Chemical Sensing of Acrolein-Amine Conjugates for Food Quality Control: A Case Study of Milk Products

Acrolein is a highly toxic unsaturated aldehyde generated from an array of sources ranging from tobacco smoke to incomplete combustion of oil, charcoal, wood, plastic and other organic substances. In food chemistry, research is exclusively focused on the detection of vaporous acrolein emitted from the oils, but not that included in the food products. Acrolein is highly reactive to various functional groups, and once produced, it can smoothly conjugate with food materials, e.g., forming 3-formyl-3,4-dehydropiperidine (FDP) adduct with lysines of proteins, a similar modification to advanced glycation end-products (AGEs). Since the correlation between acrolein-protein adducts and various disease states remains unclear, the detection of the amounts of acrolein adducts included in food products ranks at the very top in significance and urgency. We for the first time evaluated the amount of FDP as the preferential acrolein-amine conjugates included in milk products, based on our reduction-based sensor kit. We found that various amounts of FDP conjugates could be produced from various sources and from different brands, depending on pasteurization, high temperature treatment, and contents of animal fats. It was also found that the amount of FDP in milk products significantly increased when these are heated to 80–100 °C under the conditions of drinking hot milk, hot coffee with creamers, and of cooking. While biological functions of acrolein-amine conjugates and effects on human health are investigated, the FDP production in food materials under various conditions should be analyzed for their quality control. Efficient and rapid analysis should be now possible with our reduction-based FDP sensor.