No abstract

No abstract

Aim: This study evaluates the antioxidant and antibacterial activity of Anacardium occidentale and Psidium guajava methanolic leaf extracts. Place and Duration of Study: The study was carried out in the Biochemistry and Microbiology Laboratory, Department of Science Laboratory Technology, School of Pure and Applied Science, Lagos State Polytechnic, Ikorodu, Lagos- Nigeria for the period of three months between August and October 2015. Methodology: Lycophene and β-carotene was assessed using the method of Nagata and Yamashita while total phenolic and total flavonoid content was assessed by the Folin-Ciocalteau assay and aluminum chloride colorimetric assay respectively. The antioxidant activity was evaluated using the DPPH radical scavenging activity. Antimicrobial activity was assessed by the agar well diffusion technique and mode of action was evaluated by studying the leakage of UV260 and UV280 absorbing materials spectrophotometrically. Results: A. occidentale and P. guajava methanolic leaf extracts evaluated in this study possessed significant amount of antioxidant compounds lycophene, β-carotene, total phenol and flavonoids. The extracts exhibited antioxidant activity by scavenging DPPH radicals in a dose dependent pattern with IC50 of 47.45, 43.49, 41.46 and 27.21 μg/mL for A. occidentale, P. guajava, vitamin C and Gallic acid respectively. Also, the plant extracts exhibited antimicrobial activity against E. coli, S. aureus, P. auraginosa and C. albicans and disrupted microbial membrane evident in the increase in absorbance values of UV260 and UV280 absorbing materials with time. Conclusion: A. occidentale and P. guajava methanolic leaf extracts possess antioxidant and antimicrobial activity and serve as potential source of drugs.

The bacteria associated with contamination of ready-to-eat (RTE) fruit salad samples obtained from four markets namely Yaba, Ikeja, Mushin and Oyingbo in Lagos, Nigeria were studied using standard microbiological methods. The objective of this study was to investigate the distribution of pathogenic bacteria recovered from RTE fruit salad in Lagos and assess bacteria load. The total aerobic and fecal coliform counts ranged from 1.50±0.5 x 10 5 cfu/g to 1.52±0.04 x 10 9 cfu/g and 5.0±0.5 x 10 4 cfu/g to 1.49±0.09x10 8 cfu/g respectively. The isolates were identified using morphological and biochemical tests. The results were analyzed using the one-way-ANOVA test. The test revealed that the average bacteria and coliform counts were not significantly different for the four markets, respectively. A further pairwise test also revealed that there was no significant difference between the markets. The predominant pathogenic bacteria associated with contamination of the RTE fruit salad were identified as E.coli (WO1); Klebisella sp (WO2); Proteus sp (WO3); Pseudomonas sp (WO4); Morganella morganni (WO5); Enterobacter sp (WO6); Staphylococcus aureus (coagulase +) (WO7) and Staphylococcus sp (coagulase-) (WO8). The presence of coliform and other bacteria in numbers exceeding the recommended microbiological standard is a reflection of unwholesome product, hence the need for proper microbiological safety analysis of fruit salad samples prepared for human consumption.