Hydrotropic Extraction Research Articles

Ultrasound assisted hydrotropic extraction of polyphenols from green tea leaves in aqueous media

A green approach of combining hydrotrope assisted extraction with ultrasound was adopted to extract the polyphenols from tea leaves. This process significantly reduced extraction time and solvent quantity, while enhancing the quality of the final product. Sodium cumenesulfonate (NaCuS), sodium p-toluenesulfonate (NaPTS) and sodium xylenesulfonate (NaXS) were chosen for solubilizing tea polyphenols. Among the hydrotropes used, NaCuS proved to be efficient particularly in solubilizing tea polyphenols. The extraction process was thoroughly studied by varying factors such as the solid to solvent ratio (S/N), ultrasonic duration and temperature. Comprehensive solubility studies of polyphenols were conducted across different solvents, pH levels, temperatures, treatment durations and solid loadings. To optimize the experimental parameters, a central composite design (CCD) of response surface methodology (RSM) was employed. The results demonstrated that a polyphenol extraction efficiency of 68.429% was achieved at a solid to solvent ratio of 0.05, ultrasonic time of 3.2 h and temperature of 49.9 °C. This research firmly established the effectiveness of ultrasound assisted extraction for obtaining polyphenols from green tea in a highly efficient manner.

Wheat bran fractionation: Effect of steam explosion and hydrotropic extraction conditions on the recovery of sugars and lignin

Wheat bran, a major by-product of wheat processing, contains several valuable components that can serve as a potential feedstock for chemical production. This study presents a multiple-stage fractionation method, involving steam explosion and hydrotropic extraction, which were investigated with the goal of separating the main structural bran components: starch, protein, hemicelluloses, lignin, and cellulose. With prior de-starching and de-proteination, acid-catalysed steam explosion (STEX1: 218 °C, 8 min, 0.05 wt% H2SO4) solubilised up to 97% of the arabinoxylans. Higher monosaccharide yields arising from hemicelluloses were observed in the de-starched and de-proteinated bran than in untreated bran prior to steam treatment. Subsequent treatment using the 40% w/w hydrotrope solution, sodium xylene sulfonate (SXS), at 170 °C for 1 h (HEX1) showed lignin recovery of up to 42.6% from the steam-exploded bran, which was higher than 25.1% lignin recovery from the de-starched, de-proteinated and steam exploded bran. The lignin recovery values were slightly underestimated as some lignin ends up in the wash, which proved difficult to quantify. Finally, glucose monomer release during cellulose hydrolysis occurred most rapidly in the bran material that had undergone prior treatments of de-starching, de-proteination, steam explosion and hydrotropic treatment, with complete hydrolysis in less than 24 h for the de-starched, de-proteinated, steam exploded for both STEX1 and STEX3 (219 °C, 0.10 wt%, 14 min) and hydrotropically treated (HEX1). The selective release of wheat bran components in separate stages of the wheat-bran fractionating scheme provides a platform for further valorisation of each component into commercially relevant products. Structural elucidation of the recovered wheat bran lignin using 2D HSQC NMR revealed that oxidised syringyl (S′) units increased from 13.2 units per 100 C2 aromatic group (Ar) in bran without prior treatment, to 16.9 units/100 Ar in steam exploded bran and 18.2 units/100 Ar in de-starched, de-proteinated and steam exploded bran. The change in guaicyl (G) unit frequencies as well as the oxidised G units (G′) remained low across samples. As less oxidation is desired for further lignin valorisation, the results herein offer insights on future work for utilising wheat bran lignin.

A Technical process of phytoconstituents extraction using Hydrotropes: Green and Sustainable Approach

Background: The design of green and sustainable extraction methods of natural products is currently a prime topic in the multidisciplinary area of applied chemistry, biology, and technology, with the growing consumer demand for greener alternatives that do not involve any chemicals and industry concerns of sustainable, nontoxic extraction routes, the application of novel extraction technologies in the drug industry have been widely studied. Hydrotrope has fewer toxic effects, is economically friendly, and is independent of pH. These compounds can enhance the bioavailability, solubility, dissolution, extraction yield, and purity of extracted phytoconstituents. Conclusion: The recent review illustrates the extensive references to the novel extraction of Phyto active compounds through hydrotrope and depicts the summary of updated extraction technologies. The technique is recent, simple, less expensive, and environmentally advantageous. Updated advanced extraction methods like ultrasound-assisted hydrotropic extraction (UAHE), microwave-assisted hydrotropic extraction (MAHE), and ultrasonic microwave-assisted hydrotropic extraction (UMAHE) have been considered a clean, green, and efficient alternatives to conventional extraction technologies. The active phytoconstituents extraction using hydrotrope with advanced extraction technologies has claimed to enhance the extraction yield up to 99% compared with the extraction involving organic solvent of such bioactive. Consequently, when carried out at a reduced temperature, hydrotropic extraction provided a higher extraction yield in a lesser time and maintained the purity of phytoconstituents.

