Saturated fatty acids, which do not have double bonds in their alkyl chains, are often vaguely considered to be less susceptible to oxidation than unsaturated fatty acids, which do have double bonds. However, it has been known for more than half a century that even saturated fatty acids can undergo oxidation when exposed to high temperatures, producing characteristic decomposition products such as 2-alkanones and lactones—key contributors for the aroma of animal-derived foods, including dairy products and beef. It was hypothesized that specific hydroperoxide positional isomers of saturated fatty acids were involved in this phenomenon; however, at the time, it was difficult to prepare these isomers using available techniques, and as a result, the mechanism remained unexplained. In this review, we describe the mechanism by which 2-alkanones and lactones are generated through the oxidation of saturated fatty acids, as elucidated using our recently developed techniques for preparing hydroperoxide isomers. Understanding this mechanism is expected to contribute to the development of technology for creating the aroma of animal-derived foods from plant oils rich in saturated fatty acids, thereby enhancing the flavor of plant-based foods and other products.

During food production, equipment frequently becomes contaminated with oils, proteins, and microorganisms originating from ingredients, operators, and the surrounding environment. Maintaining hygiene requires regular cleaning with detergents to remove these contaminants. However, using inappropriate detergents can result in ineffective cleaning, increasing the risk of cross-contamination, food spoilage, and eventually, foodborne illness.

This review explores the challenges associated with residual oils and fats in food manufacturing and examines cleaning strategies critical to food hygiene. Oils and fats left on processing equipment can reduce the efficacy of disinfectants, allowing microorganisms to persist. In addition, degraded residues can accelerate the deterioration of fresh oils and fats introduced during subsequent processing. The present issues highlight the importance of selecting detergents tailored to the properties of the contaminants. Addressing these challenges is essential for ensuring thorough cleaning and safeguarding food safety.