ARS | Publication request: Microwave extraction of citrus peel to release pectin

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 4, 2008
Publication Date: April 23, 2008
Citation: Luzio, G.A. 2008. Microwave extraction of citrus peel to release pectin using a closed vessel reactor. Florida State Horticultural Society Meeting. Paper No. HP24.

Technical Abstract: After removal of soluble sugars and other compounds by washing, citrus peel is largely composed of pectin, cellulose and hemicellulose. In order to utilize the greatest amount of citrus peel product, it would appear reasonable that one or all three of these polysaccharides be converted to a useful material. One of the components, pectin is relatively easy to modify using enzymes and has great utility in the food industry and other applications. Thus it appears reasonable to focus on the use of pectin for the maximum utilization of fruit peel for new products from peel. Modified pectins have been shown to have calcium sensitivity which is an important functional property of pectins for use in applications which require suspension, metal ion binding or water absorption. Yield stress behavior can be important for pulp stabilization in citrus drinks while providing low viscosity for acceptable mouth feel. Modification of pectin requires the pectin to be a soluble form. Pectin is typically extracted using heat and strong acid conditions at 70 °C. New microwave technology is available which allows for rapid heating and cooling of the extract to temperatures in excess of 100 °C. Data will be presented showing the quantity and quality of pectin which can be extracted at elevated temperatures using mild acid conditions.