Isolation and partial characterization of thermostable isoperoxidases frompotato (Solanum tuberosum L.) tuber sprouts

Citation
Cfs. Boucoiran et al., Isolation and partial characterization of thermostable isoperoxidases frompotato (Solanum tuberosum L.) tuber sprouts, J AGR FOOD, 48(3), 2000, pp. 701-707
Citations number
37
Categorie Soggetti
Agricultural Chemistry","Chemistry & Analysis
Journal title
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN journal
00218561 → ACNP
Volume
48
Issue
3
Year of publication
2000
Pages
701 - 707
Database
ISI
SICI code
0021-8561(200003)48:3<701:IAPCOT>2.0.ZU;2-9
Abstract
Peroxidases (POD; EC 1.11.1.7) can cross-link cell wall polymers and may ha ve an impact on the final textural quality of potato tubers. Because heat t reatments are important during processing, the thermal properties of isoPOD s from soluble and ionically and covalently bound fractions were studied fr om both potato tubers and sprouts. For both tissues, the ionically bound fr action was the most thermostable; similar to 20% of POD activity remained a fter a heat treatment of 10 min at 90 degrees C (for sprouts). The temperat ure profile of the ionically bound sprout fraction appeared to be nonlinear and suggested the presence of a very thermostable POD, which still showed activity after a heat treatment at 100 degrees C. Visualization by using is oelectric focusing confirmed the occurrence of a thermostable isoPOD with a n IEP of 9.5, which displayed regeneration of activity after heat inactivat ion. This cationic POD was further purified by chromatography techniques, a nd by SDS-PAGE its molecular mass was estimated at 38 kDa.