|Title||Water holding capacity and enzymatic modification of pressed potato fibres|
|Source||Wageningen University. Promotor(en): Harry Gruppen, co-promotor(en): Mirjam Kabel. - Wageningen : Wageningen University - ISBN 9789461739643 - 156|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||aardappelpulp - aardappelen - vezels - celwandstoffen - polysacchariden - waterbergend vermogen - hydrolyse - enzymen - potato pulp - potatoes - fibres - cell wall components - polysaccharides - water holding capacity - hydrolysis - enzymes|
|Categories||Chemistry of Food Components|
Cell wall polysaccharides (CWPs) contribute to the water holding capacity (WHC) of fibre rich feeds, such as pressed potato fibres (PPF). However, the role of CWPs on the WHC of PPF was unidentified so far.
PPF was characterized to be abundant in arabinogalactan (AG) linked rhamnogalacturonan-I (RG-I), homogalacturonan (HG) and cellulose, next to which xyloglucan (XG) contributed the most of the hemicellulosic CWPs. The CWP network in potatoes was loosened upon starch extraction of potatoes and solubilized HG-RG-I-AG.
Analyses of the WHCs upon enzyme treatments indicated that the WHC of PPF was mainly caused by a network of insoluble, non-cellulosic CWPs such as pectic CWPs (HG-RG-I-AG) and XG. Findings in this thesis showed that AGs were better degraded than xyloglucans (XGs). Since XGs were found to be equally important in contributing to the WHC as AGs, the substantial removal of AGs, as well as XGs, should be advantageous to lower the WHC.
Other than lowering the WHC, the use of a pectinase-rich preparation improved the recovery of starch from potatoes by the degradation of mainly pectic CWPs, in particular pectic AG side chains and HG. The degradation of arabinan was observed to be inhibited by components in potato juice (PJ).