Improved Hydrotropic Extraction of Carnosic Acid from Rosemary and Sage with Short-Chain Monoalkyl Glycerol Ethers

Hydrotropic extraction in water with biobased amphiphiles is considered as an interesting alternative to conventional extraction with organic solvents. In this study, butyl, isoamyl, and pentyl glycerol ethers (C4Gly, iC5Gly, and C5Gly, respectively) are investigated for the extraction from rosemary (Rosmarinus officinalis) and sage (Salvia officinalis) of carnosic acid (CA), a powerful natural antioxidant used as an alternative to synthetic ones in food and cosmetic industries. First, interactions between CA and hydrotropes are studied to set the extraction conditions, resulting in the measurement of the solubility curves and miscibility of CA in the hydrotropic solutions. Then, C5Gly is shown to have the highest efficiency to extract CA, which is rationalized with a molecular model previously established for an alkyl polyethylene glycol ether (CiEj) series of amphiphiles based on their log P and molecular volume. Additionally, measurement of the contact angles of the hydrotropic solutions on rosemary leaves indicates that the efficiency of the hydrotrope is also dependent on the interfacial tension.

Extraction methodology of lignin from biomass waste influences the quality of bio-oil obtained by solvothermal depolymerization process

Lignin from sugarcane bagasse was extracted using three different methods such as Alkaline, Ethanosolv, and Hydrotropic extraction and the effect of each method on yield and quality of bio-oil obtained when the lignin was depolymerized through solvothermal liquefaction was studied using ethanol as solvent. The maximum lignin yield was obtained in the hydrotropic extraction method when Sodium Xylene Sulfonate was used as the hydrotropic solvent at a concentration of 1.43 M and a temperature of 90 °C. Hydrothermal experiments were performed at temperature of 250 °C with a residence time of 30 min and lignin to ethanol ratio of 1:200 g/mL respectively. Among the methods used, the Ethanosolv lignin showed the highest extent of depolymerization (86.7%) to yield bio-oil at 250 °C with reduced biochar formation at lignin to solvent ratio of 1:200. Biochar obtained was used in adsorption studies of Cadmium (Cd), Lead (Pb), Nickel (Ni), and Zinc (Zn) and results showed that more than 85% removal of all the metals under lower concentration levels.

Insight into the Isolation, Synthesis, and Structure-Activity Relationship of Piperine Derivatives for the Development of New Compounds: Recent Updates.

Currently, black pepper commands the leading position among all the spices as a spice of great commercial importance in all the world trade and finds its way into the dietary habits of millions of people worldwide. Black pepper is biologically known as Piper nigrum and contains piperine as the main active chemical constituent. This paper highlights various general methods for extracting piperine from the crude drug such as maceration extraction, hydrotropic extraction, accelerated solvent extraction, thin-layer chromatography, and extraction with ethanol & dichloromethane Ionic fluid-based ultrasonic-assisted extraction, etc. In this review, piperine and its analogs exhibit numerous pharmacological activities and synthetic schemes of insecticidal activity, anti-cancer activity, anti-inflammatory activity, anti-diabetic activity, anti-hyperlipidemic activity, antifungal activity, narcotic activity, etc. and its structure-activity relationship. The biochemistry of piperine has also been summarized in the presented article. This very exhaustive review details the complete information about piperine, its derivatives, and further processing. Furthermore, the current study summarises recent research that has linked piperine to its use as a treatment for a variety of ailments.

