Ultrasound assisted extraction of polyphenols from black chokeberry

Optimizing the Extraction of Bioactive Compounds (Polyphenols, Lipids, and Alpha-Tocopherol) from Almond Okara to Unlock Its Potential as Functional Food

Almond okara, a by-product of almond milk production, is rich in bioactive components, such as polyphenols, lipids, and alpha-tocopherol, making it a valuable functional food ingredient. This work aimed to investigate its composition while exploring two main aspects: (i) the impact of extraction time, solid-to-solvent ratio, ethanol concentration, and temperature on polyphenol recovery, and (ii) the quantification of okara's triglycerides (TG) and alpha-tocopherol contents. The polyphenols' optimal extraction conditions were 90 min, a 1:30 solid-to-solvent ratio (w/v), 50% ethanol, and 60 °C. These conditions achieved a total polyphenol yield of 523 mg GAE, tannin yield of 340 mg GAE, total flavonoid yield of 548 mg CE, and a total antioxidant capacity of 779 mg AAE per 100 g dry okara. The Peleg model effectively described the extraction kinetics. Additionally, TG levels, quantified by UHE/LPSFC-APCI-MS, in okara were comparable to those in almonds, and alpha-tocopherol levels, quantified by LC-UV, were 14,400 µg/100 g in almonds and 15,600 µg/100 g in okara. These findings highlight the potential of okara as a valuable resource, with a straightforward, scalable, and cost-effective solid-liquid extraction (SLE) method for polyphenols and a supercritical fluid extraction method for TG, for use in the functional food, nutraceutical, and cosmetic industries.

Alginate beads loaded with rambutan extract: characterization and stability during in vitro gastrointestinal digestion

BACKGROUND

Fallen young rambutan fruit is an underrated agricultural waste which may contain several bioactive compounds. In this study, fallen young rambutan fruit was assessed regarding its phenolic contents and antioxidant activities. In order to expand its utilization, rambutan extract-loaded hydrogel beads were developed by a basic spherification technique using sodium alginate. The effect of ratios of polymer and extract and different calcium sources were evaluated. The recovery of bioactive compounds from the hydrogel beads was determined using in vitro gastrointestinal digestion models.

RESULTS

Use of 50% (v/v) ethanol yielded rambutan extract with good chemical properties. The production of hydrogel beads using a ratio of 1:3 with calcium lactate provided the highest production yield of 122.94%. The hydrogel beads developed using the ratio of 1:3 with a combination of calcium lactate and calcium chloride showed high recovery of phenolic compounds and antioxidant activity after simulated intestinal digestion, which were greater compared to unencapsulated extract.

CONCLUSION

The findings demonstrate that the ratio of wall material to rambutan extract and the calcium source influence the physical properties, chemical properties and in vitro gastrointestinal digestion stability of alginate beads. The obtained hydrogel beads may have potential for application in the food or pharmaceutical industries. © 2024 Society of Chemical Industry.

Valorization of Sour Cherry Kernels: Extraction of Polyphenols Using Natural Deep Eutectic Solvents (NADESs)

The objective of this research was to optimize the natural deep eutectic solvent (NADES) extraction process from sour cherry kernels (Prunus cerasus L.). For polyphenol isolation, conventional solid-liquid extraction was employed using different concentrations of ethanol (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 96%), as well as the innovative NADES extraction technique. In the initial phase of the research, a screening of 10 different NADESs was conducted, while extraction was carried out under constant parameters (50 °C, 1:20 w/w, 60 min). NADES 4, composed of lactic acid and glucose in a molar ratio of 5:1, exhibited the highest efficiency in the polyphenol isolation. In the subsequent phase of the research, response surface methodology (RSM) was utilized to optimize the extraction process. Three independent variables, namely temperature, extraction time, and solid-liquid (S/L) ratio, were examined at three different levels. The extracted samples were analyzed for total phenol (TP) and antioxidant activity using the DPPH, ABTS, and FRAP assays. ANOVA and descriptive statistics (R2 and CV) were performed to fit the applied model. According to RSM, the optimal extraction conditions were determined as follows: temperature of 70 °C, extraction time of 161 min, and S/L ratio of 1:25 w/w.

Highly selective and sensitive molecularly imprinted sensors for the electrochemical assay of quercetin in methanol extracts of Rubus sanctus and Fragaria vesca

Quercetin (QUE) is a powerful antioxidant and one of the common phenolic compounds found in plants, vegetables, and fruits, which has shown many pharmacological activities. The complex nature of the matrix in which QUE is found and its importance and potential uses in diverse applications force the researchers to develop selective and sensitive sensors. In the present work, a novel molecularly imprinted polymer (MIP)-based electrochemical sensor was fabricated for the selective and sensitive determination of the QUE in plant extracts and food supplements. Tryptophan methacrylate (TrpMA) was chosen as the functional monomer, whereas the photopolymerization (PP) method was applied using a glassy carbon electrode (GCE). Electrochemical and morphological characterizations of the developed sensor (TrpMA@QUE/MIP-GCE) were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The linear range of the developed sensor was determined to be in the range of 1.0-25 pM, while the limit of detection (LOD) was calculated to be 0.235 pM. In conclusion, The TrpMA@QUE/MIP-GCE sensor might be classified as a promising platform for selective and sensitive determination of QUE not only in plant extracts but also in commercial food supplements because of its reliability, reproducibility, repeatability, stability, and fast response time.

