The storage life of packed shredded Iceberg lettuce dipped in glycine betaine solutions.

ABSTRACT

The effects of glycine betaine dip, packaging method, and storage time on the sensory quality of shredded Iceberg lettuce were first modeled using a statistical experimental design, followed by a second storage test verifying the effect of the glycine betaine treatment. Shredded lettuce was dipped in 0 to 100 mg/liter active chlorine solution and then in 0 to 1.0 mol/liter glycine betaine solution, packed in 25 microm oriented polypropylene film, 250 g per package, and stored at 5 degrees C for 8 days. Models with good predictability were created suggesting that the glycine betaine dip helped retain sensory quality, especially appearance (P < 0.05). The models also suggested that washing periods over 60 s were not needed and that the microperforation of packages should not exceed 0.31 mm2 per package. The modeled positive effect on sensory quality was verified in the second storage test (P < 0.05). The optimum glycine betaine concentration was 0.2 mol/liter. Chlorination of the first dip particularly retained appearance of packed lettuce.