To keep banana from turning brown in banana pudding you can use a few effective method.

One, lemon or lime juice.

Toast banana sliced in a small amount of lime or lemon juice.

The citric acid help prevent oxidation which cause browning.

Two, pineapple juice.

Pineapple juice also works well to prevent browning and adds a subtle sweetness to the bananas.

Three, ascorbic acid.

Sprinkle ascorbic acid, vitamin C powder, on the banana.

This natural preservatives slow down the browning process.

Four, cover immediately.

Ensure that the pudding covers the banana slice entirely.

Exposure to air accelerates browning, so keep them submerged helps.

Five, plastic wrap.

Place plastic wrap directly on the surface of the pudding to minimize air contact.

This method can help keep your banana look fresh and appealing in your banana pudding.