Surface Pathogen Elimination Practices for Ready-to-Eat Fishery Products
Eugene E. Evans, CFP
Food Inspector 1
New York State Department of Agriculture and Markets
International Food Protection Training Institute (IFPTI)
2014 Fellow in Applied Science, Law, and Policy: Fellowship in Food Protection
Abstract
This study examines fishery industry knowledge of surface pathogens and usage of surface pathogen elimination procedures (SPEP) on ready-to-eat, non-heat treated fishery products (NHTFP) in a convenience sample of 17 establishments in four New York City boroughs and Suffolk County, New York during the fall of 2014. These establishments included dockside unloaders, wholesale seafood distributors/fillet houses, wholesale sushi processors, wholesale cold smoked fish processors, wholesale cured fish processors, and restaurants. The study concluded that in this sample: (1) most establishments lacked appropriate surface pathogen knowledge and an SPEP; (2) cold smoked establishments appeared to be creating a potential Clostridium botulinum hazard (CBOT); and (3) the U.S. Food and Drug Administration (FDA) Fish and Fishery Products Hazards and Controls Guidance Document (Hazards Guide) and the FDA Food Code (Food Code) do not sufficiently address surface pathogen elimination and associated hazards. Recommendations include: (1) NHTFP establishments should have an SPEP in place; (2) the Hazards Guide and the Food Code should add SPEP information; and (3) sanitation guidance should be created for commercial fishermen and harvesters of fish.
Keywords: surface pathogen elimination procedures, cold smoked fish, Clostridium botulinum, sushi, cured fish, Listeria monocytogenes, Salmonella, seafood HACCP, commercial fishing, acidified sodium chlorite, calcium hydroxide, peroxyacetic acid, water phase salt (WPS), water activity (aw)
Background
Ready-to-eat, non-heat treated fishery products (NHTFP) such as cold smoked fish, cured fish, ceviche, sushi/sashimi, and gravlax are widely consumed throughout the U.S. Recent changes in consumer preferences such as an increase in consumption of “raw” products (e.g., sushi) increased the demand for NHTFP in the U.S. This increased demand also increased the potential for foodborne illnesses due to a variety of factors.
The FDA Seafood Hazard Analysis and Critical Control Points (HACCP) Regulations 21 Code of Federal Regulations (CFR) 123; the FDA Seafood and Seafood Products Hazards and Controls Guidance Document, 4th Edition (Hazards Guide); and the Food Code identify control measures for numerous biological pathogen hazards. However, the Hazards Guide and the Food Code do not cover surface pathogen elimination for establishments that process NHTFP. Additionally, the Hazards Guide does not provide specific guidance for processing of cold smoked fish in which spoilage microorganisms are significantly reduced (likely occurring during a chemical based surface pathogen elimination procedure [SPEP]). In addition, the FDA Food Code does not cover the control of surface pathogens on raw fish that is to be processed and served at retail as an NHTFP.
Commercial fishing vessels are exempt from the FDA Seafood HACCP regulation 21 CFR 123.3(k)2(i) & (ii). However, a study conducted by the Institute of Food Technologists in 2001 found 62% of surface water samples from fishing grounds were contaminated with Listeria monocytogenes (Lm) (IFT, 2001). Fish harvested from waters contaminated with Lm can have an increased risk of contamination with between 0-50% of fresh fish samples testing positive for Lm in literature reviewed by Embarek(1994). NHTFP are frequently implicated in foodborne illnesses and food recalls in the United States. For example, in 2012, a multistate outbreak of Salmonella Bareilly and Salmonella Nchanga was linked to raw scraped ground tuna with a total of 425 people infected with the outbreak strains over 28 states and the District of Columbia, with 55 people being hospitalized (CDC, 2012). In addition, Lm was responsible for 32 NHTFP Class 1 recalls in New York between 2002 and 2014, according to the New York State (NYS) Food Laboratory records.
