Effect of starter culture fermentation of milk on the production, sensory attributes and storage of Wara (a Nigerian unripened soft cheese)

Abstract

107 Ife Journal of Science vol. 22, no. 3 (2020) INTRODUCTION Wara is an unripened cheese consumed in several parts of West Africa. Wara is prepared by coagulating fresh cow milk with Sodom apple (Calotropis procera) leaf extract (Adetunji et al., 2007). Wara processing involves the use of rudimentary equipment, in many cases, starter cultures are not used and the processing conditions are not normally standardized. In an attempt to optimize the processing conditions and improve on its quality, an alternative coagulant “lemon juice” was introduced into the production of wara to reduce microbial load (Adetunji et al., 2007). The manufacture of wara is widespread in Nigeria and a similar cheese called 'Wogachi' is made in the northern provinces of Benin republic, a French speaking country to the west of Nigeria. The Fulanis of northern Nigeria are traditionally cattle rearers and they have access to excess fresh milk (from Zebu Bos indicus cattles) used in the production of traditional milk products which include wara. Wara making, which started in the northern region of Nigeria, has spread to other parts of Nigeria such as Oyo, Ogun, Ondo, Ekiti, Osun and the Benin Republic because of the nomadic life style of the Fulanis (Bamidele, 2006). Milk products prepared by lactic acid fermentation (e.g. yoghurt) or a combination of this and yeast fermentation (e.g. Kefir) are called fermented or cultured milks (Teshome, 2015). Fermented milk is the collective name for products such as yoghurt, ymer, kefir, cultured buttermilk, filmjölk (Scandinavian sour milk), cultured cream and koumiss (a product based on mares' milk). The generic name of fermented milk is derived from the fact that the milk for the product is inoculated with a starter culture which converts part of the lactose to lactic acid (Teshome, 2015). Dependent on the type of lactic acid bacteria used, carbon dioxide, acetic acid, diacetyl, acetaldehyde and several other substances are formed in the conversion process, and these give the products their characteristic fresh taste and aroma. The first example of fermented milk was presumably produced accidentally by nomads (Shah and Ravula, 2000). This milk turned sour and coagulated under the influence of probiotic microorganisms. The https://dx.doi.org/10.4314/ijs.v22i3.9