Developing local processing technology for black and green tea and evaluation of conformance to ISO standard

Purpose – The purpose of this paper is to describe a project designed with the aim of developing a black and green tea processing technology for Nigerian farmers and evaluate 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. Different grades analyzed were Dust 1, Pekoe fanning (PF), broken pekoe (BP) and Fibre. Green tea was also processed from 21 tea clones selected from the Cocoa Research Institute, Kusuku Station tea plantation located at 1,840 m above mean sea level and analyzed for quality characteristics. The methods used for the quality of black and green teas analysis were in accordance with ISO standard: ISO 9768 method (revised) was used for determining % water extract, ISO 5498 for crude fibre, ISO 1575 for % total ash, and ISO 1577 for acid insoluble ash. Other additional quality parameters evaluated for black tea were theaflavi...