Advances in physicochemical and functional characterization of Prosopis alba exuded gum for its potential application in food industry

FRANCO EMANUEL VASILE; JUDIS MARÍA ALICIA; MARÍA FLORENCIA MAZZOBRE

San Pablo, Brasil

Workshop; Advances in Molecular Structuring of Food Materials, School of Advanced Sciences; 2013

Faculty of Animal Science and Food Engineering, FAPESP

Under environmental stress conditions, the tree Prosopis alba known in Argentine as algarrobo blanco secretes a soluble polysaccharide with characteristics similar to those of arabic gum (AG). This has supported the possibility to use this currently wasted resource, as an effective AG substitute for the encapsulation of sensitive food ingredients. The aim of this study was to investigate the structural characteristics of the Prosopis alba exuded gum (ALG) by monitoring the composition, physicochemical and functional properties. For this purpose, gum tears were dissolved in distilled water at 75°C. The resulting solution was clarified by filtration, dialyzed (10 kDa MWCO), frozen at -18°C and finally freeze-dried. The sample was subjected to commonly referenced characterization tests and compared with those reported for AG. The ALG presented a protein content (7.21±0.062% db) higher than the AG (2.2±0.3% db). The tannin content (0.2±0.01% db), recognized as a toxicity parameter, was lower than those found in the literature for botanically related species. The total polyphenol content was determined in ALG (17.52±0.2 mg eq.tannic acid/g dry solid) and this was satisfactorily correlated with its antioxidant activity, measured in terms of capability to capture the ABTS radical (EC50=0.92±0.03 mg dry solid). In addition, the ALG moisture sorption isotherm was obtained. GAB model resulted the most suited to describe ALG behavior (EPP