Application of different forms of calcium to tea soil to prevent aluminium and fluorine accumulation

Abstract

Tea Camellia sinensis (L), is a well-known accumulator of aluminium and fluorine from acidic soil. A reduction is desirable as aluminium and fluorine absorbed will leach into the tea liquor through infusion, thus posing a serious threat to the health of consumers. The present study aims to investigate the effects of adding different forms of calcium on Al and F uptake by tea plants, in order to reduce the concentrations of these elements contained in the plants. All true lime materials increased the soil pH and decreased soil extractable Al and F concentrations. There were no (p < 0.05) changes in pH values when CaCl 2 was added, and a slight decrease in Al and F concentrations was observed in the treatments with CaSO 4 . Tea seedlings under the addition of CaSO 4 were the tallest and healthiest, followed by CaCl 2 , CaCO 3 , Ca(OH) 2 and CaO. Seedlings under large doses of Ca(OH) 2 and CaO were dead. Relative growth rates decreased significantly with the increase of calcium compounds except in CaSO 4 treatment. The highest Al concentration was also found in the treatment of 4000 mg CaSO 4 kg −1 ; it then decreased gradually from 3364 to 933 mg Al kg −1 in leaves. For all treatments in both varieties, F concentrations in leaves were lower than the control (374 mg kg −1 ). Calcium chloride was a suitable agent for reduction of Al and F uptake by tea plants while maintaining a high growth rate of the seedlings.

Highly selective defluoridation of brick tea infusion by tea waste supported aluminum oxides

“…Some foods and beverages, such as certain types of tea, contain high contents of fluoride . Tea is the most popular beverage in the world after water; however, the tea plant is well known to accumulate fluoride . Cases of unsightly dental fluorosis and crippling skeletal fluorosis have been reported, linked to chronic exposure to high levels of fluoride through consumption of (brick) tea .…”

Growth and nutrient uptake of tea under different aluminium concentrations

“…The stimulatory effects of Al on C. sinensis were demonstrated by Chenery2 in field studies. Aluminium stimulates the growth of excised roots and also the growth of C. sinensis in solution culture 3–5. In fact, Konishi et al 3 devised a nutrient medium for the solution culture of C. sinensis which includes 1 mmol L −1 Al.…”

Optimization of Tea Sample Preparation Methods for ICP-MS and Application to Verification of Chinese Tea Authenticity

“…On the other hand, Matsumoto et al (1996) reported that tea is one of the few plants that accumulates Al. Al salts present in tea garden soils dissociate at pH < 5.5 and produce Al 3+ in soil solution and form complexes with phosphate (AlPx) at the root surface of tea (Fung and Wong 2004). From our results, both EC and SC tea (compared with black tea from different areas and green tea from different areas) showed no significant differences in Al concentration.…”