Analysis of Nutritional Constituents in Twenty Citrus Cultivars from the Mediterranean Area at Different Stages of Ripening

摘要

Twenty Citrus cultivars grown in the Mediterranean climate were analysed at different stages of fruit maturity to determinate changes in organic acids, vitamin C and sugars. High-performance liquid chromatographic methods were used to identify and quantify of these compounds. The influences of variety, rootstocks and different stages of fruit maturity were observed. Generally, the vitamin C content was higher in varieties grafted on Troyer citrange that the corresponding cultivars grafted on Cleopatra mandarin. At commercial harvest stage, lemons, clementine mandarins and sweet oranges, showed the highest concentrations of vitamin C; citrons, limes and lemons, the higher amounts of organic acids; and mandarins and hybrids the highest amounts of sugars. Since sugars and acids played an important role in fruit flavor and their nature and concentration largely affect taste characteristic and organoleptic quality, we hope to relate genotypes and differences in final fruit quality. We have found clear differences in the content of sugars, ascorbic and organic acids for the different groups in agreement with the Citrus classification. Also climatic and cultural factors have affected to fruit quality, and anticipate or delay the collection generally results in a loss of bioactive compounds. The fruit quality was affected differently and we have observed differences in accordance with the rootstocks used but, the major differences in nutritional composition must be attributed mainly to genetic factors. The data presented are an important factor to chose varieties with a high potential as nutraceutical source.