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III. RESULTS A D DISCUSSIO S
A. FIELD OBSERVATIO OF COMMERCIAL GREE GRASS JELLY PRODUCTIO PROCESS
Field observation had been done on how to produce commercial green grass jelly gel is conventionally performed by a traditional green grass jelly traders in the Muara Empang, Bogor.
Before conducting the production of green grass jelly, green grass leaves Premna oblongifolia Merr. were washed with running water. Then, the leaves were soaked for 10 seconds with hot boiled water
blanching process. The leaves were then washed again with cold water. The flow chart of conventional green grass jelly production process can be seen in Figure 15. Documentation of field
observation can be found in Appendix 1. Green grass leaves Premna oblongifolia Merr.
and water 1:15 Crushed
Filtered using filter cloth Green grass extract
Formed in gelling container Gelling for 12 hours at room temperature
Green grass jelly Figure 15. Flow chart of conventional green grass jelly production process
B. DETERMI ATIO OF GELLI G TIME
The gelling time of the treatment without the addition of NaHCO
3
was observed by its viscosity at each interval of 30 minutes for 5 hours. Optimum gelling time is the time when the green
grass jelly is already formed with maximum texture, but not towards syneresis. Green grass jelly without the addition of NaHCO
3
was selected because it has the longest gelling time compared to other treatments. Viscosity measurement result is presented in Appendix 2. Graph of viscosity can be seen in
Figure 16. Wood Ash Solution
28 Figure 16. Graph of green grass jelly’s viscosity without addition of NaHCO
3
Viscosity of green grass jelly without addition fo NaHCO
3
increases in accordance with the time until reach the optimum viscosity, then it shall decrease by the increase of time. Farida 2012
pointed out that rheology of green grass jelly is categorized as pseudoplastic. The viscosity will be increased by the increase of concentration and decreased by the increase of shear rate. At low shear
rate, the molecule can form a gel so that viscosity increased. Meanwhile, at high shear rate, tissue damage occurs which causes a decrease in viscosity.
The optimum viscosity was obtained after 150 minutes 2.5 hours. It is happened due to gelling mechanism so that viscosity increases until reach optimum viscosity. After that, viscosity
decreases in accordance with the time. It means that syneresis was started to be happened after 2.5 hours. Based on this viscosity measurement, the optimum gelling time obtained was 2.5 hours since it
has the largest viscosity, 782.5 cP. This gelling time would be used for all of green grass jellies made.
C. DETERMI ATIO OF aHCO
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