Effects of heat pump drying temperature and dietary fat on carrot β-carotene bioaccessibility

Dehydration can significantly extend the shelf life of dried carrots and still retain nutrition of provitamin A carotenoids. In vitro digestion model was used in this study to assess the effect of drying temperatures of heat pump and dietary fat on the bioaccessibility of β-carotene in carrots. Also, low-speed centrifugation was employed to obtain β-carotene release rate in supernatant. Microfiltration was applied to obtain β-carotene micellar rate in micelle phase. These assays were used as indicators to assess the bioaccessibility of the β-carotene. Despite higher drying temperatures had a negative effect on the retention rate of β-carotene in carrots, it showed a positive impact on the micellar rate. In addition, dietary fat significantly increased the release rate and micellar rate of β-carotene for both fresh carrots and dried carrot products, with the highest release rate and micellar rate obtained when 10% dietary fat was added. Therefore, the heat pump drying process and dietary fat can significantly improve the bioaccessibility of β-carotene in carrots, which may increase the β-carotene bioavailability to human.