Modified Radical Scavenging and Antioxidant Activity Measurement of ²-Carotene with ²-Cyclodextrins Complexation in Aqueous Medium

Abstract

In order to evaluate the antioxidant capacity/activity of β-carotene (BC) in aqueous media, we investigated the inclusion complexes of BC with methyl-β-cyclodextrin (Me-β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and 2-hydroxyethyl-β-cyclodextrin (HE-β-CD) that enhance water solubility and chemical stability. The inclusion complexes (monitored by FTIR) exhibited higher solubility than free BC, and phase solubility studies showed a linear increase in the solubility with the Me-β-CD concentration. Cupric ion-reducing antioxidant capacity (CUPRAC), ABTS-persulfate, peroxyl and hydroxyl radical scavenging assays were applied. CD-complexed β-carotene exhibited less effective antioxidative and radical scavenging than free BC dissolved in acetone. β-Carotene showed the highest antioxidant capacity in the presence of HE-β-CD, and the lowest with Me-β-CD, probably due to the deeper and more hydrophobic cavity of the latter. We believe that this is the first report on devising simple spectrophotometric methods for the wholistic assessment of antioxidant activity/capacity, hydroxyl and peroxyl radical scavenging activity of β-carotene in aqueous solution with CDs.

Effect of rice bran protein concentrate as wall material adjunct on selected physicochemical and release properties of microencapsulated β-carotene

“…In the BC FTIR spectra (Figure 3), the absorption bands at 2916 cm −1 and 1450 cm −1 were due to the asymmetric/symmetric stretching and asymmetric deformation, respectively, of the C-H group. The band at 964 cm −1 likely corresponded to the trans-conjugated alkene -CH = CH- vibration (Celik et al, 2017; Moh et al, 1999). The peak at 1366 cm −1 corresponded to a methyl band (Celik et al, 2017) and the peak at 1713 cm −1 corresponded to the stretching vibration of carbonyl group (Zaibunnisa et al, 2011).…”

“…The band at 964 cm −1 likely corresponded to the trans-conjugated alkene -CH = CH- vibration (Celik et al, 2017; Moh et al, 1999). The peak at 1366 cm −1 corresponded to a methyl band (Celik et al, 2017) and the peak at 1713 cm −1 corresponded to the stretching vibration of carbonyl group (Zaibunnisa et al, 2011). In the maltodextrin FTIR spectra, the main absorption bands were at 995 cm −1 , 1358 cm −1 , and at 3279 cm −1 .…”

“…The bands at 3279 cm −1 and 1057 cm −1 corresponded to stretching vibrations of the O-H bond and C-O bond, respectively, suggesting the presence of starch that may have complexed with protein during precipitation (Piotrowicz and Salas-Mellado, 2017). The band at 2924 cm −1 corresponds to the stretching vibrations of the C-H bond (Celik et al, 2017).…”