Experimental design of hydrotropic extraction for recovery of bioactive limonin from lemon (Citrus limon L.) seeds

ABSTRACT A potential bioactive compound limonin is found in citrus fruits, especially tremendous extent in seeds. In this study, an attempt has been made to develop a novel and proficient extraction method by using the hydrotrope solution to recover limonin from lemon (Citrus limon L.) seeds. Initially, the extraction time (4 h) was screened by varying the time from 3 to 6 h by fixing the concentration of hydrotrope (sodium salicylate), raw material loading and temperature of the extraction. To enhance the yield of hydrotrope extraction, Box–Behnken experimental design (BBD) was proposed. The maximum yield of limonin recovered was 6.41 mg g−1 at optimized process conditions such as the hydrotrope concentration of 1.65 M, raw material loading of 8.08%, and temperature of 44°C. The obtained limonin yield in this study was higher compared to the other studies using different citrus seeds. The recovered limonin was identified by using Fourier Transform-Infrared Spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). Furthermore, the scavenging ability was evaluated for the extracted limonin, and it is proved to be a potent antioxidant. Therefore, the results revealed that the extraction of bioactive compounds using hydrotrope is efficient, eco-friendly and can also lower the usage of organic chemicals.

Intensified extraction of valuable compounds from clove buds using ultrasound assisted hydrotropic extraction

Essential oil and the prime compounds (eugenol and eugenol acetate) present in clove have numerous biological potentials and usages leading to the commercial importance. A symbiotic effect between sonication and the hydrotropic solution was investigated for selective extraction of valuable compounds, namely eugenol and eugenol acetate from the clove buds. The combined approach was aimed to lessen extraction time while maintaining selectivity by improving the mass transfer characteristics. Solubility study has assisted in selecting a suitable hydrotrope i.e. sodium cumene sulfonate for extraction. Using parametric study and optimization by central composite design, optimum conditions have been achieved as 38 °C temperature, 1.04 M NaCuS concentration, 8.2 g solid loading, 158 W sonication power and 30 min of extraction time with the extraction yield of 20.04 %. The prediction of the yield using models developed by the central composite design and an artificial neural network was within 5 % of the actual value, thereby providing aid for estimating the yield without experimenting. It was possible to reuse the hydrotropic solution after extraction without affecting the yield. The impact of sonication on clove buds has been assessed using the scanning electron microscope. In comparison with extraction using an open reflux system, ultrasound assisted hydrotropic extraction has tendered an eco-friendly and sustainable solution for isolating target compounds from clove buds.

An extensive parameter study of hydrotropic extraction of steam-pretreated birch

Efficient fractionation of lignocellulosic biomass is an important step toward the replacement of fossil-based products. However, the utilisation of all of the components in biomass requires various fractionation techniques. One promising process configuration is to apply steam explosion for the recovery of hemicelluloses and a subsequent hydrotropic extraction step for the delignification of the remaining solids. In this work, the influence of residence time, temperature and biomass loading on lignin recovery from birch using sodium xylene sulphonate as a hydrotrope was investigated. Our results show that residence time, temperature and biomass loading correlate positively with lignin extraction, but the effects of these parameters were limited. Furthermore, when steam explosion was implemented as the initial step, hydrotropic extraction could be performed even at room temperature, yielding a lignin extraction of 50%. Also, hydrothermal degradation of the material was necessary for efficient delignification with sodium xylene sulphonate, regardless of whether it occurs during steam explosion pretreatment or is achieved at high temperatures during the hydrotropic extraction.

Enrichment of patchouli alcohol in patchouli oil by aiding sonication in hydrotropic extraction

Patchouli alcohol, a tricyclic sesquiterpene, is a vital component of patchouli essential oil which is primarily isolated from the aerial part of Pogostemon cablin and is majorly used in fragrance industries. An intensified technique of hydrotropy coupled with sonication was investigated to enhance the purity of patchouli alcohol in patchouli oil using four different hydrotropes viz., resorcinol, p-toluene sulphonic acid, sodium salicylate, and sodium cumene sulphonate. The influence of various parameters namely sonication time (5 and 15 min), ultrasound amplitude (20–40 %), and pulse ratio (10:50 and 30:30 s) over varying concentration of hydrotropic solution (0.2–2 M) on the patchouli alcohol content was assessed using parametric study. Amongst the four hydrotropes, sodium cumene sulphonate has provided the highest purity (96.12 %) of patchouli alcohol for 0.2 M concentration, 15 min sonication time, 40 % amplitude, and 30:30 s pulse ratio against 33.13 % in pure oil. Hydrotropy combined with ultrasound treatment has enriched the composition of patchouli alcohol in patchouli oil to a larger extent when compared with hydrotropic extraction without sonication. Further, a scale-up study has provided promising outcomes suggesting a suitable alternative technique as a sustainable solution.

