ripens

Ripening is the process by which certain fruits and vegetables acquire characteristics of maturity and edibility. In plants, ripening is a developmental program that leads to changes in color, aroma, flavor, texture, and nutritional composition. In many fleshy fruits, ripening continues after harvest, especially in climacteric species, where the process can be accelerated or sustained outside the original growing context.

The process involves biochemical and physiological changes: degradation of chlorophyll reveals underlying pigments; synthesis of sugars increases sweetness; starches are broken down into sugars; tissue softens as cell wall–modifying enzymes act on pectin and related polymers; and aroma compounds develop. A key regulator is ethylene, a plant hormone that stimulates ripening and increases respiration.

Ripening patterns are classically divided into climacteric and non-climacteric fruits. Climacteric fruits (for example, tomato, banana, apple, avocado) show a rise in respiration and ethylene production at the onset of ripening and can continue to ripen after harvest. Non-climacteric fruits (for example, grape, citrus, strawberry, pineapple) do not exhibit a strong respiratory peak and often ripen best while still attached to the plant or require different postharvest handling.

Practical aspects of ripening management are central to agriculture and commerce. Temperature, humidity, packaging, exposure to ethylene, and atmospheric composition influence the rate and quality of ripening. Properly controlled ripening helps maximize flavor, texture, and market value, while premature or uneven ripening can lead to spoilage and losses.