Butter and salt aim to enhance corn's rich taste, but lemon juice is an ingredient that really makes the vegetable stand out. The citrus adds a zesty quality to corn, brightening the juicy kernels. Lemon's tart taste has an undercurrent of sweetness to it, so it doesn't reduce corn's honeyed flavor. Instead, it enhances it while providing the veggie with an acidic boost.
When we say to keep your avocados with lemon, we don't mean placing the two side-by-side in a bag the way people do to get fruits to ripen faster. Rather, a squeeze of lemon juice will help the green, ripe avocado delay the browning process it eventually undergoes after it's been cut and exposed to air. When avocados experience oxidation, their enzymes interact with the air and eventually break down, leading to a brown coloring.
Ray states that she "never make[s] a classic recipe" because mayonnaise obscures the umami-rich flavor of canned tuna. Instead, she opts to "only dress tuna with lemon juice and olive oil so you can taste the product." Whereas a creamy mayonnaise will mask the fishiness of tuna, Ray believes that olive oil and lemon juice are complementary flavors that showcase tuna's distinct flavor.