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

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.

Chemical Characterization of Different Products from the Tunisian Opuntia ficus-indica (L.) Mill.

“…Indeed, nopal has already been reused in a variety of products, such as fortified food, cosmetics, biopolymers, and flocculating agents for treating water and wastewater [ 28 , 29 , 30 ]. Peels have been valorized by the production of fortified foods, nutraceuticals, pharmaceuticals, natural colorants, and zinc oxide nanoparticles [ 27 , 31 , 32 , 33 ], while seeds have been reclaimed for the production of an edible oil with a high unsaturation degree [ 34 ], as well as a protein flour used to enrich bread and rice-based extrudates [ 35 , 36 , 37 ]. In every case, the prior knowledge of the plethora of phytomolecules constituting such by-products continues to be mandatory for explaining their technological, functional, and healthy attributes and, consequently, for researching and valorizing their potential reuses.…”

Disruptive Science and Sustainable Leadership for the Future of Colorants

“…Plants of current low economical value can also provide hidden valuable molecules. As a study reports, the use of Prickly Pear Peels of Opuntia ficus-indica (L. Miller) can be a source of colored molecules suitable for the dying of vegetal and animal fibers (Scarano et al 2020). Color fixation can often proceed successfully through physical treatment such as drying and heating, or by using natural mordants such as lemon juice, gallnut, pomegranate rind and gooseberry that can compete with metallic alternatives (Kandasamy et al, 2021).…”

Emulsions Incorporated in Polysaccharide-Based Active Coatings for Fresh and Minimally Processed Vegetables

“…Minimally processed fruits and vegetables are products that have increased their consumption in a healthy diet. These types of foods have not been physically altered from their native state and remain in a fresh form [ 2 ], representing a very promising expansion sector for the food industry [ 3 ].…”