Decontamination of pesticide residues on fruits and vegetables Preferably, the samples used in the treatment RAC study must contain a field receiving quantifiable residues as close as possible to the MRL, so that measurable residues are obtained, and transfer factors for various processed products can be determined. A transfer factor gives the ratio of the concentration of residues in processed products than the RAC. For example, if the residue concentration is 0.5 mg / kg in olives and 0.2 mg / kg in olive oil, transfer factor is 0.2/0.5 = 0.4. A factor 1 (= concentration factor) indicates a concentration effect of treatment procedures. Improve residues or by increasing the application rate, shorten the pre-harvest interval (PHI) or by removing the RAC with the active ingredient and its metabolites in vitro is not, as a general rule, desirable. Doping is acceptable only if the residues CARs can be shown to consist only of surface residues. However, PHI in certain cases, especially where residues in the RAC are near the analytical limit of determination of the treatment on the ground, at inflated prices or shorter is recommended to obtain sufficient residue levels for studies treatment.
The first step in the household or commercial food processing is the preparation of food using various mechanical processes, such as the removal of damaged or soiled or parts of plants, washing, peeling, trimming, peeling or . This often leads to a significant decrease in the amount of pesticide residues in other edible parts (Petersen et al. 1996; Celik et al. 1995; Schattenberg et al, 1996)..
WASHING
household washing procedures are normally carried out with running or standing water at moderate temperatures. Detergents, chlorine or ozone can be added to the wash water to improve the efficiency of the washing procedure (Ong et al., 1996). If necessary, several washing steps can be made accordingly.
The effects depend on physico-chemical pesticides, such as water solubility, hydrolysis rate constant volatility and the octanol-water (Pow), in collaboration with the actual physical location of residues; wash lead to a reduction of hydrophilic residues located on the surface of cultures. Moreover, the temperature of the wash water for washing and type has an influence on the level of residues. As noted by Holland et al. (1994), the hot wash and the addition of detergents are more effective than cold water washing. Washing coupled with a slight friction at the hand under tap water for 1 min removes pesticide residues significantly (Barooah and Yein, 1996). Systemic and lipophilic pesticide residues are not removed significantly by washing.
Table (1) shows examples of the effects of washing on the levels of residues of different pesticides applied to fruits and vegetables.
PEELING
The outer leaves of vegetables often contain residues of pesticides applied during the growing season. Therefore, peeling or trimming procedures to reduce the levels of residues in leafy vegetables. Peeling of roots, tubers and bulb vegetables with a knife is a common household. Many examples show that most of the residues located in or on the skin. Peeling the CCR can remove more than 50% of pesticide residues in commodities. Thus, the removal of the skin achieved almost complete removal of residue, leaving little in the edible parts. This is particularly important for fruit that are eaten with their peels, like bananas or citrus fruits. Reynolds (1996) showed that peeling or reduced size of the core residues of chlorfenvinphos, primiphos-methyl, quinalphos triazophos resulting from a transfer factor of 0.2. However, the skin peeling business processes can be used as feed or for TH.
Posted on May 25, 2010.