The NHTFP contamination problem is made more acute by the lack of labeling requirements. The FDA has set a zero tolerance for Lm and Salmonella in ready-to-eat (RTE) fish and fishery products that are sold at wholesale (Federal Food, Drug, and Cosmetic Act, 21 U.S.C. 342(a)(1)) (FDA, 2011). However, fish purchased by wholesale processors and retailers of NHTFP are often accompanied by written assurances that the fish was processed under Seafood HACCP, yet the distributor’s Seafood HACCP Plan identified the product as needing to be “cooked by end user.” There is no requirement for wholesalers to label fish boxes or otherwise indicate on invoices that the product is RAW or RTE. The identification of the product as RAW or RTE is only required on a Seafood HACCP Plan, which, in most cases, is not provided to the purchaser. As a result, contaminated raw fish and fishery products may migrate through the food supply chain to consumers who believe that the product is RTE.
Problem Statement
Ready-to-eat, non-heated treated fishery products may reach the consumer without being treated with a surface pathogen elimination procedure.
Research Questions
Three research questions were developed in order to investigate surface pathogen elimination along the supply chain of NHTFP processed in New York City and Suffolk County, NY:
1. What do fish industry dockside unloaders, wholesale manufacturers, wholesale distributors, and retailers know about surface pathogens on NHTFP?
2. What control procedures do fish industry dockside unloaders, wholesale manufacturers, wholesale distributors, and retailers have in place to control the presence of surface pathogens on NHTFP?
3. If the NHTFP establishments lack control procedures, would the establishments be willing to institute an SPEP that would be outlined in an official FDA Guidance document?
Methodology
A comprehensive review of the FDA Fish and Fishery Products Hazards and Controls Guidance Document: 4th Edition (April 2011); the 2013 FDA Food Code; and the NYS Department of Agriculture and Markets Circular 1032 Rules and Regulations Relating to Fish Processing and Smoking Establishments (1990) was conducted in order to verify the technical requirements for seafood processing. Next, seventeen on-site interviews of establishment representatives responsible for food safety were conducted at three fishing industry dockside unloaders, four wholesale fish distributors/fillet houses, two wholesale sushi processors, two wholesale cold smoked fish processors, two wholesale cured fish processors, and four restaurants serving NHTFP. The interviews were conducted in-person by the author using a semi-structured questionnaire. The questionnaire was designed to encourage open-ended comments by the respondents. The typical interview lasted 45 minutes. Finally, the NYS Food Laboratory was contacted, and they provided records of all of the Lm-positive food samples collected from 2002 to 2014 in order to identify the Lm-positive incidences from NHTFP products.
Results
Approximately 73% of the establishments interviewed (a total of 13) lacked knowledge of surface pathogens on raw fish persisting on ready-to-eat NHTFP. The remaining four establishments with knowledge of surface pathogens included two wholesale cold smoked fish establishments. Both establishments already had a validated SPEP in place. One establishment instituted a calcium hydroxide dip and potable water rinse (proprietary concentration and procedure). The second establishment instituted consecutive dips consisting of acidified sodium chlorite (ASC) and peroxyacetic acid (PAA) (proprietary concentrations and procedures) without any subsequent potable water rinse before curing and smoking. This procedure deviated from chemical manufacturer instructions and regulatory requirements, yet was admittedly done for extra protection. According to management, the lack of rinsing was done for extra protection. However, neither establishment knew their SPEP included chemicals that can also reduce spoilage microorganisms, which are a critical control for the even greater and more deadly hazard of Clostridium botulinum (CBOT). Anecdotal evidence links calcium hydroxide dips with a reduction in spoilage microorganisms. ASC has been documented to reduce seafood spoilage microorganisms (Rao, 2007), and PAA has been documented to reduce seafood spoilage microorganisms (Howarth, 2010). Both establishments lacked additional consumer protection measures for CBOT such as time/temperature indicators (TTI) on consumer-sized packages and did not increase the water phase salt (WPS) to ≥5% or decrease water activity (aW) to ≤0.97 on their cold smoked fish where a TTI was not sufficient.
The remaining two establishments consisted of a wholesale sushi manufacturer and a retail sushi restaurant. The wholesale sushi manufacturer instituted a validated SPEP using an ASC dip that adhered to the chemical manufacturer instructions and regulatory requirements. The retail sushi restaurant, owned and operated by a 4th-generation sushi chef from Japan, had procedures by which whole, previously-eviscerated fish were washed and then dried with rice paper to extract blood and pathogens. For tuna loins purchased, a 4-5 millimeter slice is shaved off the surface and discarded for surface pathogen control. Neither of these implemented procedures had any validation studies conducted to determine their efficacy.
