Colour stability and vitamin C retention of roselle juice (Hibiscus sabdariffa L) in different packaging materials

Abstract

PurposeIn Nigeria, roselle juice is quite popular among the populace presumably owing to its attractive colour, pleasant flavour and nutritional attributes. In the citrus industry, processing and packing material selection have significant effect on quality of juice product during storage. The effects of packaging materials, and storage temperature on colour and vitamin C retention of sobo juice extracted from local roselle plant were investigated.Design/methodology/approachJuice was extracted at three different temperatures: 20, 60 and 100°C for varying processing times of 5, 10, 15, 20 and 25 min respectively. Freshly extracted roselle juice was divided into three batches and independently hot‐filled into 500 mL pre‐sterilised glass, film packages and polyethylene terephthalate (PET) bottles allowing for minimum head space, capped, cooled and subsequently stored at 5 ± 1 and 28 ± 1°C respectively for eight weeks.FindingsOptimum pigment extraction was obtained in 20 min with boiling water, while colour stabilisation of the extracted juice was affected with the use of food acidulants. Colour degradation on storage was pronounced in sweetened juice with greater colour loss in product held at ambient temperature. Colour and vitamin C retention with glass and plastic bottles provide higher retention of these quality attributes under cold and ambient storage condition than with the flexible polyethylene film.Originality/valueRetention of colour and vitamin C was considerably higher in glass and PET bottles than in flexible film package. However, addition of table sugar or increasing storage temperature from 5 to 27°C affected colour stability.