Meghan Bialt-DeCelie – ’19

Modern commercialized crops have been modified over the years to grow large, plentiful, and resistant to environmental damage. The taste of something like a tomato depends on the sugars, acids, and volatile compounds that are detected by one’s receptors for taste and smell.

Researchers sequenced the tomato’s genome and investigated nearly 400 accessions among commercialized, heirloom and wild tomatoes to see what was missing in the typical grocery tomatoes. A subset of 96 tomato varieties were then tasted by a consumer panel that determined the flavor’s likeability and flavor intensity using Hedonic ratings. This gave insight on what flavors a consumer would want to taste in a tomato. The researchers found that the modern commercialized tomato had 20- 60% lower composition of 13 volatiles, such as methional and isovaleronitrile, compared to the heirloom tomato, S. lycopersicum. The volatile compounds that help give tomatoes their flavor make up concentrations at a nano and pico scale. Since the tomatoes do not necessarily need a large quantity of volatile compounds to improve taste, adjusting their concentrations should have minimal impact on yield.

In the genome-wide association study, chromosomes 9 and 11 were associated with sugar content with at the Lin5 and SSC11.1 loci. The researchers also identified a negative correlation between sugar (glucose and sucrose) content and fruit weight. This could be a concern when it comes to improving the tomato’s flavor with the sugar content because introducing a sugar associated allele into a locus like Lin5 may reduce the tomato’s size.

Modern modifications to the tomato, and many other produce, have contributed to a loss in flavor-associated compounds that consumers seek in their food. While this study gave insight to the genes and compounds associated to a tomato’s taste, the obstacle of improving taste while still maintaining the high yield and resistance of the commercial tomato is a challenge.

References:

1. Tieman, Denise, et al. A chemical genetic roadmap to improved tomato flavor. Science355.6323, 391-394 (2017). DOI: 10.1126/science.aal1556.
2. Image retrieved from: https://commons.wikimedia.org/wiki/File:Tomatoes_777.jpg