18 taste, gel color with Chromameter CR 200, syneresis rate, and pH changes. The flow diagram
of this stage is shown in Figure 11. Green grass leaves Premna oblongifolia Merr.
and water 1:15 Crushed
Filtered using filter cloth Green grass extract
Formed in gelling container Gelling for ± 5 hours at room temperature
Green grass jelly Steamed 100
o
C, 5 minutes Observation of taste, color, syneresis, and pH changes
Figure 11. Procedure of NaHCO
3
concentration determination
2.1. Gel Color
Observation of gel color was conducted by using Minolta CR 200 Chromameter to assess changes in the gel color by the addition of NaHCO
3
and also selected hydrocolloid in stage 4. In principle, this tool works by measuring the
reflection of the color produced by the sample surface. Vibrating lights contained in the device will emit a beam of xenon and produce and spread the light evenly on the
surface of the sample. Chromameter measurement results will be converted into the Hunter system with the symbol of L, a, and b. L value states brightness parameter that
have a value of 0 black to 100 white. L value indicates reflected light which produces achromatic colors of white, gray, and black. A value expressed mixed
chromatic colors red and green, with a+ positive from 0 to +100 for the red color and the a negative from 0 to 80 for the green color. B value expresses mixed chromatic
colors yellow and blue, with b+ positive from 0 to +70 for the yellow and b negative from 0 to 70 for blue.
0, 0.125, and 0.583 NaHCO
3
19
2.2. Level of Acidity pH AOAC 2000
Measurement of pH was conducted on the acidity of green grass jelly’s syneresis water. Before used, the pH meter was calibrated with buffer solution of pH
4.00 and pH 7.00. Furthermore, because the green grass jelly is semi solid product, it is necessary to prepare the sample before pH measurements performed. Green grass jelly
homogenized by shredding into small parts, then chopped or crushed until smooth. Then, 20 ml of syneresis water was placed in a glass beaker, its pH value then
measured.
2.3. Gel Syneresis AOAC 1995
Gel syneresis observed according to AOAC 1995 method by storing gel at refrigerator temperature 10°C for 24 hours, 48 hours, and 72 hours. Each gel was put
into the cup to hold the water released from the gel during storage. Gel syneresis was calculated by measuring the weight loss during storage and compared with the initial
weight of the gel. Gel Syneresis =
AB A
×100 Where:
A = initial weight of the gel before storing gram B = weight of the gel after storing gram
3. DETERMI ATIO OF HYDROCOLLOID TYPE A D CaCO
