Conventional Extraction Methods Research Articles

Ultrasound and pulsed electric field treatment effect on the thermal properties, oxidative stability and fatty acid profile of oils extracted from berry seeds

AbstractThe seeds of berry fruits which are considered as a by-product may be valorized by recovering the oil they content. Nevertheless, the conventional extraction methods are time, energy and organic solvents consuming. In order to make extraction more environmental-friendly, alternative methods, like ultrasound-assisted and pulsed electric field-assisted processes, are being developed. The procedure of extraction may however influence the quality of obtained oil. The following study aims to define the effects of ultrasound and pulsed electric field application in the extraction process on the thermal properties, i.e., oxidative stability, melting and cyclic heating/cooling profiles, thermal decomposition characteristics. Additionally, fatty acid profile assessment was included in the study. Seeds of blackberries, blackcurrants, chokeberries, raspberries and redcurrants were used to extract oil. Based on the results, it can be summarized that extraction method influenced the resistance of oils to oxidation. Ultrasound-assisted process resulted in oils with the highest oxidation induction times. Melting profile was slightly influenced by extraction method, with peak temperatures indicating the presence of low-melting and middle-melting triacylglycerol fractions. Differential scanning calorimetry with heat/cool/heat procedure let determine crystallization peak temperatures around − 60 °C, which could be associated with the specific triacylglycerol profile of berry seed oils. The courses of thermogravimetric analysis curves were comparable for all the tested samples. The fatty acid profile study revealed that all the studied thermal properties were affected by the unique fatty acid percentage share, with a great predominance of polyunsaturated fatty acids. Obtained results allowed to conclude that extraction method influenced oxidative stability, thermal properties and fatty acid profile only to some extent. The most promising extraction method among analyzed seems to be ultrasound-assisted extraction as it provided oil with high oxidative stability, typical thermal properties and unchanged fatty acid profile, without being harmful to natural environment due to possible reduction in solvent and time consumption.

GREEN EXTRACTION OF CAROTENOIDS FROM LEMON PEELS

Nowadays, there is a growing interest in fully utilizing agro-industrial wastes, with carotenoids gaining attention as valuable coloring agents. One of the potential sources for carotenoid extraction is lemon peel. The purpose of this study was to determine optimal extraction techniques for extracting as much carotenoids as possible from lemon peel. In this context, a comparison was conducted among extracts obtained via conventional, ultrasound-assisted (UAE), and ultrasound-assisted enzymatic (UAEE) extraction methods. The highest carotenoid content (0.792±0.01 mg/L) was achieved with UAEE, while the lowest (0.493±0.01 mg/L) was obtained conventionally. UAEE exhibited the highest antioxidant activity values among three methods: 753.80±5.79 mg TE/L (ABTS), 624.64±10.52 mg TE/L (DPPH), and 186.64±1.66 μmol TE/L (FRAP). In conclusion, UAEE showed promise in extracting carotenoids from lemon peel. Thus, by carotenoid extraction using green technology from waste lemon peels, with higher added value, richer in terms of phenolic composition and antioxidant properties, has been obtained.

Quality of cellulose and biostimulant extracts from Oedogonium calcareum cultivated during primary wastewater treatment

A practical two-product cascading biorefinery was developed to extract a biostimulant and cellulose from the freshwater filamentous macroalga Oedogonium calcareum grown while treating primary wastewater. Biostimulant production provides a valuable extract with production of disinfected residual biomass for further product development. Both Escherichia coli and F-specific RNA bacteriophage, indicators of human pathogens contamination, were absent from the residual biomass. The chemical composition of the biostimulant was complex, consisting of growth-promoting substances, free amino acids, and minerals. The O. calcareum cellulose fractions yielded between 9.5% and 10.1% (w/w) with purities from 84% to 90% and closely resembled microcrystalline cellulose. Biostimulant extraction improved cellulose quality by increasing crystallinity from 59% to 62%. Biomass condition, drying process, and biostimulant production influenced the crystallinity index. This study demonstrates a two-step process of biostimulant and cellulose extraction from wastewater-grown Oedogonium, simultaneously disinfecting biomass and isolating high-quality cellulose as a sustainable alternative to conventional extraction methods.

