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United States Department of Agriculture

Agricultural Research Service

Research Project: Bioproducts from Agricultural Feedstocks

Location: Bioproduct Chemistry and Engineering Research

Title: Dehydration of pollock skin prior to gelatin production

Authors
item Bower, Cindy -
item Avena Bustillos, Roberto
item Hietala, Katie -
item Bilbao-Sainz, Cristina
item Olsen, Carl
item McHugh, Tara

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 13, 2010
Publication Date: May 3, 2010
Repository URL: http://onlinelibrary.wiley.com/doi/10.1111/j.1750-3841.2010.10596.x/pdf
Citation: Bower, C.K., Avena Bustillos, R.D., Hietala, K.A., Bilbao-Sainz, C., Olsen, C.W., Mchugh, T.H. 2010. Dehydration of pollock skin prior to gelatin production. Journal of Food Science. 75, C317-C321.

Interpretive Summary: Alaska pollock is the largest commercial fishery in the U.S. with an annual catch of over 1 million tons. During pollock processing, the skins are discarded or made into fish meal, despite their value for gelatin production. The absence of gelatin-processing facilities in Alaska necessitates drying of the skins before transport to decrease the moisture content, preserving the skins and allow transport at a reasonable cost. Conventional hot-air drying is expensive so less expensive methods of drying need to be developed. We evaluated a less energy-intensive technology for reducing water in pollock skins by using regenerable, chemical dessicants. To ensure that the functional properties of gelatin obtained from dried pollock skins were not affected during drying, gelatins were prepared from each skin-drying treatment and compared with gelatin extracted from air-dried pollock skins. None of the desiccation treatments had an affect on the resulting gelatin. Thus, pollock skins may be economically stabilized for transport to a gelatin-processing facility through the use of regenerable desiccants that are already common in the food industry. Stabilizing pollock skins through reduction of water content would reduce transportation costs.

Technical Abstract: Alaska pollock (Theragra chalcogramma) is the U.S.A.'s largest commercial fishery, with an annual catch of over 1 million tons. During pollock processing, the skins are discarded or made into fish meal, despite their value for gelatin production. The absence of gelatin-processing facilities in Alaska necessitates drying of the skins before transport to decrease the moisture content, but conventional hot-air drying is expensive. This study evaluated a less energy-intensive technology, the use of desiccants for reducing water weight in pollock skins prior to shipment. To ensure that the functional properties of gelatin obtained from dried pollock skins were not affected during desiccation, gelatins were prepared from each skin-drying treatment and compared with gelatin extracted from air-dried pollock skins. None of the desiccation treatments decreased the gel strength of pollock skin gelatin, nor were there major differences in gelling temperature or viscosity among the gelatin solutions. This suggests that pollock skins can be economically stabilized for transport to a gelatin-processing facility through the use of regenerable desiccants that are already common in the food industry.Practical Application: Pollock skins destined for gelatin production can be stabilized using chemical desiccants prior to shipment. The dehydration process does not harm the functional properties of gelatin, such as gel strength, gelling temperature, and viscosity. This research suggests that fish skins can be economically stabilized for transport to a gelatin-processing facility through the use of regenerable desiccants that are already common in the food industry.

Last Modified: 4/20/2014