A novel electrochemical sensor based on a molecularly imprinted polymer for highly selective and sensitive determination of rutin from herbal supplements and plant extracts

Rutin (RUT), a natural flavonoid with various beneficial pharmacological actions such as cardioprotective, antioxidant, anti-inflammatory, neuroprotective, etc., is found in the content of many plants that are consumed daily. Due to the healthful effects, RUT is also included in the composition of various herbal supplement samples. Therefore, it is highly important to develop a sensor with high selectivity and sensitivity to determine RUT in complex samples. In this study, it was aimed to take advantage of the cheap, easy, and sensitive nature of electrochemistry and, in addition, to improve the selectivity. For this purpose, the functional monomer selected in the fabricated molecularly imprinted polymer (MIP) was N-methacryloyl-L-aspartic acid (MA-Asp) while photopolymerization (PP) was applied as the polymerization route. After completing critical optimization steps, the developed sensor (MA-Asp@RUT/MIP-GCE) was characterized electrochemically and morphologically. As a result of analytical performance evaluation in standard solution, the linear response of the sensor was found in the concentration range between 1 and 10 pM with a detection limit of 0.269 pM. The recovery studies from plant extract and commercial herbal supplement samples emphasized accuracy and applicability. In imprinting factor studies figuring out quite good selectivity, molecules with a structure similar to RUT were selected as competitors to prove the affinity of the sensor against RUT. Consequently, the MA-Asp@RUT/MIP-GCE sensor offers a more sensitive and selective method thanks to its indirect analysis approach and also stands out with the diversity of its real sample application compared to other available studies.

Analytical and chemometric strategies for elucidation of yerba mate composition

Yerba mate, a popular plant consumed mainly as an infusion, possesses nutritional and medicinal properties attributed to its secondary metabolites. This study aimed to develop strategies to elucidate the phenolic composition of yerba mate samples from Brazil, Argentina, Uruguay, and Paraguay. Optimization of ultrasonic-assisted extraction (UAE) was performed, and the extracted compounds were characterized using ultra-high-pressure liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UHPLC-QTOF-MS), molecular fluorescence and high-pressure liquid chromatography with diode-array detection (HPLC-DAD). Chemometric analysis, including parallel factor analysis (PARAFAC) and principal component analysis (PCA) explored metabolite profiles and identify patterns. PARAFAC modelling of the molecular fluorescence results revealed higher pigment content in Brazilian samples, while other countries' samples exhibited higher phenolic content. PCA modeling of HPLC-DAD results indicated that cultivated yerba mate contained higher chlorogenic acids levels, and samples from Argentina, Paraguay, and Uruguay exhibited higher concentrations of chlorogenic acids and flavonoids.

Use of sisal industrial waste (Agave sisalana Perrine) in sustainable and multifunctional cosmetic products

OBJECTIVE

Sisal is a common stiff fibre produced around the world, corresponding to approximately 70% of the commercial production of all fibres of this type. The fibres are extracted from the leaves of Agave sisalana, from which approximately 4% of their weight is obtained, with the remaining 96% considered to be residues from the process of the sisal industry. The objective of this work was to obtain a polyphenol-enriched extract from the A. sisalana residue by ultrasonically assisted extraction, characterize it chemically, evaluate in vitro antioxidant activity, and develop safe and stable photoprotective formulations for future application in cosmetic preparations.

METHODS

Ultrasonic extraction of solid plant material was performed using 50% ethanol/water (v/v). The extract was chemically characterized by high-performance liquid chromatography equipment associated with classical molecular networking and evaluated for in vitro antioxidant activity by different methodologies. Ten formulations were prepared, varying the component concentrations and the shear time. The 1.0% sisal extract was incorporated into the most stable formulations, and preliminary and accelerated stability were evaluated. The emulsions were investigated for safety by assessment of primary accumulated dermal irritability and sensitization and a dermatological clinical study of phototoxicity and photosensitization. The photoprotective formulations containing or not containing the extract that were stable after 90 days had their in vivo sun protection factor (SPF), UVA protection factor, critical wavelength, and protection against visible and blue light determined.

RESULTS

Ultrasound extraction using 50% ethanol/water (EH 50) as an extractor vehicle showed the best yield. The extract exhibited a concentration of phenolic compounds (77.93 mg of equivalent to the standard gallic acid/g) and showed in vitro antioxidant activity. Emulsions without and with 1.0% sisal extract remained stable and safe. The addition of the extract to the photoprotective formulation statistically increased the SPF when compared to the formulation without the extract and offered protection against UVA radiation, critical wavelengths, and absorption of visible and blue light.

CONCLUSION

Based on the findings, the solid residue of A. sisalana may be indicated as a component of photoprotective and antioxidant cosmetic formulations.

