Biochemistry

HEAD OF THE DEPARTMENT

Dr. PRODIP TAMULY

Email : tamulypradip11@gmail.com

DEPARTMENTAL PERSONNEL
  • Dr. (Mrs.) Sabitri Baruah
  • Dr. Lakshi Prasad Bhuyan
  • Mr. Nogen Gogoi
  • Mr. Ashok Kr. Bordoloi
  • Mrs. Binoti Devi Baruah
  • Mr. Santanu Sabhapondit
OBJECTIVE OF THE DEPARTMENT

To Generate information on various biochemical components of freshly plucked shoots, their changes during processing and in the product.

To correlate between chemical composition of tea liquors and commercial value.

To study the effect of various agro practices and climatic conditions on quality of tea.

BRIEF HISTORY OF THE DEPARTMENT

The importance of biochemistry in tea manufacture was felt since the very beginning of undertaking research in tea. Accordingly some biochemical investigations in tea were carried out in the laboratories in Calcutta and in Heeleakah Tea Estate till 1910. With the establishment of the Tocklai Experimental Station, the work continued in its Chemistry Laboratory until a separate Biochemistry Department was formed in 1937 as per the recommendation of the Engledow Commission. Dr. E.A.H. Roberts joined the department as the first Biochemist that year. At the same time the investigations on the chemistry of made tea were started in London’s Butler’s Wharf Laboratory.

In the early years, The Biochemistry Department was equipped with a “Warburg Apparatus” and the “Piezy Rollers”. The manufacture Factory and the Tasting Unit were under the control of the Biochemistry Department. Later on some equipment like Spectrophotometers and Paper Chromatography facilities were made available. However in 1960, the Miniature Factory and the Tea Tasting Unit were separated from the Biochemistry Department. Presently, modern additional equipments like HPLC (High performance liquid Chromatography), GLC (Gas Liquid Chromatography), Electrophoresis, Lyophiliser, Spectrophotometers Environmental Control manufacturing are available in the Department.

Currently the Biochemistry Department is working on several externally funded projects and two multi-institutional project. The department is also engaged in various work related to standardizing and regulatory bodies like ISO, PFA and FSSAI etc. The department is also rendering service to the tea industry by knowledge sharing through workshops and seminars, biochemical assessment of the product etc.5. Activities of the department :

This department has been constantly rendering its service to the Industry in the field of biochemistry in relation to tea and tea processing. The basic knowledge of tea chemistry is very much useful for the improvement of tea quality. This department in collaboration with Research Engineering and Tea Tasting department advises the Industry on the various aspects of tea processing in relation to quality improvement. Biochemistry Department has excellent track record of standardization of quality parameters, understanding the biochemical changes in processing. Some notable contribution of the department are chemical basis of tea quality, flavour index for Darjeeling clones, factors regulating Darjeeling Flavour, Tocklai Fermentation Test, Brightness Enhancement in Darjeeling Tea, Pigment Profile as a tool for assessing quality, TF and TR as index for quality of plains tea etc. A Tea Automation Factory has already been commissioned at Tocklai. Monitoring and control of every stage of processing is being carried out in this factory in order to eliminate human error to improve overall quality.

ACTIVITIES OF THE DEPARTMENT

This department has been constantly rendering its service to the Industry in the field of biochemistry in relation to tea and tea processing. The basic knowledge of tea chemistry is very much useful for the improvement of tea quality. This department in collaboration with Research Engineering and Tea Tasting department advises the Industry on the various aspects of tea processing in relation to quality improvement. Biochemistry Department has excellent track record of standardization of quality parameters, understanding the biochemical changes in processing. Some notable contribution of the department are chemical basis of tea quality, flavour index for Darjeeling clones, factors regulating Darjeeling Flavour, Tocklai Fermentation Test, Brightness Enhancement in Darjeeling Tea, Pigment Profile as a tool for assessing quality, TF and TR as index for quality of plains tea etc. A Tea Automation Factory has already been commissioned at Tocklai. Monitoring and control of every stage of processing is being carried out in this factory in order to eliminate human error to improve overall quality.

R & D Activities of Biochemistry Department

• Biochemistry department has been involving in various R & D activities in relation to chemistry of tea and tea processing. The department is playing leading role by contributing significantly towards the identification of various biochemical constituents of tea as a whole. It has also established the chemical basis of quality for the first time.

