Drying Rate and Product Quality Evaluation of Roselle (Hibiscus sabdariffa L.) Calyces Extract Dried with Foaming Agent under Different Temperatures

Table 1

Predicted drying time of roselle extract without foam at various air conditions.

Aw/RH	Drying time (minutes)
	30°C	40°C	50°C	60°C	70°C	80°C
0.0	572.6	410.4	256.8	214.9	153.6	116.9
0.2	587.2	419.7	261.9	218.4	155.4	117.7
0.4	656.0	451.7	275.9	226.0	158.5	118.8
0.6	nd	nd	377.0	247.2	164.5	120.5
0.8	nd	nd	nd	nd	178.6	123.2

: not dried (equilibrium moisture of the product was upper 10% wet basis).