I have only done one study where we separated the components and determined respiration rates and shelf-life of individual types of leafy greens.  Here is a link to the 

Russet spotting is strictly a visual defect.

Probably there is no single answer, since there are always details in a particular handling system that could make a difference.

As with many postharvest issues, there is no one single solution.  In this case, lettuce variety selection, maturity at harvest, pre-process handing and cooling, processing line conditions (te

I have only done one study where we separated the components and determined respiration rates and shelf-life of individual types of leafy greens. Here is a link to the paper from that study.

We have done some storage tests on packaged lettuce products. The modified atmospheres that develop in the bags to maintain visual appearance may cause the development of off-odors.