Solubility and moisture sorption isotherms of whey-protein-based edible films as influenced by lipid and plasticizer incorporation

Sung Jin Kim, Z. Ustunol

Research output: Contribution to journalArticle

75 Scopus citations


Plasticized whey-protein and whey-protein emulsion films were produced using sorbitol and glycerol as plasticizers and butterfat and candelilla wax as lipids. Protein, plasticizer, and lipid ratios were optimized to obtain acceptable free-standing flexible films. Water solubility (20°C, 24 h) and moisture sorption isotherms (0.18-0.90 aw, 25°C) of the films were determined. The experimental moisture sorption isotherm values were fitted using the Guggenheim-Anderson-DeBoer (GAB) model. Solubility and equilibrium moisture contents (EMC) of the films were influenced by plasticizer and lipid incorporation. EMCs of all films increased rapidly at aw ≥ 0.65. Incorporation of lipids reduced solubilities and EMCs of sorbitol- and glycerol-plasticized films. The effects of plasticizer and lipid type on GAB constants were also determined.

Original languageEnglish (US)
Pages (from-to)4388-4391
Number of pages4
JournalJournal of Agricultural and Food Chemistry
Issue number9
StatePublished - 2001
Externally publishedYes



  • Edible films
  • Lipids
  • Moisture sorption isotherm
  • Solubility
  • Whey protein

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Food Science
  • Chemistry (miscellaneous)

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