Process Intensification for Enzyme Assisted Turmeric Starch Hydrolysis at Hydrotropic and Supercritical Condition

The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is important to target starch removal by hydrolysis to enhance the rate and extent of extraction of curcuminoids. Enzymes are green catalysts and their activity can be enhanced by working on certain parameters. In the case of starch hydrolysis, α- amylase is more efficient when the starch is in the gelatinized form than when it is in its natural form. α-Amylase activity improves under supercritical carbon dioxide (scCO2) conditions. Certain surfactants improve α- amylase activity. Hydrotropes are a mild form of the surfactants. However, there are no reports on hydrolysis of turmeric starch in hydrotropic or supercritical (SFC) conditions. The work in this report shows beneficial effect of hydrotrope on the enzymatic reactions. There is marked enhancement in the diffusion coefficient (De) for curcuminoid extraction. The increased starch hydrolysis also improves the solid filtration rates after hydrotropic extraction of the curcuminoids. In the case of hydrotropic extraction of curcuminoids alone otherwise the filtration rate decreases due to the sticky nature of the extraction mass, caused by swelling of the starch. The present work includes hydrolysis of turmeric starch in its natural and gelatinized forms using α-amylase in hydrotrope solution (HS) and scCO2.The starch hydrolysis parameters include α-amylase concentration, solid loading concentration, scCO2 flow rate, presence of modifier in scCO2, residence time and scCO2 backpressure. The optimum hydrolysis parameters are 200 IU.cm-3 of α-amylase, at 328 K, 10 % (w/w) of turmeric loading concentration, 6.5 reaction pH, 900 rpm agitation speed for hydrotropic hydrolysis while the optimum conditions are 5 % w/w turmeric loading concentration, 40 min of scCO2 residence time, 15 cm3 of scCO2 phase modifier and 15 MPa as the scCO2 backpressure. The De for hydrolysis in the HS for turmeric starch in gelatinized form (A) was 4.1 x 10-11 m2s-1 and De for starch hydrolysis methods including in HS for turmeric starch in natural state (B), SFC condition for turmeric starch in natural state (C) and SFC for turmeric starch in gelatinized (D) were approximately 4.1 x 10-12 m2s-1. De for native turmeric starch in the absence of hydrotrope and SFC (E), and in case of gelatinized turmeric starch hydrolysis in absence of SFC and hydrotrope were 4.1x 10-14 and 4.1x 10-13 m2s-1, respectively. The filtration rates for (A), (D), (B), (C), (E) were 2 x 10-4, 1.25 x 10-11, 1.4 x 10-11, 7.3 x 10-11, 8.2 x 10-11 kgm2s-1 respectively. The De and filtration rate were noted in order (A) > (D) > (B) > (C) > (E) > (F). The 2.5 h SFC and 2.15 h HS enzyme treated turmeric powder gave 6.56 and 2.44 x 106 times increased filtration rate for curcuminoid extraction compared to untreated turmeric powder.

Hydrotropic Extraction of Carnosic Acid from Rosemary with Short-Chain Alkyl Polyethylene Glycol Ethers

Carnosic acid (CA) is a hydrophobic secondary metabolite and the main antioxidant of rosemary. Extractions of CA from whole leaves of rosemary have been performed with aqueous solutions of twelve s...

Elucidation of Changes in Cellulose Ultrastructure and Accessibility in Hardwood Fractionation Processes with Carbohydrate Binding Modules.

We have recently presented a sequential treatment method, in which steam explosion (STEX) was followed by hydrotropic extraction (HEX), to selectively fractionate cellulose, hemicellulose, and lignin in hardwood into separate process streams. However, above a treatment severity threshold, the structural alterations in the cellulose-enriched fraction appeared to restrict the enzymatic hydrolyzability and delignification efficiency. To better understand the ultrastructural changes in the cellulose, hardwood chips were treated by single (STEX or HEX) and combined treatments (STEX and HEX), and the cellulose accessibility quantified with carbohydrate-binding modules (CBMs) that bind preferentially to crystalline (CBM2a) and paracrystalline cellulose (CBM17). Fluorescent-tagged versions of the CBMs were used to map the spatial distribution of cellulose substructures with confocal laser scanning microscopy. With increasing severities, STEX increased the apparent crystallinity (CBM2a/CBM17-ratio) and overall accessibility (CBM2aH6 + CBM17) of the cellulose, whereas HEX demonstrated the opposite trend. The respective effects could also be discerned in the combined treatments where increasing severities further resulted in higher hemicellulose dissolution and, although initially beneficial, in stagnating accessibility and hydrolyzability. This study suggests that balancing the severities in the two treatments is required to maximize the fractionation and simultaneously achieve a reactive and accessible cellulose that is readily hydrolyzable.

