Location:2010 Annual Report
1a. Objectives (from AD-416)
The over-arching goal of this project is to develop new knowledge to increase the value of underutilized seafood processing byproducts as food and feed ingredients in a sustainable manner. This will be achieved by accomplishing the three listed objectives. 1. Develop new and improved feed ingredients and high value human food products using fish processing co-products. 2. Develop economical processes and methods for the collection, stabilization and storage of raw seafood byproducts to optimize their chemical, nutritional, and physical qualities for uses including food and feed ingredients, fertilizers and bio-chemicals. 3. Develop ingredients from fish processing co-products that meet larval and stage specific physiological requirements of marine fish when used in modern dietary formulations.
1b. Approach (from AD-416)
Fractions prepared from pollock and salmon byproducts such as fish meals, hydrolysates and stick water will be identified that promote growth in targeted aquaculture species fed plant protein based diets. Also, aquaculture ingredients from fish byproducts such as enriched fatty acid and phospholipid fractions will be identified that increase performance in targeted species. A continuous system for purifying and stabilizing salmon and pollock oils extracted from byproducts will be developed that can be used in smaller rural processing plants. Machine vision systems will be developed that can identify individual byproduct components such as liver and then efficiently separate the parts for further processing or packaging. Processes will be developed that improve the functional properties of fish skin gelatin films and other gelatin products in collaboration with scientists at WRRC in Albany, CA. Constituents of testes and other meals that positively affect shrimp and fish growth will be identified for use as aquaculture ingredients. The minimum levels of dietary omega 3 fatty acids required to sustain good growth and health of trout at different life stages will be determined. Economic analyses of the cost effectiveness of different methods of handling seafood processing byproducts will be provided to stakeholders. Collaborative studies between ARS and University of Alaska scientists will be conducted in the pilot plant and laboratories in Kodiak and Fairbanks, AK, and feeding trials will be conducted at the University of Idaho and the Oceanic Institute in Hawaii. Replacing 5341-31410-003-00D (10/09).
3. Progress Report
Methods were developed for the analysis of low molecular weight nitrogen compounds in fish byproducts with hydrophilic interaction liquid chromatography coupled to mass spectrometry. Tissues rich in phospholipids were identified and fractionation methods were evaluated including enrichment with membrane systems and winterization processes. Three trials were conducted to evaluate effects of nine Alaskan fisheries byproducts as feeding stimulants in plant based diets for Pacific white shrimp. Physical and chemical properties of commercial salmon oils from two processing plants were monitored over the fishing season to establish that no large changes in the fatty acid profile or fat soluble vitamins were occurring. A study was conducted to determine the concentrations of chondroitin sulfate(CS) extractable from fish byproducts in Alaska. Results indicate that extraction of CS from fisheries byproducts is possible and may lead to one or more valuable products. ARS researchers in Alaska determined that dehydrating fish skins using chemical desiccants prior to transport can stabilize the material and reduce shipping weight. The effects of using Alaska fish oil to enhance the omega-3 fatty acids of fillets from rainbow trout fed diets containing plant oils in a phase-feeding were evaluated. Diets containing Alaska pollock and rockfish oils were both effective in increasing EPA and DHA levels in trout fillets. Alaska pollock fish bone meals fed as a dietary ingredient to trout were inferior to dicalcium phosphate as a phosphorus source. Analyses were completed for NH4-N and NO3-N in soil samples after incubation of three fish meal products in field trials. A study under way is evaluating different fractions of soluble organic N for developing a predictor of available N from fish byproducts. A nutritious new cheese, possessing a pleasant smoked fish aroma, light salmon-orange color, and a distinctive smoked salmon flavor, was developed with antioxidant-rich, smoke-processed salmon oils. Gelatin from Alaska pollock was used for electrospinning pollock gelatin/poly (vinylpyrrolidone) nanofibers for potential medical and drug applications. A study has been initiated to use machine vision to identify and eventually separate salmon liver from other fish viscera components during processing. Evaluated fish oil purification using a combination of activated alumina and activated earth for adsorption. Another study evaluated salmon and menhaden oils purified using shrimp chitosan in a batch process. The effects of fish and other animal proteins on satiety was evaluated in pets (dogs) by evaluation on satiety related hormone levels. Alaska salmon waste-products and alder wood were pelletized together and used as a feedstock for gasification to produce a combustible gas. An edited proceedings has been produced from the 2009 IFT symposium "A Sustainable Future: Fish Processing Byproducts" edited by P. Bechtel and S. Smiley, and will publish in 2010 by the Alaska Sea Grant College Program, University of Alaska, 320 pages.
1. NANOFIBERS FROM FISH GELATIN Increasing the value of fish byproducts will enhance the sustainability of the Alaskan fishing industry. The potential of using gelatin from fish skin to make nanofibers was studied by researchers for ARS in Fairbanks, AK, and California. Pollock Gelatin/Poly(Vinyl Pyrrolidone) and other combinations were evaluated for their ability to be electrospun into nanofiber. Characteristics of the nanofiber parameters affecting the spinning process were evaluated. Pollock gelatin/poly nanofibers have the potential to be made into many products including medical use.
