Step 1

Wash four 1-cup plastic or freezer-safe containers with hot, soapy water. Dry thoroughly.

Step 2

Grate outer zest from oranges and set aside. Peel off and discard white membrane from oranges and section the fruit; discard any seeds. In a food processor, combine orange zest and orange sections; cover and process until orange is in small pieces.

Step 3

In a wide-bottomed microwave-safe 2-1/2-qt. bowl, combine the pineapple, sugar, lemon juice and orange mixture. Microwave, uncovered, on high for 2 to 2-1/2 minutes; stir. Heat 2 minutes longer (edges will be bubbly); stir. Microwave for 1-1/2 to 2 minutes or until mixture is bubbly in center; stir. Heat 2 minutes longer; stir. Cool for 10 minutes.

Step 4

Immediately fill all containers to within 1/2 in. of tops. Wipe off top edges of containers. Cool to room temperature, about 1 hour.

Step 5

Cover and let stand at room temperature 4 hours. Refrigerate up to 3 weeks or freeze up to 1 year. Thaw frozen marmalade in refrigerator before serving.