Brown, mushy banana slices can ruin the appeal of a vibrant fruit salad and make a banana cream pie look more like a mud pie. Enzymes in bananas react with air, causing browning on exposed surfaces. The fruit's peel provides natural protection, but once you bare the creamy flesh, you must act fast to keep it fresh. Although a brown banana doesn't pose a hazard, it isn't very appetizing. Brush the slices with lemon juice and store them in airtight containers to slow the enzyme action and minimize any color change.
Peel and cut bananas into slices. Wait until the last possible minute before serving, if possible, and work quickly.
Squeeze the juice of a lemon into a small bowl. Dip a pastry or basting brush into the lemon juice repeatedly as you swipe it gently across each cut surface and around the edge of each slice.
Position an oversize piece of plastic wrap or aluminum foil inside a food-storage container, pressing it into the bottom but letting the excess hang over the edges. Lay the banana slices in a single layer on the wrap or foil. Package large quantities in layers with an additional sheet of wrap or foil between each one.
Fold the wrap around the bananas, covering them completely, and seal the container tightly. Store the banana slices in the refrigerator for up to four days.