DRYING OF POT MARIGOLD WHOLE FLOWERS AND PETALS UNDER CONTROLLED DRYING AIR TEMPERATURE AND RELATIVE HUMIDITY.

Matouk, A.; El-Kholy, M.; Tharwat, A.; Sadat, Marwa

doi:10.21608/jssae.2016.39372

DRYING OF POT MARIGOLD WHOLE FLOWERS AND PETALS UNDER CONTROLLED DRYING AIR TEMPERATURE AND RELATIVE HUMIDITY.

Document Type : Original Article

Authors

¹ Agric Eng. Dept., Fac. of Agric., Mansoura Univ.

² Agric. Eng. Res. Institute.

10.21608/jssae.2016.39372

Abstract

A study was carried out to test and evaluate the drying behavior of pot marigold whole flowers and petals using a laboratory scale dryer with controlled air temperature and relative humidity.
The studied parameters included four different levels of drying air temperature (55, 60, 65 and 70°C) and three levels of air relative humidity (40, 50 and 60%). All the experimental runs were conducted at constant air velocity of (0.6 m/sec). The drying behavior of pot marigold whole flowers and petals during the drying process were simulated using three different thin layer drying models (Lewis’s 1921, Henderson and Pabis’s 1961 and Page's 1949 model). Final quality of the dried pot marigold whole flowers and petals was also determined. The results show that, drying rate of pot marigold whole flowers and petals increased with the increase of drying air temperature while, it was decreased with the increase of relative humidity. All studied models could describe the drying behavior of both whole flowers and petals satisfactorily. However, Page's model considered the most proper for describing the drying data in terms of higher values of (R²) and lower values of (²), (MBE), (RMSE) and (SE). In general, the drying air temperature of 70°C and relative humidity of 40% achieved the best quality in terms of total carotenoids. However, drying of pot marigold petals showed higher content of total carotenoids and shorter drying time.