To deliver berries after picking that have the maximum amount of vitamins and antioxidants is a very hard thing to do.
Two physical processes are mainly responsible for loss of vitamins and antioxidants: the natural decomposition of berries after picking from the host plant, and drying out.
For example, raspberries’ rate of decomposition is eight (8) times smaller at near 0oC than at 20oC. This is the reason that we place picked berries in the package and then in a cooler while in the field, then flash-cool them in the refrigeration room, and deliver them in coolers to retailers that store and sell them from refrigerators.
In terms of drying out, raspberries lose water 35 times faster at 25oC and 30% relative humidity than at 0oC and 90% relative humidity. In harvesting, we first evaporate any dew or raindrops in the refrigeration room, and then maintain a high humidity. The other purpose of the closed box to hold the berries is to maintain high humidity. But, at high humidity fungus starts growing. This is why harvested berries that are delivered ripe must be consumed within 1-2 days, before the fungus starts eating them. We even label each box with a date picked stamp.
Light is another cause of decomposition and drying out. It is just common sense to protect berries from light after picking. This is why all our berry boxes are closed to shield berries from light.
As far as the amounts of vitamins and minerals in berries, you can find numerous sources of information on this. For your convenience, we have listed one source in the references section.