Effects of ozone fumigation treatment on the removal of residual difenoconazole from strawberries and on their quality

Abstract

The effect of ozone fumigation on the reduction of difenoconazole residue on strawberries was studied. Strawberries were immersed in 1.0 L of aqueous solution containing 400 μL of the commercial product (250 g L(-1) of difenoconazole) for 1 min. Then, they were dried and exposed to ozone gas (O3) at concentrations of 0.3, 0.6 and 0.8 mg L(-1) for 1 h. The ozone fumigation treatments reduced the difenoconazole residue on strawberries to concentrations below 0.5 mg kg(-1), which corresponds to a 95% reduction. The strawberries treated with ozone and the control group, which was not treated with ozone, were stored at 4°C for 10 days. Some characteristics of the fruit were monitored throughout this period. Among these, pH, weight loss and total color difference did not change significantly (P > 0.05). The fumigation with ozone significantly affected the soluble solids, titratable acidity and ascorbic acid content (vitamin C) of the strawberries preventing a sharp reduction of these parameters during storage.

Determination of Haloxyfop-Methyl, Linuron, and Procymidone Pesticides in Carrot Using SLE-LTP Extraction and GC-MS

“…Vieira, Neves, and Queiroz (2007), obtained contradictory results regarding the solvent extractor volume, in which the increase of the proportion of the solvent acetonitrile volume in relation to the sample volume, from 1:1 to 1:2 (v/v) (sample/acetonitrile), increased the extraction yield from 11 % to λ-cyhalothrin, and 7 % for cypermethrin in water by liquid-liquid extraction with partition at low temperature (LLE-LTP). However, for Heleno et al (2014a), who optimized the method in terms of better chromatographic response (area), the best ratio between the sample mass and the volume of the solvent acetonitrile was 1:1 (m/v). …”

“…However, Heleno et al (2014b) reported that the agitation time on the agitator table significantly affected the difenoconazole extraction by SLE-LTP in strawberry. Heleno et al (2014a) and Freitas et al (2014) also evaluated the effect of freezing time on the chromatographic response of pesticides. Heleno et al (2014b) observed that there was no influence on the chromatographic responses when the freezing time ranged between 5 and 12 h. However, Freitas et al (2014) achieved results, in that the freezing of 3 h provided better chromatographic responses (areas) of pesticides in corn through SLE-LTP.…”

“…The variables were studied at two levels (Table 1), and the analyses were performed in duplicate. The levels of the three variables used in the factorial planning have been previously mentioned by Heleno et al (Heleno et al 2014a) and Sousa et al (2014). The effects of each variable and the interactions between the variables in the haloxyfop-methyl, linuron, and procymidone extraction were calculated using the Statistica 6.0 software (StatSolft).…”

“…This technique presents some advantages in relation to traditional techniques, such as practicality, low number of steps, a small amount of sample and organic solvents, as well as being reliable and selective. The use of SLE-LTP has been described in the literature for the extraction of pesticides in foods such as lettuce (Costa et al 2015), corn (Freitas et al 2014), strawberry (Heleno et al 2014a), pineapple (Morais et al 2014), egg (Sousa et al 2014), etc., but no specific application of this method has been found for the extraction of pesticide residues in carrot. The technique is based on the partition of analytes between the aqueous and organic phase resulting from temperature lowering (−20°C).…”

Investigation of the effect of inlet radius on the response time of a transmission type ozone sensor

“…It is now been considered for the removal of pesticide left over in strawberry [4] and the removal of Bisphenol-A from Water [5]; thus it is essential to improve on its detection because of its rise in utilization and also because of the side effects associated with undue exposure to its toxicity. Whereas loss of consciousness or even death is the consequence of exposure to 500 to 1000 parts per million (ppm) of H 2 S [6], in comparison the safe exposure limit for O 3 is 0.075ppm for 8 hours per day [7].…”