Aproximación a la caracterización de compuestos funcionales en diferentes variedades de clementinas

Résumé

Citrus fruits consumption is important in health promotion mainly due the presence of various bioactive compounds such as vitamin C (mainly ascorbic acid, AA) and fiber (especially soluble fiber). Within citrus fruits, clementines stand out for its pleasant taste due to a proper balance between soluble sugars and organic acids. In the present work, as a part of a nutritional and genetic characterization program of clementines, a first approach to characterize the content of bioactive compounds responsible for sensory and physiological functionality of 3 varieties of clementines (Basol, Clemenrubí and Clemensoon), in two stages of maturation collected during the autumn-winter season 2012 have been performed. In this sense, the content of vitamin C (ascorbic acid and dehydroascorbic) and other organic acids by HPLC-UV, soluble sugars (fructose, glucose and sucrose) by HPLC-RI and fiber (soluble and insoluble) by AOAC method has been evaluated. Clementine varieties considered in this study are a good source of fiber (2.38 g/100g, mainly soluble fiber), since the consumption of 100g covered 6.8% of the recommended daily allowance for adults (25 g per day in adults). The nutritional importance of clementines is mainly due to its high content of vitamins as vitamin C (94.70 to 101.015 mg/100g) mainly in the AA form (around 97% of total), with antioxidant potential, covering the recommended daily intake of vitamin C for an adult (80 mg AA) with the intake of 100 g. Regarding the compounds responsible for the organoleptic properties (balance sweetness / acid), sucrose was the major soluble sugar in all samples tested (2.60 to 5.44 mg/100 g, 64% of total soluble sugars), and citric acid was the main organic acid (498 to 580 mg/100g, Rubi and Basol respectively) followed by the isocitric (124 to 142 mg/100g), succinic (127 to 186 mg/100g), oxalic acid (45 to 48 mg/100g) and malic 35 to 47 mg/100g) between others. In relation to the influence of ripening stage, clementines showed an increase in vitamin C content (especially AA) and soluble sugars (mostly as sucrose), whereas citric acid content reduced throughout ripening process.