypropylation; paste viscosity; physicochemical property; syneresis