Location: Crop Improvement and Protection ResearchTitle: Insight into deterioration of fresh-cut lettuce in modified atmosphere packaging
|PENG, HUI - University Of California|
|LAVELLE, DEAN - University Of California|
|TRUCO, MARIA - University Of California|
|MICHELMORE, RICHARD - University Of California|
Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2020
Publication Date: 8/12/2020
Citation: Peng, H., Lavelle, D., Truco, M.-J., Michelmore, R., Simko, I. 2020. Insight into deterioration of fresh-cut lettuce in modified atmosphere packaging. American Society for Horticultural Science Annual Conference, August 9-13, 2020, Orlando, Florida.
Technical Abstract: Fresh-cut lettuce, the major component of ready to eat salads, is usually stored in modified atmosphere packaging (MAP) bags to avoid rapid discoloration and dehydration. However, even in MAP deterioration may start within a few days after processing. Therefore, detailed information about deterioration process of fresh-cut lettuce in MAP is important to the industry. This study documented that high temperature, physical wounding, hexanal, and ethanol could accelerate deterioration of fresh-cut lettuce in MAP. Reducing humidity inside MAP bags can slow down the deterioration process, while leaf maturity and the ratio of tissue to package volume showed a genotype-dependent response. Oxygen rather than carbon dioxide or ethylene was the major atmosphere component associated with deterioration. The optimal oxygen level for maintaining fresh-cut lettuce quality was cultivar dependent. Under low oxygen level (< 2%), cultivars with genetic predisposition for rapid deterioration displayed faster deterioration and respiration than cultivars known for slow deterioration. Many respiration related genes had consistently higher expression in the rapidly deteriorating cultivar La Brillante than in the slowly deteriorating cultivar Salinas 88, in the early stages of deterioration. Deterioration rates of F1 hybrids developed from reciprocal crosses between ‘Salinas 88’ and ‘La Brillante’ fell between those of the parental lines, suggesting an additive effect of qSL4, the locus previously identified as the main genetic factor consistently associated with the rate of deterioration in diverse populations. The position of this locus was placed into a region of 5.1 Kb on linkage group 4 by fine-mapping using a F2 population from a cross between RIL79 (a slowly deteriorating recombinant inbred line) and ‘La Brillante’. This region was predicted to carry two transcripts, a putative gene encoding a toll/interleukin-1 receptor (TIR) domain-containing protein and a non-coding RNA with unknown function. New knowledge regarding major environmental, physiological, and genetic factors associated with the deterioration of fresh-cut lettuce can be used to improve shelf life and postharvest quality of lettuce salad in MAP.