Vitamin C

2. Power in the key of C
One lemon contains a full day’s supply of ascorbic acid, or vitamin C, but that’s the whole fruit; the juice holds about a third. Lemon juice is also about 5 percent citric acid, making it a natural for slowing the browning or oxidation of fresh, raw foods: apples, avocados, bananas, and other fruits. That power, and the C, makes the lemon a real health fruit.