THESIS

5.3 Procedure for Preparation for Standard Curve
200
Prepare solutions (1 mg/ml) of standard amylose and amylopectin
following the same procedure as in steps 4.3.1 to 4.3.4 for the sample preparation
above. Prepare working solutions of mixed amylose and amylopectin for standard
curve following Appendix Table A 2. Pipette 5 ml aliquots of each mixture for the
working solutions in 100 ml volumetric flasks, each containing about 50 ml of
distilled water. Repeat measurement as a sample steps described above. Plot
absorbance at 620 nm against the assigned amylose content for the standard curve as
shown in Appendix Figure A1. Read % amylose values of the tested samples from
the standard curve as in Appendix Table 1. Amylose content was ca
Appendix Table A1 Standard working solutions for amylose determination
Amylose content Volume ratio of standard working solution (ml/100ml)
(% dry weight basic) Amylose Amylopectin 0.09N sodium hydroxide
(ml)
(ml)
(ml)
0 0 18 2
10 2 16 2
20 4 14 2
30 6 12 2
40 8 10 2
OD 620 nm
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
y = 0.1865x
R 2 = 0.9973
0 0.5 1 1.5 2 2.5
Amylose concentration (mg/100 ml)
Appendix Figure A 1 Standard curve for amylose determination