Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression

Contamination of food by mycotoxins is an important food safety concern for grains and other agricultural products. Aspergillus species are responsible for production of most of these toxins including aflatoxin and ochratoxin A (OTA). Results achieved by present study revealed that 65% of the teste...

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Main Author:	Yazdani, Darab
Format:	Thesis
Language:	English
Published:	2011
Subjects:	Aspergillus Food contamination Mycotoxins
Online Access:	http://psasir.upm.edu.my/id/eprint/113962/1/113962.pdf
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id	my-upm-ir.113962
record_format	uketd_dc
spelling	my-upm-ir.1139622024-12-04T06:45:39Z Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression 2011-07 Yazdani, Darab Contamination of food by mycotoxins is an important food safety concern for grains and other agricultural products. Aspergillus species are responsible for production of most of these toxins including aflatoxin and ochratoxin A (OTA). Results achieved by present study revealed that 65% of the tested rice samples collected from different region in Malaysia was infected by Aspergillus and/or Eurotium species. A. flavus and A. niger were the predominant species and were the major contaminants (account for 17%) in rice. 17 Aspergillus and Eurotium isolates were obtained and identified based on morphological characteristics and molecular techniques. This study also confirmed that only A. flavus starin A2 was able to produce aflatoxins B1 and B2 in culture media. Compared with other techniques, thin layer chromatography was concluded to be a favorable method as it is simple, sensitive and reliable for detecting the aflatoxins and OTA production by Aspergillus isolates. In screening of antifungal activity of Malaysian medicinal plants, it was found that both A. galanga and P. betle significantly inhibited the production of aflatoxins by A. flavus. Compared with other extracts, the chloroform extract of A. galanga exhibited the best antifungal effect and with MIC value 25 μg/mL. P. betle extract at 500 μg/mL demonstrated a complete inhibition on the production of aflatoxins and at 100 μg/mL, the same extract was able to inhibit 69.4% of the aflatoxin production in culture media. LC-MS analysis showed that the chloroform soluble fraction of methanolic extract from A. galanga possess 10 compounds, which were mainly cinnamic acid and related aromatic acids such as coumaric acid, cafeic acid and ferulic acid, whereas in P. betle extract 11 compounds was obtained, they were mainly dihydrochalcones. Aspergillus Food contamination Mycotoxins 2011-07 Thesis http://psasir.upm.edu.my/id/eprint/113962/ http://psasir.upm.edu.my/id/eprint/113962/1/113962.pdf text en public doctoral Universiti Putra Malaysia Aspergillus Food contamination Mycotoxins Mior Ahmad, Zainal Abidin
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English
advisor	Mior Ahmad, Zainal Abidin
topic	Aspergillus Food contamination Mycotoxins
spellingShingle	Aspergillus Food contamination Mycotoxins Yazdani, Darab Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
description	Contamination of food by mycotoxins is an important food safety concern for grains and other agricultural products. Aspergillus species are responsible for production of most of these toxins including aflatoxin and ochratoxin A (OTA). Results achieved by present study revealed that 65% of the tested rice samples collected from different region in Malaysia was infected by Aspergillus and/or Eurotium species. A. flavus and A. niger were the predominant species and were the major contaminants (account for 17%) in rice. 17 Aspergillus and Eurotium isolates were obtained and identified based on morphological characteristics and molecular techniques. This study also confirmed that only A. flavus starin A2 was able to produce aflatoxins B1 and B2 in culture media. Compared with other techniques, thin layer chromatography was concluded to be a favorable method as it is simple, sensitive and reliable for detecting the aflatoxins and OTA production by Aspergillus isolates. In screening of antifungal activity of Malaysian medicinal plants, it was found that both A. galanga and P. betle significantly inhibited the production of aflatoxins by A. flavus. Compared with other extracts, the chloroform extract of A. galanga exhibited the best antifungal effect and with MIC value 25 μg/mL. P. betle extract at 500 μg/mL demonstrated a complete inhibition on the production of aflatoxins and at 100 μg/mL, the same extract was able to inhibit 69.4% of the aflatoxin production in culture media. LC-MS analysis showed that the chloroform soluble fraction of methanolic extract from A. galanga possess 10 compounds, which were mainly cinnamic acid and related aromatic acids such as coumaric acid, cafeic acid and ferulic acid, whereas in P. betle extract 11 compounds was obtained, they were mainly dihydrochalcones.
format	Thesis
qualification_level	Doctorate
author	Yazdani, Darab
author_facet	Yazdani, Darab
author_sort	Yazdani, Darab
title	Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
title_short	Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
title_full	Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
title_fullStr	Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
title_full_unstemmed	Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression
title_sort	characterisation of aspergillus contaminants of milled rice and antitoxic effects of malaysian ethnomedicinal plant extracts on growth suppression
granting_institution	Universiti Putra Malaysia
publishDate	2011
url	http://psasir.upm.edu.my/id/eprint/113962/1/113962.pdf
_version_	1818586171030110208

Characterisation of Aspergillus contaminants of milled rice and antitoxic effects of Malaysian ethnomedicinal plant extracts on growth suppression

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