Abstract:
Inductively coupled plasma mass spectrometry was applied to determine the contents of iron and manganese in teas from Fujian province. The distribution and accumulation characteristics in different parts of a tea plant were analyzed. The results showed that the mineral concentrations significantly differed among the varieties of teas studied. The iron contents ranged from 73.36 mg·kg
-1 to 284.85 mg·kg
-1 with a mean of 125.60 mg·kg
-1, and manganese from 201.86 mg·kg
-1 to 4 905.78 mg·kg
-1 with a mean of 1 651.24 mg·kg
-1. Overall, the black and the green teas contained more iron than oolong tea, whereas, oolong tea had a higher manganese content than the green or the black tea. There was no significantly difference on manganese content found between the green and the black tea. Significantly differences in the mineral contents were also shown among different parts of a tea plant. The iron concentrations in different parts ranked in the order of the fine roots (6 265.07 mg·kg
-1) > taproots (3 250.77 mg·kg
-1) > main stem (2 178.56 mg·kg
-1) > stem side (1 025.81 mg·kg
-1) > old leaves (347.50 mg·kg
-1) > young leaves (135.70 mg·kg
-1). Thus, most of the iron was absorbed and accumulated in the roots and stems on a tea plant. On the other hand, the manganese in old leaves was the highest (
P < 0.05), and evenly distributed in other parts throughout the plant. In general, Tieguanyin and Meizhan teas had greater iron or manganese contents as well as on enrichment coefficients in different parts of a tea plant than Jinguanyin or Jinxuan.