Supercritical fluids extraction and fractionation of bioactive compounds from winemaking by-products
This technology describes a new and innovative biorefinery model applied to grape pomace that consists in the production of bioactive compounds (including proanthocyanidins) from grape pomace through supercritical fluid extraction (SFE) and fractionation.
SFE is a quite novel technique to extract target analytes from solid matrices that employs the unique properties of supercritical fluids (SCFs). SCFs are substances for which both pressure and temperature are above the critical values. SFE allows a fast, automatable, environmentally sustainable, selective and efficient extraction. In the case of extraction of phenolic compounds from grape pomace, the most used solvent is supercritical carbon dioxide (SC-CO2), this because it is inert, environmentally benign, essentially nontoxic, relatively non-corrosive even in the presence of water. SC-CO2 methods are principally recommended for the extraction of thermolabile compounds (as proanthocyanidins) for which low temperatures are required. Besides, CO2 is relatively cheap and readily available from renewable resources in large quantities with high purity.
Nowadays, polyphenols are conventionally extracted using organic solvents. However, these methods have several drawbacks including long processing times, low quality extract and low extraction yields. Conversely, the processes involving SCFs are sustainable, environmentally friendly and cost-efficient. The environmental benefits of using SCFs in industrial processes, such as low energy consumption during operation, show their potential of replacing the not environmental-friendly damaging conventional organic solvents. The advantages of using SCFs for isolation of natural products are related to the possibility of completely removing the solvent from the product by depressurization, together with the better stability of compounds due to lower process temperatures and lack of organic solvent. Moreover, SCFs allow the selective and rapid extraction of components or fractionation of extracts.
Stage of development
The process for the extraction of proanthocyanidins (PAs) from grape pomace through an SC-CO2 system has been already validated in the lab. The system must be transferred from a laboratory scale to a pilot or industrial scale.
Challenge and needs
Grape is the world’s largest fruit crop with an annual production of more than 67 million tons. Grapes and products obtained therefrom, such as wine, grape juice, jams, and raisins, have then obvious economic importance. Eighty percent of the worldwide grape production is used in winemaking. The wine industry produces millions of tons of residues (grape pomace) after fermentation, which represents a relevant waste management issue both ecologically and economically. Actually, the industrial recovery of grape pomace is usually performed by its partial use for tartaric acid extraction or ethanol production, and the final solid residue is sometimes cast off as fertilizer. But thanks to this approach, SFE could be utilized in the recovery of PAs from grape pomace (low-cost resource and largely available). Indeed, due to an incomplete extraction during the winemaking process, grape pomace that mainly consists of skins and seeds, is characterized by high contents of PAs.
The technology is not yet protected by a patent.
Potential markets and targets
The global proanthocyanidins market was valued at USD 186.4 million in 2015. It is projected to reach USD 280.3 million by 2025 growing at a CAGR (Compound Annual Growth Rate) of 6.0%. PAs have possible applications in pharmaceuticals & dietary supplements (CAGR= 5,1%), personal care & cosmetic (CAGR= 6,2%), and functional food & beverages (CAGR= 7,1%) industries thanks to their different properties:
- antioxidants activity (to prevent lipid oxidation and oxidative rancidity, to retard the development of off-flavors and to improve color stability);
- antimicrobial activity;
- cardioprotective properties (acting as an inhibitor of platelet activity);
- anti-carcinogenic, antiaging, anti-inflammatory and anti-allergic properties.
Production of bioactive compounds from grape pomace through supercritical fluid extraction and fractionation could be co-developed by partners embedded in the Adriatic Ionian region working in winemaking (such as distilleries) or food, pharmaceutical and cosmetic industries. Thanks to this technology, SMEs will have the expertise to extract bioactive compounds (PAs) deriving by grape pomace. In this way, the potential co-developer will broaden and diversify its range of products using winemaking by-products.