Supercritical Fluid Extraction Of Carotenoids Research Articles

Valorisation of mango peel: Proximate composition, supercritical fluid extraction of carotenoids, and application as an antioxidant additive for an edible oil

Mango peel (MP) is an important by-product of the industrial mango processing, rich in phytochemical compounds. This study optimized the operating parameters of the supercritical CO2 extraction (ScCO2) of carotenoids from MP by means of a Box-Behnken design. The MP was characterized in terms of its proximate composition, and the effects of freeze-drying and air-drying on its total carotenoid content were investigated. The carotenoids profile of the optimal ScCO2 extract was characterized by RP-UHPLC-DAD. This extract was evaluated as natural antioxidant for sunflower oil, using the Rancimat® method. MP displayed high contents of crude protein and phenolic compounds. Although freeze-drying prevented the degradation of all-trans-β-carotene, air-drying was selected for the valorisation strategy. The higher yields of carotenoids were found at 25.0 MPa, 60 °C, and 15% w/w ethanol. Under these conditions the MP-extracts protected the sunflower oil against lipid oxidation, which could be regarded as an interesting alternative for MP valorisation.

Supercritical Fluid Extraction of Carotenoids from Vegetable Waste Matrices.

The aim of this work was to evaluate a previously-developed model on supercritical fluid extraction (SFE) for carotenoid recovery from carrot peels on various carotenoid-rich fruit and vegetable wastes. To this end, 15 matrices, including flesh and peels of sweet potato, tomato, apricot, pumpkin and peach, as well as flesh and wastes of green, yellow and red peppers, were submitted to SFE under optimised conditions (59 °C, 350 bar, 15 g/min CO2, 15.5% (v/v) ethanol as co-solvent, 30 min of extraction time). The obtained extracts were characterised for their total carotenoid content, antioxidant activity and total carotenoid recovery (TCR). TCR values were greater than 90% w/w for most samples, with β-carotene being the most successfully extracted compound (TCRs 88–100% w/w). More polar carotenoids, such as lutein and lycopene, exhibited lower TCRs. A comparison with literature data suggested that carotenoid extraction is partially dependent on the composition of vegetable matrices, specifically on polysaccharide and moisture content. The results indicated that the optimised SFE conditions can be used as a general model for carotenoid extraction from various fruit and vegetable matrices and as a viable method for adding value to these waste streams by generating carotenoid-rich extracts.

Multicomponent inverse modeling of supercritical fluid extraction of carotenoids, chlorophyll A, ergosterol and lipids from microalgae

The fundamentals of analyte extractable fraction, solubility, partitioning and mass transfer resistance in supercritical fluid extraction were studied using inverse modeling. These phenomena are essential for understanding, predicting and optimizing the supercritical fluid extraction process. Carotenoids, chlorophyll A, ergosterol and total lipids were extracted from the microalgae Chlorella sp. The analytes were measured continuously in-line and on-line using UV/Vis absorption spectroscopy measurements and by evaporative light scattering detection. Various pressures, temperatures, flow rates and fractions of ethanol as a co-solvent were evaluated. The extractable fraction of carotenoids, chlorophyll A and total lipids were dependent on the co-solvent fraction in the extraction phase. The additional amount that could be extracted by using more co-solvent followed a normal distribution, indicating that analytes should not simply be categorized into weakly or strongly bound. The characteristics of diminishing extraction rates over time was accounted for by analyte partitioning rather than intra-particle diffusion limitations.

Supercritical fluid extraction of carotenoids from shantane carrot

The effect of process parameters on the efficiency of carotenes extraction from carrot samples by supercritical CO2 is studied. The degree of carotenes extraction increases to approximately 35% at rising temperature (in the range between 60 and 80°C) and pressure (up to 350 atm) at a close to stable fraction of β-carotene (64–70%) in the obtained extracts.

Integrated supercritical fluid extraction and subcritical water hydrolysis for the recovery of bioactive compounds from pressed palm fiber

