Soak berries in water and vinegar, dry in a salad spinner and store in a partially sealed, towel-lined bowl. They’ll stay mold-free in the fridge for up to seven days.
Cut an inch from the bottom of the stalks, then store upright in a container of room-temperature water. Cover the tops of the asparagus with a plastic bag and refrigerate.
Immediately after slicing apples, soak in a solution of 1/8 cup table salt in one quart of water per apple. Or soak in any acidic solution, such as lemon or orange juice—either salt or acid will prevent the apple from oxidizing. Rinse under cold water before storing.
To slow down the browning (oxidation) of sliced avocados, place the slices in a bowl on top of some onion slices. It’s probably the sulfur in onions that helps preserve the avocados.
My Take on the suggestions: I’ve tried all except the avocados this last week, and they all work, even with delicate red raspberries. I don’t have a salad spinner to dry them, so I keep a fluffy terry towel near the sink, gently roll fruit in it and let it sit for an hour or so before storing in the fridge.
To dry salad greens after washing, I lay the greens between two bath-size terry towels, gently roll, and place in the washing machine on Spin Dry. Nothing bruises, and the salad fixings don’t turn to mush in the fridge before I use them up.
Source: Sierra Club Insider, September 17-20, 2012