Location: Food Processing and Sensory Quality Research
2022 Annual Report
Objectives
Determine the effects of intensive aeration production systems parameters on fillet flavor and texture.
Approach
Catfish is the major finfish aquaculture species produced in the United States, accounting for 51 percent of US aquaculture food fish sales in 2013. However, consumption of US grown catfish products has dwindled from its maximum of 319 million pounds in 2003 to almost half at 161 million pounds sold to consumers in 2012. This reduction in consumption of U.S. catfish has been the result of increased competition by cheaper imports. A method to counter this trend would be to produce a consistently higher quality product having less variability in its taste, texture, and color. The most pressing quality problems, as identified by the Catfish Industry, are the incidence and variability of off flavors and texture of the fillets.
Because of the increased competition and decrease in consumption of US catfish there is a need to increase production efficiencies to reduce price to consumers. Toward this goal, a number of intensive pond production systems have been developed and adopted by the catfish industry over the past 10 years. This has resulted in a wide variation of production conditions, which may induce variability in product quality. The proposed research will examine the differences and variability in texture and flavor quality of the fillets resulting from the different pond management parameters for three pond production systems - conventional, split-pond, and intensively aerated. Differences found in quality attributes will assist in the refinement of catfish management decisions to produce a higher quality, more consistent product needed for increased consumer acceptance.
Progress Report
ARS scientists in New Orleans, Louisiana made progress on the objective that falls under National Program 106, Aquaculture, Component 1, Improving the Efficiency and Sustainability of Catfish Aquaculture, to determine the effects of intensive aeration production systems parameters on fillet flavor and texture.
In support of Objective 1, we collected and analyzed samples from two catfish pond types, split-ponds and intensively aerated ponds. ARS scientists analyzed daily pond water samples for the off-flavor compounds, 2-methylisoborneol (MIB) and geosmin. In addition, ARS scientists collected catfish fillets at two time-points during the year and at the time of harvest for analysis of off-flavor compounds and to determine textural differences between pond types. In addition, environmental data, such as temperature and rainfall were collected. During the study, it became apparent that the pond managers began using an algaecide. ARS scientists discovered this issue after a steady increase in MIB was followed by an immediate and nearly complete elimination of MIB a few weeks into water collection. Data obtained before the algaecide was added showed that intensively aerated ponds had higher initial levels of MIB than the split ponds. Geosmin showed an increase in concentration concurrent with the decrease in MIB, with split-ponds having higher levels than intensively aerated ponds. Fish sample analysis for catfish collected shortly after the loss of MIB in pond water showed intermediate MIB concentrations. For catfish collected after algaecide application, results demonstrated that minimal MIB concentrations were present, and increased geosmin concentrations were well below what is detectable by humans. Also in support of Objective 1, ARS scientists initiated the development of new methods for determining lipid, moisture, and protein content of raw catfish samples and the lipidomic profile. These new methods will be beneficial in future research.
In support of Objective 1 and together with an industry partner and stakeholder, we continued to investigate sources of off-flavor in fish fillets. This research demonstrated that fillets readily absorb the “muddy” or “earthy” off-flavor chemical geosmin through the fish’s gastrointestinal system. Previously, the scientific consensus was that uptake only occurred through the gills. In these studies, ARS scientists used rainbow trout as a model system. For four weeks, researchers fed fish a diet spiked with geosmin and supplied them with a continuous flow of fresh water. Higher doses of geosmin in feed resulted in significantly higher concentrations of the geosmin in fillets. By incorporating geosmin into fillets in a controlled manner, future research can further investigate its effect on product acceptability and explore strategies to limit this off-flavor in farm-raised fish of any species. These results provided evidence for a dietary route of geosmin exposure not often considered when off-flavor issues arise.
In collaboration with AquaRange Research LLC/Bozeman Fish Technology Center and the Louisiana Universities Marine Consortium (LUMCON), ARS scientists in New Orleans explored the utilization of invasive carp to produce sustainable aquaculture feed ingredients for catfish. This research is trying to determine if invasive carp are a suitable alternative to traditional sources of protein and fat, such as Menhaden fishmeal. ARS collaborators collected invasive carp from two regions in Louisiana and one in Illinois during two seasons to determine the effect of season and location on composition and nutritional quality. This research aims to determine how the compositional differences of carp impact catfish growth and composition. Diets containing carp fishmeal and fish oil resulted in catfish fingerlings with similar growth, feed intake, feed efficiency, and proximate composition to those fed menhaden diets. In addition, researchers studied ingredient interactions to enhance digestibility of soybean meal. This research could lead to developing a market for invasive carp, whose harvest will benefit Louisiana’s river ecosystems and native fish populations. It will also provide alternatives to menhaden, a fishery that is experiencing increasing limitations to annual harvests.
