Green Chemistry in the Extraction of Natural Dyes from Colored Food Waste, for Dyeing Protein Textile Materials

Abstract

The beetroot peels can be a sustainable source of betalains that can dye the wool materials through green processes based on low water and energy consumption. Green chemistry in the extraction of betalains from colored food waste/peels from red beetroot involved the use of water as a solvent, without other additives. In order for the extract obtained to be able to dye the wool, it was necessary to functionalize betalains or even the wool. Three types of sustainable functionalizations were performed, with (1) acetic acid; (2) ethanol; and (3) arginine. For each functionalization, the mechanism that can justify dyeing the wool in intense colors was elucidated. The characterization of the extract was performed with the data provided by UV-VIS and HPLC-MS analyses. The characterization of the wool dyed with the extract obtained from the red beetroot peels was possible due to the information resulting from the FTIR and CIELab analyses. The functionalizations of betalains and wool in acid environments lead to the most intense red colors. The color varies depending on the pH and the concentration of betalains.

Passion Fruit—A Potential Crop for Exploration in Malaysia: A Review

“…According to the study made by BCC research company, the global plantderived natural products were valued at US$ 22.1 billion in 2012, and sales are expected to expand to US$ 26.6 billion by 2017 at a compound ground rate (CAGR) of 3.8% (Krause & Tobin, 2013). For instance, the European country (EU) has become the world's leading producer of sugar beets, with a cultivation area of 1.74 million hectares targeting the fruit for fresh consumption, sugar production, and natural dye production (Haß, 2022;Popescu et al, 2021). In America, Solanaceae Datura stramonium are planted commercially to produce tropane alkaloids, which function as starting material in the production of different pharmaceuticals products (Moreno-Pedraza et al, 2019).…”

Beta vulgaris L.—A Source with a Great Potential in the Extraction of Natural Dyes Intended for the Sustainable Dyeing of Wool

“…These characteristics widen the scope of use of natural pigments: from the food industry and medicine to the textile industry. Retrieving information on the behavior of pigments during the processing of food or drugs (pH, time, temperature) is particularly useful, but they are not sufficient for dyeing textile materials because most natural pigments have no affinity for textile fibers; dyeing becomes possible if a mordant is used or when pigments or even textiles have been previously functionalized [ 7 ].…”

“…It can be used as source for many biologically active substances, including betalains (betacyanins and betaxanthins), a group of highly bioactive pigments, as well as flavonoids (rutin, astragalin, kaempferol), terpenoids, saponins, phenolic acids, steroids, alkaloids, vitamins, tannins, sugars. Red-violet dyes of the betacyanin (betanin, E 162) type can be extracted from red beetroot ( Beta vulgaris L.) [ 7 , 8 ]. The sub-species Beta vulgaris L. ssp.…”

“…In Romania, the garden beet/red beet is an intensively cultivated vegetable, which is why its use for obtaining red-violet dyes has a very high potential. Although betalains is preferentially used in the food industry and medicine, recent research has shown that beetroot extracts can be used in the textile industry to ecologically dye all protein materials (with Oeko-Tex label) [ 7 , 12 ].…”

“…Betalains can be extracted either from the red beet pulp or from its peels, the latter being 4 to 7 times richer in betanin (the main red color component) depending on the maturity degree of the vegetable, the variety and the climatic conditions [ 7 , 13 , 14 , 15 ]. Along with betanin, other components of beetroot peel are: isobetanin, prebetanin, neobetanin, vulgaxanthin I, vulgaxanthin II, indicaxanthin, cyclodopa glucoside, glucoside of hydroxyindole-carboxylic acid, betalamic acid, L-tryptophan, p-coumaric acid, ferulic acid and traces of unidentified flavonoids were detected [ 15 , 16 , 17 ].…”