Dearomatization of Antioxidant Rosemary Extracts by Treatment with Supercritical Carbon Dioxide

Quantitative Analyses of Nine Phenolic Compounds and Their Antioxidant Activities from Thirty-Seven Varieties of Raspberry Grown in the Qinghai-Tibetan Plateau Region

In this work, an efficient method for the rapid extraction and separation of antioxidant phenols was developed and optimized. The method was then applied to extract and separate nine phenols from 37 varieties of raspberry, in which their antioxidant activities were further investigated. First, the extraction was conducted using ultra-sonication, which was then further separated using reversed-phase high-performance liquid chromatography/ultraviolet (RP-HPLC/UV) analysis. In this step, several key parameters (volume of the extraction reagent, time of extraction, and the temperature of extraction) affecting its efficiency were investigated and optimized using the response surface methodology (RSM) combined with the Box–Behnken design (BBD) so that the optimal conditions were obtained. According to the overall results of the optimization study, the optimal conditions were chosen as follows: volume of extraction reagent = 2.0 mL, time of extraction = 50.0 min, and temperature of extraction = 50 °C. The optimal conditions were then applied to extract nine phenols, including gallic acid, catechin, chlorogenic acid, vanillic acid, syringic acid, cumaric acid, ferulic acid, rosemary acid, and quercetin from 37 raspberry varieties. The extracted phenols were characterized and their antioxidant activities, including DPPH⁻ and ABTS⁻ free radical scavenging and intracellular reactive oxygen species (ROS) activity, using HepG2 cells as the model, were subsequently studied. The findings suggested that although their contents varied among most raspberry varieties, these phenols significantly contributed toward their antioxidant capacity and scavenging intracellular ROS activities. This study provides a scientific and theoretical basis for the selection of raspberry varieties and product development in Qinghai province.

Subcritical water extraction, UPLC-Triple-TOF/MS analysis and antioxidant activity of anthocyanins from Lycium ruthenicum Murr

In this work, it has been developed an efficient method for extraction of anthocyanin from Lycium ruthenicum Murr. and the antioxidative activities research. Subcritical water extraction was investigated as a green technology for the extraction of anthocyanin from L. ruthenicum. Several key parameters affecting extraction efficiency were investigated and optimized by response surface methodology (RSM) combined with Box-Behnken design (BBD). The optimum extraction conditions and the desirability of model were the time of extraction = 55 min and the flow rate was 3 mL/min at 170 °C. At this operating condition, the content of anthocyanin was high to 26.33%. Subcritical water extraction was more efficient than using hot water or methyl alcohol for the extraction of anthocyanin. The composition of anthocyanins from L. ruthenicum has been investigated by high-performance liquid chromatography with diode array detector (HPLC-DAD) and Ultra Performance Liquid Chromatography-Triple-Time of Flight Mass Spectrometer (UPLC-Triple-TOF/MS). Seven anthocyanins have been detected, all of which were identified and quantified. Furthermore, the anthocyanins extracted by SWE showed significantly better antioxidant activity than the anthocyanins extracted by hot water or methyl alcohol according to DPPH and ABTS assay. SWE with significantly higher anthocyanin and antioxidant activity were achieved compared to conventional methods.

Influence of the CO2 Quality in the Antioxidant Activity of Rosemary Extracts Dearomatized by Supercritical Fluid Extraction

The effect of the CO2 quality (mainly related to CO2 content) in the antioxidant activity of rosemary extracts deodorized by using a supercritical fluid extraction process is analyzed. A Taguchi experimental design was used to study the influence of the CO2 quality on the antioxidant activity of the rosemary dearomatized extracts. The antioxidant activity of the rosemary extracts obtained in optimal conditions was tested with sunflower oil.

