Politecnico di Torino - Corso Duca degli Abruzzi, 24 - 10129 Torino, ITALY

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Natural dyes for textiles from winery by-products

Extraction processNatural dyesPolifenoliPolyphenolsricicloWinery by-productsZero WasteZero Waste


Polyphenols extraction from different winery by-products. Leaves and pomaces obtained from white and red grape were used in ultrasound-assisted extraction process to produce natural dyes for textile. The different phenolic composition of vegetable sources allowed to obtain textile samples with different hue and chroma due to concentration and mordant used.

Technical features

The present invention concerns the production process of natural dyes for textile from by-products of vine-growing and winemaking sectors. The new practice was carried out to valorise the winery by-products and to convert them into co-products, reducing their disposal costs. The invention improves the sustainability of winery industry focusing on a new market able to generate added value to reference sector. Phenolic fraction of pomace and leaves were extracted by an ultrasound assisted green technology. The dye solution was subsequently concentrated using reverse osmosis and then stabilized with the production of colouring powder characterized by high dyeing activity. The new natural colours were subjected to colouring tests on textiles with different results of hue and chroma.

Possible Applications

– Conversion of by-products into co-products
– Production of natural dyes for textiles sector
– Different colouring activity on textile as function of raw material, quantity and quality of polyphenols and dyeing techniques
– Production of different textiles characterized by different hue and chroma


– By-products valorization
– Improvement of industry sustainability
– Recovery of phenolic compounds from by-products
– Characterization of natural dyes
– Production of added value for winery sector