Research Studies
Study Tracker
Assessment and health risk of fluoride from Northeast Indian tea (Camellia sinensis L.): Fixing up the maximum residue level of fluoride in tea.
| Journal of Food Composition and Analysis | Kanrar B, Kundu S, Sengupta S, Yeasin MD, Paul RK, Karak T. | 127:105928.

Abstract

Highlights

  • Total fluoride (F–) content in tea varied from 16 to 314 mg kg-1.
  • F– content in tea infusion varied between 1.08 mg L-1 and 2.43 mg L-1.
  • The average transfer of F– from made tea to tea infusion was 100.46%.
  • The Hazard Quotient value of F– indicates that Indian tea would not pose any health hazard.
  • Maximum Residue Limit of 300 mg kg-1 for F– in tea has been recommended in India.

The tea plant is considered a strong fluoride (F–) hyperaccumulator plant. We have proposed the Maximum Residue Limit (MRL) of F– in tea based on 321 tea samples collected from 8 tea-growing regions of Northeast India. Total F– as well as water-soluble F– content was analysed through the ion selective electrode with the recovery percentage of 100–108 to ascertain the risk associated with F– towards human health. It has been observed that total F– contents (mg kg-1) in Cachar, Darjeeling, Dooars, North Bank, South Bank, Terai, Tripura, and Upper Assam ranged from 42.5 to 111.5, 16.0 to 168.0, 48.0 to 291.0, 36.5 to 314.0, 60.0 to 154.0, 26.5 to 233.5, 26 to 118 and 44 to 244, respectively. The F– content in tea infusion varied between 1.08 mg L-1 and 2.43 mg L-1 across all eight regions with a mean of 1.90 mg L-1. The average transfer of F– from made tea (processed young shoot of tea plants comprising a bud and 2 to 3 leaves) to tea infusion was 100.46%. Fluoride content in infusion was decreased with the increment of infusion number but increased gradually with continuous infusion time. The non-carcinogenic health risk was assessed. Calculated Hazard Quotient values were far below 1. The calculated and rounded MRL (300 mg kg-1) was recommended for F– in tea in India.

Original abstract online at https://www.sciencedirect.com/science/article/abs/pii/S0889157523008025

Excerpts:

A comprehensive review by Karak and Bhagat (2010) concluded that F– concentration in tea infusion depends on the type of tea and F– in infusions of black tea was higher than that in green tea. Zhang et al., (2023) reported F– contents of tea types representing major cultivation areas in China e.g., Guangdong and Hunan Provinces of South China, Yunnan Province of Southwest China, Henan Province of North China and areas of Fujian, Jiangsu, and Zhejiang Provinces situated at the south of the Yangtze River to assess the possible health risk for the general population. They concluded that F– content in 15.6% of samples of 218 tea leaves exceeded the Chinese maximum residue limit (200 mg kg-1). They also concluded that F– level varied between producing regions and types of tea. However, risk assessment indicated no significant health risk via simply consuming tea.

Fluoride in made tea is an obvious fact as the tea plant is an F–-hyperaccumulator (Zhang et al., 2023). Luo et al. (2021) highlighted that tea plants can absorb an enormous amount of F– from soil and 98% of total accumulated F– by tea plants is present in tea leaves. Das et al. (2017) also reported that F– in made tea exists in highly soluble form and 96–99% of total F in made can be extracted by water when 35 tea samples collected from 13 countries were analysed. This also confirms that tea is an F– supplement for human beings. Furthermore, the digestive tract can straightforwardly absorb soluble F– and the bioavailability of F– from tea is close to 100% (Tokahoglu et al., 2004) which is similar to that from drinking water (Rao, 1984).

Related Research Studies