Chlorine and ozone washes for pesticide removal from apples and processed apple sauce

The effectiveness of chlorinated and ozonated water dips in the dissipation of azinphos-methyl, captan and formetanate hydrochloride in solution and on fresh and processed apples was examined. All three pesticides in model systems solution decreased 50-100% with chlorine and ozone treatment. Captan and formetanate-HCl were both rapidly degraded in 50 and 500 mg liter(-1) chlorine solutions at pH 7 and 10.7. Ozonation was also effective in degrading the pesticides. Rate of degradation of the pesticides generally increased at higher pH and temperature. Pesticide residues on fresh apples and in processed products were also reduced by chlorine and ozone washes; chlorine (500 mg liter(-1)) being the most effective wash treatment. Ozone wash at 0.25 mg liter(-1) was not as effective owing to its low concentration, its instability in water and the high organic content of the wash water.