T Mbata, M Orji
culture, fermentation, optimization, starter, ugba
T Mbata, M Orji. Process Optimization In The Production And Preservation Of 'Ugba', A Nigerian Fermented Food. The Internet Journal of Microbiology. 2007 Volume 4 Number 2.
Ugba is a Nigerian indigenous, protein rich food obtained by solid state fermentation of seeds of African oil bean (
The unfermented seeds are bitter to taste and contain toxic alkaloids and saponins (2). The natural fermentation of the seeds which at present is still done at the house-hold level renders the product nutritious, palatable and non-toxic3. Its production, like many other African fermented foods, depends entirely on mixed fermentation by microorganisms from diverse sources, some of which may still be alive and active when the product is consumed. The method of production varies from one producer to another resulting in a none uniform product with short shelf-life.
The processes of
Some attempts to improve the packaging and keeping quality of
The present study was aimed at using starter culture and entirely different packaging technique involving screwable bottles and cans and locally adaptable pasteurization to produce and enhance the shelf-life of
Materials and Methods
The seeds of African oil bean tree (
The traditional method of
Development of Starter Cultures
The traditional method of producing
Determination of Physicochemical and Organoleptic Properties
The pH was determined using a WPAC10 pH meter. The total protein content (total nitrogen content) was determined by the fermol-titration method16. The softness/texture was determined instrumentally using a portable penetrometer and subjectively by pressing the slices between the fingers. The total sugar was determined using the phenol sulphuric acid method (16). Microbial counts were determined by the pour plate method (17).
The organoleptic tests for taste, aroma, colour, softness and sliminess were carried out using a six-man taste panelist who is very familiar with
Shelf Life Determination
Results and Discussion
The physicochemical properties of Ugba
A reduction in fermentation time was achieved in this work and this was apparently because the starter cultures used were at their exponential growth phase and have been grown in
The effect of storage on the organoleptic properties of ugba is presented in Table 3. The result shows that all the organoleptic parameters of ugba considered in the study became bad after the first week for ugba obtained from the local dealer while the parameters remained virtually the same throughout the six weeks storage period for ugba produced in this study (Table 3).
The major problems of ‘ugba' are its poor shelf life often associated with the uncontrolled fermentation and poor packaging which often allows maggots to develop on the product as a result of eggs laid by flies that gained entry into the wrapped product. The production process also renders the product vulnerable to contamination by pathogenic microorganisms. These difficulties were overcome in the present work by using known organisms (starter culture), a packaging system that does not allow the entrance of extraneous organisms into the product and the use of a pasteurization method that can easily be adapted by the local producers.
Colour, aroma, texture and sliminess are important organoleptic indices of a well fermented ugba and thus are inevitable in its shelf-life determination. These attributes of
The result of this work not only provided advances for mass production of Ugba with a standardized operational method but also provided means for the production of uniform product with reduction in fermentation time and enhanced product shelf-life. The study has also shown that
Mbata T.I. Department of Applied Microbiology and Brewing Nnamdi Azikiwe University P.M.B. 5025, Awka, Nigeria. E-mail: firstname.lastname@example.org Tel- 2348032618922