Process Intensification for Enzyme Assisted Turmeric Starch Hydrolysis at Hydrotropic and Supercritical Condition

The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is thus important to target starch hydrolysis to enhance extraction of curcuminoids. In the case of starch hydrolysis, α- amylase is more efficient when the starch is in a gelatinised form than when it is in its natural form. The present work includes hydrolysis of turmeric starch in its natural and gelatinised forms using α-amylase in hydrotrope solution (HS) and scCO2. The optimum rate of starch hydrolysis was obtained using 200 IU.cm-3 of α-amylase, at reaction conditions of 6.5 pH at 328 K when 10 % w/w of turmeric powder was stirred at 900 rpm in hydrotrope solutions. The hydrolysis in 15 MPa scCO2 at room temperature required a phase modifier and 40 min of residence time. The enzyme-treatment of gelatinized turmeric powder in HS at optimized condition has shown an improved mass transfer and the filtration rate for curcuminoid extraction compared to enzyme untreated and natural turmeric powder in hydrotropic solution as reported in earlier research (Dandekar and Gaikar, 2008). Also, the enzyme aided hydrotropic extraction was found to be superior to scCO2 assisted extraction developed in present work in regard to the energy needs and equipment design.

Sequential fractionation of the lignocellulosic components in hardwood based on steam explosion and hydrotropic extraction

BackgroundThe forest biorefinery plays an important part in the evolving circular bioeconomy due to its capacity to produce a portfolio of bio-based and sustainable fuels, chemicals, and materials. To tap into its true potential, more efficient and environmentally benign methods are needed to fractionate woody biomass into its main components (cellulose, hemicellulose, and lignin) without reducing their potential for valorization. This work presents a sequential fractionation method for hardwood based on steam pretreatment (STEX) and hydrotropic extraction (HEX) with sodium xylene sulfonate. By prehydrolyzing the hemicellulose (STEX) and subsequently extract the lignin from the cellulose fraction (HEX), the major wood components can be recovered in separate process streams and be further valorized.ResultsUsing autocatalyzed STEX and HEX, hemicellulose (> 70%) and lignin (~ 50%) were successfully fractionated and recovered in separate liquid streams and cellulose preserved (99%) and enriched (~ twofold) in the retained solids. Investigation of pretreatment conditions during HEX showed only incremental effects of temperature (150–190 °C) and hold-up time (2–8 h) variations on the fractionation efficiency. The hydrolyzability of the cellulose-rich solids was analyzed and showed higher cellulose conversion when treated with the combined process (47%) than with HEX alone (29%), but was inferior to STEX alone (75%). Protein adsorption and surface structure analysis suggested decreased accessibility due to the collapse of the fibrillose cellulose structure and an increasingly hydrophobic lignin as potential reasons.ConclusionThis work shows the potential of sequential STEX and HEX to fractionate and isolate cellulose, hemicellulose, and a sulfur-free lignin in separate product streams, in an efficient, sustainable, and scalable process.

Ultrasound Assisted Hydrotropic Extraction: A Greener Approach for the Isolation of Geraniol from the Leaves of Cymbopogon martinii

Geraniol, a prime constituent in the leaves of Cymbopogon martinii, has a varied range of biological activities and applications. For the selective isolation of geraniol, a newer concept of combining hydrotropic extraction with ultrasound was adopted to reduce the time of extraction and hydrotrope requirement while maintaining the quality of the product. Sodium cumene sulfonate was selected as a suitable hydrotrope among sodium cumene sulfonate, sodium salicylate, sodium salt of para-toluene sulfonic acid, and resorcinol using the solubilization study. The screening of extraction parameters, viz., ultrasound amplitude, cycle time, volume of hydrotropic solution, hydrotropic concentration, ultrasonic power, and sonication time, was carried out using the Taguchi method. Optimization of process parameters was performed using central composite response surface design. A 1.9012% (w/w) yield of geraniol was obtained under optimized conditions (65% ultrasound amplitude, 65 mL volume of 1 M aqueous solution of sodium cumene sulfonate, 60 W ultrasound power, 70% cycle time, and 16 min of sonication time). A microscopic study was also performed to understand the extraction mechanism. Ultrasound assisted hydrotropic extraction turned out to be a superior sustainable alternative compared to the hydrotropic extraction because of the shortening of extraction time and reduction in hydrotrope concentration.

