Objective To determinate the recovery of total polyphenolic compounds content, in vitro antioxidant activity and HPLC/ESI/MS characterization of extract from Nephelium lappaceum L. (Mexican rambutan). Methods The rambutan husk extract was obtained by aqueous extraction and a polyphenolic fraction was recovered using Amberlite XAD-16. The total polyphenolic compounds content was determined by the Folin Ciocalteu and butanol-HCI methods. In vitro antioxidant activity was performed using ABTS and ferric reducing antioxidant power methods. Results Mexican rambutan husk showed a total polyphenolic content of 582 mg/g and an evident antioxidant activity by ABTS and ferric reducing antioxidant power analysis. The HPLC/ESI/MS assay allowed the identification of 13 compounds, most of which belong to ellagitannins. Geraniin, corilagin and ellagic acid were present in the sample; the mineral composition was also evaluated. Conclusions Rambutan husk cultivated in Mexico is a promising source for the recovery of added value bioactive compounds with antioxidant activity, which have potential applications as bioactive antioxidant agents for the treatment of diseases.

The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices.
Aspergillus niger ; metabolism ; Bioreactors ; microbiology ; Carboxylic Ester Hydrolases ; metabolism ; Cell Culture Techniques ; methods ; Gallic Acid ; metabolism ; Polyurethanes ; chemistry