pectin content analysis
1.1.1 Galacturonic Acid Analysis (for Pectin Analysis)
Defattening of Mango Peel Powder (Tunchaiyaphum et al., 2013)
1. Weigh about 3 g sample and put into thimble of the soxhlet extractor.
2. Pour in 150 mL of absolute ethanol to the flask of the soxhlet extractor.
3. Extract at boiling temperature of ethanol for 4 hours.
4. Remove solid contents from the thimble. Set aside to dry.
Acid Hydrolysis of MPP (Rehman et al., 2004)
1. Mix defatted peel powder with water at pH 2.5 adjusted w/ 0.1 N H2SO4 with a substrate to water ratio of 1:40 (w/v).
2. Shake at 100 rpm in an incubator shaker at 60-90°C at 120 mins.
3. Filter contents with cheesecloth.
Reagents
Reagent A: Prepared by adding 1mL of Folin-Ciocalteau Phenol Reagent to 39mL of distilled water.
Solution A: Buffered copper solution
Prepared by adding the following to 80mL of distilled water in a 100mL volumetric flask: 1 mL glacial acetic acid, 23.2 g NaCl, 3.2 g sodium acetate
The solution is well mixed to dissolve all components, and 0.5g of CuSO4 is added, mixed again, the pH adjusted to 4.8 with the addition of NaOH solution, mixed again, and distilled water is added up to 100-mL mark. The final pH is adjusted to 4.8.
Procedure
1. Equal amounts (0.5mL) of hydrolyzed MPP filtrate and Solution A will be mixed into a test tube with screw caps. Triplicate samples must be prepared.
2. The resulting solution is boiled for 40 minutes.
3. After 40 minutes, the test tubes with samples are removed from the heat, and 4mL of prepared Reagent A is added. The sample is mixed using a vortex mixer. A colored product forms immediately.
4. The absorbance is measured at 750 nm.
Standard Curve D-galacturonic acid is used as standard with a concentration ranging from 2mg/mL to 10mg/mL (or 2 g/L to 10 g/L) for a calibration standard.
Defattening of Mango Peel Powder (Tunchaiyaphum et al., 2013)
1. Weigh about 3 g sample and put into thimble of the soxhlet extractor.
2. Pour in 150 mL of absolute ethanol to the flask of the soxhlet extractor.
3. Extract at boiling temperature of ethanol for 4 hours.
4. Remove solid contents from the thimble. Set aside to dry.
Acid Hydrolysis of MPP (Rehman et al., 2004)
1. Mix defatted peel powder with water at pH 2.5 adjusted w/ 0.1 N H2SO4 with a substrate to water ratio of 1:40 (w/v).
2. Shake at 100 rpm in an incubator shaker at 60-90°C at 120 mins.
3. Filter contents with cheesecloth.
Reagents
Reagent A: Prepared by adding 1mL of Folin-Ciocalteau Phenol Reagent to 39mL of distilled water.
Solution A: Buffered copper solution
Prepared by adding the following to 80mL of distilled water in a 100mL volumetric flask: 1 mL glacial acetic acid, 23.2 g NaCl, 3.2 g sodium acetate
The solution is well mixed to dissolve all components, and 0.5g of CuSO4 is added, mixed again, the pH adjusted to 4.8 with the addition of NaOH solution, mixed again, and distilled water is added up to 100-mL mark. The final pH is adjusted to 4.8.
Procedure
1. Equal amounts (0.5mL) of hydrolyzed MPP filtrate and Solution A will be mixed into a test tube with screw caps. Triplicate samples must be prepared.
2. The resulting solution is boiled for 40 minutes.
3. After 40 minutes, the test tubes with samples are removed from the heat, and 4mL of prepared Reagent A is added. The sample is mixed using a vortex mixer. A colored product forms immediately.
4. The absorbance is measured at 750 nm.
Standard Curve D-galacturonic acid is used as standard with a concentration ranging from 2mg/mL to 10mg/mL (or 2 g/L to 10 g/L) for a calibration standard.