Cadaverine and Putrescine in Foods, Bacteria, and Decomposition

Cadaverine and putrescine are organic compounds associated with protein breakdown, particularly in decaying animal tissue. While known for their strong odors in decomposition, these biogenic amines also occur naturally in foods and are produced by bacteria under specific conditions. Their presence affects food quality, bacterial metabolism, and forensic investigations.

Chemical Features

Cadaverine and putrescine are diamines, meaning they contain two amine (-NH₂) functional groups that contribute to their chemical reactivity. Cadaverine (1,5-pentanediamine) has a five-carbon aliphatic chain, while putrescine (1,4-butanediamine) has a four-carbon backbone. Their structures allow them to form hydrogen bonds, making them highly soluble in water and capable of interacting with biological macromolecules.

Both compounds are classified as biogenic amines, derived from amino acid decarboxylation. Cadaverine originates from lysine, while putrescine forms from ornithine through enzymatic decarboxylation. These reactions, catalyzed by lysine decarboxylase and ornithine decarboxylase, are regulated by environmental factors such as pH, temperature, and nutrient availability.

Their structural similarity to polyamines like spermidine and spermine allows them to compete for binding sites, potentially disrupting cellular functions. Excessive accumulation can interfere with membrane integrity and enzymatic activity, leading to cytotoxic effects.

Formation in Bacteria

Bacteria produce cadaverine and putrescine through enzymatic decarboxylation of lysine and ornithine, a process that helps regulate internal pH and enables survival in acidic environments. Many species, including Escherichia coli, Salmonella, Lactobacillus, and Enterococcus, can synthesize these amines in response to environmental factors like oxidative stress, nutrient availability, and pH fluctuations.

Lysine decarboxylase (LDC) and ornithine decarboxylase (ODC) are inducible enzymes, meaning their expression increases under specific conditions. Acidic environments strongly trigger decarboxylase activity, helping bacteria neutralize cytoplasmic acidity. This mechanism is particularly important for bacteria in the gastrointestinal tract, where low pH conditions challenge microbial survival.

Beyond pH regulation, cadaverine and putrescine contribute to bacterial biofilm development and stress tolerance. These diamines influence biofilm architecture by affecting cell adhesion and extracellular matrix composition. Pathogens like Pseudomonas aeruginosa and Klebsiella pneumoniae use them to enhance biofilm stability, increasing resistance to antibiotics and immune defenses.

Occurrence in Foods

Cadaverine and putrescine are present in various foods, particularly those undergoing microbial fermentation, aging, or spoilage. Their formation results from bacterial enzymatic activity, where amino acid decarboxylation leads to their accumulation. Fermented foods such as aged cheeses, dry-cured meats, and fermented fish contain these amines due to microbial metabolism. In controlled fermentation, they contribute to flavor, but excessive levels indicate spoilage or contamination.

Meat and seafood are especially prone to cadaverine and putrescine buildup under poor storage conditions. Bacteria like Enterobacteriaceae, Pseudomonas, and Clostridium convert free amino acids into biogenic amines as spoilage progresses. In spoiled fish, cadaverine concentrations can reach several hundred milligrams per kilogram, serving as a freshness indicator. While regulatory agencies set histamine limits in foods, cadaverine and putrescine are not directly regulated due to their lower toxicity.

Vegetable-based foods, including soy products like miso and tempeh, as well as fermented cabbage varieties such as kimchi and sauerkraut, also contain these amines. Unlike spoiled meats, where high levels are undesirable, their presence in plant-based ferments is considered normal. However, excessive accumulation can lead to undesirable sensory characteristics, such as bitterness and off-putting odors.

Odor Development in Decomposition

As organic matter decomposes, cadaverine and putrescine contribute significantly to the distinct odor of decaying tissue. Bacterial enzymatic activity on nitrogen-rich substrates leads to their accumulation, producing strong, lingering odors used in forensic investigations and cadaver detection.

Odor intensity depends on environmental factors such as temperature, moisture, and oxygen availability, which influence microbial metabolism. Warmer conditions accelerate bacterial growth and amine release, while anaerobic environments promote sulfur-containing compounds like hydrogen sulfide and methanethiol. These interactions create an evolving odor profile that changes as decomposition progresses.

Analytical Detection

Detecting cadaverine and putrescine in biological and food samples requires sensitive analytical techniques. Chromatographic methods, particularly high-performance liquid chromatography (HPLC) and gas chromatography (GC), are widely used for their accuracy. HPLC, often coupled with fluorescence or ultraviolet (UV) detection, uses derivatization reagents like dansyl chloride to enhance sensitivity. GC, typically paired with mass spectrometry (GC-MS), provides structural confirmation of detected compounds.

Portable methods, including enzymatic biosensors and colorimetric assays, offer rapid on-site detection. Biosensors use enzyme-based recognition elements to generate electrical signals in response to cadaverine or putrescine. Colorimetric tests, based on pH-sensitive dyes or aldehyde reactions, provide visual indications of amine presence. While convenient, these methods generally lack the specificity and precision of chromatographic techniques, requiring confirmatory lab testing.