Location: Food Processing and Sensory Quality Research
2018 Annual Report
Objectives
The overall goal of this research project is to stimulate consumer demand for catfish products and increase the profitability of the U.S. catfish industry through improved product quality.
Objective 1: Generate new processed catfish definitions for uniform sensory quality and grading standards and enable economical, accurate and real-time commercial methods to monitor sensory attributes of processed catfish.
Sub-Objective 1.A: Develop a set of guidelines for the evaluation of off-flavors in farm raised catfish and provide them to the industry through a set of workshops.
Sub-Objective 1.B: Develop instrumental methods for the economic rapid determination of color and off-flavors in farm raised catfish for use by the industry.
Objective 2: Enable new commercial value added postharvest processes and innovative packaging technologies that maintain/improve the sensory qualities and shelf life of processed catfish.
Approach
Consumption of U.S. grown catfish has dwindled from its maximum in 2003 to almost half that in 2014. There are multiple reasons for decreased catfish consumption including reduced production, imports and variability in product quality. The most pressing quality problem, as identified by the catfish industry, is the incidence and intensity of off flavors. Consumer demands in the dinner protein market are high quality products, free of defects.
This project will develop a set of guidelines for the evaluation of off-flavors in farm raised catfish and provide them to the industry through a set of workshops. A survey of existing flavor checkers at catfish processing plants will be conducted to determine the best practices currently used in the industry. Individual processors will be surveyed with regard to their flavor checking practices. Different practices will be subjected to laboratory testing to determine the most effective protocols. Once the best practices have been determined, a series of workshops will be provided to the industry to standardize the analysis of off-flavors.
Instrumental methods will be developed for an economical and rapid determination of color and off-flavors in farm raised catfish for use by the industry. In line instrumentation for color evaluation is widely used for quality assessment in a variety of agricultural products and this technology will be adapted for use by the catfish aquaculture industry. Initial experiments will focus on documenting the degree of color variation and identifying strategies to minimize variation. Currently the analysis of off-flavors for individual fillet does not appear to be economically feasible even if it were technological possible. However, a detailed evaluation of test samples may suggest procedures that could effectively assist existing flavor checker protocols to reduce variation in off-flavor. The adoption of improved analtyical methods by the industry will depend upon need, cost and effectivness. Efforts will be made to demonstrate the benefits of improved methods.
This project will develop new and improved processes, products and packaging systems that will enrich the sensory qualities and improve the shelf life of processed catfish. Marination, the process of soaking foods in seasoned, often acidic, liquids before cooking and may offer an opportunity for modulating the off-flavors found in some farm raised catfish fillets. In addition, frozen precooked catfish products will be developed that are designed to be heated in a microwave or conventional oven before serving. Studies will be conducted on precooking methods, packaging, and product quiaty duign storage. Efforts will be made to deveolop new products and extend product lines of frozen catfish products using processing equipment commonly found in the industry.
Progress Report
Progress was made on the two objectives and their sub objectives, all of which fall under National Program 306, Product Quality and New Uses, Component 1 Foods. Progress on this project focuses on Problem Statements 1.A: Define, measure and preserve/enhance/reduce attributes that impact quality and marketability and 1.C: New and improved food processing and packaging technologies. Under Objective 1. A, we made significant progress in evaluating methods used by different processing plants to evaluate off-flavor in catfish prior to their being accepted for processing. The goal is to work with the industry to identify a set of general recommendations that can be used by processing plants for evaluation of off-flavors by the flavor checkers at the plants. A study was completed to evaluate the effect of different cooking procedures on the perception of catfish flavors using a trained sensory panel. Cooking procedures used by the flavor checkers at the processing plants were evaluated by a trained sensory panel and included microwaving cooking in the following containers, brown lunch bag, French-fry boat foam tray, plastic bag and Corning ware dish covered with parchment paper. Cooking by deep frying in vegetable oil after coated with breading was also evaluated. Results indicated off-flavored fish that were breaded and oil fried were significantly less intense in dirt/earthy/musty flavor than the fish microwaved. In order to provide this information to the industry a technical bulletin titled “Effects of Cooking Methods on Catfish Flavor Using a Trained Sensory Panel” written by ARS researchers from the Southern Regional Research Center, New Orleans, Louisiana, was provided to all catfish processing plants to help them evaluate the flavor checking procedures used by their plant. Follow-up discussions with flavor checkers and others at each processing plants are ongoing to clarify the study as needed and listen to their ideas for future studies. Under Objective 1.B, machine vision methods for sorting catfish products by color continue to be evaluated. However, it has become apparent that rather than develop a system for sorting catfish fillets it would be advisable to adapt a currently available machine vision system used for color evaluation of other fish species or other food products.