An evidence-based systematic review of rosemary (Rosmarinus officinalis) by the Natural Standard Research Collaboration

An evidence-based systematic review of rosemary (Rosmarinus officinalis), including written and statistical analysis of scientific literature, expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Application of supercritical CO(2) extraction for the elimination of odorant volatile compounds from winemaking inactive dry yeast preparation

A procedure based on the application of supercritical CO(2) extraction to reduce and/or to remove odorant volatile compounds from a winemaking inactive dry yeast (IDY) preparation has been set up. By applying a factorial design, a screening of different temperatures and pressure conditions was assayed in order to determine the optimal deodorization conditions, and afterward the effect of several sample pretreatments was investigated. The best extraction conditions were achieved at 200 atm and 60 degrees C, applying the cryogenic grinding of the sample and using 40% (w/w) ethanol as cosolvent. By using these conditions, it was possible to reduce to approximately 70% of the volatile compounds present in the samples that may be released into the wines and therefore affecting their sensory characteristics. Odorant volatile compounds such as 2-methylhydroxypyrrole, 2-ethyl-6-methylpyrazine, and 2,3,5-trimethylpyrazine completely disappeared from the deodorized sample as verified by GC-O analysis. Additional experiments in model wines confirmed the low release of volatile compounds from the deodorized samples, without provoking any change to their nonvolatile composition (nitrogen compounds and neutral polysaccharides) that is related to the technological properties of these preparations.

Meat-based functional foods for dietary equilibrium omega-6/omega-3

Nutritionists encourage improving the diet by combining meat products with fish or other sea-related foods, in order to equilibrate the omega-6/omega-3 ratio. Strong scientific evidence supports the beneficial health effects of a balanced omega-6/omega-3 PUFA (poly unsaturated fatty acids) diets. In the present work, the scientific bases of new functional meat products with both a balanced omega-6/omega-3 ratio and a synergic combination of antioxidants are discussed. The aim is to contribute to the dietary equilibrium omega-6/omega-3 and to increase the antioxidant intake. Conventional meat products supplemented with a specific fatty acids and antioxidants combination led to functional foods with healthier nutritional parameters.

Supercritical CO2 extraction and purification of compounds with antioxidant activity

Supercritical fluid extraction (SCFE), based on the utilization of a fluid under supercritical conditions, is a technology suitable for extraction and purification of a variety of compounds, particularly those that have low volatility and/or are susceptible to thermal degradation. The interest in SCFE is promoted by legal limitations of conventional solvents for food and pharmaceutical uses. The physicochemical properties of supercritical CO2 (higher diffusivity, lower viscosity, and lower surface tension than conventional solvents) facilitate mass transfer and allow an environmentally friendly operation. This article presents a comprehensive compilation of data on the supercritical CO2 extraction of antioxidant compounds from vegetal materials, with particular attention to those of a phenolic nature. Aspects concerning the supercritical operation for extraction and fractionation of antioxidants compounds are considered, including equilibrium solubility of pure compounds and effects of the operational conditions on the antioxidant activity of isolated fractions. The data are compared to those reported for synthetic antioxidants and natural extracts obtained by conventional solvent extraction from vegetal matrices.

Countercurrent supercritical fluid extraction and fractionation of high-added-value compounds from a hexane extract of olive leaves

Countercurrent supercritical fluid extraction (CC-SFE) at a pilot scale plant was used for fractionation of high-added-value products from a raw extract of olive leaves in hexane. Compounds found in the raw extract were waxes, hydrocarbons, squalene, beta-carotene, triglycerides, alpha-tocopherol, beta-sitosterol, and alcohols. The CC-SFE extraction process was investigated according to a 2(3) full factorial experimental design using the following variables and ranges: extraction pressure, 75-200 bar; extraction temperature, 35-50 degrees C; and ethanol as modifier, 0-10%. Data were analyzed in terms of extraction yield, enrichment, recovery, and selectivity. Higher extraction yields were attained at 200 bar. For most of the compounds analyzed enrichment was attained at the same conditions, that is, 75 bar, 35 degrees C, and 10% ethanol. Hydrocarbons were usually recovered in the separators, whereas waxes and alpha-tocopherol remain in the raffinate. Selectivity data reveal that alpha-tocopherol is the most easily separable compound. The influence of the experimental factors on the recovery of all the compounds was studied by means of regression models. The best fitted model was attained for beta-sitosterol, with R2 = 99.25%.