Approximately 86% of establishments interviewed (a total of 15) expressed interest in implementing an SPEP outlined in an official FDA guidance document. Approximately half of these establishments indicated they would rather purchase fish from a supplier that implemented a SPEP in lieu of developing their own SPEP. The remaining 14% were two dockside unloaders who both admitted not knowing about surface pathogens. Both indicated that they do not want to institute an SPEP, but would rather place the burden of surface pathogen elimination on their customers with documentation that the purchaser would be responsible for surface pathogen elimination. Anecdotal evidence links these dockside unloaders to distributors who sell fish directly to sushi restaurants.
During the interviews, establishments that were unaware of surface pathogens on NHTFP were provided information regarding surface pathogen control. Every establishment requested guidance on SPEP, even if they already had one in place. In addition, the establishments using an SPEP and producing cold smoked fish were informed of potential Clostridium botulinum hazards.
Conclusions
The study had a number of limitations. While the 17 establishments represent each of the categories in the NHTFP seafood chain, they are at best only a small sample of the total establishments in this market. In addition, the study focused on self-reported knowledge of one individual responsible for food safety in each establishment, and no testing was carried out. However, the study clearly indicated the extent of the NHTFP surface contamination problem as shown below:
1. The clear majority of establishments lacked knowledge of seafood surface pathogens risks, despite the need for them to be knowledgeable given that up to 50% of raw seafood may be contaminated with Lm.
2. The majority of NHTFP establishments in the study lacked an SPEP, despite the need to conduct an SPEP to safely process NHTFP.
3. Cold smoked fish products that have been processed with an SPEP are being sold despite the possibility that some products can lack adequate CBOT controls. This potential hazard is due to the possibility of the reduction of spoilage microorganisms (which could not be in place to outcompete CBOT cells nor be in place to produce a foul odor when temperature-abused).
Recommendations
The study resulted in a series of recommendations:
1. The NHTFP industry should be provided with information detailing various methodologies in the development and use of SPEPs.
2. Create addendums to the Hazards Guide and Food Code that provide specific guidance when implementing an SPEP that possible additional hazards are created and that add RAW/RTE labeling requirements for NHTFP.
3. Create a commercial fishing vessel/harvester sanitation guidance document with specific controls for surface pathogens and primary processor requirements. Ultimately, harvest vessel sanitation programs need to become a prerequisite program to a structured SPEP and monitored through vessel records and testing, similar to how primary processors are required to control histamines at receiving.
4. Study cold smoked fish processing when SPEP are used that have been determined to significantly reduce or eliminate spoilage microorganisms. The study, at minimum, should address processing controls for CBOT and other pathogens in relation to WPS/aW, nitrites (where allowed), maximum smokehouse temperature, maximum smoking time, smoke contact before/after pellicle formation, and the use of TTIs and other factors deemed critical for the safe production, sale, and consumption of cold smoked fish.
Acknowledgments
I would like to express my utmost gratitude to the following people: Supervisor Roxanne Hill (New York State Department of Agriculture and Markets) for providing continuous support and insight as a supervisor and Cohort 2 Fellow; Ms. Alyssa Dickey, New York State Food Laboratory, for painstakingly sorting through 12 years of Listeria monocytogenes samples; Mr. Cameron Smoak, IFPTI Mentor, for providing hours of endless wisdom and calm through my journey as a Fellow; Dr. Paul Dezendorf, IFPTI Subject Matter Expert, for having a New York mindset that propelled me to excel immeasurably; Dr. Craig Kaml, IFPTI Subject Matter Expert, for providing unobjectionable critical analysis which cleared the path for success; and the entire IFPTI staff for everything humanly possible in creating a world class educational environment. Last, but not least, I would like to acknowledge my "fellow" Fellows for their friendship, support, knowledge and camaraderie through this journey we embarked on together as a uniquely-bonded group of professionals.
References
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