RT dataset
T1 Valorization of discarded red beetroot through the recovery of bioactive compounds and the production of pectin by surfactant-assisted microwave extraction
A1 del Amo-Mateos, Esther
A1 Fernández-Delgado, Marina
A1 Lucas, Susana
A1 García-Cubero, Mª Teresa
A1 Coca, Mónica
A2 Universidad de ValladolidInstituto de Procesos Sostenibles
K1 Microwave-assisted extraction, Galacturonic acid, Pectooligosaccharides, Polyethylene glycol, Antioxidants, Betalains
AB Discarded red beetroot (DRB) is an organic waste generated in the food industry. This study is focused on the valorization of DRB through the recovery of bioactive compounds. The characterization of the DRB juice confirmed a higher content of antioxidants (DPPH 504 ± 24 µmol TE/L, FRAP 10920 ± 440 µmol TE/L, ABTS 22012 ± 592 µmol TE/L), phenolic compounds (1789 ± 56 mg GAE/L), flavonoids (471± 17 mg CE/L) and betalains (1426 ± 24 mg/L) than commercial juices. DRB pomace contains pectin that was recovered by microwave extraction aided by a surfactant (polyethylene glycol, PEG4000). Conditions (temperature, time and surfactant concentration) for the extraction of galacturonic acid (GalA) or pectooligosaccharides (POS) were optimized by a central composite experimental design. POS were extracted at high temperatures (160 °C, 5.3 min, 8.4 g PEG4000/L, yield of 271.2 g POS/kg dry pomace). In comparison, galacturonic acid extraction was favored at moderate conditions (137 °C, 5 min, 2.5 g PEG4000/L, yield of 120.1 g GalA/kg dry pomace). The characterization of the freeze-dried hydrolysates revealed that the solid obtained under moderate temperature conditions (137 ºC) showed a higher GalA content (49.5%) and lower neutral sugars (11.4%), as GalA degrades at lower temperatures than pentoses. The recovered pectin can be considered high-methoxyl pectin, as the degree of esterification was higher than 50%. FTIR spectra of the freeze-dried hydrolysates showed functional groups consistent with pectin. MALDI-TOF-MS analysis revealed the presence of oligosaccharides of hexoses and pentoses with different structures and degrees of polymerization. Thus, DRB, a low-value vegetable waste, can be converted into high-value-added bioproducts in a biorefinery framework.
YR 2023
FD 2023
LK https://uvadoc.uva.es/handle/10324/70813
UL https://uvadoc.uva.es/handle/10324/70813
LA eng
NO Journal of Cleaner Production 389, 135995.
NO Instituto de Procesos Sostenibles
DS UVaDOC
RD 21-nov-2024