Studies on extraction of pectins from citrus peels, apple marks and sugar-beet pulps with arabinanase and galactanase

• Published in: Carbohydrate polymers 1988, Vol.9 (2), p.119-131
• Main Authors: Thibault, Jean-François, De Dreu, René, Geraeds, Carolien C.J.M., Rombouts, Frank M.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Food additives; Food Chemistry and Microbiology; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Levensmiddelenchemie en -microbiologie
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/0144-8617(88)90009-4

Pectin was extracted from citrus, apple and sugar-beet pulps, with an enzyme preparation from Bacillus subtilis. The preparation contained endo-arabinanase, endo-galactanase and residual endo-pectate lyase. Extraction conditions were 30°C and 0·03 m sodium acetate buffer, pH 5·0, so that pectate lyase activity was minimised. Under these conditions, an appreciable amount of pectin (4·9% by the buffer and 10·8% by the enzymes) could be extracted from citrus pulp, but very little from apple and sugar-beet pulps. The citrus pectin had a relatively low molecular weight (47 000) compared to acid-extracted pectin (82 000). The breakdown may be due to either enzymatic or chemical β-elimination. Significant amounts of pectin (12·9%) can also be extracted from citrus pulp with water and chelating agents. It was concluded that pectins cannot efficiently be extracted with these enzymes.