Water Sorption Isotherm of Pea Starch Edible Films and Prediction Models

Foods

Bahareh Saberi²  Quan V. Vuong²  Suwimol Chockchaisawasdee²  John B. Golding²  Christopher J. Scarlett²  Costas E. Stathopoulos¹ 

[1] Division of Food and Drink, School of Science, Engineering and Technology, University of Abertay, Dundee DD1 1HG, UKSchool of Environmental and Life Sciences, University of Newcastle, Ourimbah NSW 2258, Australia;

关键词: pea starch;    edible film;    moisture sorption isotherm;    modeling;   

DOI  :  10.3390/foods5010001

来源: mdpi

【 摘 要 】

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 above a_w = 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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.