NEW TECHNOLOGIES TO PROCESS VALUE-ADDED, HEALTHY FOODS FROM FRUITS AND VEGETABLES
Location: Processed Foods Research
Title: WATER VAPOR PERMEABILITY OF MAMMALIAN AND FISH GELATIN FILMS
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 9, 2006
Publication Date: May 1, 2006
Citation: R.J. Avena Bustillos, C.W. Olsen, D.A. Olson, B. Chiou, E. Yee, P.J. Bechtel, T.H. McHugh, 2006. Water Vapor Permeability of Mammalian and Fish Gelatin Films. Journal of Food Science. Vol 71(4):E202-E207.
Interpretive Summary: Gelatin from marine sources is a possible alternative to bovine gelatin without the risk associated to BSE outbreak. However, low gelling and melting temperature, and low gel modulus makes fish gelatins unsuitable for most mammalian gelatin applications. Currently there is no research on water vapor permeability of fish gelatins and their excellent film-forming properties, and potential high barrier efficiency can have applications for edible films and coatings.
Mammalian, warm and cold water gelatins were obtained from commercial sources. Alaskan pollock and salmon gelatins were also extracted from frozen skins for this study. Gel strength and gel setting temperatures were lower for cold water fish gelatin than for warm water fish gelatins and mammalian gelatins as related to different polypeptide coils molecular weight distribution and amino acid composition.
This study demonstrated significant differences in physical, chemical and rheological properties between mammalian and fish gelatins. Lower water vapor permeability of fish gelatin films can be useful particularly for applications related to reduce water loss in cold or frozen foods.
Water vapor permeability of cold and warm-water fish skin gelatins was evaluated and compared with different types of mammalian gelatins. Mammalian, warm and cold-water gelatins were obtained from commercial sources. Alaskan pollock and salmon gelatins were extracted from frozen skins. Water vapor permeability of 100% gelatin films was determined using the ASTM E96-80 method, modified to calculate the % relative humidity at the film underside. Molecular weight distribution, amino acid composition, gel strength, viscoelastic properties, pH and clarity were also determined for each gelatin.
Water vapor permeability of cold-water fish gelatin films was 0.93 g.mm/m2.h.kPa and significantly lower than warm-water fish and mammalian gelatin films (1.31 and 1.88 g.mm/m2.h.kPa, respectively) at 25°C, 0/80 %RH through 0.05 mm thickness films. This is related to increased hydrophobicity due to reduced amounts of proline and hydroxyproline in fish gelatins. As expected, gel strength and gel setting temperatures were lower for cold-water fish gelatin than either warm-water fish gelatins or mammalian gelatins.
This study demonstrated significant differences in physical, chemical and rheological properties between mammalian and fish gelatins. Lower water vapor permeability of fish gelatin films can be useful particularly for applications related to reduce water loss from encapsulated drugs, and refrigerated or frozen food systems.