The overall objective of the project is the development of complete recovery strategies for wine-making wastes in order to reduce their environmental impact and, above all, to valorize them in order to provide wine-makers with the possibility of selling by-products at a profitable price.
For the fulfillment of this overall objective, the following specific aims are foreseen.
Establishment of process protocols for the recovery of wine-making and distillation by-products
The complete utilization and valorization of wine-making wastes (staks, skins and seed before and after distillation) can be realized according to the scheme reported in Fig. 6.1.
Fig. 6.1: Scheme of the project approach for a complete recovery of wine-making wastes (ND: not distilled, D: distilled).
In order to valorize the typical production of the Italian regions involved in the project, by-products will be collected from the most important cultivars of the areas. The selection of the cultivars (3 red grapes Barbera, Nebbiolo, Pinot nero, and 3 white grapes Moscato, Chardonnay and Muller Thurgau) has been done considering also the phenolic and aromatic profiles, their diffusion in other European countries (Chardonnay, Muller Thurgau, Pinot Noir), their representativeness of white and red varieties, of different vinification process (for example Pinot nero is often used for a white vinification process which produces not-fermented red marcs particularly rich in polyphenolic compounds), and their actual distillation in “purity” (this will allow to evaluate the influence of distillation on the aromatic profile and phenolic composition of recovered products).
Employment of different cultivars is necessary to evaluate the influence of the variable cultivar on the chemical-physical-functional properties of the recovered products (skin and seed flours and phenols extracts). On the other hand, heterogeneity of by-products batches could impair their industrial applications. Therefore, blends of by-products with standardized composition will also be produced and assessed for potential industrial applications. Establishment of correlations between composition of by-products and their NIR-MIR spectral data will be a specific sub-aim of the project. In fact, NIR-MIR spectroscopy offers competitive advantages to food manufactures, reducing overall costs, and improving the control of product quality. In fact, this technique is characterized by speed of the analysis (10-60 s); simplicity of sample preparation; non destructive approach; no use of laboratory chemicals; simultaneous measurements of several constituents. Based on this correlation it will be possible to determine the suitable mixture of by-products to be processed in order to have recovered products with standard composition over the years, independently therefore of both cultivar variability and climate variability on the same cultivar. It is expected to facilitate the development of standard seed and skin flours and standard phenolic extracts for both red and white grapes. This solution will be definitely less expensive than treating the by-products separately by cultivar and then mixing the final recovered products.
The recovery procedures will be optimised starting from the preliminary results obtained by the partners. Therefore phenols will be recovered from skin-flours with a conventional or microwave assisted solvent extraction process. Oil will be extracted by supercritical CO2 while mechanical pressing will be carried out for production of reference oils for comparison purposes. The capabilities of the supercritical technology in the enrichment of the oil in its noble constituents (poly-unsaturated fatty acids and tocopherols) will be assessed to find out the best operative conditions to make possible a (partial) fractionation of the oil in its components.
Even stalks will be treated separately in relation to grape cultivar to explore the possibility of obtaining standardized fractions. They will be hydrolyzed by mild chemical/physical processes. Recovery of stalks is also object of an Integrated Italy-Spain action between UCSC and a Spanish partner with a consolidated experience in lignocellulosic material fractionation. For a complete by-products recovery, the residue after phenols extraction from skins will be tentatively treated together with stalks.
Developed processes need to be economically and environmentally-friendly since they are aimed to reduce the wine-industry pollution load. That’s why for both phenols recovery and stalks hydrolysis, the best procedures will be chosen on the basis of yields, purities, environmental and economic aspects (solvent and energy consumption).
o Production of different functional ingredients and additives.
The project aims at obtaining the following high-added value products:
o Skins and seed flours by simple milling. This represents, indeed, a complete utilization and valorization of winery and distillery by-products. Due to the high oil content which would reduce the shelf-life and applicability of seed flours, seeds will be previously defatted by supercritical extraction which, besides the advantages already discussed, leads to a lower oil residue in the defatted seeds. The skin and seed flours will be tested for fortification and functionalisation of different food categories. Extracted oil is, on its turn, a high-added value food product.
o Phenolic extract recovered from skins and from stalks hydrolysates. Their antioxidant properties are well known and at present exploited in many pharmaceutical and cosmetic products and a few food applications.
