Research Project: Umbrella Project for Food Safety

Location: Warmwater Aquaculture Research Unit

2024 Annual Report

Objectives
Research will address methods to determine the presence of pathogens in catfish/catfish products and to maximize elimination methods. Detection techniques will be developed to aid in processing and packaging operations, which should further enhance product safety. Specifically the new objectives are: 1. Optimize safety of aquaculture products through innovative processes for reducing microbiological, physical and chemical hazards in seafood/aquaculture products. 2. Determine the mechanisms influencing microbial survival of selected pathogens in seafood/aquaculture products. 3. Optimize the market value of seafood/aquaculture products through enhanced food safety and quality.

Approach
Catfish: Determine optimum rates of microbial reduction through innovative processing in catfish products including evaluation of consumer acceptance. Determine viable methods of hazard reduction (smoking, acidulants, antimicrobials, etc) in catfish products during processing and storage. Determine the methods by which these methods reduce hazards within the products evaluated. Enhance the physical safety of catfish fillets with innovative analysis technology. Seafood/Produce: Determine the efficacy of IQF freezing, irradiation, and high pressure processing and other technologies on the safety and quality of oysters, shrimp and produce. Objective 2. Catfish/ Seafood/Produce: Determine the mechanistic approach by which the certain pathogenic bacteria may be reduced in aquatic species. Utilize PCR analysis and other assays to determine the sensitivity and specificity of various isolates in response to innovative treatments. Objective 3. Catfish: Enhance product value through innovative smoking and further processing of catfish fillets. Value-added analysis will compared products to commodity value for product enhancement addition. Evaluate value-added products to address potential food safety issues. Seafood/Produce: Evaluate consumer acceptance of products enhanced through various processing methods. Preparation techniques, ingredient inclusion, packaging and storage methods will be evaluated at various time frames and inclusion rates to determine specie specific parameters limitations. Analyze economics of various market potentials. Catfish: Determine optimum rates of microbial reduction through innovative processing in catfish products including evaluation of consumer acceptance. Determine viable methods of hazard reduction (smoking, acidulants, antimicrobials, etc) in catfish products during processing and storage. Determine the methods by which these methods reduce hazards within the products evaluated. Enhance the physical safety of catfish fillets with innovative analysis technology. Seafood/Produce: Determine the efficacy of IQF freezing, irradiation, and high pressure processing and other technologies on the safety and quality of oysters, shrimp and produce. Objective 2. Catfish/Seafood/Produce: Determine the mechanistic approach by which the certain pathogenic bacteria may be reduced in aquatic species. Utilize PCR analysis and other assays to determine the sensitivity and specificity of various isolates in response to innovative treatments. Objective 3. Catfish: Enhance product value through innovative smoking and further processing of catfish fillets. Value-added analysis will compared products to commodity value for product enhancement addition. Evaluate value-added products to address potential food safety issues. Seafood/Produce: Evaluate consumer acceptance of products enhanced through various processing methods. Preparation techniques, ingredient inclusion, packaging and storage methods will be evaluated at various time frames and inclusion rates to determine specie specific parameters limitations. Analyze economics of various market potentials.

