Abstract/Summary

β-Carotene, a precursor of vitamin A, can alleviate the deficiency of this vitamin prevalent worldwide. Earlier research studies have addressed the extraction of β-Carotene at relatively low temperatures (up to 70 °C) due to its perceived instability at higher temperatures, as a result of which extraction rates recorded are relatively low. This study models the net rate of β-Carotene extraction by considering both extraction and degradation kinetics. The model developed, which accounts for degradation occurring in solid and extract phases, has been experimentally validated for the extraction of β-Carotene from freeze dried carrot powder into sunflower oil over a range of temperatures 90-150 °C. This study also gives insights into the application of sunflower oil as a carrier for β-Carotene during cooking and food processing, by monitoring and modelling the thermal degradation and isomerisation of β-Carotene at temperatures up to 220 °C. The modelling of extraction kinetics shows that it is possible to achieve viable extraction rates by employing temperatures in the range (90-150 °C) for relatively short times (< 5 mins). The degradation kinetics shows that almost 75% of the β-Carotene can survive heating at 180 °C for 10 mins – indicating the possibility of using β-Carotene enriched edible oils for frying. This study also reports on the formation of three isomers of β-Carotene identified using HPLC: trans-, 9-cis and 13-cis. The reaction network model developed in this study was able to account for the transient variation of the concentration of all three isomers.