SHAMSIDEEN OLUSEGUN AROYEUN, GERALD O. IREMIREN, SULE S. OMOLAJA, FEYISARA ABIODUN OKELANA, OLAIWOLA OLUBAMIWA, ROTIMI R. IPINMOROTI, AMOS A. OLOYEDE, SEMIU OLALEKAN OGUNWOLU, ANDREW DANIEL,CHRISTIANA OLAYINKA JAYEOLA, FATAI ABIOLA SOWUNMI AND LUKMAN OLA ODUNMBAKU
Purpose – This project was designed with the aim of developing a black and green tea processing technology for Nigerian farmers and evaluating the conformance of the quality of the processed tea to the recommended international standard.
Design/methodology/approach – Locally processed and graded black teas were collected from Kakara and Bangoba for analysis. The different grades analyzed were Dust 1, Pekoe fanning (PF), Broken pekoe (BP) and Fibre. Green tea was also processed from twenty-one tea clones selected from the Cocoa Research Institute, Kusuku station’s tea plantation located at 1840m above mean sea level and analyzed for quality characteristics. The methods used for the quality of black and green tea analysis were in accordance with the ISO standard. The ISO 9768 method (revised) was used for determining percentage water extract, 5498 for crude fibre, ISO 1575 for percentage total ash, ISO 1577 for acid-insoluble ash. Other additional quality parameters evaluated for black tea were theaflavins (TF), thearubigins (TR) and colour brightness (CBr) from another set of seventeen clones using Flavonost methods. Conformance to the ISO standard was assessed in all tea locally processed by the farmers in comparison to those processed under controlled conditions.
Results/findings – The results obtained in this study revealed that 59.2 per cent of the tea analyzed conformed to ISO 9768, 81.5 per cent to ISO 5498, 77.8 per cent to ISO 1575, 96.3 per cent to ISO 1576, 100 per cent conformed to ISO 1577 and 85.2 per cent to ISO 1578 respectively. In all, only 33 per cent of the processed tea conformed to international standards for black or green tea physical parameters. For black tea, the clones that conformed to the correct TF, TR and CBr were UNK, 367, 19, 74, 354, 368, 369, 353, 357, 143, 14 and 108 respectively.
Originality/value – The use of locally sourced clonal materials that conform to ISO standards from Nigeria could create new products (black and green tea) of high economic value to the farmers.
Practical implications – Production of green tea and black tea can take place locally without loss of quality if good manufacturing and hygiene practices are followed.
Keywords ISO, Tea quality, TF, TR, CBr, Conformance
Paper type Research paper