Analysis of Citrate Distribution in Strawberry Tissues

This technical report presents a study on the distribution of citric acid in strawberry fruit tissues using multimodal imaging techniques. The research employs MALDI mass spectrometry imaging (MSI) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to visualize and quantify the spatial distribution of citric acid and potassium in the tissue sections. The study outlines the methodology, including sample preparation and analysis conditions, and details the results of the imaging techniques. It was found that citric acid was predominantly located in the outer cortex of the fruit, with lower concentrations towards the pith. The report also discusses the correlation between the quantitative analysis of citric acid using the Nexera Organic Acid Analysis System and the ion intensities obtained from the MALDI-MSI images. The findings suggest that the MALDI-MSI distribution accurately reflects the true concentration of citric acid, independent of potassium distribution heterogeneity. This research contributes to the understanding of organic acid distribution in plant tissues.