Introduction: Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols, commonly referred to as FODMAPs, can aggravate symptoms of various gastrointestinal conditions, such as irritable bowel syndrome. Patients with these conditions often need to follow a low-FODMAP diet, requiring knowledge of FODMAP composition. FODMAPs are found in both natural sources (fruits and vegetables) and industrial sources (ingredients and additives). This study aimed to analyze the FODMAP composition of various fruits and vegetables of Portuguese origin.

Methods: This experimental study was carried out between October 2022 and August 2023. To determine the FODMAP content, samples were collected and analyzed enzymatically, using the Megazyme Fructan HK Assay kit, and chromatographically by HPLC-RI in the laboratory.

Results: High fructan content was found in red onion (1.47±1.18 g/100g), white onion (0.52±0.00 g/100g), and Royal Gala apple (1.77±0.07 g/100g), all measured as fresh weight. Broccoli, red capsicum, zucchini, “Rocha” pear, and “Royal Gala” apple showed high fructose concentrations. Significant amounts of sorbitol were found in pear and apple (2.19±0.12 and 0.31±0.11 g/100g, respectively).

Conclusion: Our research also included a brief study on the impact of typical Mediterranean domestic cooking procedures on FODMAP content. Overall, the results were consistent with global data and provide a solid basis for developing a database on the FODMAP content of Portuguese foods and the best cooking techniques to minimize FODMAP content. However, they also highlight the significant variability in natural products, particularly due to differences in maturation, underscoring the need for a wider range of samples to obtain consistent results.