Studies on the Antimicrobial, Nutritional and other Potential Uses of Canarium Schweinfurthii (Ube Okpoko)

Abstract

Microbiological studies of Canarium schweinfurthii pear fruit obtained from four markets in four (4) South-Eastern State of Nigeria were carried out. The results showed that five bacterial and thirteen fungal species are associated with the spoilage of the pear fruit. The bacterial genera include Klebsiella aerogenes, Streptococcus pneumoniae, Erwinia carotovora, Pseudomonas putida, and Flavobacterium spiritavorum. The thirteen fungal isolates were Aspergillus glaucus, Alternaria alternate, Sacharomyces cerevisiae, Cladosporium herbarum, Geotrichum candidum, Aspergillus terrreus, Aspergillus versicolor, Penicillium citrinium, Aspergillus niger, e.t.c. Reports of the analysis carried out in the four states showed that bacterial and fungal isolates associated with pear spoilage are evenly distributed, and not limited to a specific area. Of the thirteen fungal isolates, Fusarium monoliforme had the highest frequency of occurrence (7.4%) while Aspergillus glaucus, Geotrichum candidum, Aspergillus terreus, Aspergillus versicolor, Candida tropicalis and Saccharomyces chevalieri, each had percentage frequency of occurrence of 1.23%. Of the five bacterial isolates, Erwinia carotovora was the most widely distributed with 22.2% frequency of occurrence while Flavobacterium spiritivorum had a frequency of occurrence of 2.5%. The microbial counts of the pear fruits was found to increase with the time of storage, rising to the optimum count on the fourth day, dropping from the time the nutrients in the pears could no longer sustain the microbial load. The nutritional contents of the pear with the exception of protein were found to decrease with the time of storage/biodegradation. The wine produced from the pear had the following characteristics; pH 3.6, titratable acidity 2.6, specific gravity 1.071 and alcoholic content 6% (v/v). The results of antimicrobial activities of aqueous and ethanolic leaf and bark extracts showed that the extracts had antimicrobial activities on the test organisms at varying concentrations. The highest inhibition zone diameter of 20mm at 0.8gm/l was recorded for the ethanolic extracts against Klebsiella pneumoniae. The highest inhibition zone diameter of 15mm at 0.8gm/l was recorded for the ethanolic bark extracts against Candida albicans. The result of haemagglutination test of NDV-Lasota virus revealed that bark and leaf hot water extracts against Candida albicans. The result of haemagglutination test of NDV-Lasota virus revealed that bark and leaf hot water extracts and the control experiment showed haemagglutinin titre ratio of 1:1024. Also, the result of antibacterial activities of pulp oil extracts showed highest antibacterial activity on Salmonella typhi with mean inhibition zone diameter of 27mm at 4.0ml/ml concentration. The result of the phytochemical analysis showed the presence of alkaloids, saponins, tannins and flavonoids. This study shows that lower storage temperature of pear fruits slow down the rate of spoilage and that the pear fruit will be a good source of wine production. Further exploitation of this plant material for antimicrobial activity will possibly unveil the potential use in the treatment of diseases caused by the test organisms.