Food lipidomics - Towards standardization and advanced structural resolution

Lipids play important roles in determining the quality, nutritional properties and health effects of food. With fast development in analytical platforms, lipidomics is increasingly applied in food research, producing a large body of data for characterizing food resources, studying the impact of processing and storage, as well as for enhancing traceability and detecting fraud. Food lipids cover a large group of compounds with highly diversified composition, structures and polarities occurring in varying matrices derived from different raw materials and processing methods. Increasing use of emerging sustainable food resources e.g. insects, algae, and microbes, further adds the complexity and diversity of food lipidomes. These make food lipidomics research a highly challenging task, calling for matrix-specific optimization and standardization of the protocols and workflows. In the current food lipidomics research, lack of standardized protocols and reporting compromises reliability, repeatability and inter-laboratory comparison. While the current nontargeted lipidomics pipelines provide information on the most common lipid classes e.g. triacylglycerols and glycerophospholipids, up to the molecular species level, more powerful methods are needed to resolve lipid isomers as well as to identify and quantify less common lipid species such as betaine lipids and sulfolipids. Recently increasing effort has been made to resolve lipid isomers varying in the positions of acyl chains and double bonds, paving the way towards structural lipidomics research. Community effort is necessary to build standardized workflows and to develop powerful platforms for resolving diversified structures of food lipids. These are crucial steps for upgrading food lipidomics research to create new knowledge in lipid chemistry and to reveal the structure-function relationship of lipids in food quality and nutrition.