Why are Roasted Tomatoes More Tasty?

🍅Even people who don’t like raw tomatoes sometimes find roasted tomatoes🍕 to be delicious. That was me when I was a little boy. See also the previous article about sourness of tomatoes.

🧀Glutamic acid is an umami component found in cheese and kombu, and is also found in tomatoes. Guanyl acid is an umami component too found in shiitake mushrooms. When two umami molecules are mixed, umami is enhanced dramatically.

Guanylic acid was thought to be almost absent in most vegetables. However, it has recently been discovered that tomatoes🍅 and eggplants🍆 contain a small amount of guanylic acid, which can be further increased by heating. This fact was confirmed for 11 different kinds of tomatoes🍅. It was found that heating them in the oven increased the amount of guanylic acid by an average of 1.8 times.

However, the amount is still very small. Can we really recognize its umami? So the researchers in Japan conducted a test. They prepared three diluted carrot juices🥕 with glutamic acid. In one of them, a small amount (10 mg/L) of guanylic acid was also added. All seven panels were able to detect the juice with guanylic acid. We can distinguish carrot juice with guanylic acid and glutamic acid from carrot juice with only glutamic acid.

🍅🍅🍅These results support the possibility that guanylic acid, which is slightly increased by heating, enhances the umami of tomato.


1. “Production of Guanylic Acid by Cooking of Tomato” Nippon Shokuhin Kagaku Kogaku Kaishi, 2015, 62, 417.

2. “Production of Guanylic Acid by Heating Vegetables” 日本調理科学会誌, 2012, 45, 346.

3. The National Agriculture and Food Research Organization, Japan

Leave a Reply

Your email address will not be published. Required fields are marked *