Folia Horticulturae

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Quality changes in lettuce heads stored in a controlled atmosphere. II. Phenolic metabolism and ethylene evolution

Maria Leja, Anna Mareczek, Stanisław Rożek

Department of Plant Physiology
Faculty of Horticulture, Agricultural University
29 Listopada 54, 31-425 Kraków, Poland

Three weeks of storage of two cultivars of ground lettuce in a controlled atmosphere (CA) at 1°C (3% CO2 : 5% O2 and 10% CO2 : 11% O2) followed by its 24 hr exposure to air (5°C) caused a considerable increase in total phenols and activity of polyphenoloxidase and peroxidase. The ascorbic acid content fell drastically by 90% of its initial value, irrespective of the gas composition of CA. A high initial level of endogenous ethylene was reduced significantly after storage in CA, except for the cultivar Prado treated with 10% CO2 : 11% O2. A controlled atmosphere with 10% CO2 : 11% O2 caused a slight incraese in cell membrane permeability.

Low temperature seemed to be the main factor inducing metabolic changes although, in the case of peroxidase activity, ethylene evolution and cell membrane permeability the gas composition of CA also had a significant effect.

Leja M., Mareczek A., Rożek S., 1996. Quality changes in lettuce heads stored in a controlled atmosphere. II. Phenolic metabolism and ethylene production. Folia Horticulturae 8/2: 83-93.