Makus and Gonzalez (32) found that white asparagus is lower in phenolics (bitter components), Vitamin C, and protein, but higher in simple sugars compared to green asparagus. Fiber content is similar (Figure 11).
Makus (30) also determined the kinds and amounts of mineral nutrients in green and white 'Jersey Giant' asparagus spears. He found that green spears generally contained higher concentrations of mineral nutrients than white spears. Most of the mineral nutrients measured decreased from the spear tip to the base. Since the mineral nutrient levels found in asparagus spears are influenced by the length of the spear, reducing the inedible fibrous butt end would reduce transportation costs and provide consumers with a nutritionally better product with respect to essential minerals. Growers should expect to receive a premium for such a product.
One serving (5 spears or 93g) of green asparagus contains 20 calories, 0g fat, 0mg cholesterol, 0mg sodium, 5g total carbohydrate with a 2% daily value, 2g dietary fiber with a 7% daily value, 2g sugars, 2g protein, 10% Vitamin A, 10% Vitamin C, 2% Calcium and 2% Iron (46).
One of the most important nutrients in asparagus is folic acid (Folacin). Folic acid helps prevent birth defects, and is important for the formation of blood cells and DNA. Folacin is a B vitamin found in many vegetables. One serving of asparagus provides 60% of the U.S. Recommended Daily Allowance (RDA) of folic acid. This serving contains the largest percentage of U.S. RDA of any food (1).