How does temperature affect the concentration of flavonoids in orange juice?
Orange juice is often subjected to temperature variation during processing, pasteurization, storage and refrigeration at 4$^{\circ}$C. According to some research, there appears to be a dramatic decrease in the concentration of certain flavonoids at storage temperatures especially above 20$^{\circ}$C.

A variety of flavonoids found in orange juice includes didymin, eriocitrin, hespertin, narirutin, poncirin, apigenin and neoeriocitrin.

Effective analytical methods used to identify and quantify individual flavonoids include gas chromatography mass spectroscopy (GCMS) and high-performance liquid chromatography (HPLC).

Whilst chromatography is the most effective method of identifying specific flavonoids, you may be interested to know that ultra-violet spectrophotometry has been used to measure total flavonoid content before &amp; after treatment.