• Biochemistry of tea processing is a complex conjugation of biochemical reactions. Formation of certain biochemical constituents responsible for brightness, briskness depth of colour strength and mouth feel of the liquor is very much essential. Therefore it is very much important to regulate the processing parameters during different stages of tea processing. This department is responsible for establishing the critical role of chemical withering during processing. Regulation of chemical withering and optimizing the withering time is essential for quality. In our study it is established that 12-14 hrs withering time has been optimum to have the best cup character. In our recent study it is observed that there has been considerable improvement of quality (25-30%) by restricting moisture loss for initial 5-6 hrs during withering. In the same study withering behaviour and fermenting trend of some popular cultivars are documented which is cultivar specific.

• Recently we have completed the chemoprofiling of catechins in 105 germpalsm. Cultivars having more Assam character contain higher catechin followed by Cambod and China. Agroclimatic conditions of Assam more conducive for catechin biosynthesis. Light intensity is playing and important role in the biosynthesis of catechin.

• In addition to this chemoprofiling of volatile flavoury constituents of 30 popular Darjeeling has been completed recently. Linalool and its oxides and geraniol are the most characteristic components of Darjeeling tea. Formation of flavour is found to be the highest during rolling. Linalool, geraniol and phenyl acetaldehyde are found to be higher in Darjeeling tea made from green leaf infested by jashid than non infested one.

• Department has already initiated some work in the line of product diversification in tea. Technology has already been developed to produce tea tablets, soft drinks, tea flavour, tea toffee etc. technology for decaffeination of tea using super critical fluid extraction (SCFE) methods is almost ready for commercialization.

• Future direction of research will be to understand mechanism of stress induced biochemical reactions and to develop a regulatory mechanism to regulate certain oxidation and hydrolytic reactions through various stress during processing to produce product of choice. An integrated approach will be taken up to work out precursor product relationship. An extensive study will be initiated for chemoprofiling of biochemical parameters of black tea using LCMS, GCMS technique to establish a potential biochemical marker for GI (geographical indicator).

• A plan of research has been worked out to develop the technology for extraction and purification various secondary metabolites and antioxidants from tea to produce different by-product and value added products from tea.

CURRENT FINDINGS

1. Technology developed/Recommendations Made To The Tea Industry From The Project

Technology Developed:

  • Formulation of different types of green and black tea soft drink
  • Preparation of green soluble tea (antioxidant, beverage, natural tea colour and food additive)
  • Preparation of black soluble tea (antioxidant, beverage, natural tea colour and food additive)
  • Extraction of antioxidant from tea
  • Extraction of natural tea colour
  • Formulation of different types of tea tablet
  • Preparation of different types of tea based confectionary and bakery items.

Transferred the Technology of Green Tea Soft drink preparation to “Green Gold Assam” in November, 2011.

Assignment deed between NRDC and TRA for the following on 31st December, 2012.

  • Tea tablet.
  • Green soluble tea (antioxidant, beverage and food additive)
  • Soluble black tea (natural tea colour, beverage, food additive and antioxidant)

Study was conducted on black tea produced from 7 regions of Assam (Upper Assam, South Bank, North Bank and Barak Valley ) and West Bengal ( Dooars, Terai and Darjeeling ). The observations/recommendations are:

  • Theaflavin (TF) and thearubigin (TR) content of CTC black tea from the regions of Assam except Barak valley are comparable and higher than other regions. Quality of Barak valley, Dooars and Terai regions are also comparable. Similar trend of total soluble solid (TSS) for the regions is also observed.
  • The variation in TF and TR content of CTC black tea from the regions is responsible for differences in tasters’ quality.
  • t-2-hexen-1-ol, linalool oxide, linalool, hotrienol, trans-geraniol, and tetratricontane of Darjeeling teas found higher than the other regions
  • Theanine as well amino acid content of samples from south bank is higher than the other regions in CTC tea.
  • Distinct variation in total catechin, EGC, EGCG, ECG, TF, TR, TR1 and TR2 of Darjeeling tea with orthodox tea of other regions was observed. Hence, these chemical basis may be a criteria for fingerprint of Darjeeling tea
  • TF and TR are the key components of black tea which not only influences the sensory evaluation of tasters’ but also have high antioxidant properties
  • Nitrite scavenging activity and lipid peroxidation scavenging activity of black tea are more than free radical (DPPH) scavenging activity and super oxide scavenging activity.
  • Nitrite scavenging activity is correlated significantly with TF and TR content of black tea.
  • Lipid peroxidation scavenging activity is correlated significantly with TF content.
  • 551 black tea samples were analyzed for iron filings. The different ranges were as follows

