Epidemiological evidence has substantiated the health benefits associated with the consumption of vegetables, particularly leafy greens. Lettuce (Lactuca sativa L.) cultivars (varieties) have usually been selected based on shelf-life, transportability, and yield rather than nutritional or sensory traits. Information on the effects of seasonality and genetics on various characteristics of lettuce is limited. Nutritional, antioxidant, and sensory profiles of lettuce may vary considerably among cultivars and in response to environmental factors that may fluctuate widely throughout the growing season. Bitterness, an important flavor characteristic of lettuce, is generally thought to increase with higher growing season temperatures and may vary with phenolic content.
