Evaluation and comparison of emulsion, rheological and spectroscopic properties of FT-IR extracted pectin from peel and cap of pumpkin

Today, pectin is widely used as gelling agent and stabilizer in the food industry. The present study, pectin extraction from dried powder of peel and cap of pumpkin was performed in two different acidc and water solvents method. Finally, the samples that showed the highest pectin yield in each extraction method was selected for further experiments. Then, galacturonic acid percentage, degree of estrification, emulsifier stability, emulsifier activity, viscosity and FT-IR spectroscopy were applied to selected methods. The highest yield in acidic solvent (pH=2.5) in cap treatment of pumpkin (23.03%) and water solvent (for 3 hours) in cap treatment of pumpkin (17%) in 90 °C, 90 minutes and solvent to dry matter ratio 1:30 ml/mg was determined. According to the results, The highest percentage of galactoronic acid in pectin extracted from the cap treatment was observed in solvent acidc. The highest amount of estrification degree , emulsifiers stability and activity in pectin extracted from the peel treatment was observed in solvent acidc. Pectin extracted from cap treatment showed higher viscosity than pectin peel treatment. The viscosity of all solutions was used in the shear rate (0.05-200 r(s-1)) constant, which indicates the flow index (n) equal to 1 and the Newtonian behavior of the solution.