Rosehip Extract-Loaded Liposomes for Potential Skin Application: Physicochemical Properties of Non- and UV-Irradiated Liposomes

In the present study, rosehip (Rosa canina L.) extract was successfully encapsulated in phospholipid liposomes using a single-step procedure named the proliposome method. Part of the obtained liposomes was subjected to UV irradiation and non-treated (native) and UV-irradiated liposomes were further characterized in terms of encapsulation efficiency, chemical composition (HPLC analysis), antioxidant capacity, particle size, PDI, zeta potential, conductivity, mobility, and antioxidant capacity. Raman spectroscopy as well as DSC analysis were applied to evaluate the influence of UV irradiation on the physicochemical properties of liposomes. The encapsulation efficiency of extract-loaded liposomes was higher than 90%; the average size was 251.5 nm; the zeta potential was -22.4 mV; and the conductivity was found to be 0.007 mS/cm. UV irradiation did not cause a change in the mentioned parameters. In addition, irradiation did not affect the antioxidant potential of the liposome-extract system. Raman spectroscopy indicated that the extract was completely covered by the lipid membrane during liposome entrapment, and the peroxidation process was minimized by the presence of rosehip extract in liposomes. These results may guide the potential application of rosehip extract-loaded liposomes in the food, pharmaceutical, or cosmetic industries, particularly when liposomal sterilization is needed.

Impact of High-Pressure Homogenization on Enhancing the Extractability of Phytochemicals from Agri-Food Residues

The primary objective of the Sustainable Development Goals is to reduce food waste by employing various strategies, including the reuse of agri-food residues that are abundantly available and the complete use of their valuable compounds. This study explores the application of high-pressure homogenization (HPH), an innovative nonthermal and green treatment, for the recovery of bioactive compounds from agri-food residues. The results demonstrate that the optimized HPH treatment offers advantages over conventional solid/liquid extraction (SLE), including shorter extraction time, solvent-free operation, low temperatures, and higher yields of phenol extraction (an approximately 20% improvement). Moreover, the micronization of agri-food residue-in-water suspensions results in a decrease in the size distribution to below the visual detection limit, achieved by disrupting the individual plant cells, thus enhancing suspension stability against sedimentation. These findings highlight the potential of HPH for environmentally friendly and efficient extraction processes.

From Aloe vera Leaf Waste to the Extracts with Biological Potential: Optimization of the Extractions, Physicochemical Characterization, and Biological Activities

In the study, the optimization of the extraction from Aloe vera leaf waste was performed via varying solid-to-solvent ratio, solvent type, extraction time, and technique (maceration, heat-, ultrasound-, and microwave-assisted extractions-HAE, UAE, and MAE, respectively). The optimal extraction conditions for achieving the highest polyphenol content are a 1:30 ratio, 70% ethanol, and 30 min of HAE. Total flavonoid and protein contents were significantly higher in the extract from MAE, while total condensed tannin content was the highest in HAE. LC-MS analysis quantified 13 anthraquinone and chromone compounds. The variations in the FT-IR spectra of the extracts obtained by different extraction procedures are minor. The influence of extraction conditions on the antioxidant ability of the extracts depended on applied antioxidant assays. The extracts possessed medium inhibition properties against Staphylococcus aureus and weak inhibitory activity against Enterococcus feacalis. The extracts had stimulative effect on HaCaT cell viability. Regarding the extraction yield, there was a significant difference between the used extraction techniques (MAE > HAE > maceration and UAE). The presented study is an initial step in the production of polyphenol-rich extracts from A. vera leaf waste aimed to be used for the potential preparation of pharmaceutical and cosmetic formulations for the skin.

Comparison between Ultrasound- and Microwave-Assisted Extraction Methods to Determine Phenolic Compounds in Barley (Hordeum vulgare L.)

Barley (Hordeum vulgare L.) is one of the major cereal crops worldwide. It is grown not only to be used as fodder but also for human consumption. Barley grains are a great source of phenolic compounds, which are particularly interesting for their health-promoting antioxidant properties, among other benefits. Two extraction methods, namely ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), have been optimized and compared by using Box-Behnken design (BBD) to determine both the antioxidant power and the phenolic compound levels of the extracts. Three variables have been assessed based on these designs: solvent composition (% MeOH in water), temperature (°C), and sample-to-solvent ratio (mg sample mL^-1 solvent). The solvent composition used and the interaction between the solvent and the temperature were the most significant variables in terms of recovery of phenolic compounds and antioxidant capacity of the extracts. Short extraction times, a high precision level, and good recoveries have been confirmed for both methods. Moreover, they were successfully applied to several samples. Significant differences regarding the level of phenolic compounds and antioxidant power were revealed when analyzing three different barley varieties. Specifically, the amounts of phenolic compounds ranged from 1.08 to 1.81 mg gallic acid equivalent g^-1 barley, while their antioxidant capacity ranged from 1.35 to 2.06 mg Trolox equivalent g^-1 barley, depending on the barley variety. Finally, MAE was found to be slightly more efficient than UAE, presenting higher levels of phenolic compounds in the extracts.

Box-Behnken design based optimization of phenolic extractions from Polygonum equisetiforme roots linked to its antioxidant and antibacterial efficiencies

Purpose

The Polygonum equisetifome is a prospective plant source of high protein, unsaturated fatty acids, and useful safe bioactive molecules. Therefore, the aim of this study was to optimize the ultrasonic aqueous extraction of phenols from P. equisetifome roots using Box-Behnken design based statistical modeling, and to evaluate the antioxidant and antibacterial efficiencies of P. equisetifome root extracts against pathogenic bacteria.

