Enhanced extraction of high added-value products from Hibiscus sabdariffa using automatic solvent extractor: Kinetics and modeling

Extraction, Characterization, and Bioactivity of Phenolic Compounds—A Case on Hibiscus Genera

“…In Şahin et al, 2020, the results concerning the anthocyanin recovery for UAE were 4 mg/g dry weight, while in Deli et al, 2019, the results for UAE were 0.546 g/g extract [30,37]. Moreover, Şahin et al, 2021, obtained a maximum content of 29 mg of cianidin-3-glucoside/g dry weight [36]; whereas Zannou et al, 2020, reported a value of 10.62 mg of delphynidin-3-sambubioside/g dry weight [32]. Regarding these compounds, the most effective extraction methodology was achieved by Şahin et al, 2021, where PLE-optimized extracts were obtained [36].…”

“…From the variety of design models applied, Box-Behnken (BB) with a factorial design of 3 3 or 2 3 [30][31][32] and central composite design (CCD) with a factorial design of 2 3 [33,34] were the most popular. However, central composite rotable design (CCRD) [35] and face-centered central composite design (FCCCD) [36] were also considered.…”

“…The main extraction variables to be optimized were temperature, pressure, time, solvent composition, and sample amount, among others. With the objective of efficient extraction of polyphenols and high recovery, most studies selected as response variables the extraction yield of bioactive molecules [34]; individual phytochemical concentrations [32,33]; total phenolic, flavonoid, or anthocyanin contents [30,31,36]; and antioxidant capacity [32].…”

“…In Pimentel-Moral et al, 2020, the considered conditions were temperature and solvent composition in ethanolic-aqueous mixtures, which have implications for the modification of the dielectric constant of the solvent mixture [35]. Meanwhile, in Şahin et al, 2020, extraction time and particle size of the starting Hibiscus sample were also considered as selected parameters for optimization, while the temperature was not considered as critical [36]. In the first study, the optimum conditions were 200 • C and 100% EtOH, for a maximum concentration of individual phenolic compounds determined by HPLC-ESI-QTOF-MS. On the other hand, in the second study performed by Şahin et al, 2021, 80% EtOH, 60 min, and 0.5 mm of particle size reported to be the optimal conditions for enhancing the TPC and TAC, determined spectrophotometrically, in the Hibiscus sample.…”

“…Finally, for the analysis of anthocyanin in the obtained extracts, UV-Vis spectrophotometry with 550 nm as the maximum absorption wavelength was the methodology of the selected studies [30][31][32]36,36]. In Şahin et al, 2020, the results concerning the anthocyanin recovery for UAE were 4 mg/g dry weight, while in Deli et al, 2019, the results for UAE were 0.546 g/g extract [30,37].…”