Vitamin C and nitrate content in lettuce produced at Santa Maria/RS: preliminary studies

Abstract

Nitrate, vitamin C contents and yield factors were determined in samples of lettuce produced of Santa Maria/RS, Brazil. The analysis were carried out at the Laboratory of Food Science and Technology of the UFSM, in october 1998. The content of vitamin C varied from 19,2 mg.100g-' to 41,9 mg.100g-, with a mean content of 29,3 mg.100g-'. Forty percent of the samples analyzed presented leaf fresh weight lower then 200,0 g per plant, with an average of 196,2 g per plant. With regard to the leaf dry weight 30% of the samples analyzed presented values lower than 8 g per plant and an average of 9,6 g per plant. Forty percent of the samples analyzed presented less than 20 leaves per plant, with a mean of 22,7 leaves per planta. Eighty percent of the samples presented nitrate level higher than 500 mg.kg' of fresh weight (FW). The highest value of nitrate was 984,4 mg.kg' of FW and the lowest was 450,9 mg.kg' of FVV. The content of nitrate determinated on the samples are below the maximum limit established by European Community for lettuce produced on field (2500 mg.kg- 1 of FW), also below the limit permited in Germany (2000 mg.kg-' of FW) and in Austria (1500 mg.kg' of FW), indicating that plants produced on spring in Santa Maria/RS do not present risk to the human health due to nitrate content.