scispace - formally typeset
Search or ask a question
Author

J.J. Essia Ngang

Bio: J.J. Essia Ngang is an academic researcher. The author has contributed to research in topics: Chemistry & Food science. The author has an hindex of 2, co-authored 2 publications receiving 137 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: The essential oils of Xylopia aethiopica, Monodora myristica, Zanthoxylum xanthoxyloïdes and Z. leprieurii, four Cameroonian plants used as spices in local food, showed antibacterial and antifungal activity.

147 citations

Journal ArticleDOI
TL;DR: In this article , a secondary predictive model of microbial inactivation scale during the combined process of mild heat treatment of fruit juices in combination with natural aroma compounds has been reported as an alternative to conventional pasteurization.
Abstract: Mild heat treatment of fruit juices in combination with natural aroma compounds has been reported as an alternative to conventional pasteurization to better preserve their nutritional value. However, its antimicrobial efficiency varies from one juice to another. This study aims at developing a secondary predictive model of microbial inactivation scale during such combined process. Carvacrol was used as aroma compound and acid-adapted L. monocytogenes as target microorganism. The inactivation kinetics of this bacteria were followed in simulated fruit juices using a Central Composite Design with pH (2-6), °Brix (0-24), temperature (55-65 °C), and carvacrol concentration (0-60 μL/L) as independent variables. Curves were fitted to the Weibull inactivation model, and data collected used to generate two predictive models of the inactivation scale parameter through multiple regression analysis following an empirical and a mechanistic (based on Gamma concept) approach. The best of the two models was then validated using real fruit (orange, pineapple, and watermelon) juices. The empirical model where only the four variables tested were considered showed a lower statistical performance compared to the mechanistic model where octanol-water partition coefficient (Ko/w) and vapour pressure (Vp) of carvacrol at the treatment temperature were integrated (R2 0.6 and 0.9; Accuracy factor 1.5 and 1.3; Sum of Squared Error 3.6 and 1.1, respectively). No significant difference was observed between inactivation scale values obtained with real juices and the predicted values calculated using this mechanistic model. The Ko/w and Vp of the aroma compound used are key parameters that determine the efficiency of the above-described combined treatment.

2 citations

Journal ArticleDOI
TL;DR: In this article, the authors evaluated the influence of LAB isolated from cow's milk produced locally in Cameroon on the organoleptic and physicochemical quality of soft cheese with bloomy rind.
Abstract: The changing of the diversity of lactic acid bacteria (LAB) from one locality and another is one of the main reasons of the organoleptic and physicochemical differences encountered in the same class of cheese. The objective of this work was to evaluate the influence of LAB isolated from cow's milk produced locally in Cameroon on the organoleptic and physicochemical quality of soft cheese with bloomy rind. To this effect, 05 LAB (IS1, IS2, IS3, IS4 and IS5) were isolated to fresh milk and selected after macroscopic, microscopic and biochemical characterizations. After tests of acidification, fermentation type, compatibility between LAB and LAB concentration on milk coagulation, the combined IS1-IS4-IS5 and IS2-IS3-IS5 were retained to produce 02 soft cheeses with bloomy rind namely respectively FROCAM 145 and FROCAM 235. When used at concentrations of 3×107 CFU/mL, these combined LAB coagulate fresh renneted milk after 3 hours at 26°C. During the production of FROCAM 145, the combined IS1-IS4-IS5 resulted in a firm, moist curd and a pH reduction of 14 and 15% respectively after the milk maturation and ripening of FROCAM 145. This cheese recorded 100% mould recovery, with protein, lipid and calcium content of 6.7, 62.2 and 0.1% respectively. On the other hand, during the production of FROCAM 235, the combined IS2-IS3-IS5 resulted in a dry and crumbly curd. The pH recorded with this combined LAB after maturation of the milk and ripening of FROCAM 235 is 12 and 17% respectively. The FROCAM 235 recorded a low mould recovery estimated at 20% and a protein, lipid and calcium content of 7.8, 65.1 and 0.3% respectively. From a microbiological point of view, FROCAM 145 and FROCAM 235 did not record any contamination by Listeria monocytogenes, Salmonella and Staphylococci. The sensory analysis shows that FROCAM 145 was more appreciated than FROCAM 235 with scores of 0.74 and 0.24 respectively. In view of these results, the IS1-IS4-IS5 combinations isolated from Cameroonian milks present a certain technological interest in the transformation of milk into cheese.
Journal ArticleDOI
TL;DR: In this article , the in vitro antioxidant properties of the extract were evaluated using DPPH, ABTS and FRAP tests and the results demonstrate potent anti-typhoid activities of the hydroethanolic of Detarium microcarpum root bark extract through antioxidant properties and high inhibitory affinity of its compounds on some bacterial key enzymes that justify its use as traditional medicine to typhoid fever.

