Kinetics of Maneb Degradation during Thermal Treatment of Tomatoes

Kontou, S; Tsipi, D; Tzia, C

dc.contributor.author	Kontou, S	en
dc.contributor.author	Tsipi, D	en
dc.contributor.author	Tzia, C	en
dc.date.accessioned	2014-03-01T01:20:42Z
dc.date.available	2014-03-01T01:20:42Z
dc.date.issued	2004	en
dc.identifier.issn	0021-8561	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16016
dc.subject	Degradation	en
dc.subject	Ethylenethiourea	en
dc.subject	Kinetics	en
dc.subject	Maneb	en
dc.subject	Pesticide	en
dc.subject	Processing	en
dc.subject	Tomatoes	en
dc.subject.classification	Agriculture, Multidisciplinary	en
dc.subject.classification	Chemistry, Applied	en
dc.subject.classification	Food Science & Technology	en
dc.subject.other	2 imidazolidinethione	en
dc.subject.other	carbon disulfide	en
dc.subject.other	maneb	en
dc.subject.other	article	en
dc.subject.other	chemical reaction kinetics	en
dc.subject.other	degradation	en
dc.subject.other	energy	en
dc.subject.other	food processing	en
dc.subject.other	gas chromatography	en
dc.subject.other	health hazard	en
dc.subject.other	high performance liquid chromatography	en
dc.subject.other	high temperature procedures	en
dc.subject.other	homogenate	en
dc.subject.other	pH	en
dc.subject.other	temperature dependence	en
dc.subject.other	tomato	en
dc.subject.other	Chromatography, Gas	en
dc.subject.other	Chromatography, High Pressure Liquid	en
dc.subject.other	Fruit	en
dc.subject.other	Fungicides, Industrial	en
dc.subject.other	Heat	en
dc.subject.other	Hydrogen-Ion Concentration	en
dc.subject.other	Kinetics	en
dc.subject.other	Lycopersicon esculentum	en
dc.subject.other	Maneb	en
dc.subject.other	Thermodynamics	en
dc.subject.other	Lycopersicon esculentum	en
dc.title	Kinetics of Maneb Degradation during Thermal Treatment of Tomatoes	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/jf030539r	en
heal.identifier.secondary	http://dx.doi.org/10.1021/jf030539r	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	The kinetics of maneb degradation in tomato homogenates at high temperatures and at two pH values (4 and 9) and the rate of formation of the toxic metabolite, ethylenethiourea (ETU), were studied. Maneb was measured as carbon disulficle by headspace gas-chromatography and ETU by high-performance liquid chromatography with photodiode array detection. First-order kinetics adequately described the degradation of maneb in tomato homogenates. The degradation rate constants exhibited an Arrhenius temperature dependence in the range from 50 to 90 degreesC and the apparent activation energy (Ea) was calculated to be 36 KJ mol(-1) in homogenates with natural pH (4). Raising temperature from 60 to 75 and to 90 degreesC, ETU formation was significantly increased. Interestingly, the selectivity toward ETU showed a downward trend when the total conversion increased at longer heating times. When the pH of the tomato homogenates was adjusted to 9, the degradation of maneb proceeded faster at both 60 and 90 degreesC. The combination of alkaline pH and the highest temperature (90 degreesC) resulted in the maximum ETU conversion rates. The results of the present study on the fate of maneb and ETU residues during tomato processing, may prove valuable in estimating potential risk from dietary exposure.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Journal of Agricultural and Food Chemistry	en
dc.identifier.doi	10.1021/jf030539r	en
dc.identifier.isi	ISI:000220039800032	en
dc.identifier.volume	52	en
dc.identifier.issue	5	en
dc.identifier.spage	1212	en
dc.identifier.epage	1219	en