Exploring the potentialities of a biodegradable polymeric film in sample preparation: An optimized “white” protocol to extract and quantify emerging contaminants in water

BackgroundThe introduction of white analytical chemistry encourages the development of methods characterized by a balance among greenness, productivity/feasibility and analytical performances. In the environmental analysis of emerging contaminants (ECs), for which high sensitivity and specificity are mandatory, the use of green and sustainable sample preparation needs to be coupled to a reliable analytical determination. Herein, an extraction method based on the use of a biodegradable polymeric film (Mater-Bi) and coupled to LC-MS/MS analysis was developed for the sensitive determination of ECs in wastewater. ResultsThe interaction among a range of ECs and the Mater-Bi film (a commercially available patented blend of polybutylene-terephthalate, starch and fatty acids) was investigated by two sequential experimental designs, to simultaneously study several factors and optimize extraction efficiency. The final method, resembling a fabric phase sorptive extraction, involved pH and ionic strength modification of the sample, 1h extraction and desorption in ethanol. Satisfactory recoveries from real wastewater were obtained for sixteen analytes (56–116 %), as well as excellent precision (inter-day relative standard deviations below 10 % for most compounds). Matrix effect was in the range 88–116 % at the lower pre-concentration factor, but also acceptable in most cases at the higher pre-concentration factor. LODs in matrix, from 0.004 to 0.159 μg L−1, were lower than or comparable to those from recent studies employing green extraction procedures. The method demonstrated its applicability to samples from wastewater treatment plants, allowing quantification of pharmaceuticals and UV filters at the μg L−1 and ng L−1 levels, respectively. SignificanceFor the first time, the synthetic biopolymer Mater-Bi, so far unexplored for the use in analytical chemistry, was exploited for a green, simple and extremely cheap extraction protocol. The optimized method is suitable for several ECs, guaranteeing very good accuracy, precision and specificity, also thanks to the LC-MS/MS analysis. The evaluation by green and white analytical chemistry metrics highlighted its superiority to conventional extraction methods.

Composition and functionality differences of oat protein concentrates: Potential of less refined concentrates obtained by wet milling

The objective of this study was to determine differences in composition and functionality for oat protein concentrates. This was achieved by comparing preparations extracted at different pH levels using either a twin screw press or alkaline extraction followed by isoelectric precipitation. Extraction by twin screw technology provided a higher protein yield compared to isoelectric precipitation. Analysis by SDS-PAGE revealed similar protein composition regardless of the extraction method or extraction pH except for extraction at pH 6. Extraction at a higher pH led to a higher protein purity and yield, while extraction closer to the isoelectric point of the protein resulted in less pure concentrates. All extracts were freeze-dried, and their composition and functionality were compared. Thermal analysis of the protein concentrates extracted by twin screw pressing showed a higher denaturation enthalpy compared to protein isolates prepared by isoelectric precipitation, suggesting that the native structure of the proteins is preserved to a higher extent. All protein fractions exhibited the typical U-shaped solubility profile, except for the concentrate extracted at pH 6, which showed an increase in solubility with increasing pH. Oat protein concentrates prepared by twin screw pressing had a higher affinity for binding to oil than to water, and this was also higher than for isoelectric precipitated protein extracts. Overall results demonstrate a potential for twin screw technology as a viable alternative to conventional wet extraction methods for producing less refined fractions from oats with tunable functional properties.

Sustainable dye extraction: Annatto powder production in a fountain confined spouted bed

AbstractThis study proposes an efficient and sustainable process for annatto powder production using a fountain confined spouted bed. With widespread applications in industries such as food, pharmaceuticals, and cosmetics, conventional extraction methods face environmental and economic challenges. Our study explores a solvent‐free and eco‐friendly approach using mechanical attrition within a fountain confined spouted bed, offering a cost‐effective solution for annatto cultivation. We systematically investigated the impact of four parameters—fountain confiner position and length, draft tube diameter, and airflow velocity—employing experimental design, multiple regression analysis, particle swarm optimization, and computational fluid dynamics–discrete element method (CFD‐DEM) simulations. The proposed optimization condition shows significantly higher collision intensity, improving annatto powder production compared to other central composite design tests. This study contributes to developing of a sustainable and economically viable method for dye production, with potential implications for annatto‐producing regions globally.

Transient analysis of growth/decay in materials utilizing a digital exponential peeling method

AbstractAn algorithm is proposed to implement digital peeling to determine dominant time constants of an exponential transient process. The method is simpler to implement and reduces computational time to a large extent in comparison to other techniques widely used. Apart from a synthetic test function, the algorithm has been implemented on reported experimental transient decay curves of Cs2HfCl6 (CHC) single crystal scintillation to verify its efficacy. Finally, drain current detrapping transients of unpassivated AlGaN/GaN high electron mobility transistors (HEMTs) are analyzed to determine the trap energy levels and concentrations. The validation of this digital peeling technique is also carried out by comparing with conventional method of time constant extraction from HEMT current transients. The extracted exponentials from the transient data efficiently fits well with the experimental data and can be extensively used for transient analysis. The digital peeling technique has wide applicability and can be used to analyze all exponential processes which occur in all domains of science.

Optimization of Extraction Conditions of Bioactive Compounds From Kurdistan Species Urtica dioica.

Phytotherapeutics derived from medicinal plants treat various illnesses, including viral infections such as SARS, MERS, and SARSCoV-2, as well as bacterial and fungal diseases. It highlights ongoing research into the chemical compositions of plant components for developing new drugs, with a particular emphasis on anti-cytotoxic agents for anticancer drugs. Traditional extraction methods have limitations, leading to the exploration of environmentally friendly technologies such as ultrasound-assisted, supercritical fluid, microwave-assisted, and accelerated solvent extraction. The paragraph concludes by stating the aim of a specific study to optimize extraction conditions of bioactive compounds from Urtica dioica in Kurdistan, comparing conventional and non-conventional extraction methods, solvents, and extraction times. The study was conducted between June 2022 and August 2022, fresh leaves and stems of U. dioica plant were collected and sequentially underwent four extraction methods (maceration, Soxhlet, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) by using petroleum ether, chloroform, ethanol, and distilled-water as solvents. The results highlighted significant variations in the yields of bioactive compounds based on the extraction method, solvent type, and duration. Among conventional methods, Soxhlet was the most powerful method and had the most extraction yields, while maceration had the lowest yields. The modern techniques surpassed the conventional methods by producing high extraction yields within a shorter time (a few minutes) and using a lesser amount of solvent. Consequently, UAE and MAE emerge as the most efficient techniques. Hence, MAE effectively produced the highest extraction yields and is considered the preferred technique. The choice of solvents significantly influenced the extraction yields, with ethanol consistently emerging as an effective solvent across various extraction methods. In contrast, petroleum ether demonstrated the lowest efficacy as a solvent. Furthermore, the results unveiled the impact of extraction time on yields, indicating a correlation between increased time and extraction yield in certain cases. Extraction is a very critical step in the study of medicinal plants. The amount of extracted compounds is significantly affected by the extraction method, solvent, and time. Ethanol stands out as the most effective solvent, producing the highest yields of bioactive compounds, while petroleum ether yields the least. Additionally, extraction yield shows a direct relation with extraction time. Soxhlet being the most powerful among conventional methods and maceration yields the least. Modern techniques, particularly UAE and MAE, surpass conventional methods by achieving high yields in shorter times with less solvent. MAE, in particular, offers advantages such as shortened extraction time, increased efficiency, reduced labor, and enhanced selectivity, making it the preferred method for extracting bioactive compounds from aerial parts U. dioica.

