ARS | Publication request: Sensory analysis of rainbow trout, oncorhynchus mykiss, fed enriched black soldier fly prepupae, hermetia illucens

Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 6, 2011
Publication Date: February 20, 2011
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Sealey, W.M., Gibson, T.G., Barrows, F., Tomberlin, J.K., Ross, C., St. Hilaire, S. 2011. Sensory analysis of rainbow trout, oncorhynchus mykiss, fed enriched black soldier fly prepupae, hermetia illucens. Journal of the World Aquaculture Society. Vol 42, No.1, 2011.

Interpretive Summary: The demand for seafood has been rising steadily worldwide for the last 15 years. All wild fisheries are now at, or above, the maximum sustainable harvest yields, so aquaculture must make up this difference which makes aquaculture the fastest growing segment of agriculture. Fish meal (wild harvested sardines anchovies, herring etc.) has been the primary ingredient in aquaculture feeds for many years. In the last decade, however, rising fish meal prices, intense regulation of nutrients in hatchery effluents, and the debate on the sustainability of fish meal as an aquafeed ingredient has intensified research in this area. A wide variety of plant based ingredients, terrestrial animal by-products , and more recently bio-fuel co-products and algae’s have been investigated. Yet there is more interest in natural type ingredients for fish such as insect meals. A study was conducted to determine the nutritional quality of black soldier fly larvae for rainbow trout and if there is an effect of feeding these insects on the fillet quality of trout. Experimental diets were fed for 8 weeks and no difference in growth was observed among the fish fed fish based diets or diets with insect meal. Also, a group of 30 untrained panelists did not detect a significant difference in a blind comparison of fish fed the fish meal containing control diet as compared to fish fed diets containing soldier flies.

Technical Abstract: A growth trial and fillet sensory analysis were conducted to examine the effects of replacing dietary fish meal with black soldier fly (BSF) prepupae, Hermetia illucens, in rainbow trout, Oncorhynchus mykiss. A practical-type trout diet was formulated to contain 45% protein; four test diets were developed by substituting 25 and 50% of the fish meal with normal (BSF) or fish offal-enriched black soldier fly (EBSF) prepupae. Dietary fat was adjusted to approximately 20% lipid using fish oil and poultry fat. Diets were fed to three replicate tanks of fish per treatment (10 fish/tank) for 8 wk. After the trial, three fish per tank were sampled for determination of hepatosomatic index, intraperitoneal fat ratio and muscle ratio, and muscle proximate and fatty acid composition. Fish remaining after sampling were used for sensory evaluation. Growth of fish fed the EBSF diets was not significantly different from those fish fed the fish meal-based control diet, while the growth of fish fed the BSF diets was significantly reduced as compared to the control diet. A group of 30 untrained panelists did not detect a significant difference in a blind comparison of fish fed the fish meal containing control diet as compared to fish fed the EBSF or BSF diets.