CTC (Crush, Tear and Curl) black tea, as one of the most representative black tea, is a very popular beverage in the world owing to its potential health benefits. However, the presence of toxic elements has gained more and more public health concerns. The contents of elements in tea were affected not only by growth environment but also by the technology of manufacturing process. Unfortunately, the studies of the influence of manufacturing process on the levels of elements in final tea products were very limited. In this study, the influence of manufacturing process on the levels of iron (Fe), copper (Cu), chromium (Cr), nickel (Ni) and manganese (Mn) in CTC black tea were determined by inductively coupled plasma mass spectrometry (ICP-MS). It was found that the concentrations of Fe and Cu in tea leaves could greatly increase after rolling by rotorvane, which was proved to be the key stage affecting the Fe and Cu levels in final made tea. However, Cr and Ni contents in tea leaves increased greatly after cutting by CTC rollers. There was no significant difference among Mn concentrations in tea samples obtained from different stages according to the one-way ANOVA analysis (p > 0.05). The effect of brewing time and brewing times on the transfer rates were investigated. Ni displayed the highest transfer rate with the value of 75.74%, while the transfer rates of Cu, Cr and Mn were 30.08%, 26.62% and 34.98%, respectively. With respect to the recommended daily allowance, the Fe, Cu, Cr and Ni in CTC black tea do not pose significant risk to human health while concerns should be paid to Mn since its HQ was still large than 1% even considering the bioavailability.
Food Control – Elsevier
Published: Jul 1, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera