WWW.WA S .ORG • WORLD AQUACULTURE • MARCH 2022 65 ( C O N T I N U E D O N P A G E 6 6 ) The pH ranges from 6.0 to 6.8 and a dried fish product with a pH above 7.0 is considered unfit for human consumption (Farid et al. 2014, Binici and Kaya 2017). Food Safety and Quality Concerns for Dried, Salted Fish The common food safety and quality concerns for dried, salted fish are histamine poisoning, susceptibility to microbial spoilage and introduction of various contaminants. To a lesser extent, there is also a concern about the high salt content of the product. HistaminePoisoning Histamine is an organic nitrogenous compound that may cause adverse reactions when consumed in high amounts (Visciano et al. 2014, Simora and Peralta 2018). Generally, the maximum levels of histamine in dried, salted fish products should be not more than 200 ppm to be considered safe for human consumption (PNS 2006b). Ingestion of food items with histamine levels above 200 ppm has adverse effects on the human body (Chung et al. 2017, Mavromatis and Quantick 2002, US FDA 2011). Histamine is formed by decarboxylation of histidine by enzymes secreted by Gram-negative bacteria found in the intestines and gills of fish (Tortorella et al. 2014, Feng et al. 2016). The formation of histamine is often caused by mishandling of fish during salting and drying. Histamine formation is increased at temperatures > 21.1 C (US FDA 2011, Feng et al. 2016). Thus, fish should be handled at cooler temperatures, preferably below 20 C to retard the formation of histamine (Visciano et al. 2014). Controlling histamine can be achieved by storing fish < 4 C (Hungerford 2010, Feng et al. 2016, FSSAI 2016). Storage of fish at lower temperatures, however, does not fully eliminate histamine but only decreases its formation rate (Hungerford 2010, US FDA 2011). Different cooking methods have various effects on the histamine level of food. Grilling and frying causes higher histamine levels compared to raw and boiled food (Chung et al. 2017). Dried, salted fish poses a high risk of elevated histamine levels as it is often stored above 32 C and fried prior to consumption. Microbial Spoilage Although salting of fish lowers water activity and causes osmotic shock to microbial cells, the fish product is susceptible to spoilage by halophilic microorganisms. For example, Vibrio parahaemolyticus, a halophilic and heat-stable microorganism naturally found in raw fish, causes gastroenteritis (Rahman 2009, Wang et al. 2015). The microorganism can grow even after intensive drying (Rahman 2009, Alfonzo et al. 2017). Dried, salted fish can harbor pathogenic bacteria and become very hazardous when ingested. Generally, Clostridium botulinum type E and V. parahaemolyticus are the main microorganisms of concern as these are often found in fish and fish products (Novotny et al. 2004, Köse 2010). However, other microorganisms such as Clostridium perfringes, Staphylococcus spp., Salmonella spp., Shigella spp., and Vibrio cholerae can also be potentially found in dried, salted fish that are mishandled and under-processed (Novotny et al. 2004, Köse 2010, Yam et al. 2015). Halotolerant fungi, such as Aspergillus flavus, Penicillium sp., Aspergillus niger, and Mucor sp. can survive the salting and drying process and cause premature spoilage (Chakrabarti and Varma 2009). Microorganisms can also come from the bodies of water fromwhich fish are harvested. Waters can contain different microorganisms that can survive the drying and salting process. Different bodies of water can have high levels of coliform that exceed standards and render the product unsafe for human consumption. With high levels of fecal coliform from the water source, public health is threatened because these bacteria can survive the sundrying process (Köse 2010, Logesh et al. 2012, Raña et al. 2016). Physical Contaminants Physical contaminants, such as filth and introduction of parasites may also occur during drying. Salt used for salting may contain microplastics that stay on the surface of the fish as it dries (Karami et al. 2017). Insects and other small filth may also become contaminants as the drying procedure allows exposure of fish to the environment. With such exposure, entrance of parasites is most likely to occur through insects such as flies (Flowra et al. 2014, Köse 2010). Flies may transmit other parasites and contaminants such as roundworms, nematode larvae and maggot eggs (IIRR 1995). Once flies have contact with the fish surface, there is a greater chance of food contamination. Food contamination allows parasites to enter the human body and may cause various diseases. ElevatedSaltContent There have also been concerns about the salt content of dried, salted fish (HHS 2010). Most dried, salted fish sold in the market has a high sodium content that negatively impacts consumer health, especially cardiovascular diseases, if sodium intake is unregulated for a long time (Cajuday and Revale 2016, HHS 2010). Notes Abigail Ann Alano Ching and Myrna Benita Z. Luna, Department of Food Science and Nutrition, College of Home Economics, University of the Philippines-Diliman, Quezon City, Philippines 1101 Janice Alano Ragaza, Department of Biology, School of Science and Engineering, Ateneo de Manila University, Katipunan Avenue, Loyola Heights, Quezon City, Metro Manila, Philippines 1108 Corresponding author: J.A. Ragaza, jragaza@ateneo.edu References Alfonzo, A., W. Randazzo, M. Barbera, C. Sannino, O. Corona, L. Settanni, G. Moschetti, A. Santulli and N. Francesca. 2017. Effect of salt concentration and extremely halophilic archaea on the safety and quality characteristics of traditional salted anchovies. Journal of Aquatic Food Product Technology 26(5):620-637. Anenias, M.A., A.M. Mabeza, T.R. Miciano and E.C. Sison. 1978. Studies on traditional methods of fish smoking in the Philippines. www.fao.org/apfic/publications/detail/en/c/419940/. Arvanitoyannis, I.S., A. Veikou and P. Panagiotaki. 2012. Osmotic dehydration: theory, methodologies, and applications in fish, seafood, and meat products. Pages 161-189 In R. Bhat, A.K. Alia, and G. Paliyath, editors. Progress in Food Preservation. JohnWiley & Sons Ltd. Chichester, West Sussex, UK. Ashbolt, N.J., W.O.K. Grabow and M. Snozzi. 2001. Indicators
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