Lettuce (Lactuca sativa) cv. smooth, after being selected and washed, was cleaned with chlorine water at 5ºC, with 150ppm of free chlorine and pH adjusted to 6.0, rinsed and centrifuged for 8 minutes at 2200rpm. Right after, the lettuce leaves were packaged in plastic bags made of nylon poli 5 layers, with and without modified atmosphere (N2 having 20ppm of O2 and 20ppm of maximum moisture) and stored at 4ºC. During 5 days there were pH, soluble solids concentration measurements and acid analysis (mL NaOH 0,1M/100g lettuce leaves). The products became acid, detectable by a pH decrease in both atmospheres. A raise in acidity was shown, being the highest marks for the control samples (without modified atmosphere) and there was no soluble solids variation. Results have shown that technological progress is being reached aiming to improve the vegetable's quality and shelf life.
lettuce; minimally processed vegetables; modified atmosphere
