Why do tomatoes turn red or hard

Tomatoes turn red but feel hard to the touch, usually due to incomplete ripening or variety characteristics. Possible reasons include premature harvesting, low-temperature storage, variety differences, insufficient ethylene exposure, or planting conditions.

1. Premature harvesting

Commercial tomatoes are often harvested before they are fully ripe to extend their transportation and storage period. Although the appearance of these tomatoes turns red due to ethylene ripening, the flesh has not undergone a natural ripening process, resulting in a harder texture. It is recommended to leave it at room temperature for a few days after purchase to allow it to soften naturally.

2. Low temperature storage

Low temperature in the refrigerator can inhibit pectinase activity in tomatoes, hinder pectin decomposition, and soften the fruit. If immature tomatoes are refrigerated, there may be a phenomenon where the color turns red but the hardness is maintained. When storing, avoid temperatures below 10 degrees Celsius.

3. Variety Characteristics

Some tomato varieties, such as steak tomatoes and Roman tomatoes with thicker flesh, still maintain a harder texture after maturity. The hardness and taste of this type of variety are related, not immature performance. When choosing, attention should be paid to distinguishing the characteristics of the variety.

4. Insufficient contact with ethylene

Natural maturation requires sufficient action of ethylene gas. If tomatoes are stored in an environment with excessive ventilation or stored separately, insufficient ethylene concentration can cause skin pigments to change faster than fruit flesh softening. Tomatoes and fruits with high ethylene release, such as bananas and apples, can be placed together to accelerate ripening.

5. The influence of planting conditions

Insufficient light, small temperature difference, or excessive nitrogen fertilizer during the growth process of tomatoes may lead to insufficient sugar accumulation and the phenomenon of coloring before softening. This type of fruit has a lighter flavor, so it is recommended to choose tomatoes grown outdoors during the season.

When selecting tomatoes in daily life, gently pinch the area around the stem, as this part of the mature fruit will slightly sink. Hard tomatoes can be used for stewing or grilling, and when softened, they are more suitable for raw consumption. Store in a cool and ventilated place, avoiding direct sunlight to accelerate decay. If it remains hard and odorless for a long time, it may be a chemical ripening product, and it is recommended to consume it with caution. Planting enthusiasts can improve fruit quality by controlling water and fertilizer and ensuring sufficient light.