Potato tuber pectin structure is influenced by pectin methyl esterase activity and impacts on cooked potato texture.
Although cooked potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase activity (PME) as a potential factor impacting on textural properties. In this study, tuber PME isoform and gene expression profiles have been determined in potato germplasm with differing textural properties as assessed using an amended wedge fracture method and a sloughing assay, revealing major differences between the potato types. Differences in pectin structure between potato types with different textural properties were revealed using monoclonal antibodies specific for different pectic epitopes. Chemical analysis of tuber pectin clearly demonstrated that, in tubers containing a higher level of total PME activity, there was a reduced degree of methylation of cell wall pectin and consistently higher peak force and work done values during the fracture of cooked tuber samples, demonstrating the link between PME activity, the degree of methylation of cell wall pectin, and cooked tuber textural properties.
Ross
Heather A
HA
Plant Products and Food Quality Programme, Scottish Crop Research Institute, Dundee DD2 5DA, UK.
Wright
Kathryn M
KM
McDougall
Gordon J
GJ
Roberts
Alison G
AG
Chapman
Sean N
SN
Morris
Wayne L
WL
Hancock
Robert D
RD
Stewart
Derek
D
Tucker
Gregory A
GA
James
Euan K
EK
Taylor
Mark A
MA
D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D005511:Food Handling; D010368:Pectins / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D035281:Plant Tubers / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D011198:Solanum tuberosum / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
D010940:Plant Proteins; D010368:Pectins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase