Pressurized Hot Ethanol Extraction of Carotenoids from Carrot By-Products

Abstract

Carotenoids are known for their antioxidant activity and health promoting effects. One of the richest sources of carotenoids are carrots. However, about 25% of the annual production is regarded as by-products due to strict market policies. The aim of this study was to extract carotenoids from those by-products. Conventional carotenoid extraction methods require the use of organic solvents, which are costly, environmentally hazardous, and require expensive disposal procedures. Pressurized liquid extraction (PLE) utilizes conventional solvents at elevated temperatures and pressure, and it requires less solvent and shorter extraction times. The extraction solvent of choice in this study was ethanol, which is a solvent generally recognized as safe (GRAS). The extraction procedure was optimized by varying the extraction time (2–10 min) and the temperature (60–180 °C). β-Carotene was used as an indicator for carotenoids content in the carrots. The results showed that time and temperatures of extraction have significant effect on the yield of carotenoids. Increasing the flush volume during extraction did not improve the extractability of carotenoids, indicating that the extraction method was mainly desorption/diffusion controlled. Use of a dispersing agent that absorbs the moisture content was important for the efficiency of extraction. Analysing the content of β-carotene at the different length of extraction cycles showed that about 80% was recovered after around 20 min of extraction.

Capacity of natural β-carotene loaded microemulsion to protect Caco-2 cells from oxidative damage caused by exposure to H2O2

“…Conventional methods for the extraction of natural β-carotene from cellular structures require large amounts of organic solvents which are costly, environmentally hazardous, and need expensive disposal procedures (Mustafa, Trevino, & Turner, 2012). Also, the traditional extraction of natural β-carotene is no longer recommended because of the risk of organic solvent residues and loss of β-carotene as a consequence of solvent evaporation (Illés, Daood, Biacs, Gnayfeed, & Mészáros, 1999).…”

Sustainable analytical chemistry—more than just being green

“…However, the replacement of a quite toxic solvent with a less toxic one is perhaps not as clear, especially since different quantities of solvents are needed to achieve the same result. One of our approaches has been to replace hexane with hot ethanol in the extraction of carotenoids from carrot [48]. Our calculations showed that for the extraction of 1 g of β-carotene, 1.4 kg of ethanol at 60 °C was needed as a solvent, while approximately only 90 g of THF at ambient temperature was needed to achieve the same extraction, based on solubility data [49].…”

Extracts from mango peel by-product obtained by supercritical CO2 and pressurized solvent processes

“…Pressurized liquid extraction uses liquid solvents at elevated temperature and pressure, which produces a reduction in the solvent surface tension; which facilitates the penetration of solvent into the matrix pores. The process causes a matrix disruption, therefore enhancing the mass transfer of the analyte from the sample to the solvent (Mustafa, Trevino, & Turner, 2012).…”