Cited by
More filters
Journal ArticleDOI
TL;DR: Many plant species are used in traditional medicine in Cameroon to treat infectious diseases, and several interesting openings have originated for further inquiry following IN VITRO antimicrobial activity evaluation.
Abstract: In Cameroon, infectious diseases are amongst the most commonly notified diseases and largest cause of mortality. Many plants are used locally in traditional medicine for their treatment. The aim of the present review is to summarize currently available evidence and knowledge concerning Cameroonian plants used to treat bacterial and fungal infections, and the efficacy of plant-derived extracts and compounds. The traditional uses of plants in the treatment of infectious diseases have been collected and tabulated. The antimicrobial activity of the extracts and the chemical constituents of most of these plants are summarized in this report. Plants used traditionally in Cameroonian medicine, with laboratory work on any part or products, have been documented. Numerous extracts and compounds have been tested for antimycobacterial, antibacterial and antifungal efficacy and some of them were significantly active. Most of the bioactive compounds isolated were phenolics and alkaloids. In conclusion, many plant species are used in traditional medicine in Cameroon to treat infectious diseases, and several interesting openings have originated for further inquiry following IN VITRO antimicrobial activity evaluation. However, much work is still to be done to standardize methods and cut-off points for describing the antimicrobial activity, and on the study of the mechanisms of action.

483 citations

Journal ArticleDOI
TL;DR: The chemical composition of the essential oils obtained from the leaves, the barks of the stem and the root, as well as from the fresh and dried fruits of Xylopia aethiopica, growing in Ghana, was investigated by gas chromatography/mass spectrometry analyses and beta-Pinene was predominant in all cases.
Abstract: The chemical composition of the essential oils obtained from the leaves, the barks of the stem and the root, as well as from the fresh and dried fruits of Xylopia aethiopica, growing in Ghana, was investigated by gas chromatography/mass spectrometry analyses. Kovats indices, mass spectra, and standard compounds were used to identify a total of 93 individual compounds. The monoterpene hydrocarbons formed the main portion in all studied samples. β-Pinene was predominant in all cases, while trans-m-mentha-1(7),8-diene was the main compound in the essential oils of the leaves and the barks of roots and stems. Their potential antioxidant activity was also investigated and found to be significant in scavenging superoxide anion radical. Keywords: Xylopia aethiopica; Ghana; volatile constituents; leaves; fruits; stem bark; root bark

198 citations

Journal ArticleDOI
TL;DR: Some natural products are potential therapeutic perspective for the prevention and treatment of chemotherapy and radiotherapy-induced side effects and further studies are required to validate the efficacy of natural products in cancer patients, and elucidate potential underlying mechanisms.
Abstract: Cancer is the second leading cause of death in the world. Chemotherapy and radiotherapy are the common cancer treatments. However, the development of adverse effects resulting from chemotherapy and radiotherapy hinders the clinical use, and negatively reduces the quality of life in cancer patients. Natural products including crude extracts, bioactive components-enriched fractions and pure compounds prepared from herbs as well as herbal formulas have been proved to prevent and treat cancer. Of significant interest, some natural products can reduce chemotherapy and radiotherapy-induced oral mucositis, gastrointestinal toxicity, hepatotoxicity, nephrotoxicity, hematopoietic system injury, cardiotoxicity, and neurotoxicity. This review focuses in detail on the effectiveness of these natural products, and describes the possible mechanisms of the actions in reducing chemotherapy and radiotherapy-induced side effects. Recent advances in the efficacy of natural dietary supplements to counteract these side effects are highlighted. In addition, we draw particular attention to gut microbiotan in the context of prebiotic potential of natural products for the protection against cancer therapy-induced toxicities. We conclude that some natural products are potential therapeutic perspective for the prevention and treatment of chemotherapy and radiotherapy-induced side effects. Further studies are required to validate the efficacy of natural products in cancer patients, and elucidate potential underlying mechanisms.

191 citations

Journal ArticleDOI
TL;DR: The results of the antibacterial assays indicated that all tested extracts exert antibacterial activities, with the minimum inhibitory concentration values varying from 32 to 1024 μg/ml.
Abstract: The emergence of multi-drug resistant (MDR) phenotypes is a major public health problem today in the treatment of bacterial infections. The present study was designed to evaluate the antibacterial activities of the methanol extracts of eleven Cameroonian spices on a panel of twenty nine Gram negative bacteria including MDR strains. The phytochemical analysis of the extracts was carried out by standard tests meanwhile the liquid micro-broth dilution was used for all antimicrobial assays. Phytochemical analysis showed the presence of alkaloids, phenols and tannins in all plants extracts. The results of the antibacterial assays indicated that all tested extracts exert antibacterial activities, with the minimum inhibitory concentration (MIC) values varying from 32 to 1024 μg/ml. The extracts from Dichrostachys glomerata, Beilschmiedia cinnamomea, Aframomum citratum, Piper capense, Echinops giganteus, Fagara xanthoxyloides and Olax subscorpioidea were the most active. In the presence of efflux pump inhibitor, PAsN, the activity of the extract from D. glomerata significantly increased on 69.2% of the tested MDR bacteria. At MIC/5, synergistic effects were noted with the extract of D. glomerata on 75% of the tested bacteria for chloramphenicol (CHL), tetracycline (TET) and norfloxacin (NOR). With B. cinnamomea synergy were observed on 62.5% of the studied MDR bacteria with CHL, cefepime (FEP), NOR and ciprofloxacin (CIP) and 75% with erythromycin (ERY). The overall results provide information for the possible use of the studied extracts of the spices in the control of bacterial infections involving MDR phenotypes.

144 citations

Journal ArticleDOI
TL;DR: The overall results of the present study provide supportive data on the use of some Cameroonian plants for cancer treatment and indicate that the anti-angiogenic properties of the most active extracts were able to inhibit angiogenesis by more than 50% in quail embryo.

143 citations