Methods

In this study, the box-behnken design was used to optimize the extraction of phenols. The extraction temperature (30–70°C), ultrasound assisted extraction (UAE) time (1–9 min), and liquid-solid ratio (35–45 mL/g) were investigated as the factors that influence the phenolic yield (Y1) and their DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (Y2).

Results

The optimal conditions for both responses were 50°C, 5 min, and 40 mL/g. At these conditions, Y1 reached its maximum to be 45.321 mg GAE/g dry weight and Y2 to be 120.354 μmol Trolox/g dry weight. The P. equisetifome roots contained water soluble phenol, high anthocyanin, and condensed tannins. Interestingly, the P. equisetifome extracts showed a relation to its antioxidant and antibacterial activities, FRAP (Ferric-reducing/antioxidant power), and ABTS scavenging activity were determined. The morphological and physico-chemical features of the extract were analyzed using SEM-EDX, FT-IR, and minimum inhibitory concentration (MIC) was analyzed against several pathogenic bacteria. The antibacterial activity of the extract showed that the extract is more efficient against Staphylococcus aureus, while the P. equisetifome extracts showed efficient MIC against S. aureus, followed by Bacillus cereus.

Suggestions

The relation of P. equisetifome extracts to its antioxidant, and antibacterial efficiencies open a new avenue of their potential uses in the food and pharmaceutical industries.

A Case Study for the Extraction, Purification, and Co-Pigmentation of Anthocyanins from Aronia melanocarpa Juice Pomace

Chokeberry (Aronia melanocarpa) pomace is a by-product from the juice industry very rich in anthocyanins and other bioactive components. Recovery and purification of anthocyanins from the pomace is a viable valorization strategy that can be implemented to produce high-value natural food colorants with antioxidant properties. In this study, chokeberry pomace was subjected to enzyme-assisted extraction using commercial pectinases. The extracts were further purified by adsorption-desorption using an acrylic resin and stabilized by co-pigmentation with ferulic acid. The anthocyanin concentration and antioxidant activity of the extracts were unaffected by the enzymatic treatment at the conditions tested. The total phenolic content of the extracts suffered minor variations depending on the enzyme formulation used, whereas the dissolved solid content increased in all cases. The adsorption-desorption strategy allowed a 96% recovery of the anthocyanins initially present in the extract, whereas the co-pigmentation treatment magnified the intensity of the color in terms of absorbance, and improved the stability during storage up to one month.

Phenolic Compounds Recovery from Blood Orange Peels Using a Novel Green Infrared Technology Ired-Irrad®, and Their Effect on the Inhibition of Aspergillus flavus Proliferation and Aflatoxin B1 Production

The intensification of total phenolic compound (TPC) extraction from blood orange peels was optimized using a novel green infrared-assisted extraction technique (IRAE, Ired-Irrad^®) and compared to the conventional extraction using a water bath (WB). Response surface methodology (RSM) allowed for the optimization of ethanol concentration (E), time (t), and temperature (T) in terms of extracted TPC and their antiradical activity, for both WB extraction and IRAE. Using WB extraction, the multiple response optimums as obtained after 4 h at 73 °C and using 79% ethanol/water were 1.67 g GAE/100 g for TPC and 59% as DPPH inhibition percentage. IRAE increased the extraction of TPC by 18% using 52% ethanol/water after less than 1 h at 79 °C. This novel technology has the advantage of being easily scalable for industrial usage. HPLC analysis showed that IRAE enhanced the recovery of gallic acid, resveratrol, quercetin, caffeic acid, and hesperidin. IR extracts exhibited high bioactivity by inhibiting the production of Aflatoxin B1 by 98.9%.

Comparison between the use of polyether ether ketone and stainless steel columns for ultrasonic-assisted extraction under various ultrasonic conditions

The ultrasound-assisted extraction (UAE) was conducted using the stainless steel (SS) and polyether ether ketone (PEEK) columns and analyzed with high-performance liquid chromatography (HPLC) to understand the mechanism of ultrasound-assisted chromatography (UAC). Empty SS and PEEK columns were used to extract dyes from a fabric under identical conditions with several parameters including the initial ultrasonic bath temperatures (30 °C and 40 °C), ultrasound power intensities (0, 20, 40, 60, 80, and 100 %), ultrasound operation modes (normal and sweep), and ultrasound frequencies (25 kHz, 40 kHz, and 132 kHz) to compare their extraction capabilities. After 30 min of extraction, the amount of extract was determined by HPLC. The PEEK material was significantly affected by ultrasonic radiation compared to the SS material, especially at a higher temperature (40 °C), power intensity (100 %), and frequency (132 kHz) with sweep mode. At a maximum power density of 45 W/L, the extraction effectiveness ratio of PEEK to SS was in the range of 1.8 - 3.9 depending on the specific frequency, initial temperature, and with or without temperature control. The most optimal ultrasound frequencies, in terms of enhancing extraction effectiveness, are in the order of 132 kHz, 40 kHz, and 25 kHz. Unlike the SS material, the PEEK material was more affected by temperature and acoustic effects under identical conditions, especially at 132 kHz ultrasound frequency. In contrast, at lower frequencies of 40 kHz and 25 kHz, no significant differences in the acoustic effects were observed between the PEEK and SS materials. The findings of this study contribute to elucidating the roles of column materials in UAE and UAC.

