posted on 2023-12-22, 06:29authored byCatarina
S. Rebelo, Pedro Velho, Eugénia A. Macedo
Antioxidant-rich food supplements can effectively address
widespread
nutritional deficiencies in the human diet and simultaneously reduce
the concentration of reactive oxygen species (ROS) due to the free
radical scavenging activity of antioxidants, minimizing inflammation
and oxidative stress. Resveratrol (RVT) is a very important antioxidant
which can be extracted from food industry byproducts such as grape
skins, contributing to a more circular economy and reducing the environmental
impact of the extraction processes. In this work, RVT was successfully
extracted in the aqueous two-phase systems (ATPSs) {ethyl lactate
(1) + Na3Citrate or K3Citrate or Na2Succinate or NaKTartrate (2) + water (3)} at 298.15 K and 0.1 MPa,
which provided biocompatible and sustainable extractive media. The
studied ATPS yielded partition coefficients (K) above
unity, indicating a preference for the top phase (rich in ethyl lactate),
which hints at a successful extraction of this phenolic compound.
Larger tie-lines generally resulted in larger partition coefficients
(K) and larger extraction efficiencies (E), favoring solute migration to the top phase. The most promising
partition coefficients (K = 40 ± 6 and 41 ±
9) and extraction efficiencies (E/% = 98 ± 1
and 95.0 ± 0.6) were obtained for the longest tie-lines (TLL
= 77.66 and 70.73 m%) for {ethyl lactate (1) + K3Citrate (2) + water (3)} and {ethyl lactate (1) + NaKTartrate
(2) + water (3)}, respectively. Additionally, the effect of pH on
the UV–vis absorbance spectrum of RVT was studied to minimize
errors in solute quantification, resulting in low antioxidant mass
losses (<5%).