Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract

The uses of natural products in the elimination of microorganism contaminations in food have increased nowadays. In this study, air-dried leaf methanolic extract of Cosmos caudatus Kunth was used. The antimicrobial activity of C. caudatus extract and time-kill curve analysis was evaluated agai...

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Main Author: Mohamed Yusoff, Nor Asma Husna
Format: Thesis
Language:English
Published: 2015
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Online Access:http://psasir.upm.edu.my/id/eprint/71266/1/IB%202015%2034%20IR.pdf
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spelling my-upm-ir.712662019-11-13T04:16:44Z Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract 2015-12 Mohamed Yusoff, Nor Asma Husna The uses of natural products in the elimination of microorganism contaminations in food have increased nowadays. In this study, air-dried leaf methanolic extract of Cosmos caudatus Kunth was used. The antimicrobial activity of C. caudatus extract and time-kill curve analysis was evaluated against foodborne pathogens. The stability of extract at different pH and temperature also were evaluated. The identification and quantification of bioactive compounds were conducted using LC-MS/MS and HPLC. Three representative microorganisms were observed under transmission electron microscope (TEM). The effect of C. caudatus extract on natural microflora in selected food materials and its sensory acceptability were tested at different concentrations of extract for different exposure time. The toxicity level of extract was assessed using Artemia salina spp. Results showed that all tested foodborne pathogens were susceptible to C. caudatus extract at different range of MIC value from 6.25 to 50.00 mg/ml. Time-kill curve study shows that all tested foodborne pathogens can be killed by the extract with different time-killing curve. Generally, the antimicrobial activities of C. caudatus extract were not significantly affected on tested pH and temperatures. LC-MS/MS analysis identified the presence of rutin, quercetin 3-O-glucoside, quercetin 3-O-arabinoside, quercetin 3-O-rhamnoside and quercetin. HPLC analysis showed the highest concentration was quercetin rhamnoside (29.66 mg/g). All the identified active compounds proved possess antimicrobial activities. TEM observation showed changing on the pathogen cells’s structure. Generally the significant reduction of natural microflora in raw food materials were started at 0.05% of C. caudatus extract for 10 min of exposure time, and the sensory acceptability at this concentration and time were accepted by the panellists. The toxicity study demonstrated that C. caudatus extract was not toxic to A. salina (LC50 = 3.54 mg/ml). In conclusion, C. caudatus extract exhibits antimicrobial activities, thus can be developed as natural sanitizer for washing raw food materials. Cosmos (Plants) - Analysis Microbial sensitivity tests Phytochemicals 2015-12 Thesis http://psasir.upm.edu.my/id/eprint/71266/ http://psasir.upm.edu.my/id/eprint/71266/1/IB%202015%2034%20IR.pdf text en public doctoral Universiti Putra Malaysia Cosmos (Plants) - Analysis Microbial sensitivity tests Phytochemicals
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Cosmos (Plants) - Analysis
Microbial sensitivity tests
Phytochemicals
spellingShingle Cosmos (Plants) - Analysis
Microbial sensitivity tests
Phytochemicals
Mohamed Yusoff, Nor Asma Husna
Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
description The uses of natural products in the elimination of microorganism contaminations in food have increased nowadays. In this study, air-dried leaf methanolic extract of Cosmos caudatus Kunth was used. The antimicrobial activity of C. caudatus extract and time-kill curve analysis was evaluated against foodborne pathogens. The stability of extract at different pH and temperature also were evaluated. The identification and quantification of bioactive compounds were conducted using LC-MS/MS and HPLC. Three representative microorganisms were observed under transmission electron microscope (TEM). The effect of C. caudatus extract on natural microflora in selected food materials and its sensory acceptability were tested at different concentrations of extract for different exposure time. The toxicity level of extract was assessed using Artemia salina spp. Results showed that all tested foodborne pathogens were susceptible to C. caudatus extract at different range of MIC value from 6.25 to 50.00 mg/ml. Time-kill curve study shows that all tested foodborne pathogens can be killed by the extract with different time-killing curve. Generally, the antimicrobial activities of C. caudatus extract were not significantly affected on tested pH and temperatures. LC-MS/MS analysis identified the presence of rutin, quercetin 3-O-glucoside, quercetin 3-O-arabinoside, quercetin 3-O-rhamnoside and quercetin. HPLC analysis showed the highest concentration was quercetin rhamnoside (29.66 mg/g). All the identified active compounds proved possess antimicrobial activities. TEM observation showed changing on the pathogen cells’s structure. Generally the significant reduction of natural microflora in raw food materials were started at 0.05% of C. caudatus extract for 10 min of exposure time, and the sensory acceptability at this concentration and time were accepted by the panellists. The toxicity study demonstrated that C. caudatus extract was not toxic to A. salina (LC50 = 3.54 mg/ml). In conclusion, C. caudatus extract exhibits antimicrobial activities, thus can be developed as natural sanitizer for washing raw food materials.
format Thesis
qualification_level Doctorate
author Mohamed Yusoff, Nor Asma Husna
author_facet Mohamed Yusoff, Nor Asma Husna
author_sort Mohamed Yusoff, Nor Asma Husna
title Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
title_short Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
title_full Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
title_fullStr Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
title_full_unstemmed Antimicrobial activity, phytochemical analysis and toxicity test of Cosmos caudatus Kunth extract
title_sort antimicrobial activity, phytochemical analysis and toxicity test of cosmos caudatus kunth extract
granting_institution Universiti Putra Malaysia
publishDate 2015
url http://psasir.upm.edu.my/id/eprint/71266/1/IB%202015%2034%20IR.pdf
_version_ 1747812995926327296