Effects of Food Disinfectants on Vitamin C Content of Lettuces

Abstract

Aim: This study aims to determine the changes occur in the amounts of ascorbic acid after lettuce samples are left in different concentrations of different food disinfectants. Materials and Methods: Lettuce samples in different thicknesses (1 and 2 cm) are left in distilled water (pH=6.54) and food disinfectants as chlorine (50 ppm-pH=7.38; 200 ppm-pH=8.01, calcium oxide (0.1% Calceramic®-pH=9.14), acetic acid (0.5%,2%,5%; pH=2.35,2.78;3.11) for 5 and 15 minutes. 2,6-dichlorofenolyndifenol spectrophotometric method have been used in ascorbic acid analysis. Changes in the ascorbic acid amounts of lettuces after leaving in disinfectants are expressed with respect to baseline and as percent (%) in addition to losses when waiting in distilled water. Results: When the samples were left in distilled water for 5 minutes, 23.83% loss occurred in 1 cm thick lettuce samples and 18.40% loss occurred in 2 cm thick lettuce samples. After leaving in 50 ppm concentration of chlorine for 5 and 15 minutes, an amount of losses were 24.40% and 34.72% in 1 cm thick lettuce and 20.08% and 31.71% in 2 cm thick lettuce. After waiting in 200 ppm concentration chlorine, the loss amounts increased compared to the loss amounts in 50 ppm chlorine. When the vegetables were left in 0.1% calcium oxide for 5 minutes, losses in addition to the distilled water were 39.76% in 1 cm thick lettuce and 35.41% in 2 cm thick lettuce. Ascorbic acid losses observed after the lettuce were left in acetic acid solutions (0.5%,2%,5%) were less compared to the other disinfectants. When the waiting period of all applications was increased to 15 minutes, the amounts of losses were also increased. Conclusion: When the food disinfectant is in acidic pH, the waiting period decreases and cutting thickness of lettuces increases, then the ascorbic acid retention increases relatively.