Marmalade

Marmalade is a sweet, tangy fruit preserve made from the juice and peel of citrus fruits boiled with sugar and water. The well-known version is made from bitter orange, but other citrus fruits such as lemons and limes can also be used. Bitter orange is mostly used in marmalade because of its high pectin content, which gives a thick consistency to its marmalade. In addition, the balance of acid and... (Wikipedia)