FORM - 2 THE PATENTS ACT, 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10 and Rule 13) A TEA PRODUCT HINDUSTAN UNILEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Unilever Limited, Unilever House, B.D. Sawant Marg, Chakala, Andheri (East), Mumbai - 400 099, Maharashtra, India The following specification particularly describes the invention and the manner in which it is to be performed. Technical Field The present invention relates to a process for producing a tea product. More particularly the present invention relates to a process for producing a black tea product. Background of the invention In the world of tea, black tea is one of the most commonly known tea products. Black tea is generally prepared by a process which includes the steps of withering, macerating, fermenting and firing/drying. The characteristic colour, flavour and aroma of black tea are produced during fermentation. The term fermentation is traditionally used in the tea processing to refer to enzymatic oxidation. The tea is dried at high temperature after fermentation to arrest the enzyme action and to bring down the moisture to a low level. The sensory properties of black tea are of prime concern. The key sensory properties of a black tea beverage are its colour, appearance and aroma. The colour of the beverage is particularly important. A rich red coloured liquor is preferred by consumers. There are tea manufacturing processes for improving the sensory properties of black tea product disclosed in the art. US2006/0228447 (Unilever, 2006) discloses a process for manufacturing a cold water soluble black leaf tea comprising the steps of (a) optionally withering freshly plucked tea leaf, (b) macerating the leaves, (c) allowing the leaves to ferment, (d) firing the leaves to arrest fermentation and (e) then drying them to yield black leaf tea, the process being characterised in that the tea leaves are treated before fermentation or before mid-fermentation with a pH lowering agent, followed by treatment during fermentation with ascorbic acid, salts of ascorbic acid or mixtures thereof at mid-fermentation or later in an amount that is sufficient for the black leaf tea to be infusible in water at 5 to 100°C. US2008/0118602 (Unilever, 2008) discloses a process for the manufacture of a tea product which is readily infusible an