Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/28/2004
Publication Date: 7/16/2005
Citation: Olsen, C.W., Avena Bustillos, R.D., Olson, D.A., Chiou, B., Yee, E., Mc Hugh, T.H. 2005. Tensile and puncture properties of mammalian and fish gelatin films. Meeting Abstract No. 109-5. IFT Annual Meeting. July 2005. New Orleans, LA.
Technical Abstract: Gelatin from cold and warm water fish skins are becoming readily available as new food and industrial uses are devised. Differences on amino acid composition and molecular weight distribution compared to mammalian gelatins affect physical properties and potential applications of fish skin gelatins. Edible coatings and films are also becoming an important tool to reduce water vapor and oxygen permeability to increase shelf-life of food systems. Tensile strength and puncture resistance of fish skin gelatin films are important parameters to define potential food applications. The objective was to evaluate tensile strength and puncture resistance of gelatins films from mammalian skins, cold water and warm water fish skins. 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. Tensile strength and % elongation were measured on gelatin film strips after equilibration at different %RH. Puncture force and deformation were measured at different %RH equilibrium on circular gelatin films using an Instron Universal Testing Instrument. Gel physical properties, molecular weight composition and amino acid content were also determined. Tensile strength at 31 %RH and 25°C was significantly lower for pollock skin gelatin films (50.8 MPa) than for catfish gelatin films (74.1 Mpa), cow hide gelatins (95.6 Mpa) and porkskin gelatins (112.9 Mpa). Elongation was also significantly lower for pollock skin gelatin (2.4%), while cow hide gelatins had higher elongation (11.1%). Tensile and puncture strength decreased, and elongation and puncture deformation increased at higher % RH equilibrium for each gelatin films. This behavior is related to amino acid composition and molecular weight distribution. This study demonstrated significant differences in physical, chemical and rheological properties between mammalian and fish gelatins. Lower tensile and puncture properties of fish gelatin films need to be accounted for applications in foods systems.