Title
The effect of storage of whole potatoes of three cultivars on the patatin and protease inhibitor content; a study using capillary electrophoresis and MALDI-TOF mass spectrometry
Author
Pots, A.M.
Gruppen, H.
van Diepenbeek, R.
van der Lee, J.J.
van Boekel, M.A.J.S.
Wijngaards, G.
Voragen, A.G.J.
Publication year
1999
Abstract
The content and biological activity of patatin and the protease inhibitors of molecular size 20-22 kDa present in whole potato tubers were investigated as a function of storage time. The amount of buffer-extractable protein decreased gradually during storage of whole potatoes of the cultivars Bintje and Desiree for 47 weeks whereas, for Elkana, it increased after approximately 25 weeks. The patatin proportion of the extractable protein did not decrease significantly during storage, whereas the proportion of PP20-22 protease inhibitors decreased. All cultivars contained several different patatin isoforms. Bintje and Desiree showed patatin populations with two masses whereas for Elkana, only one molar mass was found. Patatin isoforms of the three cultivars examined showed no significant differences in stability towards degradation as was concluded from capillary electrophoresis analysis. No inactivation of patatin or protease inhibitors by partial degradation of these proteins was observed using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF MS), whereas enzyme-activity assays suggested that the biological activity, especially in the cultivar Bintje, decreased markedly at the break of dormancy.
Subject
Capillary electrophoresis
MALDI-TOF
Potato protein
Storage
buffer
capillary electrophoresis
cultivar
determination of content
dormancy
enzyme activity
enzyme assay
enzyme degradation
enzyme inhibitor
enzyme stability
mass spectrometry
matrix assisted laser desorption ionization time of flight mass spectrometry
molecular size
patatin
physiology
postharvest period
potato
proteinase
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DOI
https://doi.org/10.1002/(sici)1097-0010(199909)79:12<1557::aid-jsfa375>3.0.co;2-k
TNO identifier
234905
ISSN
0022-5142
Source
Journal of the Science of Food and Agriculture, 79 (12), 1557-1564
Document type
article