Cytinus hypocistis (L.) L.: Optimised heat/ultrasound-assisted extraction of tannins by response surface methodology

Abstract

Tannins are a class of phenolic compounds commonly found in plants and studied for their bioactive and inhibitory enzyme properties. Cytinus hypocistis (L.) L. is a wild edible parasitic plant whose biological properties have been correlated with its high tannin content. Thus, studying the extraction of tannins from C. hypocistis will give comprehensive clues to enhance the recovery of these high added-value bioactive compounds. The present work applied Response Surface Methodology (RSM) to optimise tannins extraction using Heat-Assisted (HAE) and Ultrasound-Assisted (UAE) methods. Two three-factor Rotatable Central Composite Designs were used to assess the linear, quadratic, and interaction effects of the independent variables on the target responses. The obtained results from both extraction systems revealed high ethanol percentages as the critical factor in increasing tannin content. The optimum global processing conditions predicted by the polynomial models were 95.1 min, 46.4 • C, and 74.3% ethanol for HAE; and 18.7 min, 327.4 W, and 69.3% ethanol for UAE. Following these conditions, 200 mg and 178 mg of total tannins per g of extract were recovered using HAE and UAE, correspondingly. Although HAE presented a higher final response, the UAE stood out as a time-saving technique.

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“…This shows that their response surface had a curvature, and the TTC value reached a maximum under the optimal conditions of the variables, and a further increase in the variables would decrease TTC values. A previous study of tannins obtained from Cytinus hypocistis (L.) via the UAE method reported that the highest TTC was obtained at a higher solvent concentration …”

“…A previous study of tannins obtained from Cytinus hypocistis (L.) via the UAE method reported that the highest TTC was obtained at a higher solvent concentration. 24 2.1.5. Effect of Variables on Antioxidant Activity.…”

Evaluation of parasite and host phenolic composition and bioactivities − The Practical Case of Cytinus hypocistis (L.) L. and Halimium lasianthum (Lam.) Greuter

“…V. Silva et al, 2020;Silva et al, 2021a). Galloyl-bis-HHDP-glucose, for example, is always the major compound identified in the extract, but its extracted concentrations decreased from the sample harvested in 2018-2019 and 2020.…”

“…The extracts were prepared using Heat-Assisted Extraction (HAE) at the optimum global condition determined during previous work; the samples (0.8 g) were mixed with a hydroethanolic solution (40 mL; 95.1 min, 46.4 • C, and 74.3%). The mixture was extracted in a water bath, as previously described (Silva et al, 2021a). A total of five hydroethanolic extracts were prepared: the whole C. hypocistis (CH); parasited H. lasianthum aerial parts (PHLAP); parasited H. lasianthum roots (PHLR); non-parasited H. lasianthum aerial parts (HLAP); and non-parasited H. lasianthum aerial roots (HLR).…”

“…Recent studies pointed to C. hypocistis as a potential source of biologically active compounds with cosmeceutical interest (Maisetta et al, 2019;Silva et al, 2021a;Zucca et al, 2015). Although its high tannin content has been correlated to its bioactivities, no studies on the host phytochemical profile have been performed.…”