In this chapter, the effect of processing fruit jams on the active components was evaluated. The results showed that fresh fruit characteristics changed during processing and after storage. Water content changed due to boiling and adding pectin into fruit jam, also fiber content was lost during separation steps such as peeling, filtration, or stem removal. The vitamins and minerals, water-soluble vitamins, and fat-soluble vitamins are susceptible to oxidation and can be lost during cooking by leaching into the cooking liquid. In addition, phenolic compounds, antioxidant and flavonoid components were affected by light, pH, temperature, and added pectin into the jam during processing of all fruits and during storage at different temperatures, as well as oxygen availability under many conditions. In spite of the reduction in these valuable compounds, jam processing retained good amounts of them during storage.