Mycotoxins Detection and Fungal Contamination in Black and Green Tea by HPLC-Based Method.

K Pakshir,H Khodadadi,Z Mirshekari,K Zomorodian,A Hadaegh,H Nouraei,Z Zareshahrabadi

doi:10.1155/2020/2456210

Abstract

The fungal contamination and total aflatoxins (AF) and ochratoxin A (OTA) of tea samples were examined. A total of 60 tea samples were extracted and treated with immunoaffinity columns. The amount of AF and OTA were determined by using high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). Tea samples were cultured and the fungi were identified. The results showed that 24 (40%) samples were contaminated with AFs and none of the tea samples were above the acceptable limit of AFs (≥10 μg/kg). All of the samples were contaminated with OTA where only 3 black tea samples (6.6%) and 1 green tea sample (6.7%) were detected to have more than the standard limits of toxin (10 μg·kg−1). The mean concentration of OTA in the black tea was higher than green tea. Aspergillus niger was the predominant fungi isolated from black and green tea samples. Considering the high contamination of mycotoxins in tea samples, regular monitoring in the tea process for improving quality is recommended.

Highlights

Tea (Camellia sinensis) is one of the most common aromatic beverages around the world
Five grams of each tea sample was added to 45 ml of sterile distilled water containing 0.05% tween 80, shaken with the vortex for 2 min, 100 μl of suspension was inoculated on to sabouraud dextrose agar containing chloramphenicol and 6% NaCl (Sigma Chemicals, USA) and incubated at 25°C till 7 days. e fungal colonies were counted, and the total fungal load was calculated and reported as a colony-forming unit (CFU) per gram based on International Commission on Microbiological Safety for Foods (ICSMF) protocol. e colonies were subcultured to determine the qualitative/quantitative outcome and identified as the taxonomic schemes for Aspergillus, Penicillium, Mocur, and other unknown fungi [16,17,18]
Consumption of black and green tea is common among Iranian people, and the mycotoxin is highly resistant to temperature, so care must be taken in quality control of tea production

Summary

Introduction

Tea (Camellia sinensis) is one of the most common aromatic beverages around the world. It is an enjoyable and widely consumed drink after water [1]. Ere are five basic types of tea with different tastes which are Black, Green, Oolong, Puerh, and White. Tea has been used as a traditional treatment for different conditions, such as blood pressure reduction, decreasing LDL cholesterol, being antidiabetic, recovering gut health, improving heart health, and reducing the risk of stroke and cancer. Black tea has many antioxidants compounds that are health beneficial and it can help to reduce inflammation. Green tea is one of the healthiest beverages on the planet and it is rich in polyphenol antioxidants, including catechin and minerals [3]. Green tea is one of the healthiest beverages on the planet and it is rich in polyphenol antioxidants, including catechin and minerals [3]. ese combinations can have influential effects on health, including improvement of brain function and exhibits antineurodegenerative (antiParkinson and anti-Alzheimer) and antidepressant effects

Methods

Findings

Discussion

Conclusion