Do not put tomatoes in the refrigerator
Their genes are freezing
After being stored in the refrigerator, tomatoes and some other vegetables and fruits lose a fair amount of flavor. But why is this happening? Until now, the reason has eluded scientists. And I would really like to understand the reason: after all, if we understand the mechanism of this process, we will be able to develop suitable storage methods in the future or even create such varieties of tomatoes that will not be afraid of the cold.
And finally, recently, a group of scientists led by Harry Klee from the University of Florida in Gainesville tackled the problem of tomatoes losing their taste with all seriousness. Deciding to study the expression of more than 25,000 genes in two varieties of tomatoes, they looked at these genes before cooling, during cooling and after returning tomatoes to room temperature. (Article by Zhang et al. Chilling-induced tomato flavor loss is associated with altered volatile synthesis and transient changes in DNA methylation published in PNAS – VM.)
And here's what it turned out: hypothermia – the main stress for tropical and generally heat–loving plants, such as tomatoes - reduces the activity of hundreds of genes. Some of these genes produce enzymes responsible for the synthesis of volatile chemicals that make tomatoes taste sweeter and give them a complex attractive aroma.
Many of the enzymes, having ceased to be synthesized during cooling, did not reappear, even after the tomatoes were heated to room temperature again. Taste tests confirmed that after lying in the refrigerator, tomatoes lost their taste and aroma.
Further analysis showed that cooling leads to changes in DNA methylation, affecting many genes. Since methylation is a common mechanism for turning genes on and off for a long time, this may explain the long-term effect of cooling on taste, says Klee.
With this information, geneticists will eventually be able to replace low-temperature-sensitive enzymes in tomatoes to make them more suitable for storage and transportation in refrigerators. Or – at least – advise producers to grow tomato varieties for long-term storage with such gene variants that are naturally less susceptible to such changes under the influence of cold.
Elizabeth Baldwin, a plant physiology researcher at the U.S. Department of Agriculture laboratory in Fort Pierce, Florida, agrees: "With this knowledge, we will certainly be able to make the necessary selection or genetic manipulation."
Another conclusion from the work of the Cli, for the near future, so to speak, is very simple: do not store tomatoes in the refrigerator – they are not well there.
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21.10.2016