You just ate a fresh ripe tomato from a local producer or your garden and compared it to a tomato you bought at the supermarket.
Did you experience a different taste?

The taste of a food is determined by its total content of vitamins, minerals, trace elements, and various other phytochemicals.

Sodium.
Sodium is a metal that is popular mainly as one of the constituents of salt (a chemical compound of Sodium and Chlorine). Sodium, however, can be found in foods such as spinach, beetroot, carrot, celery, and various types of drinking water (tap water, mineral water, spring water).
Sodium is the ingredient that gives a salty taste to food with an intensity proportional to its concentration. In particular, Sodium activates specific nerve receptors on the surface of our tongue, which sends a message to the brain about each food's saltiness.
In the example mentioned, a ripe tomato, through adequate and proper cultivation, will absorb all the necessary Sodium, which will give the desired natural-salty taste result. Of course, this will not happen with a tomato that was cut before its final ripening in soil with low sodium content.

Vitamin C
Vitamin C is chemically known as ascorbic acid.
As an acid it gives an acidic taste to the final product.
For example, the acidic taste of vitamin C in an orange, or a tomato, is familiar. At the same time, other organic food acids, such as malic acid in apples, citric acid in lemons, have a similar taste.

Sour taste.
The bitter taste is mainly due to tannins, phytochemicals with potent antioxidant and antimicrobial action present in blueberries, berries, grapes, etc.

Sugars.
The known sweet taste of fruits and some vegetables, such as red sweet peppers, or sweet onions, is due to the content of simple sugars, such as glucose, fructose, and sucrose disaccharide.

Metallic taste.
Mineral taste in the mouth after eating a food, or drink, is generally not desirable. It may indicate an increased concentration of various metals such as Zinc, Iron, Chromium, Copper, or even a chronic disease sign.
Simultaneously, the different concentrations of different natural metals in the water, such as Calcium and Sodium, give a different taste to the different types of water consumed (e.g., mineral water).