Strategies for the breeding of eggplants with improved nutritional quality

Eggplant (Solanum melongena L.) has a high antioxidant activity because of its high content of phenolics. Therefore, the development of materials with higher concentration of these compounds is of interest. However, the oxidation of phenolics is associated with the browning of the fruit flesh after exposure to the air. In consequence, in addition to evaluating if it is possible to develop new materials with high content of phenolics, it is also important to study if low or moderate browning can be obtained in these materials. Here, we present the results obtained in 40 eggplant varieties (16 local varieties and 24 hybrids obtained between them) evaluated for phenolic content and for changes in color parameters L*, a* and b* after exposure of the fruit flesh to the air for 10 min (L-0*-L-10*, a(0)*-a(10)* and b(0)*-b(10)*). A wide variation among varieties, both in the local varieties and their hybrids, has been found for phenolic concentration (313.6-765.2 mg/kg), as well as in the browning parameters. The results of the hybrid-midparent regression analyses show that while the regression coefficient for the content in phenolics is moderately high (b=0.50), it is low for the browning parameters (b 0.20). The study of the relationship between the concentration of phenolics with the browning parameters shows that only a part of the variation observed in the increase in browning parameters (lower than 20% in all cases) is due to increases in the content of phenolics. One of the hybrids tested had high content of phenolics (>740 mg/kg) and moderate browning. These results suggest that by exploiting existing variation, it is possible to develop new varieties, either hybrid or not, with a higher content of phenolics while maintaining low levels of browning. The results presented provide information of relevance for the development of new eggplant materials with improved quality.