Lycopene Estimation in Tomato Lines Using Infrared Absorbance and Tomato Analyzer

The color of red tomatoes (Solanum lycopersicum L.) is mostly from the carotenoid pigment lycopene, which is of interest to consumers and the tomato industry because of its purported protective effects against diabetes, cardiovascular events, and some cancers. Lycopene content was measured in at least 179 tomato lines with pink, red, and dark red fruit derived from a diverse genetic background to determine the level of variation for lycopene and to develop prediction models. Two methods (Tomato Analyzer or DigiEye) for quantifying total lycopene and to develop prediction models were tested on tomato fruit to find a high throughput lycopene measurement system suitable for screening hundreds of lines in a breeding program. The tomato lycopene content ranged from 28 to 133 mg•kg−1 of tomato sample, indicating a wide variation in the set of tomato lines. Using this variation, lycopene prediction models were developed. Though a single equation could not be developed using data from the DigiEye or Tomato Analyzer to predict lycopene content of tomato fruit, individual equations within color groups proved useful in predicting lycopene content (r = 0.77, P < 0.05). Our data indicate that rapid analysis of tomato fruit, kept relatively intact, can be done to accurately predict lycopene content in a wide range of fruit colors.