Environmentally friendly swift and perfect extraction procedures for analysing the phytochemistry and proximate nutritional biochemistry of biomaterial processed from Avicennia marina leaves

Conventional extraction methods have mislaid their best possible performance because of the slow extraction process using demand in inexperienced and innovative technologies. Concerning this view, several eco-friendly novel techniques alienate to develop by us for the entire extraction of nutrients and phytocompounds from plant sources. The specific organic, inorganic chemical compounds have been explored using ultra sonication and GC-MS assisted techniques. The results are evident to facilitate the ultrasonic and GC-MS supported extraction descent that is less solvent consumed, green analytical methods suitable for complete speedy bioactive compounds drawing out. This study has revealed the occurrence of nutrients, phytochemicals, with biological value, and also the GC-MS analysis exposed 20 peaks through 20 individual chemical compounds, and all the compounds are deliberated as energetic medicinal bioactive compounds. Likewise the FE-SEM is used to find out the topographical characteristics of biomaterial and the FTIR analysis.

The impact of ultrasonic-assisted extraction on the in vitro hypoglycemic activity of peach gum polysaccharide in relation to its conformational conversion.

Peach gum (PG) is an exudate of the peach tree (Prunus persica of the Rosaceae family), which consists primarily of polysaccharides with a large molecular weight and branching structure. Consequently, PG can only swell in water and does not dissolve easily, which severely limits its application. Current conventional extraction methods for PG polysaccharide (PGPS) are time consuming and inefficient. This study investigated the impact of ultrasonic-assisted extraction (UAE) on PGPS structure and conformation, and their relationship to hypoglycemic activity in vitro. In comparison with conventional aqueous extraction, UAE enhanced PGPS yielded from 28.07-32.83% to 80.37-84.90% (w/w) in 2 h. It drastically decreased the molecular size and conformational parameters of PGPS, including weight-average molecular weight (Mw), number-average molecular weight (Mn), z-average radius of gyration (Rg), hydrodynamic radius (Rh) and instrinsic viscosity ([η]) values. Peach gum polysaccharide conformation converted extended molecules to flexible random coil chains or compact spheres with no obvious primary structure alteration. Furthermore, UAE altered the flow behavior of PGPS solution from that of a non-Newtonian fluid to that of a Newtonian fluid. As a result, PGPS treated with UAE displayed weaker inhibitory activity than untreated PGPS, mostly because UAE weakens the binding strength of PGPS to α-glucosidase. However, this negative effect of UAE on PGPS activity was compensated by the increased solubility of polysaccharide. This enabled PGPS to achieve a wider range of doses. Ultrasonic-assisted extraction is capable of degrading PGPS efficiently while preserving its primary structure, resulting in a Newtonian fluid solution. The degraded PGPS conformations displayed a consistent correlation with their inhibitory effect on α-glucosidase activity. © 2024 Society of Chemical Industry.

From bottom-up to cell surface proteomics: detergents or no detergents, that is the question.

Measuring the expression levels of membrane proteins (MPs) is crucial for understanding cell differentiation and tissue specificity, defining disease characteristics, identifying biomarkers, and developing therapeutics. While bottom-up proteomics addresses the need for accurately surveying the membrane proteome, the lower abundance and hydrophobic nature of MPs pose challenges in sample preparation. As MPs normally reside in the lipid bilayer, conventional extraction methods rely on detergents, introducing here a paradox - detergents prevent aggregation and facilitate protein processing, but themselves become contaminants that interfere with downstream analytical applications. Various detergent removal methods exist to mitigate this issue, including filter-aided sample preparation, SP3, suspension trapping, and membrane mimetics. This review delves into the fundamentals of each strategy, applications, merits, and limitations, providing insights into their effectiveness in MP research.

Comparative extraction of melon seed (Cucumis melo L.) oil by conventional and enzymatic methods: Physicochemical properties and oxidative stability

Oil was extracted from melon seeds with three different methods (Soxhlet, cold-pressed, aqueous enzymatic extraction), aiming to evaluate its physicochemical properties and oxidative stability. The melon seed oil contained high levels of linoleic acid (53.6 %–70.8 %, w/w), squalene (101.1–164.7 mg/100 g), and β-sitosterol (119.5–291.9 mg/100 g). Results showed that the choice of the extraction method did not alter the fatty acid composition, but impacted on the physicochemical properties, the content of bioactive compounds and oxidative stability of the oil. Specifically, melon seed oil obtained by aqueous enzymatic extraction (AEE) exhibited higher tocopherol content and better oxidative stability compared to the oil obtained by other two extraction methods. Overall, AEE is a promising oil extraction method and could be an alternative to conventional oil extraction methods that could be implemented for the production of high-quality melon seed oil.

