TEST RESULTS
FOR PHYSICOCHEMICAL PARAMETERS
Flavonoids | Theaflavins | Crude Fibre | Pesticide Residues | Acid-Insoluble Ash | Total Ash | WaterSoluble Ash | Water Extract | Alkalinity of WaterSoluble Ash Expressed as KOH | Added Colouring Matter | Iron Filings | Lead | Copper | Aflatoxins Flavonoids
Indian Standard has not specified any requirement for total flavonoids.
Black tea develops different types of flavonoids. These flavonoids have antioxidant abilities and may help prevent heart disease and some types of cancer.
• Total flavonoids were found in the range of 6.25 per cent–55.69 per cent w/w (mass/mass). Red Label had the highest amount and Goodricke the lowest.
Theaflavins
There is no standard requirement for theaflavins either.
• Theaflavins were found in the range of 0.78 per cent–2.15 per cent w/w (mass/mass). Marvel had the highest amount and Taj Mahal the lowest.
Theaflavins are primarily responsible for the darker colour and stronger flavour of black tea. These have been proved to be effective as antioxidants and have many uses – from treating headaches and staving off allergies to protecting the heart and reducing cancer risk.
Crude Fibre (on dry basis)
Crude fibre is a measure of the quantity of indigestible components present in foods. These components have little food value but because of their effect on the digestive system, they are thought to help with such problems as diabetes and high levels of blood cholesterol. Crude fibre is an important parameter in the quality evaluation of tea and influences its sensory properties.
As per FSS Regulations and Indian Standard, crude fibre in tea shall not be more than 16.5 per cent. • Crude fibre was found within the specified limit of
16.5 per cent. Pesticide Residues Pesticide is a chemical or biological agent (such as a virus, bacterium, antimicrobial, or disinfectant) that deters, incapacitates, kills, or otherwise discourages pests. Pesticides may cause acute and delayed health effects in people who are exposed. Such adverse health effects range from simple irritation of the skin and eyes to more severe effects like affecting the nervous system, mimicking hormones causing reproductive problems, and causing cancer.
We have conducted tests for following pesticides residues as per requirements of FSSAI.
a) Dicofol: Maximum permissible limit is 5.0 mg/kg.
• It was not detected in any of the samples.
b) Ethion: Maximum permissible limit is 5.0 mg/kg.
• It was not at all detected in 12 brands. Traces of ethion were found in Rungta’s and Goodricke but
these were well below the specified limit. Thus, all the brands passed this test.
c) Fenazaquin: Maximum permissible limit is 3 mg/ kg.
• It was not detected in any of the samples.
d) Glufosinate ammonium: Maximum permissible limit is 0.01 mg/kg.
• It was not detected in any of the samples.
e) Glyphosate: Maximum permissible limit is 1.0 mg/kg.
• It was not detected in any of the samples.
f) Propargite: Maximum permissible limit is 10.0 mg/kg.
• It was not detected in any of the samples.
g) Quinalphos: Maximum permissible limit is 0.01 mg/kg.
• Traces of this pesticide were found in Rungta’s – at 0.04 mg/kg, these went above the specified limit. Hence, this brand is not recommended for consumption.
Acid-Insoluble Ash (on dry basis)
Acid-insoluble ash indicates the presence of impurities like sand, dirt and dust in food. As per Indian Standard and FSS Regulations, acid-insoluble ash in tea should not be more than 1.0 per cent by mass. • Acid-insoluble ash was found within the specified limits. It was lowest in Rungta’s (0.11 per cent) and highest in Fresh & Pure (0.64 per cent).
Total Ash (on dry basis)
As per Indian Standard and FSS Regulations, total ash in tea shall be between 4.0 per cent and 8.0 per cent. • Total ash in all brands was within the permissible range.
Water-Soluble Ash
Water-soluble ash is part of the total ash dissolved by water under the conditions specified in Indian Standard. As per both FSS Regulations and Indian Standard, the water-soluble ash component of total ash shall be a minimum 45 per cent by mass.
• The water-soluble ash component of total ash was found to be above the minimum requirement of 45 per cent. Thus, all brands passed in this test.
Alkalinity of Water-Soluble Ash Expressed as KOH
Alkalinity of the water-soluble ash is either the amount of acid required to neutralise the aqueous extract of the total ash or the amount of alkali equivalent to this acid. As per FSS Regulations, it should be between 1.0 per cent and 3.0 per cent of total ash; as per Indian Standard, it should be in the range of 1.19 per cent–2.62 per cent. All the tea samples were found within the specified limit.
Water Extract (on dry basis)
It refers to the soluble matter extracted from a test portion by boiling water under the conditions specified in Indian Standard, expressed as a percentage by mass on a dry basis. As per both Indian Standard and FSS Regulations, water extract shall not be less than 32 per cent. All samples met the requirement set by the standards. Water extract was highest in Red Label (63.52 per cent) and lowest in Nova (32.81 per cent).
Added Colouring Matter
Colour adulteration is not acceptable from the point of view of consumers’ health. As per FSS Regulations and Indian Standard, colouring matter shall be negative/absent in tea.
• Colouring matter was absent in all the samples.
The iron content present in tea is classified as ‘inherent iron’ and ‘iron filings’. The former is of plant origin (nonmagnetic part), while the latter is extraneous in nature (magnetic part). In tea-manufacturing process, a lot of machinery made of iron are utilised to crush, tear, curl and roll the withered leaf after harvesting. For example, tea leaves are dried in a sieve fitted with a mesh and leaves are cut using iron rollers. The powder is crushed in an iron machinery. Due to continuous wear and tear of these machines, the metallic iron particles may get stuck to the tea grains. Iron Filings
The national standards have capped the maximum limit for iron particles in tea powder at 250 mg per kilogram. Iron filings were not found in any of the brands tested.
Iron Overload?
An excess of iron in the human body can cause overloading and lead to diseases like liver cirrhosis, osteoporosis, scurvy, heart failure and oesophageal cancer.
Heavy Metals
a) Lead: Lead contamination of food poses a serious health issue. Consumption of even a small amount of lead can cause lifelong health problems and repeated exposure will have lasting and detrimental effects. As per Indian Standard and FSS Regulations, lead in tea shall not be more than 10 mg/kg. • Lead was found within the specified limit in all the 14 brands.
b) Copper: Copper is an essential mineral required by the body for bone and connective tissue production, and for coding specific enzymes that carry out a range of functions, from eliminating free radicals to producing melanin. However, overconsumption of copper may lead to cramps, diarrhoea and vomiting in the short term, and to depression, schizophrenia, hypertension, senility and insomnia in the long term. Copper in large amounts can even be poisonous. As per Indian Standard and FSS Regulations, copper in tea shall not be more than 150 mg/kg. • Copper was found within the specified limit in all the brands.
Aflatoxins
Aflatoxins are poisonous and cancer-causing chemicals that are produced by certain moulds ( Aspergillus flavus and Aspergillus parasiticus) that grow in soil, decaying vegetation, hay and grains. Aflatoxins are highly toxic compounds and can cause both acute and chronic toxicity in humans and many other animals. Four types of aflatoxins are naturally found in foods. These are aflatoxins B1, B2, G1 and G2. Aflatoxin B1 is the most commonly found in food and also the most toxic.
There is no standard requirement for aflatoxins. These are expected to be absent in tea. Aflatoxins were not detected in any of the samples.