Effect of Ripening and Growing Conditions on the Content in Ascorbic Acid in Paprika Landraces

Abstract

Spain is one of the most important centres of diversity for Capsicum annuum peppers and the highest producer and exporter in Europe, and a plethora of ecotypes can be found throughout the country. Such genetic heritage offers the opportunity of selecting materials adapted to organic cultivation. In addition, ascorbic acid (AA) is a bioactive compound of paramount importance and therefore studies on the effect of organic cultivation on AA levels can provide an added value to those genotypes selected for organic cultivation. In this work C. annuum landraces were submitted to a comparative study (organic vs. conventional cultivation). Fruits from each accession and growing condition were sampled at both unripe and fully ripe stages and AA levels were estimated by potentiometric titration. Genotype (G), ripening stage (RS), growing conditions (GC), and G×GC and G×RS interactions contributed significantly to the observed variation. In addition, ripening increased AA in all accessions. Futhermore, the average AA content was higher in the organic plot at both unripe and fully ripe stages. In this way, most organic-produced accessions showed similar or higher values than those observed in the conventional plot. Finally, a significant genotype×growing conditions interaction was found for fully ripe stage, suggesting that there are ample opportunities for selecting vitamin C-rich paprika landraces adapted to organic cultivation.