CABI Blog

Have you ever wondered whether jam contains anything healthy? Fruits and vegetables are chock full of antioxidants and other wonderful cancer fighters, but is it all lost when you make jam? I wrote about this for Nutrition and Food Sciences Database recently because a paper in Journal of Science of Food and Agriculture has some answers. The conclusion is that jam processing does destroy much of the phenolics and antioxidants that are present in fruit but a significant amount remains.

Fruits do not keep unless preserved in some way, and preserving as jam is popular, after all it keeps at room temperature, and doesn't require much equipment to produce. I do lots of it myself. Very little research has been done into the effects of jam processing and storage on nutrients so this paper is a welcome one.

The study examined jam from strawberries, cherries, figs, apricots and oranges and recorded the phenolic compounds, anthocyanins and antioxidant activity for each as fresh fruit, as jam and after 5 months of storage as jam. They found that strawberries had the highest  amount of total phenolics, followed by cherry, apricot, fig. and orange. Strawberry also had the highest level of antioxidants and anthocyanins.

Processing reduced the phenolics between about 70-90%  depending on the jam with the losses for orange jam being the lowest. Anthocyanins were reduced by a similar percentage during processing while antioxidant losses were between 10 and 50%.

Storage didn't result in losses as large as for processing, indeed strawberry and cherry retained phenolics and anthocyanins during storage.

Before you reach for the jam pot – this research unfortunately doesn't mean jam is all that good for you -it contains a lot of sugar.

Read the paper at Effect of jam processing and storage on total phenolics, antioxidant activity, and anthocyanins of different fruits

Photo by PatriciaR