Optimization of natural dyes extraction from local crops

Nowadays, different classes of synthetic dyes are used for a broad range of application because of their lasting colour and wide range of colour choices. However, synthetic dyes have harmful effects on the environment and human beings. The negative impact of the discharge of synthetic dyes on aquatic ecosystem as well as the toxicity of chemicals used in dyes preparation has encouraged the revival in the use of natural colorants. Natural dyes obtained from plants, animals or minerals are considered renewable and sustainable bioresources that could become an eco-friendly alternative. Many plant species were used since antiquity in textile applications, food industry, cosmetics or medical applications. Cotinus Coggygria Scop. is a flowering plant of the family of Anacardiaceae, widespread in a large area from southern Europe, in Italy it is widespread in the areas of Marche and Umbria. Cotinus extract is a source of different interesting compound among which polyphenols, especially tannins, and flavonoids with interesting antioxidant, antibacterial and dyeing activities. In this work the traditional aqueous extraction method of active compounds, polyphenols and flavonoids, from Cotinus Coggygria Scop. was performed and the aqueous extract was analyzed for total phenolic compounds (TPC) and total flavonoids compounds (TFC) by means of UV/Vis spectroscopy. The maximum extraction values achieved as TPC and TFC were 270.3 mgGAeq/g of raw material dry basis and 154.77 mgQeq/g of raw material dry basis, respectively. In addition pigments of Cotinus were obtained by means of spray dryer technique and analaysed for colorimetric coordinates and thermal degradation profile.