Characterization of hop pectins shows the presence of an arabinogalactan-protein

A. Oosterveld, A.G.J. Voragen, H.A. Schols

Research output: Contribution to journalArticleAcademicpeer-review

76 Citations (Scopus)

Abstract

Hop pectins were extracted from spent hops using acid extraction conditions and were characterized chemically. The acid extraction of spent hops resulted in a yield of 2°containing 59 f polysaccharides. The hop pectins under investigation had a relatively high molecular weight and an intrinsic viscosity comparable to that of commercially available apple and citrus pectins. The low degree of methyl esterification of these pectins implicates that they are mainly suitable for use in calcium gels. The degree of acetylation and the neutral sugar content were relatively high. A high molecular weight fraction which contained arabinogalactan-proteins was shown to be present in the hop pectin extract after preparative size-exclusion chromatography. Additionally, a fraction with a lower molecular weight was present containing mainly homogalacturonans. The arabinogalactans in the high molecular weight population consisted of (13)- and (13,6)-linked galactans highly branched with arabinose and galactose side-chains. The protein part of the arabinogalactan-protein (13€was found to be rich in cystein, threonin, serinin, alanin, and hydroxyprolin. The molecular weight distribution of the hop pectin after degradation with the enzymes endopolygalacturonase plus pectin methyl esterase suggested that the arabinogalactan-protein present in the hop pectin extract was linked to the pectin and that the arabinogalactan-protein itself had a fairly low molecular weight.
Original languageEnglish
Pages (from-to)407-413
JournalCarbohydrate Polymers
Volume49
DOIs
Publication statusPublished - 2002

Keywords

  • Arabinogalactan-protein
  • Humulus lupulus
  • Pectin
  • Spent hops

Fingerprint

Dive into the research topics of 'Characterization of hop pectins shows the presence of an arabinogalactan-protein'. Together they form a unique fingerprint.

Cite this