Red ripe tomatoes of various sizes.
Food - Drink
The Reason Some Tomatoes Are Found With A White Ring Inside
The common cause of a white ring inside a tomato is that the plant's soil had a potassium deficiency, and the fruit couldn't absorb enough magnesium and calcium to ripen properly.
However, too much sun exposure can create pale tissue inside a tomato, especially when the leaves are also pruned excessively, leaving the fruits without proper shade.
When tomatoes are exposed to too much heat while growing, they have trouble producing lycopene, the chemical that gives them their signature red hue.
While a less desirable reason may create a white ring inside your tomato, such as bugs or mold, a lack of nutrients is the cause of discoloration, more often than not.
The good news is that if your "ringed" tomato is fresh and you don't notice any signs of spoilage, it's typically safe to eat, and the ring can be cut out if you're bothered by it.