Hydrotropic Extraction of Xanthones from Mangosteen Pericarp

A novel separation process for extraction of xanthones from mangosteen pericarp was investigated using aqueous hydrotrope solution. The hydrotropes sodium salicylate was used for the extraction. The effects of factors such as hydrotrope concentration, extraction temperature and solid loading were investigated by using Response Surface Methodology (RSM). The optimal conditions to obtain the highest yield of xanthones were 2M sodium salicylate, extraction temperature of 40°C and 3% solid loading. This hydrotropic extraction technique is simple and cost effective for the separation of bioactive compounds.Key words: Xanthones; Hydrotropes; Hydrotropic extraction

Green hydrotropic extraction technology for delignification of sugarcane bagasse by using alkybenzene sulfonates as hydrotropes

A process for the delignification of sugarcane bagasse using aqueous hydrotropic solutions is investigated. The optimum conditions for the maximum delignification (85%) of bagssse comprise of temperature (388K), hydrotrope concentration (30% w/w), and bagasse loading (5wt%) in 240min. The delignification process was modeled as the extraction of lignin from the solid biomatrix to estimate its diffusivity at 3.43×10−13m2/s and activation energy 16.2kJ/mole. The isolated lignin is characterized in detail for surface functionality, nature and morphology (irregular shape, flaky/smooth surface, and amorphous nature), molecular weight (3791g/mole), phenolic compounds, and thermal stability (633K), by using, infrared spectrocopy (IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), gel permeation chromatography (GPC), mass spectroscopy, UV spectroscopy, and differential scanning calorimetry analysis (DSC), respectively. The bagasse delignification using aqueous hydrotropic solutions has potential to overcome the problem of breaking of the cellulosic material in the conventional delignification processes.

Hydrotropic Extraction of Citral from Cymbopogon flexuosus(Steud.) Wats.

A novel technique for the extraction of citral from the leaves of Cymbopogon flexuosus (Steud.) Wats. using hydrotropic solutions (sodium salicylate and sodium cumene sulfonate) was investigated. The yield of citral was dependent on the concentration of hydrotrope, solid loading, temperature, and size of the plant material. Using the Taguchi method, the extraction was optimized, and both the hydrotropes gave the highest yield of citral at a concentration of 1.75 M, 5% solid loading, a temperature of 30 °C, and a size of 0.25 mm of the plant material. Sodium salicylate gave a better extraction yield of citral than sodium cumene sulfonate. The microscopic analysis of plant leaves provided insight into the extraction mechanism. A kinetic study was carried out to check the extraction efficiency for both the hydrotropes. The hydrotropic solution was successfully recycled. Using hydrotropic extraction, citral could be extracted under normal operating conditions, and the use of traditional organic solvents could...

Citrus Bioactive Limonoid Extraction using Environment-friendly Hydrotropy

Citrus consumption has been shown to promote human health due to presence of several bioactive compounds. In the process of understanding the health benefits of citrus, we need to isolate and characterize these compounds. Limonoids are one of such prominent, but lesser-known phytonutrients that have been shown to prevent cancers of the mouth, skin, lung, breast, and colon. With the growing interest in the health-promoting properties of citrus limonoids, the demand for these bioactives has significantly increased. It has been critical to explore environment-friendly extraction methods rather than using hazardous organic solvents. A water-based hydrotropic extraction of limonoid aglycones from sour orange (Citrus aurantium L.) seeds was developed. Two hydrotropes, sodium salicylate (Na-Sal) and sodium cumene sulfonate (Na-CuS), were studied for extraction efficiency using the Box Behnken experiment design method. The extraction efficiency of prominent aglycone limonin was observed depending on hydrotrope concentration, extraction temperature, and percentage of raw material loading. Response Surface Analysis (RSA) of data predicted the optimum conditions for maximum yield. Recovery of aglycones from filtered extract is also easily achieved by mere dilution using water at pH 3 or 7 or by partitioning the extract with dichloromethane. At optimum conditions, limonin yield of 0.46 mg/g seeds in the case of Na-Sal extraction and 0.65 mg/g seeds in the case of Na-CuS extraction was achieved. The results demonstrated that the hydrotropic extraction process of limonoid aglycones has practical commercial importance. This project is based upon work supported by the USDA–CSREES IFAFS #2001 52102 02294 and USDA–CSREES #2005-34402-14401 “Designing Foods for Health” through the Vegetable and Fruit Improvement Center.