Progress Report
Progress was made on all objectives with a major focus on the ensuring (1) the food safety of catfish, seafood and produce, and are under the National Program 108-Food Safety, Component I: Food Borne Contaminants, and (2) food quality improvement under the National Program 306-Quality and Utilization of Agricultural Products, Component I: Foods. Production, processing and distribution of fish, seafood and produce are very diverse and extensive, and the system is vulnerable to the introduction of contaminants through the environment, natural processes, and the delivery system. Significant progress was made to optimize the safety of aquaculture products through innovative processes for reducing microbiological, physical, and chemical hazards in seafood/aquaculture products. We continued to acquire and install critical research equipment and personnel trained. Our major achievement was substantial progress on the construction of the Northern Gulf Aquatic Food Research Center (NGAFRC) funded at $8 million from other federal and state sources. The NGAFRC will be constructed on an 8 acre site in Ocean Springs, Mississippi. Currently, architects have completed the final documents, construction bid documents are to be released in the summer of 2024, and construction of the first of three phases is expected to begin in the early Fall of 2024. The NGAFRC will greatly improve our research capabilities and program and our ability to attract and recruit researchers with national and international reputations. Our ongoing strong and productive partnership with the USDA-Agricultural Research Service (ARS) and the catfish aquaculture and processing industry continues to demonstrate major strides towards improving the safety and quality of the fillet and by-products. We have completed research improving our ability to test and identify harmful pathogens as part of catfish and other aquatic food safety, made progress on removal strategies for off-flavors in farmed freshwater fish, and developed a singulation system for catfish fillets handling and processing. All of these efforts are published in peer reviewed journals. As part of an ongoing effort to expand the impact of this research program, an MSU internal request for proposals was issued and funded by the Mississippi Center for Enhancing Utilization and Safety of Catfish and Other Aquatic Foods. The RPF requested research with emphasis on application component that addresses one of the following two objectives: 1). Detect, characterize, and eliminate the pathogens, toxins, chemicals, allergens, and biologics that are accumulated in catfish and other aquatic food products as affected by production environment and food processing and packaging methods. 2). Apply advanced scientific and engineering principles to enhance manufacturing efficiency, meat and protein yield, food quality, shelf-life storage stability and product innovations and add value to bycatch and byproducts for expanding markets and/or increasing profitability of the aquatic food industry. Last year, 2023, five projects were funded for a 12 month period starting July 1, 2023. Awards are intended to be seed grants for new and innovative research. Funds are intended to build capacity for success in peer-reviewed science in terms of refereed publications and external competitive grants. These five funded projects are 1). “Effects of chitosan on pathogenic and spoilage microbiota impacting the pre-harvest productivity and post-harvest safety and shelf life of Mississippi raised catfish”, 2.), "Evaluating the silage technology to add value to catfish processing plants' by-products”, 3). “Hyperspectral detection of off-flavor causing cyanobacteria in catfish aquaculture with unmanned aerial systems”, 4.) “Recycling Catfish Bone for Plastic Composite 3D Printing”, and 5.) “Effects of environmental stress and antimicrobials on the health, microbiome, and product shelf-life of channel and hybrid catfish”. Published findings will be included in the next annual report. Recently, an additional seven projects were funded for a 12 month period starting July 1, 2024. Accomplishments from each of these seven awarded projects will be included in the next annual report. The seven funded projects are 1). “Understanding the accumulation and transmission of microbial-derived toxins in catfish and associated risk factors”, 2). “Assessing Consumer Awareness and Preferences for Food Safety Enhanced Catfish Products”, 3.) “Automated Preparation Technology for Skewering Operations”, 4.) “Optimizing ingredient formulations and processing variables associated with the marination of catfish”, 5.) “Assessment of chemical residues in store-bought catfish from Mississippi groceries”, 6.) “Evaluating the silage technology to add value to catfish processing plants' by-products year 2”, and 7.) “A Comprehensive Culturomics Approach to Recover and Characterize Catfish Spoilage Bacteria”. The published results from these funded projects will greatly enhance the research results made possible by this collaboration with USDA-ARS.

Accomplishments
1. Development of an assay to detect species-specific and pathogenic genes of Vibrio parahaemolyticus. Vibrio parahaemolyticus can cause severe gastroenteritis in humans who consume contaminated seafood. Traditionally, detecting this bacterium and its harmful genes requires complex laboratory tests. ARS researchers at Mississippi State University location, developed a simpler and faster method using multienzyme isothermal rapid amplification (MIRA) combined with a lateral-flow dipstick (LFD) assay for field use. The new test identifies Vibrio parahaemolyticus in just 20 minutes and can detect tiny amounts of DNA and bacteria, matching the sensitivity of complex lab tests. Trials demonstrated the assay's effectiveness in identifying the bacterium in oysters, proving it to be a quick and sensitive tool for detecting harmful genes of Vibrio parahaemolyticus.

