Pectinases, like other industrial enzymes are usually expensive. The use of pineapple peel pectin as substrate is triggered by the large tones of pineapple waste generated in Nigeria. Oil extraction by mechanical/chemical means have associated disadvantages. This research aimed at employing locally produced pectinase for coconut-oil extraction and to compare the yield with commercial pectinase. Fifty grammes of dried pineapple peel powder were employed for pectin production. Aspergillus niger isolated from cassava meal was employed to produce pectinase using submerged fermentation for seven days. The activity of pectinase was determined at 24 h interval. The pectinase was partially purified using 3% activated carbon, characterized and employed to extract oil from coconut. The yield of pectin from the pineapple peels was 24.8% after 1 h of extraction time. Highest pectinase activity was observed on day five. Optimum conditions were 40°C, 5.0 and 1% respectively for temperature, pH and substrate concentration. The enzyme was completely inactive after 5 min of heating at 90°C and metal ion (Mg2+) stimulated its activity. The mean oil yield from the locally produced pectinase was greater than the commercial pectinase. The pectinase produced from this study enhanced coconut-oil extraction when compared with the mechanical method.

Pectinases are a group of enzymes that catalyze the breakdown of pectin. Pectinase producing Aspergillus niger was obtained from a five-day old Eba (Cassava flakes). Response surface methodology was used for optimizing the process of the pectinase produced. Four independent variables which are, temperature, pH, substrate concentration and time of Heating at 70 o C were used to optimize the significant correlation between the effects of the variables on pectinase production. A second-order polynomial was fitted to data and validated by ANOVA. The results revealed maximum pectinase production at pH 6.0, 50 o C Temperature, 0.02% substrate concentration and the enzyme lost all its activity within 7 min of heating at 70 o C. The study revealed that optimization of pectinase through RSM could improve the enzymatic characteristics and yield of the enzyme. The models used were highly significant with a correlation coefficient (R 2 ) of 0. Mots-clés: la pectinase, Aspergillus niger ; la méthodologie de surface de réponse ; plan composite centra

Objectives: Dacryodes edulis is a versatile plant in many African countries, as its various parts are employed to treat several diseases. Like most plants used in traditional medicine, the possible mechanism by which D. edulis functions is still unknown. This study was designed to investigate the components of the plant seed with a view of justifying its use as traditional medicine. Methods: The seed oil of D. edulis was exhaustively extracted with a Soxhlet extractor from 500 g seeds and 200 g seeds of D. edulis using ethanol and petroleum ether as solvent, respectively. The extraction solvent was removed to obtain the oil which was then subjected to antimicrobial activity test to determine its activity against the following clinical isolates namely Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Escherichia coli using gentamycin as positive control. Phytochemical screening and gas chromatography-mass spectrometry (GC-MS) analyses were carried out following standard methods Results: Ethanolic extract resulted in a higher percentage of oil yield (11.6%) than petroleum ether (5.3%). D. edulis seed oil showed remarkable activity against Gram-negative and Gram-positive isolates: E. coli, Bacillus spp, and S. aureus but not against P. aeruginosa. The presence of saponins, quinones, cardiac glycosides, terpenoids, and phenol was confirmed during qualitative phytochemical screening, and the preliminary results from GC-MS analysis show the presence of terpinen-4-ol, 4,6,6-trimethyl bicyclo[3.1.1]hept-3-en-2-one, ethyl 14-methyl-hexadecanoate, methyl 19-methyl-eicosanoate, squalene, C-14 to C-18 fatty acids, and their esters. Conclusion: The study, therefore, confirms that the use of D. edulis as component of traditional medicine may be justified.

This research was to investigate the chemical composition, antioxidant activity, and microbial profiles of Cola lepidota fruits. One hundred grams each of the fruit exocarp, mesocarp and endocarp were blended and analyses were carried out by the following standard methods. Active acidity and vitamin C contents were 5.5 and 6.34 mg 100 g^–1 in endocarp, 4.5 and 14.39 mg 100 g^–1 in mesocarp and 6.7 and 10.02 mg 100 g^–1 for exocarp. Moisture and carbohydrate contents of 12.31 and 68.72% were in the mesocarp while protein and crude fibre contents of 8.13 and 26.18% were in the exocarp and endocarp. Iron (Fe), zinc (Zn) and manganese (Mn) contents were 1.79, 0.27 and 0.57 mg 100 g^–1 in exocarp while lead (Pb), cadmium (Cd) and chromium (Cr) were absent in the endocarp. Predominant isolates were Aspergillus niger, Saccharomyces cerevisiae, Aspergillus flavus, Bacillus, Staphylococcus and Pseudomonas species. C. lepidota had no antimicrobial effect against the tested organisms. Tannins, flavonoids, terpenoids, phenols, coumarins and anthocyanins were present while alkaloids, quinolones, glycosides, steroids and cardiac glycosides were absent. The fruit was observed to have antioxidant property by hydrogen peroxide scavenging activity. This study presents C. lepidota as good for human consumption and can be exploited for animal feed production.

Foods are essential vehicles in human exposure to antibiotic resistant bacteria which serve as reservoirs for resistance genes and a rising food safety concern. Antimicrobial resistance, including multidrug resistance (MDR), is an increasing problem globally and poses a serious concern to human health. This study was designed to synthesize data regarding the prevalence of MDR bacteria associated with foods and drinks sold within Nigeria in order to contribute to the existing findings in this area. A comprehensive literature search on the prevalence of multi-drug resistant bacteria associated with foods and drinks in Nigeria from 2015 to 2020 was conducted using three databases; PubMed, Science Direct and Scopus. After screening and selection, 26 out of 82 articles were used for the qualitative data synthesis. Of the total of one thousand three hundred and twenty-six MDR bacteria reportedly isolated in all twenty-six articles, the highest prevalence (660) was observed in drinks, including water, while the lowest (20) was observed in the article which combined results for both protein and vegetable-based foods. Escherichia sp. had the most frequency of occurrence, appearing as MDR bacteria in ten out of the twenty-six articles. Salmonella sp. appeared as MDR in seven out of the twenty-six articles included in this study, in all seven articles where it was reported, it had the highest percentage (85.4%) prevalence as MDR bacteria. Public health personnel need to ensure critical control during the production and handling of foods and drinks, as well as create more awareness on proper hygienic practices to combat the spread of MDR bacteria.