Effects of extraction time and temp., sucrose, acidulants, packaging materials and storage temp. on the colour and vitamin C retention of sobo juice (roselle juice; a popular drink in Nigeria) extracted from local roselle plant were investigated. Juice was extracted at 20, 60 or 100(deg)C for 5, 10, 15, 20 or 25 min. Freshly extracted roselle juice was divided into 3 batches and independently hot-filled into 500 ml pre-sterilized glass bottles, film packages or PET bottles allowing for min. head space, before being sealed, cooled and subsequently stored at 5 +/- 1 or 28 +/- 1(deg)C for 8 wk. Optimum pigment extraction was obtained in 20 min with boiling water, while colour stabilization of the extracted juice was affected with the use of food acidulants. Colour degradation on storage was more pronounced in sweetened juice with greater colour loss in products held at ambient temp. Retention of colour and vitamin C was higher in glass and plastic bottles under cold and ambient storage conditions than in the flexible polyethylene film. However, addition of table sugar or increasing storage temp. from 5 to 27(deg)C affected colour stability.
