Why Use Lemon in Recipes?
First — and most obviously — lemons add lemony flavor to dishes. As a charter member of the citrus family, the lemon hits both sweet and sour notes. In addition to adding its own distinctive flavor, the acidity of lemon juice and zest sharpens the other flavors in a dish. In some dishes, such as tomato sauce or mashed potatoes, a lemon can bring out the other scents and tastes while remaining undercover itself. Some cooks and chefs consider lemon as important a flavor enhancer as salt, using the peel (or a slice or wedge) as a garnish, or adding juice or zest at the end of cooking as a finishing touch.
Lemons are versatile, equally at home in sweet and savory dishes. Both salt and natural sugars combine well with the citric acid in lemons. That acid can enhance and intensify the chemical reactions that occur during the baking process. If you bake and don’t use animal ingredients, then lemon juice (or straight citric acid powder) can help substitute for animal-based ingredients like eggs and buttermilk and contribute to leavening. (Not-so-fun fact: Commercial citric acid powder used to come from lemon juice, but is now mass-produced by feeding sugar to a particular fungus.)
Lemons can also affect the texture and color of other plant foods. Lemon juice can help red foods (including red cabbage, red grapes, plums, cherries, cranberries, strawberries, and raspberries) retain their color and not turn purple or blue. This color enhancement is not a universal phenomenon, though — lemon juice can cause greens to fade if added too early in the cooking process.
Lemon juice can also inhibit the browning caused by oxidation in cut fruits like apples, pears, bananas, peaches, and avocados. Guacamole, for example, stays green for a good while if there’s enough lemon juice in it — but try lemonless guac, and you’ll be in for a grey-brown mess in short order.
As if all these culinary benefits weren’t enough, lemons provide significant benefits to human health as well. They’re anti-inflammatory and antimicrobial, and they offer protection against cancer and parasites. Lemons are high in antioxidants, most notably vitamin C (your average lemon contains almost 31 milligrams), which can strengthen immunity, aid in the absorption of iron, and prevent the development of chronic disease. Lemons are also good sources of flavonoids — which are, surprisingly, not tasty robots, but rather phytonutrients responsible for an astounding array of health benefits in the human body.
(Excerpt from The Food Revolution Network)