In collaboration with NP306 scientists at Southern Regional Research Center, ARS scientists in New Orleans, Louisiana developed and prepared 100 samples of five new catfish products that were ready-to-cook by the consumer, using microwave or baking cooking methods. Nutritional and compositional content of the products was determined. In collaboration with scientists at the University of Arkansas at Pine Bluff and Texas State University, consumers evaluated the experimental catfish products to determine how the sensory and other organoleptic properties affected the consumers’ level of acceptance and willingness to pay for the products.
FPSQ is updating facilities for in-house rearing and processing of fish for better control of external factors that influence research results.
Accomplishments
1. Composition and nutritional attributes of ready-to-cook catfish products. ARS scientists in New Orleans, Louisiana, developed five new ready-to-cook catfish products, including both breaded and marinated catfish, for use as baked or microwaved meals. Scientists determined the nutrient content of the samples, including protein, moisture, fat, fiber, ash, carbohydrates, minerals, amino acids, and fatty acids. ARS scientists also determined the triglyceride, cholesterol, saturated fatty acids, and unsaturated fatty acids, which showed differences between the breaded and marinated products. In collaboration with scientists at the University of Arkansas at Pine Bluff and Texas State University, consumers evaluated the products for sensory and other organoleptic properties. Scientists also determined consumer willingness to pay for the products. Results demonstrated that all products were acceptable from a consumer standpoint, with the baked products preferred.
2. Texture differences were found between channel and hybrid catfish. With the increased use of hybrid catfish in the US, possible quality changes needed to be studied. Using instrumental texture analysis, ARS scientists in New Orleans, Louisiana, have shown that differences exist between the cooked fillets of the two common catfish types produced in the US, channels and hybrids. Also, the way the fillets are frozen and stored, such as fresh, frozen, or individually quick-frozen (IQF) effected texture. Firmness, toughness, and chewiness were most associated with the catfish type, with hybrids being lower than channels, while other texture attributes were indicative of the cold-storage methods, where IQF fillets had higher cohesiveness and lower adhesiveness and both frozen and IQF had higher springiness. For differences that might cause consumer complaints, scientists will need to study genetics, environment, and pond management practices to better understand the causes and improve catfish quality.
Review Publications
Bland, J.M., Grimm, C.C., Bechtel, P.J., Deb, U., Dey, M. 2021. Proximate composition and nutritional attributes of ready-to-cook catfish products. Foods. 10(11):2716. https://doi.org/10.3390/foods10112716.
Bland, J.M., Ardoin, R.P., Li, C.H., Bechtel, P.J. 2022. Instrumental texture differentiation of Channel (Ictalurus punctatus) and Hybrid (Channel x Blue, Ictalurus furcatus) catfish fillets. Foods. 11(13),1875. https://doi.org/10.3390/foods11131875.
Choi, H., Taghvaei, M., Smith, B., Ganjyal, G. 2022. Biochemical analysis of protein compositions among pea (Pisum sativum) cultivars grown in the Northwest U.S. ACS Food Science and Technology. 2:1067-1076. https://doi.org/10.1021/acsfoodscitech.1c00460.
Eggleston, G., Triplett, A., Bett Garber, K., Boue, S., Bechtel, P. 2022. Macronutrient and mineral content in sweet sorghum syrups compared to other commercial syrup sweeteners. Journal of Agriculture and Food Research. 7. Article 100276. https://doi.org/10.1016/j.jafr.2022.100276.
Mattison, C.P., Vant-Hull, B., de Castro, A., Chial, H.J., Bren-Mattison, Y., Bechtel, P.J., de Brito, E.S. 2021. Characterization of anti-ana o 3 monoclonal antibodies and their application in comparing brazilian cashew cultivars. Antibodies. 10(4):46. https://doi.org/10.3390/antib10040046.
Yazar, G., Kokini, J.L. and Smith, B., 2022. Effect of endogenous wheat gluten lipids on the non-linear rheological properties of the gluten network. Food Chemistry, 367, p.130729. https://doi.org/10.1016/j.foodchem.2021.130729
