Structure formation in sugar containing pectin gels – Influence of Ca2+ on the gelation of low-methoxylated pectin at acidic pH

The impact of rhamnogalacturonan-I side chain monosaccharides on the rheological properties of citrus pectin

“…In addition to these structural alterations, the lower abundance of neutral sugars after enzymatic treatment might be directly associated to low hydrogen bonding activity. The neutral sugars, specifically Ara f , which contain hydroxyl groups have been reported to contribute to the gelling of citrus pectin at temperatures below 50 C (Kastner et al, 2012). The same variations in the SDR were observed in the case of Le based samples and the resulting GP, IST and CST are summarised in Table 4.…”

“…The GP was defined as the temperature at which the storage modulus (G 0 ) crossed the loss modulus (G 00 ), the point at which polymer solution undergoes a transition from liquid-like to more solid-like behaviour (Winter, 1987) (Mezger, 2006). Besides typically using the crossover between the G 0 and G 00 to determine and characterize the GP of pectin gels, the first derivative of G 0 as a function of time (dG 0 /dt) was used to exactly determine the point at which gelling started to occur, as described previously for low methyl esterified pectin citrus gels (Kastner, Einhorn-Stoll, & Senge, 2012). A rheometer MCR101 from Anton Paar, (Graz, Austria) equipped with CC10 geometry was used for the gelling measurements.…”

“…Two values were extracted from the curves obtained, the initial structuring temperature (IST) and the critical structuring temperature (CST). While IST is the temperature at which the value dG 0 /dt is different from 0 for the first time, the CST is the extrapolated temperature from the point at which a strong increase in dG 0 /dt is observed (Kastner et al, 2012). At the same time as the sample was being loaded in the rheometer, approximately 50 mL of sample were poured into a Petri dish (6 cm in diameter and 2 cm high) equipped with adhesive tape allowing filling to minimum 1 cm above the brim, making it possible to evenly cut the gel surface after curing.…”

Effect of Ca2+, Fe2+ and Mg2+ on rheological properties of new food matrix made of modified cell wall polysaccharides from apple

“…Contrary to iron and calcium addition, magnesium caused a decrease of viscosity of MPS with increasing concentration. Changes in viscosity of MPS in calcium hydroxide solutions are associated with the cross-linking ability of polysaccharides, especially low-methylated pectin chains with calcium cations (Cybulska et al, 2012;Fang et al, 2008;Fraeye et al, 2010;Kastner et al, 2012;Ralet et al, 2003;Ventura et al, 2013;Videcoq et al, 2011;Yang et al, 2013;Yapo & Koffi, 2013). A significant increase of viscosity in the case of the addition of iron lactate may be explained as an ability of divalent iron ions to interact with polysaccharides resulting in the forming of an intermolecular network similar to the structure of Ca 2+ -low-methylated pectin.…”

“…To ensure edibility as well, the delivery system might be made of cell walls from fruit and the desired thickening could be gathered from pectin gelling ability. Most of the previous studies on pectin extracted from fruit or vegetable cell walls have concerned the ability of interaction of low methoxyl pectin chains with calcium cations (Cybulska, Pieczywek, & Zdunek, 2012;Fang et al, 2008;Fraeye et al, 2010;Kastner, Einhorn-Stoll, & Senge, 2012;Ralet, Crépeau, Buchholt, & Thibault, 2003;Ventura, Jammal, & Bianco-Peled, 2013;Videcoq, Garnier, Robert, & Bonnin, 2011;Yang, Zhang, Hong, Gu, & Fang, 2013;Yapo & Koffi, 2013). However, the review of the literature has revealed that there is only very little information on the interaction of pectin with other divalent metal cations, such as magnesium and iron.…”