The flavor of a tomato is an interaction between its taste and aroma. Now, researchers have revealed that the pigments that determine the colors of tomatoes also affect their flavor.
The color of tomatoes is produced by combinations of different types of pigments, including carotenoids and chlorophylls. These pigments can also affect the accumulation of flavor-related compounds such as sugars, which affect the taste of tomatoes, and volatile organic compounds (VOCs), which determine the aroma. As tomato fruits ripen from green to red, the amounts of pigments and flavor-related compounds change but until now the relationship between color and flavor has been unclear.
Pigments like carotenoids have no taste, but they are precursors for compounds called apocarotenoid-VOCs (AC-VOCs) which produce the fruity/floral smell of tomatoes and increase the perception of sweetness–characteristics that appeal to us.
The team measured the amounts of carotenoids and chlorophylls in 157 different varieties of tomato and then analyzed the flavors of each variety to find the links between pigments and flavor. The results showed that tomato varieties with an abundance of chlorophyll also had a high sugar content, contributing to a sweet taste. They also found that the carotenoid profiles of the fruit reflected the appearance of the fruit, as well as AC-VOC levels.
The pigment profile of one of the orange-colored varieties called “Dixie Golden Giant” was particularly interesting, It had very high levels of AC-VOCs, but the carotenoid content wasn’t that high. The team discovered that the pigment prolycopene was abundant in this variety, which explained the high AC-VOC levels.
The carotenoid content of fruit is influenced by growing conditions, like temperature and amount of light. By looking at the pigment profiles and AC-VOC content of fruits in different environments, it may be possible to find ways of improving AC-VOC production, which is good for both consumers and producers.
The team is exploring analyzing pigment concentrations in large numbers of samples of other fruits and vegetables.
Source: University of Tsukuba