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United States Department of Agriculture

Agricultural Research Service

Title: Dehydration As a Stabilization Method for Alaskan Pollock Skins Prior to Gelatin Extraction

Authors
item McHugh, Tara
item Avena Bustillos, Roberto
item Pan, Zhongli
item Olson, Donald
item Olsen, Carl
item Chiou, Bor-Sen
item Yee, Emma
item Bechtel, Peter
item Bower, Cynthia
item Pantoja, Alberto

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 28, 2004
Publication Date: July 16, 2005
Citation: Mc Hugh, T.H., Avena Bustillos, R.D., Pan, Z., Olson, D.A., Olsen, C.W., Chiou, B., Yee, E., Bechtel, P.J., Bower, C.K., Pantoja, A. 2005. Dehydration as a stabilization method for alaskan pollock skins prior to gelatin extraction. Meeting Abstract No. 99C-24. IFT Annual Meeting. July 2005. New Orleans, LA.

Technical Abstract: Pollock is the largest Alaskan fish catch. A large amount of skins, a by-product from mince mechanical separation, is being produced, but not well utilized. Fish gelatin is a high value product with increasing demand for food and industrial applications that could be produced using the dried skins. Drying can stabilize the fish skins and reduce shipping and storage costs. It is still unknown how drying processes affect the yield and physical/chemical quality of gelatin extracted from dried skins. The objective was to evaluate yield and quality factors of gelatin extracted from pollock skins stabilized by using hot air drying and freeze-drying. Frozen pollock skins were dried using a hot air dryer and a freeze dryer, respectively. Gelatins were extracted from the dried and frozen skins. Yield, clarity, pH, gel strength, viscoelastic properties, water vapor permeability and tensile properties, as well as protein molecular weight distribution of the gelatins were compared. Yield of dry gelatin from frozen pollock skins was 11%, while yield from freeze-dried and air-dried pollock skins were 10% and 8% based on the weight of frozen pollock skins. Gel strength was reduced from 2.2 N in gelatin from frozen pollock skins to 1.8 N in gelatins from freeze-dried and air-dried skins. Gelation temperature increased from 4.2°C for frozen skin gelatin to 4.8°C and 6.10°C for the freeze-dried and air-dried skin gelatins, respectively. The yield and property changes could be due to the differences on molecular weight distribution of polypeptide coil segments caused by partial denaturation of collagen. There was no difference in pH, clarity of gels, water vapor permeability, tensile strength and elongation of films among the three gelatins. This research demonstrated the feasibility to stabilize pollock skins by different drying techniques without substantially hindering yield and quality of extracted gelatin.

Last Modified: 9/2/2014