What is the cellular activity behind massaged greens? Most recipes I have seen and used call for greens (kale, chard, collard, turnip, beet, etc) to be massaged in salt and/or lemon juice (or other acidic liquid) for 3-5 minutes, resulting in a dense leafy salad. The preparation is fantastic as it takes away the sharpness of raw greens while keeping them raw, and in a fraction of the time. 

As the textural and taste characteristics are more akin to cooked greens (less strong in flavor, crisp but not tough to the tooth) than eating them raw, I would like to know how massaging greens works at a cellular level to achieve these results.


What happens to the greens to affect this change?
Is the physical manipulation what causes the change?
Does the addition of salt or vinegar or lemon juice actually have a chemical or physical effect, or are these elements to benefit the flavor?
The physical massaging of the greens starts to break down the cell walls (made of mainly cellulose in plants), rendering the greens more tender. The addition of salt could be to help draw our more moisture from the greens, or it could just be for seasoning like vinegar or lemon juice.