Histamine Testing For Fish and Fishery Products

Introduction

Fish is a popular choice for a healthy and delicious meal, but did you know it can sometimes contain histamine, a compound that can trigger allergic reactions and other uncomfortable symptoms? In this blog post, we'll dive deep into histamine in fish, its causes, symptoms, and how to minimize the risks associated with histamine poisoning.

What is Histamine?

Histamine is a naturally occurring compound found in various foods and produced within our bodies. It plays a crucial role in our immune response and acts as a neurotransmitter. However, when histamine levels become too high, it can lead to a range of adverse reactions, commonly referred to as histamine intolerance or histamine poisoning.

The Role of Histamine in Fish

Histamine in fish primarily develops due to the decarboxylation of histidine, an amino acid found in fish muscle. This process occurs when certain conditions are met, such as inadequate refrigeration or improper handling of fish. Histamine levels in fish can rise significantly if these conditions are not controlled.

Causes of Histamine Formation

Temperature: Histamine formation is most common in fish that are not properly stored at low temperatures. The ideal temperature for fish storage is below 39°F (4°C).

Time: The longer fish sits at temperatures above 39°F, the higher the histamine levels can become.

Spoilage: Fish that has begun to spoil or decay is more likely to contain elevated histamine levels.

Fish Species: Some fish species are more susceptible to histamine formation than others. Tuna, mackerel, mahi-mahi, and sardines are among the most histamine-prone species.

Symptoms of Histamine Poisoning

Consuming fish with high levels of histamine can lead to histamine poisoning, also known as scombroid fish poisoning. Symptoms typically occur within minutes to hours after eating affected fish and can include:

Skin flushing and itching
Headache
Rapid heart rate
Nausea and vomiting
Diarrhoea
Abdominal cramps

Importance of testing

Reason	Benefit	Description
Food Safety	Consumer Health	Prevents histamine poisoning by identifying fish with high levels before reaching consumers.
Regulatory Compliance	Following the Rules	Ensures businesses comply with government regulations on histamine content, avoiding legal issues and recalls.
Quality Assurance	Maintaining High Standards	Safeguards the quality of fish products, protecting a company's reputation and ensuring consumers get high-quality seafood.
Traceability	Pinpointing the Problem	Helps identify the source of contamination if high histamine levels are detected, allowing for corrective actions.
Preventing Economic Loss	Saving Money	Protects businesses and the fishing industry as a whole by preventing costly recalls and lawsuits.
Educating Stakeholders	Spreading Knowledge	Encourages better handling and storage practices throughout the fishing industry, ultimately benefiting consumers with safer seafood.

Recall incidents

In a recent food safety incident, an updated recall alert has been issued for a range of tuna products. The recall, initiated on February 28, 2020, was prompted by the discovery of elevated levels of histamine, a chemical compound that can pose health risks when consumed in excess.

Regulations and standards

The information you have about the FDA's new guidance level for histamine in fish seems accurate. Here's a breakdown of the key points:

FDA lowers histamine limit: In 2023, the FDA issued a draft Compliance Policy Guide (CPG) recommending a stricter limit for histamine in certain fish with high histamine-forming potential.
New limit: The new recommended level is 35 parts per million (ppm), which is significantly lower than the previous recommendation of 50 ppm.
Reason for change: This update aligns the FDA's guidelines with international standards and reflects a focus on stricter control of histamine levels to ensure consumer safety.

Codex Alimentarius: Maximum level of 200 mg/kg.

European Union: Varies depending on the fish type, with 100 mg/kg for high-histamine fish and 200 mg/kg for others.

India (FSSAI): Maximum level of 100 mg/kg.

Analysis Parameters for Testing Histamine in Fish

Category	Parameter	Description
Mandatory Analysis Parameters	Histamine concentration	The most important parameter to measure, as it directly determines the safety of the fish for consumption. Regulatory limits for histamine concentration in fish are set by national and international organizations, such as the European Commission and the Codex Alimentarius Commission.
Optional Analysis Parameters	Histidine decarboxylase activity	Histamine decarboxylase (HDC) is the enzyme responsible for converting histidine into histamine. Measuring HDC activity can be an indirect way to assess the potential for histamine formation in fish.
	Bacterial counts	Histamine is produced by certain bacteria that grow on fish during spoilage. Measuring total bacterial counts or the counts of specific histamine-producing bacteria can help to identify fish that are at high risk of histamine formation.
	Temperature history	The rate of histamine formation increases with temperature. Measuring the temperature history of fish can help to identify potential problems with temperature control during storage and transport.

Testing methods

Method	Description
High-Performance Liquid Chromatography (HPLC)	The most important measure of fish safety. Directly determines if fish is safe for consumption.
Enzyme-Linked Immunosorbent Assay (ELISA)	Measures the enzyme that converts histidine to histamine. Indirect indicator of potential histamine formation.
Lateral Flow Immunoassays (LFIAs)	Measures total bacterial growth or specific histamine-producing bacteria. Identifies fish at risk of histamine formation.
Biosensors (Emerging)	Tracks temperature fluctuations during storage and transport. Higher temperatures increase histamine formation risk.

Eurofins role in testing Histamine in fish

Eurofins provides comprehensive services for testing histamine in fish and seafood products testing

Eurofins offers an ELISA kit for the quantitative and sensitive detection of histamine in fish extracts. The test has a detection limit of 0.8 ppm and can reliably quantify histamine levels in fish, cheese, and wine. This ELISA kit allows for rapid screening of histamine in fish and fish products.
In addition, Eurofins provides a lateral flow assay for the semi-quantitative analysis of histamine in fresh, frozen, canned, salted, and oil-packed fish as well as fish meal. This rapid test can detect histamine levels down to 50 ppm.
Eurofins has developed and validated a gradient RP-HPLC method with DAD detection for the determination of histamine in fish and fish products. This method has been used for the analysis of various fish-based products and has been tested through participation in European proficiency tests to ensure reliability of results.
Eurofins' testing portfolio for fish and aquaculture also includes testing for other quality parameters related to histamine, such as total volatile basic nitrogen (TVBN) and indole. These tests can provide additional insights into the freshness and potential spoilage of fish products.

Overall, Eurofins offers a comprehensive set of analytical tools to detect and quantify histamine in a wide range of fish and seafood products, supporting the seafood industry in ensuring food safety and quality.