title: Morphological changes of blocklets during the gelatinization process of tapioca starch.
abstract: After combined hydrolysis by α-amylase and β-amylase at room temperature, spherical blocklets in diameters of 27-60nm were observed on the surface of tapioca starch granules by scanning electron micrography (SEM). Tapioca starch (1%, w/w, db, distilled water) was heated by using a rapid visco analyzer (RVA) in four different programs, then the samples were settled and freeze dried, respectively. The SEM images showed that the blocklets swelled at 52°C; the swollen blocklets deformed to olive shape, and linked by molecular chains, formed bead-like structure at 62°C; they started to merge at 72°C (pasting temperature); then the blocklets fused together and their shapes disappeared completely, and the gel network formed at 95°C. Furthermore, the morphological changes of the blocklets were not simultaneously.
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China. Electronic address: huangjunrong@sust.edu.cn.
authors.forename: Junrong
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China.
authors.forename: Maomao
authors.initials: M
authors.lastname: Wei
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China.
authors.forename: Ruizhen
authors.initials: R
authors.lastname: Ren
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China.
authors.forename: Shuxing
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology,Weiyang District, 710021 Xi'an, Shaanxi Province, China.
authors.forename: Daqing
authors.initials: D
authors.lastname: Yang
mesh_terms: D005782:Gels / Q000737:chemistry*; D006868:Hydrolysis; D002365:Manihot / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013696:Temperature
chemical_list: D005782:Gels; D013213:Starch
keywords: Blocklets; Enzymolysis; Gelatinization; SEM; Tapioca starch