Chemical Hazards Nursel Söylemez Milli · Biogenic amines · nitrosamines · PAHs · HAAs · 2 min read
Several groups of potentially harmful compounds can be formed in meat products during processing and storage. Among them, biogenic amines (BAs), N-nitrosamines (NAs), polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HAAs) have been studied extensively because of their toxicological relevance and their close link to common processing practices.
Biogenic amines, including histamine, tyramine, putrescine, cadaverine, tryptamine and phenylethylamine, are formed mainly through the microbial decarboxylation of free amino acids. Their accumulation is favoured by poor raw material quality, inadequate hygiene, high storage temperatures and the activity of decarboxylase-positive microorganisms, especially in fermented sausages and dry-cured products. High intake of histamine and tyramine can cause adverse reactions such as headache, flushing and hypertensive effects. BA levels are also regarded as useful indicators of freshness and hygienic quality.
A close relationship exists between biogenic amines and N-nitrosamines. Secondary amines, including those derived from putrescine and cadaverine through cyclization, can react with nitrosating agents formed from nitrite to produce nitrosamines such as N-nitrosodimethylamine, N-nitrosopyrrolidine and N-nitrosopiperidine. Many nitrosamines are considered probable human carcinogens. Their formation is promoted by high nitrite levels, high cooking temperatures, low pH and the presence of precursor amines. Ascorbate, erythorbate and tocopherols are used to inhibit nitrosation.
Polycyclic aromatic hydrocarbons are formed through incomplete combustion and pyrolysis of organic material. In meat products, they are introduced mainly during traditional smoking and direct-flame grilling, particularly when fat drips onto the heat source. Benzo[a]pyrene, classified as carcinogenic to humans, is used as a marker compound, and maximum levels for benzo[a]pyrene and the sum of four PAHs have been established in European Union legislation for smoked meat products. Controlled smoking conditions, indirect smoke generation and liquid smoke can substantially reduce PAH contamination.
Heterocyclic aromatic amines are formed during the high-temperature cooking of muscle foods through reactions involving creatine or creatinine, free amino acids and sugars. Compounds such as PhIP, MeIQx and DiMeIQx are among the most frequently detected. Their levels increase with cooking temperature, time and the degree of surface browning. Lower cooking temperatures, frequent turning, marinating and the addition of antioxidant-rich ingredients such as spices, herbs and fruit extracts have been reported to reduce HAA formation.
These compounds share several features. They are formed or accumulated as a result of processing, they are present at low concentrations within complex matrices, and their formation is affected by many interacting factors. Reliable determination requires sensitive analytical methods, mainly high-performance liquid chromatography and gas chromatography coupled with mass spectrometry, together with appropriate extraction and clean-up procedures.
Minimizing the formation of BAs, NAs, PAHs and HAAs requires attention throughout the production chain, from raw material hygiene and additive selection to processing conditions and consumer cooking practices.