Why bagged salad mix turns brown faster when shredded carrots/ cabbage are added?

My supervisor and I were discussing this the other day, and frankly, we can't figure it out. Maybe we're overlooking something obvious. Any and all insights are welcome!!! [img]null[/img]

[logose]

Lettuce and Carrots need a higher humidity (98-100%) than cabbage(90%). So cabbage will deterioate faster. Also cabbage gives off ethylene gas and causes other veggies to go bad quicker than normal. The carrots are affected too. They get bitter and start going bad.
Also the carrots have a higher sugar content than the other vegetables and this could contribute to the overripening of lettuce

Thank you so much for your help. This has been driving my supervisor and I absolutely crazy!!! Merci mille fois!!!

[CampChef]

Ethylene is definitly the killer. I have always had an ethylene chart posted in any kitchen I run. I get them from the PMA (Produce Marketing Assoc.) If you follow ethylene storage guidelines, you can get all your produce to keep better.

Every time I cut my lettuce with a knife at home, it turns brown around the edges. If I tear it off the head it stays green. This tells me that the blade makes it turn brown faster.
Mass produced lettuce is definately cut with a blade. I believe that is why it turns brown after opening.

I have torn lettuce and mixed it with cabbage and carrots and it lasts alot longer than the bags I buy in the store.

Hope this helps!