title: Inhibition of wheat starch retrogradation by tea derivatives.
abstract: The effect of four industrial tea derivatives (tea polyphenols [TPS], tea water-soluble extracts [TSE], tea polysaccharides [TSS], and green tea powder [GTP]), on the retrogradation of wheat starch was investigated using texture profile analysis (TPA), differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and the α-amylase-iodine method. The addition of the four tea derivatives resulted in decreased hardness and increased cohesiveness of the starch gel as shown by the TPA test. The DSC data demonstrated an increase in the enthalpy change of starch gelatinization and a decrease in the enthalpy change of starch recrystallite dissociation. The RVA results indicated that the peak viscosity, representing the intermolecular forces of wheat starch, was reduced after addition of TPS, TSE, and TSS, respectively, but was increased by GTP. Furthermore, the half crystallization time in the Avrami equation almost doubled after the separate addition of the tea derivatives.
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Hangzhou Tea Research Institute, China Coop., Hangzhou 310016, China.
authors.forename: Haihua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Binghua
authors.initials: B
authors.lastname: Sun
authors.affiliation: Hangzhou Tea Research Institute, China Coop., Hangzhou 310016, China.
authors.forename: Shikang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Hangzhou Tea Research Institute, China Coop., Hangzhou 310016, China.
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address: yqtian@jiangnan.edu.cn.
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Tian
mesh_terms: D019649:Food Industry; D006244:Hardness; D007700:Kinetics; D010936:Plant Extracts / Q000737:chemistry; D012995:Solubility; D013213:Starch / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D010936:Plant Extracts; D013662:Tea; D014867:Water; D013213:Starch
keywords: Avrami equation; Retardation effect; Retrogradation; Tea; Wheat starch