Subcritical water extraction of antioxidant compounds from rosemary plants

Subcritical water extraction at several temperatures ranging from 25 to 200 degrees C has been studied to selectively extract antioxidant compounds from rosemary leaves. An exhaustive characterization of the fractions obtained using subcritical water at different temperatures has been carried out by LC-MS, and the antioxidant activities of the extracts have been measured by a free radical method (DPPH). Results indicate high selectivity of the subcritical water toward the most active compounds of rosemary such as carnosol, rosmanol, carnosic acid, methyl carnosate, and some flavonoids such as cirsimaritin and genkwanin. The antioxidant activity of the fractions obtained by extraction at different water temperatures was very high, with values around 11.3 microg/mL, comparable to those achieved by SFE of rosemary leaves. A study of the effect of the temperature on the extraction efficiency of the most typical rosemary antioxidant compounds has been performed.

Supercritical Fluids and the Food Industry

This paper reviews the use of supercritical fluids in various aspects of the food industry, and is divided into six different areas: modeling of supercritical fluids, separation of extracted material, supercritical carbon dioxide as a solvent for extraction, supercritical fluids and analytical uses, and supercritical fluids and novel methods of food processing. An assortment of solutes are covered in the extraction section of the paper, including antineoplastic agents and lipids. The analytical methods section covers supercritical fluid chromatography, pesticide detection, and lipid analysis. The novel methods section discusses supercritical fluid extrusion and a new method of eliminating hexane from soybean oil.

Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver

The effects of a water-soluble extract (WSE) of rosemary and its purified antioxidant rosmarinic acid (RA) on xenobiotic metabolizing enzymes (XME) were studied in rat liver after dietary administration. The modulation of phase I enzymes such as cytochrome P450 (CYP) 1A, 2B, 2E1, 3A, and phase II enzymes such as glutathione S-transferase (GST), quinone reductase (QR) and UDP-glucuronosyltransferase (UGT) was evaluated by measuring enzyme activities with specific substrates. Protein levels of CYPs and rGST A1/A2, A3/A5, M1, M2 and P1 were measured using antibodies in Western blots. Caffeic acid was also studied because it results from RA biotransformation in rat after oral administration. Male SPF Wistar rats received the different compounds at 0.5% (w/w) incorporated into their diet for 2 weeks. WSE, containing RA, flavones and monoterpenes enhanced CYP 1A1, 2B1/2, 2E1 and GST (especially rGST A3/A5, M1 and M2), QR and UGT. On the contrary, no modification of XME was observed in response to RA or CA (except for a slight increase of UGT activity after CA treatment). The induction of XME by WSE could be attributed to flavones, monoterpenes or an additive effect of all components.

Liquid chromatographic-mass spectrometric analysis of supercritical-fluid extracts of rosemary plants

A two-step supercritical fluid extraction process of rosemary leaves, on a pilot plant scale, is proposed to divide the oleoresin into two fractions with different antioxidant activities and essential oil composition. Rosemary leaves were extracted by using different conditions of pressure and temperature as well as different conditions for fractionation of the extracts. Conditions can be tuned to selectively extract one antioxidant fraction with almost no residual aroma. In the present investigation, the antioxidant fraction was exhaustively studied in terms of antioxidant activity measurements as well as of chemical composition. An LC-MS method was adapted to perform the analysis and identification of the compounds responsible for the antioxidant activity of the extracts. Different extraction and fractionation conditions were studied in order to correlate the process conditions with the antioxidant activities obtained.

Supercritical fluid extraction and fractionation of different preprocessed rosemary plants

Two-step supercritical fluid extraction of rosemary leaves at selected conditions of pressure and temperature is proposed to divide the oleoresin into two fractions with different antioxidant activities and essential oil compositions. Rosemary leaves obtained from different sources have been extracted and evaluated in terms of antioxidant activity and essential oil yield and composition. Also, a new device is proposed to improve the performance of the technique in terms of sample collection after SFE.