Valorization of Phenolic and Carotenoid Compounds of Sechium edule (Jacq. Swartz) Leaves: Comparison between Conventional, Ultrasound- and Microwave-Assisted Extraction Approaches

Chayote leaves are known for culinary and traditional medicine applications. This work intended to recover carotenoids and phenolic compounds from chayote leaves using the ultrasound-assisted extraction (UAE). A Box-Behnken design was employed to investigate the impact of extraction time, temperature, and ultrasonic power on the recovery of total carotenoids, total phenolic compounds, and antioxidant activities. For comparative purposes, chayote leaf extracts were prepared by maceration (ME) and microwave-assisted extraction (MAE), using the same time and temperature conditions optimized by UAE. Extraction at 50 °C and 170 Watts for 30 min provided the optimal UAE conditions. UAE showed better extraction efficacy than ME and MAE. The HPLC analysis of the extracts showed that the xanthophyll class was the main class of carotenoids, which constituted 42-85% of the total carotenoid content, followed by β-carotene and tocopherol. Moreover, 26 compounds, classified as phenolic acids, flavonols, flavonoids and other polar compounds, were identified in the chayote leaf extracts. Flavonols accounted for 55% of the total compounds quantified (the major compound was myricetin) and phenolic acids represented around 35%, mostly represented by ferulic acid, chlorogenic acid and (+)-catechin. This study revealed the potential of UAE as an effective green extraction technique to recover bioactive compounds from chayote leaves, for food, and for pharmaceutical and cosmetic applications.

Valorisation, Green Extraction Development, and Metabolomic Analysis of Wild Artichoke By-Product Using Pressurised Liquid Extraction UPLC-HRMS and Multivariate Data Analysis

Valorisation of food by-products has recently attracted considerable attention due to the opportunities to improve the economic and environmental sustainability of the food production chain. Large quantities of non-edible parts of the artichoke plant (Cynara cardunculus L.) comprising leaves, stems, roots, bracts, and seeds are discarded annually during industrial processing. These by-products contain many phytochemicals such as dietary fibres, phenolic acids, and flavonoids, whereby the most challenging issue concerns about the recovery of high-added value components from these by-products. The aim of this work is to develop a novel valorisation strategy for the sustainable utilisation of artichoke leaves' waste, combining green pressurised-liquid extraction (PLE), spectrophotometric assays and UPLC-HRMS phytochemical characterization, to obtain bioactive-rich extract with high antioxidant capacity. Multivariate analysis of the major selected metabolites was used to compare different solvent extraction used in PLE.

Optimization of ultrasound-assisted extraction of phenolic content & antioxidant activity of hog plum (Spondias pinnata L. f. kurz) pulp by response surface methodology

Background

The pulp of hog plum (Spondias pinnata L. f. kurz) has been documented as a potential source of nutritional, physiological, and pharmacological purposes due to its phenolic content (TPC) and antioxidant activity. However, an optimal extraction condition for hog plum pulp remains elusive. Optimization of extraction process conditions using Ultrasound-assisted extraction (UAE) technique has recently attracted research interest.

Objectives

The present study focused on optimizing the UAE extraction conditions of TPC and antioxidant activities (DPPH and FRAP) from hog plum pulp by using response surface methodology (RSM).

Methods

The RSM with a three-factor-three-level Box-Behnken design (BBD) was used to optimize the extraction conditions. The BBD was used to investigate the effects of three independent variables, X₁: ultrasonic temperature (40–60 °C), X₂: ultrasonic time (30–60 min), and X₃: ethanol concentration (40–80%) on TPC, DPPH and FRAP assays. Fifteen experimental trials have been carried out to optimize the UAE extraction conditions. A second-order polynomial model was used for predicting the responses. Statistically, the model was validated using an analysis of variance (ANOVA).

Results

The ANOVA results revealed that UAE extraction temperature, time, and ethanol concentration had a significant (p < 0.01) influence on the TPC, DPPH, and FRAP, suggesting that all extraction parameters included in this investigation were crucial to the optimization process. For TPC, DPPH, and FRAP, the R² values were 0.9976, 0.9943, and 0.9989, respectively, indicating that the models developed based on second-order polynomials were satisfactorily accurate for analyzing interactions between parameters (response and independent variables). RSM analysis showed that the optimal extraction parameters which maximized TPC, DPPH, and FRAP were 52.03 °C temperature, 30 min, time, and 79.99% ethanol. Under optimal conditions, experimental values for TPC, DPPH, and FRAP were 370 ± 26 mg GAE/100g DM, 57 ± 7%, and 7650 ± 460 mg AAE/100 g DM, respectively. The experimental values showed a good agreement with the predicted values with residual standard error values below 0.2% under optimum conditions. Pearson's correlation coefficients (r) demonstrate that the TPC showed a weak positive correlation with DPPH (r = 0.3508) and moderate correlation with FRAP (r = 0.3963).

Conclusion

The experimental results agreed with the predicted values, confirming the model's appropriateness and RSM's efficacy in optimizing the UAE extraction conditions. This optimized UAE extraction method may be effective in the industrial extraction process; moreover, further research should be conducted to determine the efficacy of these extracts when applied to food.

