TIME OF DAY AT HARVEST EFFECT ON POSTHARVEST LETTUCE QUALITY
MOCCIA, S.; FREZZA D.; CHIESA, A.
Abstract
Pre-harvest conditions such as variety, crop season
and time of day harvest influence on lettuce quality and the postharvest behaviour.
The objective of this study were to determine whether the time of day at harvest
in two types of lettuce influences on the parameters quality and losses during
the storage. Butterhead lettuce („ Kagra-mer Sommer(<) and Latin lettuce
(„ Crimor") grown open field were harvested at 6.00, 12.00 and 18.00
hr. in a test conducted between 23/10/96 and 26/12/96. After harvest four treatments
storage with each lettuce type were made: a) unwrapped material and b) material
in PD 961 EZ bag at ambiental temperature, c) unwrapped material and d) material
in PD 961 EZ bag in a chamber using a temperature similar to supermarket shelf
(8sC, HR 70%). Daily weight losses and sensory observations such as colour,
brightness, decay and freshness were measured. Results indicate significant
differences between storage periods (4, 8, 12 days) for unwrapped treatments
in both storage conditions, and for wrapped treatments only at ambiental temperature.
Weight losses were relationed with the variety, storage treatment and time of
day at harvest. Lowest losses percentage were measured in wrapped treatments
without significant differences