Understanding the influence of processing conditions on the extraction of rhamnogalacturonan-I “hairy” pectin from sugar beet pulp

Sugar beet pectin is rich in rhamnogalacturonan-I (RG-I) region, which is a potential source of prebiotics. RG-I pectin cannot be extracted the same way as commercial homogalacturan-rich pectin using hot acid. Therefore, this study has explored several alternative methods, including microwave-assist...

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Bibliographic Details
Main Authors: Yujie Mao, Rui Lei, John Ryan, Fatima Arrutia Rodriguez, Bob Rastall, Afroditi Chatzifragkou, Charles Winkworth-Smith, Stephen E. Harding, Roger Ibbett, Eleanor Binner
Format: Article
Language:English
Published: Elsevier 2019-06-01
Series:Food Chemistry: X
Online Access:http://www.sciencedirect.com/science/article/pii/S2590157519300288
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Summary:Sugar beet pectin is rich in rhamnogalacturonan-I (RG-I) region, which is a potential source of prebiotics. RG-I pectin cannot be extracted the same way as commercial homogalacturan-rich pectin using hot acid. Therefore, this study has explored several alternative methods, including microwave-assisted extraction (MAE) and conventional-solvent extraction (CSE) at atmospheric pressure using different solvents, and microwave-assisted hydrothermal extraction (MAHE) under pressure using water. No conclusive differences in microwave and conventional heating were found with heating rate controlled. The optimum treatment times of both MAE and CSE at 90 °C atmospheric pressure and regardless of the solvents used were 120 min; however, MAHE at 130 °C under pressure can dramatically reduce the time to 10 min. Alcohol-insoluble solids (AIS) extracted using pH13 solvent by MAE had both the highest RG-I yield at 25.3% and purity at 260.2 mg/g AIS, followed by AIS extracts using water by MAHE with 7.5% and 166.7 mg/g AIS respectively. Keywords: Microwave-assisted extraction, Hydrothermal, Acid-free, Hairy pectin, Novel prebiotics, Rhamnogalacturonan-I, Sugar beet pulp
ISSN:2590-1575