| Abstract: |
The present investigation was carried out in an effort to open a new research area for the possibility of making use of some essential oils to prepare natural biocides. For this purpose, 6 essential oils (fennel, peppermint, caraway, eucalyptus, geranium 6.1. Antimicrobial activity of essential oils:Results showed that fennel, peppermint and caraway oils gave a complete inhibition for the growth of Alternaria alternata, Penicillium italicum, Penicillium digitatum and Botrytis cinerea. On the other hand, eucalyptus, geranium and lemon oils were less e6.2. Preparation of biocides:Fennel, peppermint and caraway oils were selected for the preparing of biocides. It was obvious that emulgator B.L.M., emulgator B.L.M. + tween 20 or tween 80 were the most successful emulsifiers for the formulation of essential oils after mixing with difThe results of physico-chemical properties indicated that oils alone did not gave any emulsion in water. While, the formulated oils passed successfully through emulsion stability tests (spontaneous emulsification, cold stability and heat stability) and di6.3. Antimicrobial application of the prepared biocides.6.3.1. In vitro application of the prepared biocides:Results showed that different formulations of fennel, peppermint and caraway oils gave a complete inhibition for the growth of Alternaria alternata, Penicillium italicum, P. digitatum and Botrytis cinerea. However, all formulations and individual essentia6.3.2. In vivo application of the prepared biocides.6.3.2.1. On potato:6.3.2.1.1. Preliminary experiments:Preliminary experiment was carried out to select the most effective concentration of the formulated fennel, peppermint and caraway oils and optimum soaking period for inhibition the dry rot development on potato. In this respect, concentrations of 250, 506.3.2.1.2. Protective and therapeutic capacities.One group of each formulated oils were selected and tested with the most effective concentration and optimum soaking period (selected from the preliminary experiment). Each tested group contained five formulations from F1 to F5. The results indicated that6.3.2.2. On orange:6.3.2.2.1. Preliminary experiments:Preliminary experiment was carried out to select the most effective concentration of the formulated fennel, peppermint and caraway oils and optimum soaking period for inhibition the green rot development on orange fruits. In this regard, concentrations of6.3.2.2.2. Protective and therapeutic capacities.One group of each essential oil were selected as a representative formulation group and each contained 5 formulations. The most effective concentration and the optimum soaking period were selected from the preliminary experiment. The results showed that g6.4. Interaction effect of biocides and gamma radiation.The effect of combined treatment of biocides and different doses of gamma radiation on potato tubers and orange fruits for extending its shelf life during storage for periods of 150 and 75 days, respectively were studied and the obtained results could be 6.4.1. Potato:1- The results showed that formulated fennel, peppermint and caraway oils delayed the decay of tubers up to 90 days. Also, gamma radiation delayed tubers decay as compared with control. In addition, the interaction of formulated oil and different doses of2- Also, inhibition of sprouting during storage was observed as a result of combination treatments.3- The weight loss percentage in treated potato was less than that of control samples.4- The results of biochemical analysis of potato tubers indicated that the combination treatments were effective for maintaining the chemical constituents (total soluble sugars, starch content, phenol content, indole acetic acid content and total free ami6.4.2. Orange:1- The observed data demonstrated that the application of different formulated volatile oils either with or without different doses of gamma radiation extended the storage ability of orange fruits and caused a decrease in a percentage of decay as compared2- Also, the percentage of weight loss was decreased as a result of treatments in comparison with control.3- Values of total soluble solids, titratable acidity, vitamin C and total soluble sugars contents of the treated fruits were compared to the untreated ones.
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