Effects of Methods and Durations of Extraction on Total Flavonoid and Phenolic Contents and Antioxidant Activity of Java Cardamom (Amomum compactum Soland Ex Maton) Fruit

Free radicals contribute to the pathophysiology of degenerative diseases which increase mortality globally, including mortality in Indonesia. Amomum compactum Soland. Ex Maton fruit from the Zingiberaceae family, also known as Java cardamom, contains secondary metabolites that have high antioxidant activities. The antioxidant activity of the methanol extract of Java cardamom fruit correlates with its flavonoid and phenolic compound contents, which can be affected by different methods and durations of extraction. This study aimed to measure and compare the effects of extraction methods and durations on total flavonoid and phenolic contents (TFCs and TPCs) and subsequent antioxidant activities by the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical, ferric reducing antioxidant power (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), and cupric ion reducing antioxidant capacity (CUPRAC) assays. Methanol extracts of Java cardamom were produced by continuous shaking (CSE), microwave-assisted (MAE), or ultrasonic-assisted extractions (UAE) for three different durations. CSE for 360 min resulted in the highest TFCs (3.202 mg Quercetin Equivalent/g dry weight), while the highest TPCs (1.263 mg Gallic Acid Equivalent/g dry weight) were obtained by MAE for 3 min. Out of the investigated methods, MAE for 3 min resulted in the highest antioxidant activity results for the extracts. We conclude that the polyphenolic antioxidant yield of Java cardamom depends on two parameters: the method and the duration of extraction.

Improvement of the Ultrasound-Assisted Extraction of Polyphenols from Welsh Onion (Allium fistulosum) Leaves Using Response Surface Methodology

Welsh onion (Allium fistulosum) leaves contain several bioactive compounds that can be extracted and used to develop new value-added products (e.g., functional foods and dietary supplements). In the current work, optimal ultrasound-assisted extraction (UAE) conditions to obtain extracts with high polyphenols content and DPPH (1,1-diphenyl-2-picrylhydrazil) scavenging activity were identified using response surface methodology. A complete 3^k factorial design was used to evaluate the effect of different variables of the UAE (extraction temperature, time, and ethanol concentration) on the polyphenols content and the DPPH scavenging activity of the extracts. The best conditions for UAE to reach both the highest values of total polyphenols content (51.78 mg GAE/100 g) and DPPH scavenging activity (34.07 mg Trolox equivalents/100 g) were an extraction temperature of 60 °C, time of 10 min, and ethanol concentration of 70% v/v. The antioxidant activity of the extracts obtained at the optimal conditions was also evaluated by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays obtaining values of 155.51 ± 2.80 μM Trolox/100 g and 1300.21 ± 65.55 μM Trolox/100 g, respectively. Moreover, these extracts were characterized by UHPLC-ESI+-Orbitrap-MS analysis finding that cyanidin (6.0 mg/kg) was the phenolic compound found in the highest amount followed by quercetin-3-glucoside (4.4 mg/kg).

Ultrasonic Extraction of 2-Acetyl-1-Pyrroline (2AP) from Pandanus amaryllifolius Roxb. Using Ethanol as Solvent

2-acetyl-1-pyrroline (2AP) is the compound that gives out the typical aroma and flavour of pandan leaves (Pandanus amaryllifolius Roxb.). This research incorporates ultrasonic extraction to extract the aromatic compound in pandan leaves. The parameters varied in this study are the extraction time, sonicator amplitude, concentration of solvent and the mass of pandan leaves. The experiment was conducted using a central composite design (CCD) model generated by the response surface methodology (RSM). From the extraction process, it can be deduced that the effect of leaves’ mass is comparably higher than other parameters, while sonicator amplitude gives the most negligible impact on the process. The obtained p-value was 0.0014, which was less than 0.05. The high R-squared 0.9603 and adjusted R-squared 0.8809 indicate the model is well agreed with the actual data. The optimal control variables of ultrasonic extraction of 2AP are at an extraction time of 20 min, 60% of solvent concentration, amplitude of 25% and 12.5 g of pandan leaves, which produced 60.51% of yield of the extract and 1.43 ppm of 2AP. It is found that the mass of pandan leaves and the concentration of solvent have a significant impact on the extraction process of 2AP.

Extraction techniques in food industry: Insights into process parameters and their optimization

This review presents critical evaluation of the key parameters that affect the extraction of targeted components, giving due consideration to safety and environmental aspects. The crucial aspects of the extraction technologies along with protocols and process parameters for designing unit operations have been emphasized. The parameters like solvent usage, substrate type, concentration, particle size, temperature, quality and storage of extract as well as stability of extraction have been elaborately discussed. The process optimization using mathematical and computational modeling highlighting information and communication technologies have been given importance aiming for a green and sustainable industry level scaleup. The findings indicate that the extraction processes vary significantly depending on the category of food and its structure. There is no single extraction method or universal set of process conditions identified for extracting all value-added products from respective sources. A comprehensive understanding of process parameters and their optimization as well as synergistic combination of multiple extraction processes can aid in enhancement of the overall extraction efficiency. Future efforts must be directed toward the design of integrated unit operations that cause minimal harm to the environment along with investigations on economic feasibility to ensure sustainable extraction systems.

