Microbiological evaluation of shelflife indices of fermented African locust bean cake stored under different preservative treatments

Abstract

This study was carried out on the preservation of fermented Parkia biglobosa Seeds sourced from Local Producers and laboratory produced. The local and fermented laboratory controlled samples were treated with 0.5ml of freshly prepared ginger extract. Another set of control was left untreated. The samples were stored at ambient temperature for 30 and 120 days. Contaminant isolates were identified from locally produced, laboratory treated and untreated (Control) using standard procedure. The analysis consisted of Aerobic and Anaerobic mesophilic count, Staphylococcus count and fungal count, detection of E. coli, S. aureus, Salmonella sp, Mucor sp and Rhizopus sp. The proximate analysis and organoleptic assessment of the purchased, Laboratory treated and laboratory untreated (control) were carried out using standard procedure at 30 and 120 days. Isolated and characterized bacterial isolates at 30 and 120 days in the treated and control locust bean cake were E.coli only isolated in Kwanar yandaddawa, Staphylococcus aureus was isolated in all the purchased Locust bean cake, Salmonella sp was not detected and a predominant fungal species were Mucor and Rhizopus. There was log reduction between 30 and 120 days reated locust bean cake; the Control shows Log increase. The mean proximate composition percentage differences between 30 and 120 days shows nutritional quality of treated locust bean cake. Organoleptically, the judges rejected control daddawa as a result of what the panelist termed as “unpalatable taste and partially pleasant aroma” due to off flavor. The growing interest in use of natural products of plant origin therefore gives Ginger extract an advantage in developing a practical approach for the preservation of African locust bean cake. Keywords : African locust bean cake, preservatives, log reduction, nutritional quality, shelf life.