title: Factors affecting microstructure, physicochemical and textural properties of a novel Gum tragacanth-PVA blend cryogel.
abstract: Gum tragacanth (GT) gels are usually formed by using chemical crosslinkers which cause safety concerns owing to their toxicity. This study introduces a novel and safe method for gelation of GT in the presence of small amounts of polyvinyl alcohol (PVA) followed by successive freeze-thaw (F-T) cycles. Gel formation was performed at two GT: PVA mixing ratios (1:1 and 3:1), four F-T consecutive cycles and two different thawing temperatures (25 and 5°C). Gel fraction, syneresis as well as mechanical properties and microstructural characteristics of the resultant gels were then studied. Gel fraction and mechanical properties improved by increasing F-T cycles and decreasing thawing temperature. Gel fraction increased by increasing the number of F-T cycles and decreasing the thawing temperature. Syneresis increased by increasing F-T cycles at GT: PVA mixing ratio of 1:1; whilst it was diminished at GT: PVA mixing ratio of 3:1. Microstructural observations by SEM confirmed mechanical properties.
authors.affiliation: Department of Food Chemistry, Research Institute of Food Science and Technology, PO Box: 91735-147, Mashhad, Iran. Electronic address: nushin.niknia@gmail.com.
authors.forename: Nushin
authors.initials: N
authors.lastname: Niknia
authors.affiliation: Department of Food Nanotechnology, Research Institute of Food Science and Technology, PO Box: 91735-147, Mashhad, Iran. Electronic address: r.kadkhodaee@rifst.ac.ir.
authors.forename: Rassoul
authors.initials: R
authors.lastname: Kadkhodaee
keywords: Cryogel; Gum tragacanth; Mechanical properties; PVA; SEM