2. CLEAN WASTE FROM ALASKA The presence of contaminants can affect the marketability of fish byproducts. Scientist with the ARS in Fairbanks, AK, collaborated with scientist from the Institute of Environmental and Human Health, Texas Tech University, to screen a number of fish oils and meals made from Alaska byproducts. Persistent organic contaminants (organochlorine pesticides and polychlorinated biphenyl) were not detected in any of the samples analyzed from Alaska. These results suggested byproducts from cold water marine fish caught in Alaska are free of persistent organic pollutants.
3. PHYSICAL AND CHEMICAL PROPERTIES OF COMMERCIAL SALMON OIL Fish oil extracted from byproducts may add value to the commercial fishing industry. A study was conducted by ARS scientist in Fairbanks, AK, and industry collaborators to examine the physical and chemical properties of commercial fish oil collected from two different salmon oil and meal processing plants as it changed over one salmon fishing season. Results indicated the oils were good sources of vitamins A, D, and E and there were no large changes seen in the fatty acid profiles or vitamin levels over the course of the fishing season, although steps may be needed to protect the oils collected early in the season. Over the course of a fishing season, these salmon oils are of high and consistent quality.
4. SHRIMP FEEDING STIMULANTS FOR USE WITH PLANT BASED DIETS Pacific white shrimp show reduced growth when fed diets where soy protein is substituted for fish meal. Shrimp aquaculturists can remedy reduced growth due to plant-based diets by stimulating increased consumption rates with selected fish byproducts. Scientist from The Oceanic Institute, Hawaii, in collaboration with University of Alaska and ARS scientists in Fairbanks conducted trials to evaluate effects of nine Alaskan fisheries byproducts and feeding stimulants in plant based diets for the Pacific white shrimp. Results found that Alaskan byproducts can be effective supplements in stimulating shrimp fed soy protein based diets to increase consumption, and the effect depended on inclusion levels.
5. UV-B LIGHT AND FISH SKIN GELATIN PROPERTIES Cold-water fish skin gelatins have characteristic physical properties significantly different from either warm-water fish skin or mammalian gelatins; however, some applications require improvement of physical properties to resemble those of other types of gelatins. Collaborating scientists at the ARS laboratories in Albany, CA, and Fairbanks, AK, embarked on studies to alter the physical properties of dried cold water fish skin gelatins using UV-B light. Results indicated that UV-B light can induce protein chain modifications to the dried and milled cold water fish skin gelatins. The modifications can increase gel strength, gel set temperature, and aqueous viscosity, as well as affect the mechanical properties of gelatin films. UV-B modified cold-water fish skin gelatins can be used for specific applications as food thickeners and emulsifiers at different temperature ranges.
6. DEHYDRATING POLLOCK SKINS PRIOR TO SHIPMENT Pollock skins destined for gelatin production currently must be transported to processing facilities outside of Alaska. Untreated, the skins contain roughly 80% water making transport expensive. ARS researchers from Alaska and California have determined that dehydrating fish skins using chemical desiccants prior to transport can stabilize the material and reduce shipping weight. Results show that dehydration does not harm the functional properties of gelatin, including gel strength, gelling temperature, and viscosity. This research suggests that fish skins can be economically stabilized for transport through the use of reusable desiccants commonly employed in the food industry.
7. FISH BONE MEALS AS A SOURCE OF DIETARY PHOSPHORUS Alaskan fish bones can be made into a meal that may become a useful dietary phosphorus source for rainbow trout. Scientist at the University of Idaho in collaboration with University of Alaska and ARS scientists evaluated the physical and chemical properties of bone meals derived from Alaskan pollock. Performance characteristics were determined for rainbow trout fed a balanced dietary mix of plant-proteins supplemented with either fish bone meal (FBM) derived from Alaskan seafood processing byproducts or dicalcium phosphate. Results indicated that meals with FBM were inferior to dicalcium phosphate as dietary phosphorus sources suggesting that the phosphorus in bone meals produced from Alaska seafood processing waste may require additional processing to increase phosphorus availability.
8. ENERGY FROM PYROLYSIS OF SALMON BYPRODUCTS One potential use for fish processing byproducts is as an energy source. University of Alaska and ARS, Fairbanks, AK, researchers, collaborated to optimize conditions of pyrolysis for using salmon processing wastes to generate energy. Alaska salmon waste-products and alder wood were pelletized and gasified to produce a combustible gas. Results indicated that up to 21% salmon waste enhanced the gasification of alder. Fish processing byproducts are a source of energy.
9. SNACK FOODS FROM SALMON BYPRODUCT POWDERS Many Alaskan products are at a disadvantage in competing in international markets due in part to high transportation costs. One way to reduce transportation costs and avoid refrigeration is to develop new products made from dried fish byproduct powders. Scientists from ARS laboratories in Albany, CA, and Fairbanks, AK, made dried salmon flakes using an infrared dryer that were subsequently milled to powder. The powders were formulated with starch, water, and seasonings, and then extrusion molded for deep frying and infrared drying. These shelf-stable fish snacks produced from salmon byproduct powders can be incorporated into shelf-stable ethnic fish snacks as well as pet foods.
Chiou, B., Avena Bustillos, R.D., Bechtel, P.J., Imam, S.H., Glenn, G.M., Orts, W.J. 2009. Effects of Drying Temperature on Barrier and Mechanical Properties of Cold-Water Fish Gelatin Films. Journal of Food Engineering. 95(2), 327-331.