Novel Zero Headspace Solid-Liquid Extraction for the Recovery of Polyphenolic Fractions from Grape Pomace

Grape pomace (GP) is a good source of high-value compounds as up to 60% of grape polyphenols remain in it after wine-making. To overcome traditional membrane technologies’ d rawbacks, such as fouling, a novel Zero Head Space extraction (ZHE) procedure was developed. The reaction vessel comprised a filtration device with a nitrocellulose membrane. The separation was performed at 50 lb/in2 and 23 °C, with no headspace during the process. Water and methanol (both acidifie d) were evaluated as solvents during two extraction stages for the recovery and fractionation of polyphenols. Aqueous extract (AE) was mainly constituted by monomeric polyphenols while Methanol extract (ME) presented less soluble compounds, as well as a higher concentration of total anthocyanin content than AE. Additional methanolic (CE) and acetone (CAE) extractions of residual GP showed CE presented a similar profile to ME (at a lower concentration), indicating ZHE efficiency at extracting polyphenols in GP. CAE presented a non-resolved hump, characteristic of high proanthocyanidins’ polydispersity. ZHE rendered a monomeric fraction in ME (mean Degree of Polymerization, mDP of 1.38). Residual GP (cake) extractions demonstrated oligomeric polyphenol retention; mDP up to 3.05 when acetone was used. Fractionation of GP polyphenols was successfully established using a Zero Head space extractor.

Antimicrobial, antioxidant, and pH-sensitive polyvinyl alcohol/chitosan-based composite films with aronia extract, cellulose nanocrystals, and grapefruit seed extract

Aronia or black chokeberry (Aronia melanocarpa), cellulose nanocrystals (CNCs), and grapefruit seed extract (GSE) were used for the preparation of multifunctional polyvinyl alcohol/chitosan (PVA/CS) composite films with pH-sensitivity, antimicrobial, antioxidant, and UV-barrier properties. Aronia extract showed total phenolic content of 297 ± 0.5 μg GAE/mg aronia extract, potent antioxidant activity, and high color-response efficiency. Isolated CNCs showed a needle-like structure with a length of 470 nm and a width of 35 nm. The tensile strength of the PVA/CS composite film increased by 74% after the incorporation of CNCs, whereas the film flexibility was enhanced by 75% after adding GSE. The PVA/CS-A (aronia extract) composite film showed a significant color change at different pHs and potent antioxidant activity. At the same time, the PVA/CS-G (GSE) showed the highest antimicrobial activity against Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive) bacteria. The PVA/CS-CGA composite film, reinforced with CNCs/GSE/Aronia extract, showed the highest UV-barrier (95.5%), highest antioxidant activity (95%), potent antimicrobial activity, pH-sensitivity, lowest water vapor permeability (WVP), and desirable mechanical properties. The multifunctional properties of the produced composite films encourage their use as active and intelligent food packaging films to extend shelf life and monitor food quality.

Colorant and antioxidant properties of freeze-dried extracts from wild berries: use of ultrasound-assisted extraction method and drivers of liking of colored yogurts

This work aimed at developing powders rich in antioxidants and pigments from two wild berries: maqui (Aristotelia chilensis) and murra (Rubus ulmifolius). Fruits were subjected to successive ultrasound-assisted extractions (UAE) and then freeze-dried. Physical properties, anthocyanin stability of powders, and their performance as natural colorants in yogurts were evaluated. The optimum extraction methods were: UAE for 10 min in murra, and without UAE (control) in maqui, with juice extraction yields ranging between 80 and 82%. Maqui powder exhibited ≈ 2.8 times more polyphenol and anthocyanin content than murra. However, murra powder showed better stability characteristics as powder colorant since it exhibited greater protection of anthocyanins by means of copigmentation phenomena. Regarding consumer's perception of colored yogurt, samples with 4% and 8% maqui powder could be considered as future prototypes to be launched into the market. The obtained powders may be used in different industrial food applications.

Alternative Methods of Bioactive Compounds and Oils Extraction from Berry Fruit By-Products—A Review

Berry fruit by-products are a source of polyphenol compounds and highly nutritious oils and can be reused to fulfill the requirements of the circular economy model. One of the methods of obtaining polyphenol-rich extracts or oils is extraction. Applying conventional solvent extraction techniques may be insufficient to reach high polyphenol or lipid fraction yields and selectivity of specific compounds. Alternative extraction methods, mainly ultrasound-assisted extraction, pulsed electric field-assisted extraction, microwave-assisted extraction and supercritical fluid extraction, are ways to improve the efficiency of the isolation of bioactive compounds or oils from berry fruit by-products. Additionally, non-conventional techniques are considered as green extraction methods, as they consume less energy, solvent volume and time. The aim of this review is to summarize the studies on alternative extraction methods and their relationship to the composition of extracts or oils obtained from berry waste products.

Effect of Ultrasound and Enzymatic Mash Treatment on Bioactive Compounds and Antioxidant Capacity of Black, Red and White Currant Juices

Ultrasound treatment is recognized as a potential technique for improvement in the nutritional values of fruit juices. This study was initiated with the objective of evaluating bioactive compounds and some important quality parameters of black (BC), red (RC) and white (WC) currant juices obtained from fruit mash preliminarily treated by enzymes combined with ultrasound. Individual and total phenolic content (TPC), anthocyanins, color parameters, ascorbic acid, antioxidant capacity (TEAC), juice yield, pH, titratable acidity, and soluble solids were investigated. Significant increases in the levels of TPC and antioxidant capacity of sonicated samples were observed. However, ultrasound treatment had no effect on individual phenolic compounds of juices. Sonication of mash before juice pressing did not cause any noticeable changes in ascorbic acid content. Only in the case of WC was an increase in content of vitamin C noticed. The color of juices obtained after treatment was similar to the control sample. It was demonstrated that enzymatic combined with ultrasound treatment of mash for different colored currant fruit did not have any dismissive effect and could even improve some parameters of the juice obtained.

