Premium
Sorption Isotherm and Plasticization Effect of Moisture and Plasticizers in Pea Starch Film
Author(s) -
Zhang Y.,
Han J.H.
Publication year - 2008
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2008.00867.x
Subject(s) - plasticizer , polyol , starch , monosaccharide , sorption , glycerol , materials science , chemical engineering , adsorption , sorbitol , polymer chemistry , chemistry , organic chemistry , composite material , polyurethane , engineering
Pea starch films were produced with various plasticizers (glucose, fructose, mannose, sorbitol, and glycerol). Effects of plasticizer content (4.34 to 10.87 mmol/g of dry starch) and storage relative humidity (RH) (11.3% to 75.4%) on moisture content (MC), tensile strength (TS), elongation (E), modulus of elasticity (EM), and water vapor permeability (WVP) were evaluated using response surface methodology. MC was influenced strongly by RH. Glycerol‐plasticized films had the highest MC, indicating that water molecules played a more important role in plasticizing starch films. Monosaccharide‐plasticized films and polyol‐plasticized films had similar TS values. However, monosaccharide‐plasticized films had higher E values and lower EM values than polyol‐plasticized films, meaning monosaccharides had better efficiency in plasticizing starch films. Recrystallization happened in glucose‐ and sorbitol‐plasticized films when they were stored in high RH. Sorption isotherm studies showed the similar adsorption and desorption profiles for all 3 monosaccharide‐plasticized films and a hysteresis. The Flory‐Huggius model fitted experimental data best for starch films, while the BET model fitted the data marginally.