title: Dry heat treatment affects wheat bran surface properties and hydration kinetics.
abstract: Heat stabilization of wheat bran aims at inactivation of enzymes which may cause rancidity and processability issues. Such treatments may however cause additional unanticipated phenomena which may affect wheat bran technological properties. In this work, the impact of toasting on wheat bran hydration capacity and hydration kinetics was studied. Hydration properties were assessed using the Enslin-Neff and drainage centrifugation water retention capacity methods, thermogravimetric analysis and contact angle goniometry, next to more traditional methods. While equilibrium hydration properties of bran were not affected by the heat treatment, the rate at which the heat treated bran hydrated was, however, very significantly reduced compared to the untreated bran. This phenomenon was found to originate from the formation of a lipid coating during the treatment rendering the bran surface hydrophobic. These insights help to understand and partially account for the modified processability of heat treated bran in food applications.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20 - Box 2463, 3001 Leuven, Belgium.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Jacobs
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20 - Box 2463, 3001 Leuven, Belgium.
authors.forename: Sami
authors.initials: S
authors.lastname: Hemdane
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20 - Box 2463, 3001 Leuven, Belgium.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Delcour
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20 - Box 2463, 3001 Leuven, Belgium. Electronic address: christophe.courtin@biw.kuleuven.be.
authors.forename: Christophe M
authors.initials: CM
authors.lastname: Courtin
mesh_terms: D004043:Dietary Fiber / Q000032:analysis*; D019649:Food Industry / Q000379:methods*; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D014908:Triticum / Q000737:chemistry*; D014867:Water / Q000032:analysis; D017155:Wettability
chemical_list: D004043:Dietary Fiber; D014867:Water
keywords: Autoclave; Hot air oven; Hydration equilibrium; Hydration kinetics; Hydrophobic coating; Microwave; Toasting; Wheat bran