EFFECT OF DIFFERENT DRYING METHODS ON MINT LEAVES PHYSICAL AND QUALITY PROPERTIES

Document Type : Original Article

Authors

Ag. Eng. Dept., Fac. of Ag., Menoufia Univ., Egypt.

Abstract

Three  drying methods were used for drying mint leaves, oven drying (40, 50, 60 and 70 oC), microwave drying (180, 360, 540, 720 and 900 Watt) and direct solar drying with three levels of load (0.5, 1.25 and 5kg/m2).The drying characteristics and the quality aspects of the dried mint leaves were studied. From  initial moisture content (7.65 g.w/g.d.m.)  to achieve the equilibrium moisture content the drying time was 5 minutes by microwave drier at use powers 900 and 720 Watt with loading level 0.5 kg/m2, while the highest time took for drying mint was 20 hours to achieve equilibrium moisture content when use oven drier at 40 oC. Meanwhile, the solar drier required 8 hr. to achieve the final moisture content of mint leaves (0.11 g. w./g. d .m) at both 1.25 and 0.5 kg/m2 loading levels. The results showed that drying of the mint leaves at temperature 50 oC with loading rate 1.25 kg/m2  was the best treatment from all treatments were studied in this work to getting the highest amount of essential oil. Midili - kucuk, model adequately described the oven and solar drying behaviors and logarithmic model adequately described the microwave drying behaviors.

Keywords

References

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