Before NEW treatment leaves were evaluated for total
mesophilic aerobic bacteria and pseudomonads by plating decimal
dilutions of sample onto PCA and Pseudomonas Selective Agar respectively. Overcome 3 h, a lot
of 100 g of leaveswaswashed for 2 min in 1L of NEW or sterile tap water (1L) at 4 C.
Lettuce leaves not contaminated with P. chicorii I3C and washed
with sterile water were used as a control. After dipping treatments,
leaves were dried using a vegetable centrifuge and packed, under
passive modified atmosphere, in 30 40 cm polyethylene bags. The
samples were stored for 14 days at 4 C. Growth kinetics of total
mesophilic bacteria and Pseudomonadaceae were monitored during
cold storage. During cold storage the appearance of spoilage
symptoms as well as discolorations were monitored on both
inoculated and control lettuce leaves. The evaluation of leaf surface
browning index was based on a scale from 1 to 5 (Rico et al., 2008),
where 1 ¼ no browning, 3 ¼ moderate/vascular bundles reddishbrown
and 5 ¼ severe browning for individual leaves. The assay
was repeated three times measuring the browning index independently
for each trial on three different bags (N ¼ 9).