Diffusion and sorption of allyl isothiocyanate in the process of fumigation of maize

Abstract

The purpose of this work was to evaluate the transport of allyl isothiocyanate (AITC) by means of the sorption mechanism and the diffusion of AITC through maize grains. The experimental procedure to study the sorption mechanism was conducted by injection of AITC in glass flasks containing the grains. Kinetic models of zero, first and second order were fitted to AITC concentration data, with the purpose of determining the sorption rate (k). For the study of diffusion, a prototype was utilized in which the components are a gas chamber and a cylindrical column in which the grains were stored. At the interval of 110 min, samples in the chamber and in the column were collected, which were immediately injected into the gas chromatograph. In order to determine the effective diffusion coefficient (D ef ) of AITC through maize grains, the term referring to the sorption rate was added to the diffusion equation. The kinetic model of the first order was the one that best fitted the experimental data for the sorption mechanism, and k was 6.26 x 10 -4 s -1 . The D ef of AITC through grains was 7.2 x 10 -3 cm 2 s -1 . It was concluded that the transport of AITC through maize grains is slow, due to the low value of D ef and high sorption rate of this component by the grains.

Response of Aspergillus niger Inoculated on Tomatoes Exposed to Vapor Phase Mustard Essential Oil for Short or Long Periods and Sensory Evaluation of Treated Tomatoes

“…Phase on Inoculated Tomatoes Treated for Short Periods of Time. Since mustard EO had been previously reported to be extremely effective in preventing mold growth [8,[23][24][25][26], selected additional experiments were conducted: inoculated tomatoes were prepared as described before and the previously determined MIC was used to evaluate the efficacy of mustard EO in vapor phase when applied for short periods of time. In the first experiment, MIC, double MIC (2M), and triple MIC (3M) of mustard essential oil were poured on the filter paper, placed in the plastic containers, sealed with Parafilm, and exposed for 1, 2, 4, or 24 h; after these treatments, the tomatoes were placed in clean and sealed containers without EO.…”

Fumigant toxicity of mustard essential oil and its main compound alone and combinations with modified atmosphere treatments against Tribolium confusum du Val., 1863 (Coleoptera: Tenebrionidae)

“…Several studies have shown fumigant action of various essential oils and their compounds against some stored-product insects (Shaaya et al, 1997;Huang et al, 2000;Tunç et al, 2000). A number of studies showed that mustard essential oil and its major component, allyl isothiocyanate, have high toxicity against both Sitophilus zeamais (Motschulsky, 1855), Tribolium confusum du Val., 1863 (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (Fabricius, 1792) (Worfel et al, 1997;Tsao et al, 2002;Paes et al, 2011), indicating their potential use in protecting grain and other stored products. Paes et al (2011) reported that the vapor of mustard essential oil resulted in high mortality of all life stages of S. zeamais.…”

“…A number of studies showed that mustard essential oil and its major component, allyl isothiocyanate, have high toxicity against both Sitophilus zeamais (Motschulsky, 1855), Tribolium confusum du Val., 1863 (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (Fabricius, 1792) (Worfel et al, 1997;Tsao et al, 2002;Paes et al, 2011), indicating their potential use in protecting grain and other stored products. Paes et al (2011) reported that the vapor of mustard essential oil resulted in high mortality of all life stages of S. zeamais. However, there were significant differences in toxicity of mustard essential oil to its life stages.…”

“…Several studies revealed that mustard essential oil and its major component, allyl isothiocyanate, had high fumigant toxicity against stored grain insects (Worfel et al, 1997;Tsao et al, 2002;Paes et al, 2011) and potential use for controlling stored grain insects. However, the problems regarding to decrease in the efficacy of mustard essential oil and its major component due to requiring their high toxicity values and exposure times to obtain the complete mortality of stored-product insects and a possible weak penetration power in bulk commodity limited to be potential alternative to current fumigants (especially phosphine) for controlling stored-product insects.…”

Computational Fluid Dynamics (CFD) simulating heated air from wood burning inside a poultries barn

“…O3, CO2) (PAES et al, 2011), as well as studies on pressure, temperature and speed distribution of air and fuel mixture in gas furnaces or burners , and others. Therefore, this study aimed to evaluate the efficiency of a firewood furnace air-heating system through simulation in the CFD device for a poultry house interior.…”