S.No. Range No. of Samples
1
<50 ppm
528
2
51 – 100 ppm
15
3
101 – 150 ppm
3
4
151 – 200 ppm
2
5
201– 250 ppm
3
Total
551

 

i. Regulation of moisture loss during initial stage of withering is one of the most important factors to improve the quality. Loss of moisture should not exceed 1 to 1.5% in the early part of the withering to improve brightness and briskness of liquor.

ii. Rise of leaf temperature beyond 30-320C during withering is detrimental to quality specially the brightness and briskness. This is due to decline in polyphenol oxidase activity and degradation of catechin content. Restriction of catechin degradation could be achieved by restricting moisture loss at higher temperature.

iii. By regulating degree of maceration during CTC, the percentage of degradation of gallocatechins can be regulated. This will result increase in theaflavin digallate content along with the improvement of brightness and briskness of liquor.

iv. Optimum fermentation time reduces with rise of withering temperature, degree of withering and percentage of moisture loss in the initial stage of withering.

v. Optimum temperature during fermentation is found to cultivar specific i.e. for T.3E/3, S.3A/3 having Assam character is 25-260C while for cultivars having cambod character like TV23, TV26, TV9 is 300C.

vi. Cultivar having more Assam character i.e. T.3E/3, S.3A/3 produces better quality with moisture percentage slightly higher than 70% while cultivar like TV23, TV26, and TV9 produces better cup character around 69% of moisture in the withered leaf.

vii. There is a reduction of fermentation time to the extent of 15-20 min under enhanced level of oxygen during fermentation.

viii. Application of vacuum during withering improves the quality in terms of TF and flavour formation.

ix. Volatile flavour formation is found to be higher at 300C as compared to 250C and 350C during fermentation.

x. Optimisation of fermentation time of some commonly used tea cultivars at different temperature is completed.

Bulletins Published For Technology Transfer:

Publication of bulletin is under process.

Name Of Projects Completed Within Last 10 Years With Principal Investigator:

Internally Funded Projects:

  1. Biochemical aspects of tea processing to enhance the brightness of tea liquor as well as infusion. P.I.  Dr. P. Tamuly
  2. Biochemical Aspects of Flavour Genesis in Tea and Tea Processing. P.I. Dr. P. Tamuly.
  3. Effect of physico chemical condition during drying on biochemical constituent of made tea and their contribution towards quality. P.I. Dr. P. Tamuly
  4. Study on biochemical mechanism of storage deterioration of tea to enhance the shelf life.  P.I. Dr. P. Tamuly
  5. Study on physical properties of tea shoots and its affect on quality.  P.I. Dr. P. Tamuly

Externally Funded Projects:

  1. Niche pathway of catechin Biosynthesis in Tea. P.I. Dr. P. Tamuly
  2. Development of Technology for Product Diversification and value added items of tea. P.I. Dr. P. Tamuly, 10th Plan project, Tea Board
  3. Establishment of chain quality testing laboratories and strengthening of existing analytical facilities at regional centers and Tocklai. P.I. Dr. P. Tamuly, 10th Plan project, Tea Board
  4. Developing Production System for Tea Polyphenols and their Condensed   Products  (Funded by NMITLI, CSIR)  P.I. Dr. P. Tamuly.
  5. Extraction, identification and quantification of volatile flavoury constituents (VFC) in TRA released Darjeeling clones and standardization of process variables in Darjeeling Tea with special reference to VFC-TRA. (NTRF Project) P.I. Dr. M. Hazarika
  6. Development of Methodologies for the Extraction of Food Grade Secondary          Metabolites from Tea and Up-scaling the Methods for Commercial Purpose.  P.I. Dr. (Mrs.) S. Baruah, 11th Plan project, Tea Board
  7. Establishment of chain of quality testing laboratories and strengthening of Existing analytical facilities at regional centers and Tocklai. P.I. Dr. L.P. Bhuyan, 11th Plan project, Tea Board

Current Project With Name Of The P.I, Period, Any Collaboration, Sanctioned Amount And Name Of The Sponsored Organization

1. Title of the project: “Deliver understanding on process controls in black tea manufacturing process”.

  • P.I. : Dr. P. Tamuly,
  • Period : 2 (two) years,
  • Sanctioned amount : Rs.16.128 lacs.
  • Collaboration with Unilever R & D., Bangalore
  • Funded by: Unilever Industries Private Limited, Bangalore

2. Title of the project: “Inward Leaf Inspection System for Indian Tea Industries “
Collaborative Project between TRA and C-DAC