Influence of extraction conditions on properties of seed xyloglucan.

Xyloglucans are water-soluble polysaccharides that serve as storage in cotyledonary tissues from seeds of Hymenaea courbaril among other Leguminosae. The use of xyloglucans is dependent on their solution properties. We now examine the influence of different times of extractions on its properties. Xyloglucans were obtained from milled and defatted cotyledons of H. courbaril by aqueous extraction at 25 degrees C for 0.25, 0.5, 1, 5, 15, 24, and 48 h. Composition data showed that increase in time lead to the increased protein contamination and arabinose content. Xyloglucans obtained with longer times of extraction had an average molar mass greater than those obtained with shorter times. The hydrodynamic radius and the radius of gyration also increased with the increase in the time of extraction. The ratio R(g)/R(h) was calculated and the values decreased slightly for increasing times of extraction. The effect of time also affected the viscosity which increased with the increase in time of extraction, and the longer ones probably contributing to the aggregation of xyloglucans.