Abstract:

The physico-chemical and nutrition properties of four types of carrot powder, obtained respectively by hot air
drying (HAD), short- and medium-wave infrared drying (S&MID), vacuum microwave drying (VMD) and vacuum drying
(VD), were compared and discussed. Results showed that a* value (redness to greenness) and rehydration ratio of carrot
powder produced by different drying methods followed the decreasing order: S&MID ＞ VD > VMD > HAD. The oilholding
capacity of carrot power obtained by four drying methods had no significant differences. The highest total sugar
content and β-carotene contents were observed in S&MID carrot power, and VD carrot power was the richest in VC. In
summary, short- and medium-wave infrared drying is suitable for industrial production of carrot powder due to the excellent
product quality.

Key words: hot air drying, short- and medium-wave infrared drying, vacuum microwave drying, vacuum drying, carrot powder, quality