Optimization of the Extraction of Proanthocyanidins from Grape Seeds Using Ultrasonication-Assisted Aqueous Ethanol and Evaluation of Anti-Steatosis Activity In Vitro

Abstract

Conventional extraction methods of proanthocyanidins (PAC) are based on toxic organic solvents, which can raise concerns about the use of extracts in supplemented food and nutraceuticals. Thus, a PAC extraction method was developed for grape seeds (GS) and grape seed powder using food-grade ethanol by optimizing the extraction conditions to generate the maximum yield of PAC. Extraction parameters, % ethanol, solvent: solid (s:s) ratio, sonication time, and temperature were optimized by the central composite design of the response surface method. The yields of PAC under different extraction conditions were quantified by the methylcellulose precipitable tannin assay. The final optimum conditions were 47% ethanol, 10:1 s:s ratio (v:w), 53 min sonication time, and 60 °C extraction temperature. High-performance liquid chromatography analysis revealed the presence of catechin, procyanidin B2, oligomeric and polymeric PAC in the grape seed-proanthocyanidin extracts (GS-PAC). GS-PAC significantly reduced reactive oxygen species and lipid accumulation in the palmitic-acid-induced mouse hepatocytes (AML12) model of steatosis. About 50% of the PAC of the GS was found to be retained in the by-product of wine fermentation. Therefore, the developed ethanol-based extraction method is suitable to produce PAC-rich functional ingredients from grape by-products to be used in supplemented food and nutraceuticals.

Sonoprocessing improves phenolics profile, antioxidant capacity, structure, and product qualities of purple corn pericarp extract

“…Nevertheless, as the extraction time increases beyond the optimal time, CT begins to decrease, possibly due to CT's transformation into anthocyanins. A comparable trend has been stated by Lv et al [60] , Dzah [24] , and Thilakarathna and Rupasinghe [61] on CT extraction using ultrasound. In terms of extraction time and TPC, it was observed that the influence was significant ( p < 0.05), as shown in Table 3 , and a quadratic effect was observed, as seen in the RS and perturbation plot ( Fig.…”

Prediction of the Adult T-Cell Leukemia Inhibitory Activity of Blueberry Leaves/Stems Using Direct-Injection Electron Ionization-Mass Spectrometry Metabolomics

“…PACs are oligomers or polymers of flavan-3-ol molecules linked via inter-flavan linkages. Oligomeric and polymeric PACs predominantly consist of catechin and epicatechin monomers [ 23 , 24 ]. As PACs are polymers, they cannot always be represented by a constant molecular weight or molecular formula.…”

Proanthocyanidins from Vaccinium vitis-idaea L. Leaves: Perspectives in Wound Healing and Designing for Topical Delivery

“…The interest in utilizing proanthocyanidins in the pharmaceutical industry has considerably increased over time with the discovery of their beneficial functions [ 27 ]. One possible approach is via skin application and incorporation into dermal formulations, such as polymeric films, which offer many advantages in terms of effective drug delivery and improved patient compliance [ 19 , 20 ].…”