Technological measures for treating chlorophyll of fresh anise fruit by using saturated steam

Abstract

Based on indigenous knowledge and chemical characteristics of chlorophyll composition, we conducted experiments on using saturated steam to treat chlorophyll from fresh star anise fruit in laboratory and piloting. The fresh anise fruit were steamed at different temperature: 110 ± 2oC; 115 ± 2oC;120 ± 2oC; 125 ± 2oC, and 130 ± 2oC. The results showed that: 1 - the time needed to treat chlorophyll on the surface of fresh star anise fruits inversely correlated with temperature of saturated steam used; 2 - Underdone steaming the anise fruit surface retains light green color, while overheating leads to distorting surface with mushiness and dark black color. Under laboratory conditions, corresponding to above mentioned temperature of
saturated steam; chlorophyll treatment process took from 36 to 61 seconds. Under pilot conditions with an equipment of 400kg/hour, the time required for treatment is from 70 to 90 seconds. The loss of essential oil during chlorophyll treating process with using saturated steam was estimated at. 3.71 - 4.02% of total amount of essential oil in star anise fruit in laboratory, while this number was 3.85 - 4.27% at pilot scale. Although the essential oil loss was higher than that in boiling water method - which was 2.82 - 3.22%, the essential oil content of dried star anise fruit after chlorophyll treatment
by steaming is higher than that required for exporting.