BIOPRESERVATIVE EFFECT OF LACTIC ACID BACTERIA ON MICROBIOLOGICAL, SHELF-LIFE AND SENSORY QUALITY OF UGBA, A TRADITIONAL NIGERIAN FERMENTED FOOD
*1Ome, A.P.,1Olaoye, O.A. and 2Edeji, U.F.
1Department of Food Science and Technology, Michael Okpara University of Agriculture, Umudike, Abia State.
2Department of Biotechnology, Federal Institute of Industrial Research Oshodi, Lagos, Nigeria.
Email:talk2omepeter@gmail.com
ABSTRACT
The study was conducted with the aim of evaluating the biopreservative potentials of lactic acid bacteria isolated from ugba and the safety nature of the product. The LAB isolates used as starter cultures in this study are Lactobacillus plantarum, which have been isolated from ugba in aprevious study by same authors, based on their ability to produce considerable quantities of lactic acid under a reduced pH and good fermentative activity exhibited. The pure culture were successively screened and used (in single) toferment African oil bean slices. The samples were subjected to shelf-life study and microbiological analysis. Sample B inoculated with LAB starter culture was able to store for more than 7 days with less microbial load showing improved keeping qualities than those products processed locally that were purchased from the market that started spoiling from day 4. The results also showed that the following bacterial isolates were involved in the fermentation: Bacillus spp., Lactobacillus spp., Streptococcus spp., Micrococcus spp., and spoilage of ugba: Proteus spp., Staphylococcus spp., Pseudomonas spp., Escherichia coli. Fungal contaminants: Penicilliumspp., Aspergillusspp and Rhizopusspp., were also observed.Sample B had good sensory attributes especially in appearance and texture while Sample D was rated best in taste and aroma (flavour). It was concluded that pure cultures of Lactobacillus plantarumused as starter culture had good biopreservative effect on the fermented African oil bean slices as antimicrobial agents by improving the safety and keeping qualities of the product.
Keywords: Biopreservation, lactic acid bacteria, microbiological, sensory, shelf life, starter cultures, ugba.