Effect of mechanical damage of greenhouse lettuce on some biochemical processes occurring in it during storage
Maria Leja, Anna Mareczek
Department of Plant Physiology
Faculty of Horticulture, Agricultural University
29 Listopada 54, 31-425 Kraków, Poland
The effect was investigated of mechanical damage such as
"squeezing" and "chopping" of greenhouse lettuce
stored at high (20°C, 4 days) and low (5°C, 7 days) temperature on
phenolics, polyphenoloxidase, and peroxidase activity, free amino acids,
ethylene production, and cell membrane permeability.
A considerable increase in total phenols, enzyme activity and amino acids content was found during
the storage of lettuce, irrespective of the storage temperature. In the
autumn experiment a slight dominance of polyphenoloxidase and peroxidase
activity in wounded lettuce leaves as compared with intact onces was
observed. The increase in free amino acids in damaged lettuce was higher
than in intact heads, particularly in lettuce stored at high temperature.
A rapid ethylene production was noted just after damage, significantly higher in wounded leaves than in
intact ones. The membrane permeability of lettuce grown in the autumn
cycle, measured either after wounding or during storage was drastically
higher in damaged lettuce leaves than in intact ones. Lettuce cultivated
in the spring cycle was significantly less sensitive to wounding than that
grown in autumn.
Leja M., Mareczek A., 1995. Effect of mechanical damage of greenhouse lettuce on
some biochemical processes occuing in it during storage. Folia Horticulturae 7/1: 75-89.