In vitro antioxidant properties of Prosopis alba exudate gum from northeast region of Argentina

FRANCO EMANUEL VASILE; ANA MARÍA ROMERO; MARÍA ALICIA JUDIS; MARÍA FLORENCIA MAZZOBRE

Cancún, Quintana Roo

Congreso; Latin Food 2016; 2016

Asociación Mexicana de Ciencia de los Alimentos

The search of new hydrocolloids has been addressed to currently undervalued natural resources. In this context, vegetable gums arise as an interesting alternative, especially when they are obtained from non-exploited autochthonous sources. Prosopis alba, is one of the most widely spread trees in the northeast region of Argentina. Under environmental stress conditions, this tree excretes an exudate gum whose protective activity against microorganisms and insects was attributed to phenolic compounds. These bioactive substances could impart useful functional properties, if the exudate gum is employ as food component. Therefore, the objective of this work was to evaluate the in vitro antioxidant activity of P. alba exudate gum (PAG) in comparison with commercial Acacia senegal (arabic gum, AG), used as reference due to its botanical similarity. For this purpose different in vitro essays were performed to evaluate the PAG behavior in terms of different antioxidant mechanisms. Both, PAG and AG presented a similar scavenging activity of ABTS+? synthetic radical, that depended linearly on gum concentration. However, PAG showed a higher scavenging activity against OH radicals (50.61 ± 0.48 % inhibition/mg gum db.) and a higher reducing power (2.19 ± 0.05 mg ascorbic acid eq./g gum db.) respect to AG (46.08 ± 0.24 % inhibition/mg gum db. and 1.06 ± 0.01 mg ascorbic acid eq./g gum db., respectively). These results were related to the higher content of polyphenols (9.55 ± 0,06 mg galic acid eq./g gum db.), especially flavonoids (2.53 ±0.04 mg quercetin eq./g gum db.) in PAG. PAG also presented better chelating activity than GA, which was attributed to its high tannin content (5.78 ± 0.04 mg eq. tannic acid eq./g gum db.). Antioxidant properties of PAG, could be interesting not only for its use as protectant of easily oxidized food components, but also for its potential health benefits. The antioxidant activity expands the functionality of the suited gum for its use as a novel functional ingredient, with the imminent benefits of employing an actually unknown source.