Leafy vegetables, such as lettuce ( Lactuca sativa L), have been identified as a potential source of perchlorate exposure to humans. Perchlorate is of concern because excessive amounts may impair thyroid function by inhibiting iodide uptake by the sodium iodide symporter. Perchlorate has been identified as an oxidation product in sodium hypochlorite. Dilute hypochlorite solutions are widely use...

Stored cut lettuce gradually turns brown on the cut section after several days of storage, because cutting induces phenylalanine ammonia-lyase (PAL) activity, the biosynthesis of polyphenol is promoted, and the polyphenols are oxidized by polyphenol oxidase. Here, the effect of heat shock treatment at 50 degrees C for 90 s on the quality of cut lettuce during cold storage was examined. The heat...

Background In the early 20 century, California produced only little lettuce . For 1909, Knott and Tavernetti [4] reported that lettuce was produced on 595 acres in California, which corresponded to 11% of the total U.S. acreage. Lettuce production increased dramatically in the 1920s (Figure 1). While 6,100 acres were harvested in 1919 , the harvested area reached 112,000 acres by 1930 . The mar...

Lettuce mosaic, caused by the potyvirus LMV, is a serious viral disease of lettuce crops world-wide. Beside seed control, one of the leading strategies to control LMV is the use of the recessive resistance genes mo11 and mo12. In an attempt to characterize the functional role of the translation initiation factor eIF4E in lettuce susceptibility to LMV, we cloned Ls-eIF4E cDNAs from a collection ...

Lettuce (Lactuca sativa L.) is one of the most important leafy vegetable that is consumed during its vegetative growth. The transition from vegetative to reproductive growth is induced by high temperature, which has significant economic effect on lettuce production. However, the progression of floral transition and the molecular regulation of bolting are largely unknown. Here we morphologically...

The potential for lettuce field-coring harvesting knives to cross-contaminate lettuce heads with pathogens was evaluated. Rings and blades of the harvest knives artificially contaminated with Escherichia coli O157:H7 (EHEC), were used to core three successive heads of iceberg lettuce. The coring rings and blades were inoculated by dipping into soils containing EHEC at concentration ranges of 1-...

Aims: The objective of this study was to determine the influence of mild heat treatment, storage temperature and storage time on the survival and growth of Listeria monocytogenes inoculated onto cut iceberg lettuce leaves. Methods and Results: Before or after inoculation with L. monocytogenes, cut iceberg lettuce leaves were dipped in water (20 or 50°C), containing or not 20 mg l chlorine, for ...

Lettuce and leafy greens have been implicated in multiple foodborne disease outbreaks. This study quantifies cross contamination between lettuce pieces in a small-scale home environment. A five-strain cocktail of relevant Escherichia coli O157:H7 strains was used. Bacterial transfer between single inoculated lettuce leaf pieces to 10 non-inoculated lettuce leaf pieces that were washed in a stai...

Title of Document: LOCAL LETTUCE: HEAT TOLERANT ROMAINE CULTIVARS AND VERMICOMPOST SOIL AMENDMENT TO INCREASE SUSTAINABILITY IN THE MID-ATLANTIC. Anna Wallis M.S., 2014 Directed By: Dr. Chris Walsh Plant Science and Landscape Architecture Local production of lettuce in the Mid-Atlantic utilizing heat-tolerant romaine cultivars and vermicompost soil amendment has the potential to significantly i...

Lettuce drop, caused by the soil borne pathogen Sclerotinia sclerotiorum, is one of the most common and serious diseases of lettuce worldwide. Increased concerns about the side effects of chemical pesticides have resulted in greater interest in developing biocontrol strategies against S. sclerotiorum. However, relatively little is known about the mechanisms of Streptomyces spp. as biological co...