Pressed palm fiber (PPF), a residue obtained from palm oil industry, is a source of bioactive compounds, such as carotenoids, which are used as food additives. It also has cellulose and hemicellulose that can be used to yield fermentable sugars for the production of second generation ethanol. Supercritical fluid extraction (SFE) of pressed palm fiber provides an oil rich in carotenoids while subcritical water hydrolysis (SubWH) produces hydrolysates with high amounts of fermentable sugars. In this work, the effects of pressure (15–30MPa) and temperature (318 and 328K) on SFE of carotenoids were investigated. The SFE extract with highest carotenoid content was obtained at 318K and 15MPa (2.3% d.b., 0.81mg β-carotene/g extract). After the extraction, the influence of process temperature (423–633K), pressure (15 and 25MPa), solvent:feed ratio (120 and 240), and residence time (1.25–5min) on SubWH of the extraction residue was studied. At the temperature of 523K, the highest total reducing sugar yield (11–23g glucose/100g carbohydrate) and the highest biomass conversion (40–97%) were obtained for any pressure and solvent:feed ratio. The highest selectivity for saccharide formation was found at 423K (20–59mol glucose/mol furfural equivalent). Optimal conditions for high saccharide formation and low sugar degradation product in subcritical hydrolysis were obtained at 523K, 15MPa, solvent:feed ratio of 120, residence time of 2.5min with a total reducing sugar yield of 22.9g glucose/100g carbohydrate and a conversion of 84.9%.

Supercritical fluid extraction of carotenoids and chlorophylls a, b and c, from a wild strain of Scenedesmus obliquus for use in food processing

Faster and more selective extraction methods are urged to recover food-grade pigments and antioxidants from microalgae – which do not resort to food-incompatible and environment-unfriendly solvents. Hence, this study ascertained the influence of pressure, temperature, CO2 flow rate and a polar co-solvent upon the yields of carotenoids and chlorophylls in supercritical fluid extraction of Scenedesmus obliquus biomass. The highest carotenoid yield was attained at 250bar and 60°C. The yields of chlorophylls, when using plain CO2, increased slightly with pressure, but decreased with temperature and CO2 flow rate; the highest yield of chlorophyll a was at 4.3gCO2min-1, whereas ethanol as co-solvent increased all yields except that of chlorophyll c. The highest ratio of total carotenoids to chlorophyll a was reached at 250bar and 60°C. A remarkable selectivity was observed under these operating conditions, which may enable easy separation and purification of the aforementioned pigments.

Kinetics of the supercritical fluid extraction of carotenoids from microalgae with CO2 and ethanol as cosolvent

Abstract The kinetics of the supercritical fluid extraction of carotenoids from microalgae has been studied. The solvent systems used were supercritical carbon dioxide and CO 2 + 5% ethanol as a cosolvent. A penetration model developed by other authors was applied that, due to the spherical form of the cellular microalgae, was based on the application of the mass balance to a spherical particle. The fit of the model is satisfactory and it was able to predict in a reasonable way the extraction yield of the process. The comparison between experimental and calculated data provided a value for the internal diffusion coefficient and this allowed an analysis of the influence of the different variables in the extraction process.

Supercritical fluid extraction of carotenoids and chlorophyll a from Synechococcus sp.

Supercritical carbon dioxide extraction of carotenoids and chlorophylls is an alternative to solvent extraction because it provides a high-speed extraction process with a simple purification stage. In the study described here, carotenoid and chlorophyll extraction with supercritical CO 2 was explored using dry biomass from a marine cyanobacterium Synechococcus sp. as the raw material. The operation conditions were as follows: pressures of 100, 200, 300, 400 and 500 bar, temperatures of 40 , 50 and 60 °C. Analysis of the extracts was performed by measuring the absorbance and by using an empirical correlation. The results demonstrate that the highest extraction yield of total carotenoids is obtained operating at a pressure of 300 bar and a temperature of 50 °C. The most appropriate operating conditions to obtain the best yield in the extraction of chlorophyll a are 500 bar and 60 °C. The highest carotenoids/chlorophylls (Carot/Chlor) ratio is obtained at 200 bar and 60 °C. Under these operating conditions a higher selectivity is obtained and this should facilitate the separation and purification of the two extracted pigments.

Determination of Optimum Conditions for Supercritical Fluid Extraction of Carotenoids from Carrot (Daucus carota L.) Tissue

The extraction and assay of antioxidant vitamins, such as carotenes, by traditional solvent extraction (TSE) require multiple steps, are time-consuming, and consume large amounts of organic solvent. Supercritical fluid extraction (SFE), a newer method for extracting natural products, is cost effective and eliminates toxic organic waste. The objective of this study was to optimize SFE of carotenoids from freeze-dried carrots and to compare this extraction to TSE. To optimize SFE for carotenoids, a factorial experiment was conducted. The factors assessed were the temperature of the sample chamber (30, 40, or 50 °C), the pressure of the extraction fluid (300, 400, or 500 atm), and cosolvent modification (5 or 10% ethanol). The optimum conditions for extraction of α-carotene and β-carotene by SFE were 50 °C, 300 atm, and 10% cosolvent ethanol. Total provitamin A activity (α- plus β-carotene) was greater in SFE than in TSE. The time required for SFE is 1 h as compared to 6 h for TSE. SFE is a reliable and improved method for extraction of carotenoids from carrot tissue.