2. Off-flavors and innovative removal strategies for farmed freshwater fish. Farmed freshwater fish are vital for meeting global protein demands, but off-flavors limit their appeal and consumer acceptance. Identifying and eliminating these off-flavors is crucial for both consumer satisfaction and industry success. ARS researchers at Mississippi State University location, examined the mechanisms behind off-flavor formation in farmed freshwater fish and presents innovative methods for their removal in aquaculture and post-harvest stages. Common off-flavors in freshwater fish include fishy, grassy, earthy, mushroom, muddy, and metallic tastes. Key strategies for off-flavor removal include ozone treatment, cold plasma, molecular sieves, edible coatings, photocatalysis, and probiotics. The review summarizes how protein degradation, microbial action, and lipid oxidation contribute to these off-flavors. The fish exhibit eight primary off-flavors, with fishy, earthy, and metallic being the most prominent. Six innovative removal strategies show promise for effectively addressing these off-flavors.

3. Development of a singulation system for handling catfish fillets. Among the various catfish products, fillets are particularly common and typically stored chilled or frozen after initial processing. However, when these fillets are removed from storage for further processing, they often stick together and require manual separation. This manual effort is necessary for steps like breading and quick-freezing the individual fillets. Due to a shortage of labor and rising costs, there is a pressing need for automated methods to handle this task, which would help boost the profitability of the United States. catfish industry. ARS researchers at Mississippi State University location, introduced a new system that uses water buoyancy and underwater streams to automatically separate catfish fillets. Researchers have examined and fine-tuned several operational parameters to improve the system's efficiency and output. They have also established guidelines for continuous production, ensuring that the process remains effective and productive. The insights from this research are expected to pave the way for more advanced and efficient singulation technologies for catfish and other fish species.

Review Publications
Zhou, Y., Zhang, Y., Hong, H., Luo, Y., Li, B., Tan, Y. 2023. Mastering the art of taming: reducing bitterness in fish by-products derived peptides. Food Research International. 173(1). Article 113241. https://doi.org/10.1016/j.foodres.2023.113241.
Zhou, Y., Zhang, Y., Liang, J., Hong, H., Luo, Y., Li, B., Tan, Y. 2024. From formation to solutions: Off-flavors and innovative removal strategies for farmed freshwater fish. American Journal of Medicine. 144:104318. https://doi.org/10.1016/j.tifs.2023.104318.
Jing, Y., Liu, W., Lu, Y., Lyu, J., Yang, X., Wu, D., Zhang, X. 2024. Development of a singulation system for handling catfish fillets. International Journal of Advanced Manufacturing Technology. 128:81-89. https://doi.org/10.1007/s00170-023-11867-3.
Bela-Ong, D.B., Thompson, K., Kim, H.J., Park, S., Jung, T.S. 2023. CD4+ T lymphocyte responses to viruses and virus-relevant stimuli in teleost fish. Fish and Shellfish Immunology. 142:109007. https://doi.org/10.1016/j.fsi.2023.109007.
Park, S., Zhang, Y. 2024. Development of multienzyme isothermal rapid amplification (MIRA) combined with lateral-flow dipstick (LFD) assay to detect species-specific tlh and pathogenic trh and tdh genes of vibrio parahaemolyticus.. Pathogens. 13(1):57. https://doi.org/10.3390/pathogens13010057.
Zhang, Y., Chang, S. 2023. Microbial Transglutaminase Cross-Linking Enhances the Textural and Rheological Properties of the Surimi-like Gels Made from Alkali-Extracted Protein Isolate from Catfish Byproducts and the Role of Disulfide Bonds in Gelling. Journal of Functional Foods. 12(10):2029. https://doi.org/10.3390/foods12102029.
Chen, R., Chang, S., Gillen, A.M., Chen, P., Zhang, B. 2024. Relationships between protein and other chemical composition and texture of tofu made from soybeans grown in different locations. Journal of Food Science. 89:1428-1441. https://doi.org/10.1111/1750-3841.16922.
Liu, A., Phillips, K., Jia, J., Deng, P., Zhang, D., Chang, S., Lu, S. 2023. Development of a qPCR Detection Approach for Pathogenic Burkholderia cenocepacia Associated with Fresh Vegetables. Food Microbiology. 115:104333. https://doi.org/10.1016/j.fm.2023.104333.