Sustainability: Obtaining Natural Dyes from Waste Matrices Using the Prickly Pear Peels of Opuntia ficus-indica (L.) Miller

Pierpaolo Scarano,Alessia Postiglione,Carmine Guarino,Daniele Naviglio,Antonello Prigioniero,Rosaria Sciarrillo,Maria Tartaglia

doi:10.3390/agronomy10040528

Pierpaolo Scarano, Alessia Postiglione + Show 5 more

Open Access

https://doi.org/10.3390/agronomy10040528

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Abstract

In this work, the effect of dyes extracted through the Naviglio method (an eco-innovative solid-liquid extraction technique) was tested, which proved interesting for such an extraction. The dyes extracted from Opuntia ficus-indica (L.) Miller waste were treated to maximize the extraction of the coloring molecules. The extraction method was compared with conventional methods under the same conditions. The results showed that the extracts obtained with the different techniques, in the same extraction conditions (solvent, pH, temperature, time), were richer in the pigments for the extract obtained with the Naviglio method. The stability of the dyes was tested before the staining. A plant-based fiber, cotton, as well as an animal-based fiber, wool, were chosen for the staining tests. For the two types of fiber, two etching methods were used: one with rock alum, a method widely used to fix a color and one with lemon juice, a method used for a long time by rural populations who practiced the coloring of hides and tissues. In addition, the qualitative content of the pigments was also verified with an HPLC profile of the Opuntia ficus-indica (L.) Miller extracts. Ultimately, the results suggest that the Opuntia ficus-indica (L.) Miller fruit can be of great interest as a natural source of dyes and be used for tinctures.

Highlights

The agricultural and food industries are sensitive to the disposal and/or reuse of waste, especially due to the increasing amounts of waste in their production processes
The parts of Opuntia ficus-indica (L.) Miller are divided into fruits, cladodes and flowers; these parts have been frequently used as food for humans and farm animals, and in folk medicine, thanks to their nutritional properties and beneficial activities [4]
With a view to the circular economy, the dyes obtained from natural sources and from waste matrices deriving from the agro-food industry are increasingly at the center of research for their ecological value and non-toxicity

Summary

Introduction

The agricultural and food industries are sensitive to the disposal and/or reuse of waste, especially due to the increasing amounts of waste in their production processes. Recent studies have shown that there is an increasing interest in the nutri-energetics area, an industrial compartment which plans to transform agro-food waste into nutraceutical products, protein and organic fertilizers as well as textile fiber products. The Opuntia ficus-indica (L.) Miller belongs to the Cactaceae family and is found in nature as a weed edible plant (WEP), but there are large commercial plantations in South America (Mexico, Brazil and Chile) and Southern Europe (Italy and Spain). The parts of Opuntia ficus-indica (L.) Miller are divided into fruits, cladodes and flowers; these parts have been frequently used as food for humans and farm animals, and in folk medicine, thanks to their nutritional properties and beneficial activities [4]. Physical chemical differences exist between the cultivars of the different colors confirmed, in particular between the orange and the green fruit [6]; the difference in color induces variability in the nutritional and antioxidant properties of the fruit [7,8]

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