Effects of Simulated Acid Rain on Main Nutritional Indicators of Three Leafy Vegetables

The purpose of this paper was to identify content changes in the main nutritional indicators of three com- mon leafy vegetables, and to provide a theoretical basis for the protection of leafy vegetables from acid rain. The ex- periment investigated the effects of simulated acid rain on four main nutritional indicators, including soluble sugar, total free amino acid, soluble protein and vitamin C during the application of simulated acid rain(SAR) in pak- choi(Brassica rapa chinensis), rape(Brassica campestris L.) and lettuce(Lactuca sativa Linn. vat. ramosa Hort). The vegetables were respectively exposed to SAR of pH=7.0, 5.6, 5.0, 4.0, 3.0 and a control level of pH=6.5. The con- centrations of the four main nutritional indicators were determined at harvest. The results show that nutritional quality of the three leafy vegetable species decreased with the declining of pH values of SAR. The higher the acidity of SAR was, the more significant the inhibitions were. Nutritional quality of lettuce was the most affected by simulated acid rain, followed by pakchoi and rape. The change range of soluble protein content was higher than those of the other three indicators' contents, which indicates that soluble protein is most sensitive to simulated acid rain.