Phenolic additives/ingredients with improved solubility in both hydrophilic and hydrophobic media by means of suitable modifications. Based on previous partners’ experience, phenolic extracts have a limited solubility in the solvent used for their recovery. Solubility improvement is therefore necessary to guarantee market exploitation. Addition of maltodextrins, surfactants or esterification processes will be investigated to produce modified phenolic extracts. Innovative market application of the recovered phenolic compounds as natural biocides in coatings formulation will be investigated together with new uses as multifunctional food ingredients/additives.
o Sugars from stalks hydrolysis. Removal of phenols, together with eventual post-hydrolysis treatment, aim producing at the same time fermentable sugars and phenolic extracts.
o Cellulose and lignin from stalks fractionation, which can be used for plastic and fibers production.
o Production of a catalogue of demonstrated food and no-food application for the developed functional ingredients and additives.
In order to guarantee a successful commercialization of the recovered by-products, the project aims realizing a sort of catalogue reporting for each developed product the information regarding:
o Chemical-physical characterization (that need to be standardized)
o Effect on the growth rates of different microbiological populations
o Use-instructions (typical conditions required for their storage and employment)
o Example of successful applications. The research will provide case studies for both food and non food applications. Regarding food applications, bakery products, dairy products and fruit-based products will be investigated. Regarding non-food application, since cosmetic and pharmaceutical application are already well-known and exploited in products available on the market, the innovative usage as natural biocide will be investigated.
o Industrial exploitation of the achieved results.
Dissemination activities will be required for implementation of the by-products recovery technologies at industrial scale. The project activities and obtained results will be broadly disseminated through publications on scientific papers, technical papers, local newspapers, announcement/articles in industry journals/media. A project web-site will be activated from the beginning of the project. Specific workshops will be organized to present the results to wine-makers and distilleries, to the general public and to companies potentially interested in the industrial production and/or application of the developed ingredients/additives. The workshop will focus on virtual demonstration of the developed recovered strategies and feasibility studies. A dossier will be prepared to be submitted to political institutions to favor the full implementation in Italy the European Dir. CE/479/08 that does not oblige anymore wine-makers to send marcs to distillation.
Expected Scientific benefits
The project will contribute to advance the knowledge in recovery strategies of agro-food by-products. Due to the complexity of the subject, an interdisciplinary approach with competences in engineering, environment and food science is required and addressed by this consortium. The knowledge and experience already gained by each partners, and the knowledge gained during the project, will be shared among all the partners and broadly disseminated to reach an out-standing progression in the sector.
Expected Technical Benefits
According to the reform CE/479/08, the compulsory distillation of grape marc and lees, together with the economic helps to distilleries, the minimum price to be given to wine-makers and the acquisition of produced alcohol by the EC have been removed. Even though for the moment Italy has decided to leave compulsory the delivery of marc and lees to recognized distilleries, as well as contribution to distilleries but only for the production of alcohol meant for energy or industrial application, it is clear how management of grape marc is going to become more expensive for wine industry. In fact, following the General EU Directive on wastes 2006/12/EC, Member States must take the necessary measures to ensure that waste is recovered or disposed of without endangering human health and without using processes or methods which could damage the environment. Such a directive is applicable to any substance the holder discards or intends or is required to discard.
The project results will offer wine-makers and distilleries feasible technical solutions to solve their problems related to waste management. The proposed solution will, indeed, allow wine-makers to make a profit of their by-products, increasing their production margins which could be invested in further research and promotion necessary to gain competitiveness toward other European and world wine producers.
Project goals and AGER objectives
Ager objectives are to fund scientific and technological research able to strengthen the competitive and sustainable development of wine sector industries, with reference to their typicalness and taking into consideration the specific European policy. Ager aims at offering wine-makers strategies and solution to gain competitiveness against the ever more emerging wine market from USA, Australia and South Africa. Recovery of high added-value oenological by-products is one of the indicated research lines in the Ager call.
The project goals aim at recovering high-added-value ingredients and additives from wine-making by-products in order to give wine-makers the possibility of increase their actual margins to spend on promotion, market research and product development. The research will apply to by-products generated by wine-makers located in the Italian regions Piemonte-Lombardia-Trentino and therefore results exploitation will be preferentially reserved to such regions.
The project has been planned considering the current legislation of the wine sector and of waste management and project results are expected to contribute towards reducing environmental pollution linked to wine-making wastes, increasing environment sustainability.
For industrial exploitation of results, it is expected that already existing companies will implement the developed technologies extending their own product portfolio. Alternatively, new industrial activities might be started following this project contributing to economical development of the involved Regions. This will also help young researchers finding a suitable occupation. The research teams of all partners include young researchers and PhD students, and fellowships for employing new temporary staff will be afforded by the received funding.