In Vitro Antineoplastic and Antiviral Activity and In Vivo Toxicity of Geum urbanum L. Extracts

This study evaluated the in vitro antineoplastic and antiviral potential and in vivo toxicity of twelve extracts with different polarity obtained from the herbaceous perennial plant Geum urbanum L. (Rosaceae). In vitro cytotoxicity was determined by ISO 10993-5/2009 on bladder cancer, (T-24 and BC-3C), liver carcinoma (HEP-G2) and normal embryonic kidney (HEK-293) cell lines. The antineoplastic activity was elucidated through assays of cell clonogenicity, apoptosis induction, nuclear factor kappa B p65 (NFκB p65) activation and total glutathione levels. Neutral red uptake study was applied for antiviral activity. The most promising G. urbanum extract was analyzed by UHPLC–HRMS. The acute in vivo toxicity analysis was carried out following OEDC 423. The ethyl acetate extract of aerial parts (EtOAc-AP) exhibited the strongest antineoplastic activity on bladder cancer cell lines (IC₅₀ = 21.33–25.28 µg/mL) by inducing apoptosis and inhibiting NFκB p65 and cell clonogenicity. EtOAc and n-butanol extracts showed moderate antiviral activity against human adenovirus type 5 and human simplex virus type I. Seventy four secondary metabolites (gallic and ellagic acid derivatives, phenolic acids, flavonoids, etc.) were identified in EtOAc-AP by UHPLC–HRMS. This extract induced no signs of acute toxicity in liver and kidney specimens of H-albino mice in doses up to 210 mg/kg. In conclusion, our study contributes substantially to the detailed pharmacological characterization of G. urbanum, thus helping the development of health-promoting phytopreparations.

Use of Conventional and Innovative Technologies for the Production of Food Grade Hop Extracts: Focus on Bioactive Compounds and Antioxidant Activity

This study investigated the use of conventional and innovative extraction methods to produce food-grade hop extracts with high antioxidant capacity and content in bioactive compounds. Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60 °C; innovative extractions were performed using two ultrasound systems, a laboratory bath (US) and a high-power ultrasound bath (HPUS), and a high-pressure industrial process. For CONV, US, and HPUS extractions the effect of the extraction time was also tested. Experimental results showed that extraction method, temperature, and time affect to a different extent the phenolic profile and have a significant effect (p < 0.05) on the total phenolic content, total flavonoid content, antiradical capacity (ABTS), chlorophyll α, and total carotenoids content. Overall, US and CONV 60 °C extractions showed the highest extraction efficiency for almost all the investigated compounds, however, the extraction method and time to be used strongly depends on the target compounds to extract.

Functionalized Biscuits with Bioactive Ingredients Obtained by Citrus Lemon Pomace

In this study, functionalized biscuits were prepared through the enrichment of dough with lemon peel and natural antioxidants extracted from lemon pomace. Lemon pomace extract (LP_E) was analyzed for total phenolic content before addition, and then a known concentration of 50 mg kg⁻¹ was used for the formulation of enriched biscuits. Three different biscuit samples were compared to a control biscuit, without the addition of functional ingredients. The main physicochemical, microbiological, and sensory aspects of doughs and biscuits enriched with LP_E were investigated. The enriched biscuits showed higher phenolic content and antioxidant activity than the control one and a longer induction period (IP), which means that the enriched products had a higher intrinsic resistance to lipid oxidation, thanks to the antioxidant effect exerted by the added fresh lemon peel and the LP_E. Furthermore, from a sensorial point of view, they showed suitable acceptability, in terms of appearance, flavor, and aromatic attributes. Thus, results indicated that the incorporation of lemon processing by-products allowed the production of functional enriched biscuits with improved antioxidant properties.

Green non-conventional techniques for the extraction of polyphenols from agricultural food by-products: A review

Food processing industry is accompanied with the generation of a great production of wastes and by-products exceptionally rich in bioactive compounds (especially phenolics), with antioxidant activity. The recovery of these health molecules constitutes a key point for the valorization of by-products, with the possibility of creating new ingredients to be used for the formulation of food and cosmetic products. One of the main limitations to reuse by-products is linked to the high cost to obtain bioactive compounds, consequently in order to exploit these resources commercially valuable it is necessary to develop innovative, economic and environmentally friendly extraction strategies. These extraction methods should be able to reduce petroleum solvents, energy consumption and chemical wastes, protecting both environment and consumers and ensuring safe and high-quality final products. The purpose of this review is to summarize current knowledge and applications of the new extraction techniques such as supercritical fluid extraction, pressurized liquid extraction, ultrasound assisted extraction applied to polyphenols extraction from agricultural food by-products. Particular attention has been paid to theoretical background, highlighting mechanisms and safety precautions. Authors concluded that relevant results of these techniques represent an opportunity to industrial scale-up, improving the extraction yields, minimizing time, costs and environmental impact.