Preparation and characterization of Xyloglucan films extracted from Tamarindus indica seeds for packaging cut-up 'Sunrise Solo' papaya.

Xyloglucan was extracted from Tamarindus indica (T. indica) seeds from industrial residue, presenting a glucose, xylose and galactose ratio of 1.41:1.31:1 respectively, with aim of elaborating a film. A Central Compound Rotatable Design (CCRD) with Xyloglucan variables from T. indica (XylTi) and Glycerol (Gly) was used to prepare the film. The films were analyzed for water vapor permeability, thickness, opacity, moisture, tensile strength, elongation at break, Scanning Electron Microscopy, thermogravimetric analysis and FT-IR. A significant (p < 0.05) influence of XylTi and Gly was observed, resulting in an increase in moisture (24.09%), tensile strength (20.70 MPa) and elongation at break (50.84%), with an increase in the independent variables. The best results for this work proposal were the film with 4.5% XylTi/1.5% Gly (T3). The T3 film was used in evaluating the efficiency of the optimized film for packaging cut-up 'Sunrise Solo' papaya, and the results showed a higher mass loss than the PVC film and statistically the same for ethylene and carbon dioxide production. It is concluded that films made with xyloglucan from T. indica seeds obtained from the residue of the fruit pulp industry presented good physical characteristics, highlighting the T3 elaboration, and are viable for manufacturing food packaging.

Isolation of a lectin and a galactoxyloglucan from Mucuna sloanei seeds.

A lectin and a galactoxyloglucan were characterized from Mucuna sloanei seed cotyledons. The galactoxyloglucan, isolated by water extraction and ethanol precipitation, had Glc:Xyl:Gal proportions in a molar ratio of 1.8:1.7:1.0 and a molar mass (M(w)) of 1.6x10(6)g mol(-1). The lectin (sloanin), isolated from the same seed by affinity chromatography on cross-linked Adenanthera pavonina galactomannan, gave two protein bands by SDS-PAGE (36 and 34 kDa) and one peak by gel filtration (63.6 kDa). Its N-terminal sequence indicated approximately 69% identity with soybean agglutinin to leguminous lectins. Circular dichroism (CD) spectra established that sloanin predominantly contains beta-sheet structures. Sloanin has approximately 5.5% carbohydrate and displayed hemagglutinating activity against rabbit and enzyme treated human erythrocytes, inhibited only by D-Gal containing sugars. The interaction between sloanin and storage cell-wall galactoxyloglucan was tested by affinity chromatography and fluorescence spectroscopy.