The EPM Project 23RPT03 GrainMetfor the development of CRMs characterised for water content constituted of plant-origin bulk materials

Water and moisture content varies greatly in the food products. It is an essential parameter that can affect their stability, freshness, and nutritional quality. Therefore, an assay for the amount of water and moisture is one of the most important analytical procedures that can be performed on a food product. However, it is also one of the most difficult measurement methods from which to obtain accurate and precise data. It can be applied to a wide variety of food products but requires close attention to the analytical conditions used and the maintenance of constant conditions for each analysis. Water and moisture content determination is necessary to support quality and fair trade for example in the grain market. It is fundamental both from an economic and human health point of view. Indeed, the commercial value of grain and its derivatives is evaluated based on its dry weight. Similarly, from a human health point of view, water presence leads to the activation of fermentation processes, microbial growth, and chemical deterioration reactions, as well as changing the flavour, texture, and appearance of the product. Moisture can deteriorate harvest quality and safety, playing a crucial role in establishing the market value of the final product as well as the well-being of the final consumer. Knowing the precise amount of water present in a grain sample is crucial for the quality assessment of plant-origin bulk materials in the agricultural sector. The terms “water content” and “moisture content” are often used synonymously. However, this creates a problem as they are fundamentally different. Water content reveals exactly the content of water inside a certain product. In comparison, moisture content does not identify a specific measurand and includes all volatile compounds in this product, not only water. Currently, the main method used for the determination of moisture content is based on a thermogravimetric principle, the loss on drying method (LOD), where the mass loss during the drying process is measured. This only allows for information about the total mass loss of all volatile compounds, and no information about the water content specifically. The main disadvantage of this method is that it is not known when all the volatile compounds have truly vanished and this results in very long drying times. Nevertheless, Karl Fischer titration is a chemical procedure which is highly selective to water only, allowing for a very accurate determination of water content. It is a widely used technique in many industries, and the European Partnership on Metrology (EPM) 23RPT03 project “Metrology for standardised moisture and water content measurement in plant-origin bulk materials in support of International and European food safety and trade – GrainMet” aims at developing a volumetric Karl Fisher titration method for water content determination in plant-based bulk materials. Furthermore, metrological traceability paths, certified reference materials (CRMs) and EURAMET calibration and measurement guides will be developed. Moreover, GrainMet focuses on the knowledge transfer related to the new measurement capabilities to support emerging NMIs/DIs.