Optimization of Extraction of Natural Antimicrobial Pigments Using Supercritical Fluids: A Review

Abstract

It has become increasingly popular to replace chemically synthesized compounds with natural counterparts mostly found in natural sources, such as natural pigments. The conventional extraction processes for these compounds are limited by the toxicity and flammability of the solvents. To obtain pure extracts, it is always a longer process that requires several steps. Supercritical fluid extraction (SFE) is a cutting-edge green technology that is continuously increasing and expanding its fields of application, with benefits such as no waste produced, shorter extraction time, automation, and lower solvent consumption. The SFE of natural pigments has high potential in food, textiles, cosmetics, and pharmaceuticals; there are a number of other applications that can benefit from the SFE technique of natural pigments. The pigments that are extracted via SFE have a high potential for application and sustainability because of their biological and antimicrobial properties as well as low environmental risk. This review provides an update on the SFE technique, specifically as it pertains to the optimization of health-promoting pigments. This review focuses on antimicrobial pigments and the high efficiency of SFE in extracting pure antimicrobial pigments. In addition, the optimal conditions, biological activities, and possible applications of each category are explained.

An eco-friendly method of extracting alizarin from Rubia tinctorum roots under supercritical carbon dioxide and its application to wool dyeing

“…After the static time, the valve was adjusted to allow cooled, liquefied scCO 2 to pass through the extracting vessel (dynamic conditions). In the dynamic mode, the plant matrix is regularly fed with fresh CO 2 , and the extracted components are moved from the extraction vessel into the collecting system 41 , 42 .…”

Green Antimicrobials as Therapeutic Agents for Diabetic Foot Ulcers

“…However, the techniques used to isolate these small bioactive molecules have not always been the most environmentally friendly. The conventional extraction methods have contained numerous toxic and flammable solvents, used high temperatures and energy demands, and extended extraction times that lead to molecule degradation [ 36 , 37 ]. The implementation of green chemistry in extraction processes is essential to reduce the release of chemicals hazardous to human health and the environment [ 36 ].…”

“…The implementation of green chemistry in extraction processes is essential to reduce the release of chemicals hazardous to human health and the environment [ 36 ]. Extraction methods based on green principles consume less energy, exploit alternative solvents, and utilize sustainable resources while producing high-quality and safe extracts [ 36 , 37 ].…”

Insight into Green Extraction for Roselle as a Source of Natural Red Pigments: A Review

“…Extraction is the process of separating constituents from natural substances using chemical or physical means. As a part of its efforts to conserve the environment, the global community has recently adopted green extraction [ 64 , 65 ]. ScCO 2 as green extraction is based on methods that take less energy, permit the use of alternative solvents and renewable resources, and provide extracts that are both safe and high quality.…”

“…In addition, the SFE extract has no residual solvent, making it very pure. Furthermore, the solvent of SFE can be recycled using a compressor, thus it will reduce the production cost [ 64 ].…”