Food composition at present: new challenges

Food composition data is important for stakeholders and users active in the areas of food, nutrition and health. Newchallenges related to the quality of food composition data reflect the dynamic changes in these areas while the emerging technologies create new opportunities. These challenges and the impact on food composition data for the Mediterranean region were reviewed during the NUTRIMAD 2018 congress of the Spanish Society for Community Nutrition. Data harmonization and standardization, data compilation and use, thesauri, food classification and description, and data exchange are some of the areas that require new approaches. Consistency in documentation, linking of information between datasets, food matching and capturing portion size information suggest the need for new automated tools. Research Infrastructures bring together key data and services. The delivery of sustainable networks and Research Infrastructures in food, nutrition and health will help to increase access to and effective use of food composition data. EuroFIR AISBL coordinates experts and national compilers and contributes to worldwide efforts aiming to produce and maintain high quality data and tools. A Mediterranean Network that shares high quality food composition data is vital for the development of ambitious common research and policy initiatives in support of the Mediterranean Diet.The authors gratefully acknowledge the contributions of the many members of EuroFIR and RICHFIELDS project (funded by the European Union’s Horizon 2020 research and innovation funding programme under grant agreement no. 654280) partners who contributed to the developments referred to in this articleinfo:eu-repo/semantics/publishedVersio

A theoretical and empirical investigation of nutritional label use

Due in part to increasing diet-related health problems caused, among others, by obesity, nutritional labelling has been considered important, mainly because it can provide consumers with information that can be used to make informed and healthier food choices. Several studies have focused on the empirical perspective of nutritional label use. None of these studies, however, have focused on developing a theoretical economic model that would adequately describe nutritional label use based on a utility theoretic framework. We attempt to fill this void by developing a simple theoretical model of nutritional label use, incorporating the time a consumer spends reading labels as part of the food choice process. The demand equations of the model are then empirically tested. Results suggest the significant role of several variables that flow directly from the model which, to our knowledge, have not been used in any previous empirical work

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data