Impact of cooling temperature and wrapping on storage quality of lamb's lettuce (Valerianella locusta L.)

Lamb's lettuce (Valerianella locusta L.) is occasionally stored by the growers before delivering to the vegetable auctions in anticipation of better prices. The aim of this experiment was to optimize the storage methods that can be used at the level of the grower. Plants from commercial growers were stored at 1 and 4°C. Half of the storage boxes at each temperature were wrapped in shrink-film. At 5, 7, 14 and 21 days after storage the plant quality was determined by a panel of experts. Withering of the plants was higher without wrapping. Wrapping combined with higher temperatures reduced withering but favoured leaf rot. However, the plants that were wrapped and stored at 1°C still met the requirements of the retail after 21 days. Withholding the wrapping application until plant temperature has reached the temperature set point could optimize the storage quality because the wrapping slows down the cooling process. Nevertheless, storage by the grower beyond two weeks is not advised. Yellowing of the leaves becomes an issue and as this process accelerates with higher temperatures, problems could occur further down the distribution chain.