title: Water Sorption Isotherm of Pea Starch Edible Films and Prediction Models.
abstract: The moisture sorption isotherm of pea starch films prepared with various glycerol contents as plasticizer was investigated at different storage relative humidities (11%-96% RH) and at 5 ± 1, 15 ± 1, 25 ± 1 and 40 ± 1 °C by using gravimetric method. The results showed that the equilibrium moisture content of all films increased substantially aboveaw= 0.6. Films plasticized with glycerol, under all temperatures and RH conditions (11%-96%), adsorbed more moisture resulting in higher equilibrium moisture contents. Reduction of the temperature enhanced the equilibrium moisture content and monolayer water of the films. The obtained experimental data were fitted to different models including two-parameter equations (Oswin, Henderson, Brunauer-Emmitt-Teller (BET), Flory-Huggins, and Iglesias-Chirife), three-parameter equations Guggenhiem-Anderson-deBoer (GAB), Ferro-Fontan, and Lewicki) and a four-parameter equation (Peleg). The three-parameter Lewicki model was found to be the best-fitted model for representing the experimental data within the studied temperatures and whole range of relative humidities (11%-98%). Addition of glycerol increased the net isosteric heat of moisture sorption of pea starch film. The results provide important information with estimating of stability and functional characteristics of the films in various environments.
authors.affiliation: School of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia. bahareh.saberi@uon.edu.au.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Saberi
authors.affiliation: School of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia. vanquan.vuong@newcastle.edu.au.
authors.forename: Quan V
authors.initials: QV
authors.lastname: Vuong
authors.affiliation: School of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia. csuwimol@gmail.com.
authors.forename: Suwimol
authors.initials: S
authors.lastname: Chockchaisawasdee
authors.affiliation: School of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia. john.golding@dpi.nsw.gov.au.|NSW Department of Primary Industries, Ourimbah NSW 2258, Australia. john.golding@dpi.nsw.gov.au.
authors.forename: John B
authors.initials: JB
authors.lastname: Golding
authors.affiliation: School of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia. c.scarlett@newcastle.edu.au.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Scarlett
authors.affiliation: Division of Food and Drink, School of Science, Engineering and Technology, University of Abertay, Dundee DD1 1HG, UK. costas.stathopoulos@newcastle.edu.au.
authors.forename: Costas E
authors.initials: CE
authors.lastname: Stathopoulos
keywords: edible film; modeling; moisture sorption isotherm; pea starch