Influence of intrinsic and extrinsic factors on rheology of pectin–calcium gels

Pectin homogalacturonans: Nanostructural characterization of methylesterified domains

“…Both the DB and DB abs values estimated for this HG (36.7% and 11.0%, respectively) are in line with previously reported values for other randomly demethylesterified pectins (Daas et al, 1999;Fraeye et al, 2009;Ngou emazong et al, 2011;Str€ om et al, 2007).…”

Anti-homogalacturonan antibodies: A way to explore the effect of processing on pectin in fruits and vegetables?

“…The DB abs is defined as the amount of non-methylesterified mono-, di-and trigalacturonic acids released by the enzyme relative to the total amount of GalA residues in pectin or mPGA, both methylesterified and non-methylesterified. In this way, DB abs gives information about the absolute number or length of blocks present in the pectin/mPGA, without correction for DE (Fraeye, Doungla, et al, 2009;Guillotin et al, 2005). An overview of the DE, DB and DB abs for the different samples is given in Table 2 (pectin) and Table 3 (mPGA).…”

“…Typical reductions in DE that are observed during processing are e.g. from 60% to 35% for carrot (Sila, Smout, Vu, Van Loey & Hendrickx, 2005) and from 75% to 45% for strawberry (Fraeye, Doungla, et al, 2009). Not only the degree, but also the pattern of esterification appears to play a role in the texture properties of fruits and vegetables.…”

Influence of pectin structure on texture of pectin–calcium gels

“…The gel properties are mainly determined by the ability to form stable eggbox-type junction zones, hence the availability of blocks of NMG, long enough for cooperative binding of Ca 2+ ions. As a result, gel properties depend not only on the degree, but also on the pattern of methoxylation Thibault & Rinaudo, 1985;Thibault & Rinaudo, 1986;Willats et al, 2001;Strom et al, 2007;Luzio and Cameron, 2008;Fraeye et al, 2009aFraeye et al, , 2009b.…”

“…Such texture loss can be partly compensated by the action of PME which is naturally present in plant systems, or can be added exogenously. PME hydrolyses methoxyl esters with formation of carboxylic acid groups which can interact with Ca 2+ ions, forming a calcium-pectate network (Fraeye et al, 2009a(Fraeye et al, , 2009bVan Buggenhout et al, 2009).…”