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Inactivation of A. ochraceus spores and detoxification of ochratoxin A in coffee beans by gamma irradiation.
J Food Sci. 2012 Feb; 77(2):T44-51.JF

Abstract

Ochratoxin A (OTA) produced in food by Aspergillus ochraceus is known to cause adverse health effects. Among the plantation products, green coffee beans are prone to fungal attack and get contaminated with OTA frequently. A fungal strain isolated from green coffee beans was characterized by morphological analyses as well as internal transcribed spacer (ITS) and 5.8S rDNA sequencing, turned out to be A. ochraceus, however, nontoxigenic. Hence, additional strains of A. ochraceus were procured and characterized for toxin production. Presterilized green coffee beans were spiked with a toxigenic strain and treated with gamma radiation. Minimum inhibitory dose (MID) of gamma radiation for 10(4) and 10(8) spores of A. ochraceus strain per 10 g of green coffee beans was found to be approximately 1 and approximately 2.5 kGy, respectively. The radiation treatment (10 kGy) almost degraded the preformed or in vitro added OTA (50 ppb) in coffee beans. OTA degradation was found to be enhanced with increase in moisture content. Cytotoxicity in terms of cell viability was found to be reduced significantly for radiation treated OTA in MTT [3-(4,5-dimethylthiazole-2yl)-2,5-diphenyl tetrazolium bromide] assay as well as flow cytometric analysis when studied using human intestinal epithelial (Int-407) cells. Similar finding was also observed with E. coli MG1655 cells. Thus the inclusion of gamma radiation treatment in the postharvest processing chain of green coffee beans could help in eliminating toxigenic fungi as well as destroying preformed OTA without affecting the sensory attributes.

PRACTICAL APPLICATION

In general, mycotoxins including ochratoxin A (OTA) are highly stable to detoxifying agents. Green coffee beans are prone to fungal attack and could get frequently contaminated with the OTA due to improper drying or rehydration during storage. Gamma radiation processing of green coffee beans was found to eliminate the A. ochraceus spores as well as inactivate OTA without affecting its sensory attributes. Thus inclusion of gamma radiation in the postharvest processing chain of green coffee beans would be very useful for consumer safety and coffee trade.

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Publisher Full Text (DOI)

Authors+Show Affiliations

Kumar S
Food Technology Div, Bhabha Atomic Research Centre, Mumbai 400 085, India.
Kunwar A
No affiliation info available
Gautam S
No affiliation info available
Sharma A
No affiliation info available

MeSH

Aspergillus ochraceusCell LineCell SurvivalCoffeeConsumer Product SafetyEscherichia coliFood ContaminationFood MicrobiologyHumansIntestinesOchratoxinsSpores, Fungal

Pub Type(s)

Journal Article

Language

eng

PubMed ID

22339551

Citation

Kumar, Sanjeev, et al. "Inactivation of A. Ochraceus Spores and Detoxification of Ochratoxin a in Coffee Beans By Gamma Irradiation." Journal of Food Science, vol. 77, no. 2, 2012, pp. T44-51.
Kumar S, Kunwar A, Gautam S, et al. Inactivation of A. ochraceus spores and detoxification of ochratoxin A in coffee beans by gamma irradiation. J Food Sci. 2012;77(2):T44-51.
Kumar, S., Kunwar, A., Gautam, S., & Sharma, A. (2012). Inactivation of A. ochraceus spores and detoxification of ochratoxin A in coffee beans by gamma irradiation. Journal of Food Science, 77(2), T44-51. https://doi.org/10.1111/j.1750-3841.2011.02572.x
Kumar S, et al. Inactivation of A. Ochraceus Spores and Detoxification of Ochratoxin a in Coffee Beans By Gamma Irradiation. J Food Sci. 2012;77(2):T44-51. PubMed PMID: 22339551.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Inactivation of A. ochraceus spores and detoxification of ochratoxin A in coffee beans by gamma irradiation. AU - Kumar,Sanjeev, AU - Kunwar,Amit, AU - Gautam,Satyendra, AU - Sharma,Arun, PY - 2012/2/21/entrez PY - 2012/2/22/pubmed PY - 2012/6/19/medline SP - T44 EP - 51 JF - Journal of food science JO - J Food Sci VL - 77 IS - 2 N2 - UNLABELLED: Ochratoxin A (OTA) produced in food by Aspergillus ochraceus is known to cause adverse health effects. Among the plantation products, green coffee beans are prone to fungal attack and get contaminated with OTA frequently. A fungal strain isolated from green coffee beans was characterized by morphological analyses as well as internal transcribed spacer (ITS) and 5.8S rDNA sequencing, turned out to be A. ochraceus, however, nontoxigenic. Hence, additional strains of A. ochraceus were procured and characterized for toxin production. Presterilized green coffee beans were spiked with a toxigenic strain and treated with gamma radiation. Minimum inhibitory dose (MID) of gamma radiation for 10(4) and 10(8) spores of A. ochraceus strain per 10 g of green coffee beans was found to be approximately 1 and approximately 2.5 kGy, respectively. The radiation treatment (10 kGy) almost degraded the preformed or in vitro added OTA (50 ppb) in coffee beans. OTA degradation was found to be enhanced with increase in moisture content. Cytotoxicity in terms of cell viability was found to be reduced significantly for radiation treated OTA in MTT [3-(4,5-dimethylthiazole-2yl)-2,5-diphenyl tetrazolium bromide] assay as well as flow cytometric analysis when studied using human intestinal epithelial (Int-407) cells. Similar finding was also observed with E. coli MG1655 cells. Thus the inclusion of gamma radiation treatment in the postharvest processing chain of green coffee beans could help in eliminating toxigenic fungi as well as destroying preformed OTA without affecting the sensory attributes. PRACTICAL APPLICATION: In general, mycotoxins including ochratoxin A (OTA) are highly stable to detoxifying agents. Green coffee beans are prone to fungal attack and could get frequently contaminated with the OTA due to improper drying or rehydration during storage. Gamma radiation processing of green coffee beans was found to eliminate the A. ochraceus spores as well as inactivate OTA without affecting its sensory attributes. Thus inclusion of gamma radiation in the postharvest processing chain of green coffee beans would be very useful for consumer safety and coffee trade. SN - 1750-3841 UR - https://www.unboundmedicine.com/medline/citation/22339551/Inactivation_of_A__ochraceus_spores_and_detoxification_of_ochratoxin_A_in_coffee_beans_by_gamma_irradiation_ L2 - https://doi.org/10.1111/j.1750-3841.2011.02572.x DB - PRIME DP - Unbound Medicine ER -