DM And Glorimetric Analysis Essay

DM and GalA content were determined according to the method reported by Aina et al., [32] and Food Chemical Codex 1996 [33]. 0.1g of pectin was weighed into a 250 mL conical flask, then wetted with 5mL ethanol. 100mLof deionized water was added, then six drops of phenolphthalein (0.1% in ethanol) indicator to each sample. Pectin dispersions were stirred until it was fully dissolved, thereafter, the solution was titrated slowly with 0.1N NaOH until the colour of the indicator just changed to light pink. The methoxyl (MeO) contents were determined by adding 25 mL of 0.25 N NaOH to the neutral solution, mixed thoroughly, and was allowed to stand for 30 minutes at room temperature in the flask. 25 mL of 0.25N HCl was added to the solution. Finally, the neutralized solution was titrated with 0.1M NaOH till the end point was reached. The volume of 0.1M NaOH used in the final titration was used to calculate DM as follows:
DM(%)=(Normality of alkali*Volume of alkali (mL)*31*100)/(mass of sample (mg))
Where normality of alkali was 0.1N, 31represent molar mass of methoxyl group, and volume of alkali is the final volume of NaOH used in the titration.
GalA content was calculated according to the formula below: …show more content…
HT-29 cells were seeded at 2.0 × 104 cells/ml in a 96 well-plate for 24 hours in RPMI1640 medium containing 10% fetal bovine serum and 1% penicillin-streptomycin for 24 hours, thereafter the cells culture were incubated with pectin concentration range in RPMI 1640 medium containing 1% FBS for 24 hours. Medium surrounding cells was removed from each well into a pre-labeled 1ml Eppendorf tube for centrifuging at 5000x g for 5 minutes. 50µL of supernatant was pipetted into a new labeled 96 well plate into which 50µL of master mix (containing 96% buffer and 4% LDH substrate) was added to each well and incubated for 10 minutes then absorbance measured in a spectrophotometer at