Under Objective 2, ARS researchers made significant progress in developing value added products for adaption by the seafood industry to meet market demands for nutritious and convenient catfish products. A precooked catfish fillet product could be reheated in a microwave oven has developed to avoid the safety issues of a lack of uniform heating during microwave cooking of raw catfish fillets. The quality and storage stability of the frozen precooked product was evaluated during frozen storage for up to 10 months. Other catfish products developed included battered products designed to be baked rather than fried or par-fried. Also, marinated products were made using fillets that had more of the skin-fat layer removed. These products are being evaluated in a marketing study conducted by the faculty of the University of Arkansas Pine Bluff, Arkansas. Another approach used in this objective was to develop a masking agent that would reduce detection of the undesirable earthy/musty off-flavor compounds. A study is underway examining the effects of different marinating agents on sensory evaluation of the earthy/musty off-flavor compounds and analysis of the content of the off-flavored compounds in catfish fillets. The overarching goal is to develop catfish products that will appeal to consumer segments that have traditionally not purchased catfish.
Accomplishments
1. Results of evaluation of methods used by catfish flavor checkers. To reduce the incidence of off-flavors in catfish products, fish from each pond are evaluated for the presence of off-flavor before the fish are accepted for processing into products. A survey was conducted of the procedures used by the flavor checkers at different processing plants and differences were found in the procedures used by the flavor checkers at the different processing plants. Using a trained sensory panel, ARS researchers at the Southern Regional Research Center in New Orleans, Louisiana, evaluated the effect of the different cooking procedures used by the flavor checkers at different processing plants on the perception of catfish flavors. Cooking procedures evaluated included microwaving fish in brown lunch bag, french-fry boat, foam trays, plastic bags, Corning ware dish covered with parchment paper and deep fat frying. Results indicted off-flavor in fish was less intense in the oil fried fish than in fish microwaved in a brown lunch bag or a plastic bag. The study, in the form of a technical bulletin, was provided to all catfish processing plants to help them evaluate the flavor checking procedures used by their processing plant. This study is the first step in developing a set of recommended procedures for evaluation of catfish flavor by catfish processing plant flavor checkers.
Review Publications
Bechtel, P.J., Bland, J.M., Woods, K., Lea, J.M., Brashear, S.S., Boue, S.M., Daigle, K.W., Bett Garber, K.L. 2018. Effect of par frying on composition and texture of breaded and battered catfish. Foods. 7:46. https://doi:10.3390/foods7040046.
Bonilla, F., Chouljenko, A., Reyes, V., Bechtel, P.J., King, J.M., Sathivel, S. 2018. Impact of chitosan application technique on refrigerated catfish fillet quality. Journal of Food Science and Technology. 90:277-282.
Tan, Y., Haoran, G., Chang, S.K., Bechtel, P.J., Mahmoud, B.S. 2018. Comparative studies on the yield and characteristics of myofibrillar proteins from catfish heads and frames extracted by two methods for making surimi-like protein gel products. Food Chemistry. https://doi.org/10.1016/j.foodchem.2018.07.201.
Bland, J.M., Bett Garber, K.L., Li, C.H., Brashear, S.S., Lea, J.M., Bechtel, P.J. 2018. Comparison of sensory and instrumental methods for the analysis of texture of cooked individually quick frozen and fresh-frozen catfish fillets. Food Science and Nutrition. 1692-1705. https://doi.10.1002/fsn3.737.
