Screening of Escherichia coli O157:H7 contamination and nitrate content on Butterhead lettuce from market outlets

• Main Authors: Yusoff, Siti Fairuz, Tengku Muda Mohamed, Mahmud, Haron, Farah Farhanah
• Format: Article
• Language: English
• Published: Institute of Medico-Legal Publications 2018
• Online Access: http://psasir.upm.edu.my/id/eprint/73835/1/COLI.pdf; http://psasir.upm.edu.my/id/eprint/73835/; http://www.ijphrd.com/issues.html

Escherichia coli O157:H7 is classified as biological hazard that can produce a bloody diarrhea due to its toxins. While nitrate in vegetables is classified as a chemical hazard if ingested greater than limit and risk getting gastrointestinal cancer and methemoglobinaemia. A study was conducted to obtain the information on E. coli O157:H7 contamination and nitrate content in Butterhead lettuce from local suppliers. The number of colonies E. coli O157:H7 from the lettuce was enumerated using standard plate count and the nitrate content was measured using nitrate meter. From the experiment, it was found that E. coli O157:H7 contamination of Butterhead lettuce in Malaysia is still within the safe limit for the consumers while the nitrate content was distributed differently between leaf structures; midrib, outer adult leaf blade and young leaves. Lettuce midrib and outer adult leaf blade had a higher concentration of nitrate compared to the young leaves.