Blueberry Pectin Extraction Methods Influence Physico-Chemical Properties.

Area of Science:

• Food Science and Technology
• Biochemistry
• Plant Polysaccharides

Background:

• Pectin, a complex polysaccharide, is widely used in the food industry as a gelling agent, thickener, and stabilizer.
• Highbush blueberries are a rich source of bioactive compounds, including pectins, which have potential functional properties.
• Understanding the physico-chemical characteristics of blueberry pectin is crucial for its application as a functional ingredient.

Purpose of the Study:

• To sequentially extract and characterize pectins from highbush blueberry powder using different solvents.
• To evaluate the impact of alcohol precipitation on the removal of anthocyanins and low molar mass pectins.
• To determine the physico-chemical properties, including composition, molar mass, and rheological behavior, of different blueberry pectin fractions.

Main Methods:

• Sequential extraction of pectin using water, chelator, and sodium carbonate solvents.
• Fractionation of pectins via alcohol precipitation or dialysis.
• Characterization of pectin fractions for neutral sugar and uronic acid content, molar mass, and rheological properties.

Main Results:

• Water-soluble fractions were high methoxyl pectins with high molar mass, rich in neutral sugars.
• Chelator-soluble fractions were low methoxyl pectins, rich in uronic acids, with a more linear structure and high molar mass.
• Alcohol precipitation was more effective than dialysis in removing anthocyanins and low molar mass pectins.
• Sodium carbonate-soluble fractions contained protein and had low molar mass.

Conclusions:

• Blueberry pectins exhibit diverse physico-chemical properties depending on the extraction solvent and fractionation method.
• The characterized blueberry pectin fractions possess desirable properties for use as functional ingredients in food and beverages.
• Alcohol precipitation is an effective method for purifying pectin by removing anthocyanins.