Solubility of (+)-catechin in water and water-ethanol mixtures within the temperature range 277.6–331.2K: Fundamental data to design polyphenol extraction processes

Solubility of daidzin in different organic solvents and (ethyl alcohol+water) mixed solvents

“…However, there is also a stronger entropic effect (i.e., more positive D diss S o values) for the (daidzin + tetrahydrofuran) mixture. The more positive are the values of D diss S o , the greater the degree of randomness or disorder of the solution and the more favourable is the dissolution process [29].…”

A green ultrasound-assisted extraction process for the recovery of antioxidant polyphenols and pigments from onion solid wastes using Box–Behnken experimental design and kinetics

“…Although total polyphenol extraction from onion solid wastes was shown to decline at temperatures higher than 40 • C (Khiari et al, 2009), the effect of temperature on the extraction yield in polyphenols is in several instances positive Brahim et al, 2014;Qu et al, 2010), because higher temperatures facilitate polyphenol diffusion and increase solubility (Boussetta et al, 2011;Galanakis et al, 2013). In addition, the solubilisation of polyphenols such as catechin, has been shown to be endothermic and thus thermodynamically favoured at higher temperatures (Cuevas-Valenzuela et al, 2014). On the other hand, temperature cannot be increased beyond certain limits, as this has been proven detrimental to anthocyanins (Cacace and Mazza, 2002;Jing and Giusti, 2007;Monrad et al, 2010).…”

Kinetics of Ultrasound-Assisted Flavonoid Extraction from Agri-Food Solid Wastes Using Water/Glycerol Mixtures

“…By contrast, total polyphenol extraction from OSW has been shown to decline at temperatures higher than 40˝C [20]. Furthermore, it has been demonstrated that solubilization of catechin, an abundant RGP constituent, is endothermic and, thus, thermodynamically favored at higher temperatures [21]. Similar phenomena may hold true for other RGP constituents too.…”