Grape Seeds Proanthocyanidins: Advanced Technological Preparation and Analytical Characterization

Abstract

A “green” solvent-free industrial process (patent pending) is here described for a grape seed extract (GSE) preparation (Ecovitis™, Spain) obtained from selected seeds of Veneto region wineries, in the northeast of Italy, by water and selective tangential flow filtration at different porosity. Since a comprehensive, non-ambiguous characterization of GSE is still a difficult task, we resorted to using an integrated combination of gel permeation chromatography (GPC) and electrospray ionization high resolution mass spectrometry (ESI-HRMS). By calibration of retention time and spectroscopic quantification of catechin as chromophore, we succeeded in quantifying GPC polymers up to traces at n = 30. The MS analysis carried out by the ESI-HRMS method by direct-infusion allows the detection of more than 70 species, at different polymerization and galloylation, up to n = 13. This sensitivity took advantage of the nanoscale shotgun approach, although paying the limit of missed separation of stereoisomers. GPC and MS approaches were remarkably well cross-validated by overlapping results. This simple integrated analytical approach has been used for quality control of the production of Ecovitis™. The emerging feature of Ecovitis™ vs. a popular benchmark in the market, produced by a different technology, is the much lower content of species at low n and the corresponding increase of species at high n.

Proanthocyanidins and Where to Find Them: A Meta-Analytic Approach to Investigate Their Chemistry, Biosynthesis, Distribution, and Effect on Human Health

“…Indeed, reversed phase columns are able to separate oligomers of equivalent molecular mass into their isomers, but proanthocyanidins bigger than tetramers have a large number of isomers which elute together causing an overlap of the retention time. Consequently, isomers of the same oligomers are recorded in the chromatogram in a single and large unresolved peak that cannot be neither identified and/or quantified [ 110 ].…”

“… Cluster distribution of proanthocyanidins in plant kingdom based on the total proanthocyanidin content according to previously published data [ 87 , 88 , 90 , 91 , 92 , 93 , 95 , 96 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 ]. Euclidean distances were calculated with the average linkage method.…”

A Comparative Study of the Influence of Various Fungal-Based Pretreatments of Grape Pomace on Phenolic Compounds Recovery

“…In line with sustainable development and increasing consumer demand for the use of natural rather than synthetic resources, there is great interest in the reuse of GP for various purposes, such as the production of fertilizers, animal feed, functional foods, pharmaceuticals, cosmetics, industrial enzymes, composites, biopolymers, as biomass for biofuel production, to its use for mushroom cultivation, and as an additive to improve building insulation [ 1 , 6 , 7 , 8 ]. These alternative uses of GP, as well as its market potential, are still under development, but some products are already available on the market, such as Bioflavia, an organic red grape skin powder used as a dietary supplement, grape seed extract capsules (Ecovitis TM ) rich in oligomeric proanthocyanidins, and grape seed oil [ 9 , 10 ].…”

Mediterranean Edible Plants: An Assessment of Their Antioxidant, Radical Scavenger Properties and Their Use as Super Foods, Nutraceuticals, Functional Foods

“…Expecting a high consumption of cereals, fruit, vegetables and legumes, the Mediterranean diet requires a much less intensive use of natural resources (soil, water) and greenhouse gas emissions than the model based on the consumption of meat and animal fats [ 10 ]. Vitis vinifera L. grape skin and seeds are clear examples of waste products that are useful as an energy reserve [ 11 , 12 ].…”

“…This translates into a reduction in greenhouse crops and related environmental impact, as well as supply and transport costs from distant countries. A “green” solvent-free industrial process was described for a grape seed extract preparation from selected seeds of Veneto region wineries, in the northeast of Italy, by water and selective tangential flow filtration at different porosities [ 12 ]. It respects the territory and biodiversity, through different sowing in each area and crop rotation, in order to also guarantee food security.…”