Nutritional value and phytochemical relevance of Dioscorea comorensis, an endemic yam from the Comoros Islands

The Comoros Islands present a large variety of products and food items, but most of the people lack awareness about the nutritional value and quality of these local resources, contributing to food insecurity. Dioscorea comorensis, a yam species endemic to the Comoros Islands, may represent a valuable crop, meeting the health-promoting needs of the local population. This research aimed to assess the chemical composition of D. comorensis flour for potential food applications. Standardized methods were used for proximate analysis. Mineral elements were evaluated by UV-visible spectrophotometry and atomic absorption spectrometry, while dietary fiber and starch were assessed by formic acid insolubility and polarimetric assays, respectively. Phytochemical characterization involved spectrophotometric tests for total antioxidant capacity (FRAP assay) and total polyphenols (Folin-Ciocalteu method), complemented by HPLC analyses for individual phenolics, vitamin C, organic acids, and sugars. The results showed a high dry matter (86.84%) and carbohydrate (79.52%) content, with significant levels of dietary fiber (19.6%) and protein (5.42%), supporting its role as a health-promoting and energy-rich food source. Mineral analysis highlighted excellent potassium amounts (869.6 mg/100 g), together with relevant quantities of copper, magnesium, and phosphorus. Phytochemical fingerprinting identified significant levels of total polyphenols [42.01 mg GAE/100 g of dried weight (DW)], phenolic acids, flavonols, and organic acids, contributing to a significant antioxidant capacity (8.65 mmol Fee+/kg). Although vitamin C content was limited, the species showed a large spectrum of health-promoting molecules. This preliminary study highlighted that D. comorensis may be considered as a culturally relevant and nutritionally rich crop with potential for integration into sustainable dietary strategies in the Comoros Islands, even if further studies are recommended to evaluate its potential as a health-promoting food application.