Ultrasound-based strategies for the recovery of microalgal carotenoids: Insights from green extraction methods to UV/MS-based identification

Carotenoids, versatile natural pigments with numerous health benefits, face environmental concerns associated with conventional petrochemical-based extraction methods and limitations of their synthetic equivalents. In this context, this study aims to introduce eco-friendly approaches using ultrasound-based strategies (probe and bath) for the extraction of carotenoids from microalgae, initially focusing on Microchloropsis gaditana and subsequently evaluating the versatility of the method by applying it to other microalgae species of interest (Tisochrysis lutea, Porphyridium cruentum, and Phaeodactylum tricornutum) and defatted microalgal residues. Among the approaches evaluated, the 5-min ultrasonic probe system with ethanol showed comparable carotenoid recovery efficiency to the reference method (agitation, 24 h, acetone) (9.4 ± 2.5 and 9.6 ± 3.2 mg g−1 carotenoids per dry biomass, for the green and the reference method, respectively). Moreover, the method's sustainability was demonstrated using the AGREEprep™ software (scored 0.62 out of 1), compared to the traditional method (0.22 out of 1). The developed method yielded high carotenoid contents across species with diverse cell wall compositions (3.1 ± 0.2, 2.1 ± 0.3, and 4.1 ± 0.1 mg g−1 carotenoid per dry biomass for T. lutea, P. cruentum, and P. tricornutum, respectively). Moreover, the application of the method to defatted biomass showed potential for microalgal valorization with carotenoid recovery rates of 41 %, 60 %, 61 %, and 100 % for M.gaditana, P. tricornutum, T. lutea, and P. cruentum, compared to the original biomass, respectively. Furthermore, by using high-performance liquid chromatography with a diode array detector (HPLC-DAD) and high-resolution mass spectrometry (HRMS), we reported the carotenoid and chlorophyll profiles of the different microalgae and evaluated the impact of the eco-friendly methods. The carotenoid and chlorophyll profiles varied depending on the species, biomass, and method used. In summary, this study advances a green extraction method with improved environmental sustainability and shorter extraction time, underscoring the potential of this approach as a valuable alternative for the extraction of microalgal pigments.

Radioprotective Effects of Thymus Vulgaris L. Essential Oil on Human Peripheral Blood Mononuclear Cells

Purpose: Generated free radicals by ionizing radiations, as powerful cytotoxic agents, can damage DNA and proteins. Thymus vulgaris L (thyme) plant is a rich source of antioxidant phenolic compounds, which makes it a preferable candidate for medical applications. Given this, we set out the present study to investigate the effectiveness of thyme essential oil on Human Peripheral Blood Mononuclear Cells (PBMCs) as a radioprotector agent against ionizing radiations.
 Materials and Methods: We extracted the thyme essential oil by the conventional Clevenger extraction method. Heparinized peripheral blood samples were also collected from five male volunteers, aged 22-25, without a history of smoking and irradiation. PBMCs were isolated and the maximum nontoxic concentrations (85µg/ml (of thyme essential oil were determined based on the result of the MTT method. In the next step, the PBMCs were cultured in the presence of thyme essential oil before and after X-irradiation with doses of 0.25 and 2.00 Gy.
 Results: The most radioprotective effect was observed in the dose of 2.00 Gy for thyme-treated cells 24 hours before the irradiation (p-value ≤ 0.001) by a survival enhancement factor of 1.67, compared to the control group.
 Conclusion: Our results showed that thyme essential oil can be used as an effective radioprotector agent for PBMCs against ionizing radiations. The most radioprotective effect was observed in the presence of thyme essential oil during irradiation.

Natural deep eutectic solvent as a green extraction medium for the ultrasonic-assisted extraction of sinapine thiocyanate from black mustard seeds

Herein, several choline chloride-based (ChCl) natural deep eutectic solvents (NADESs) were investigated for the ultrasonic-assisted extraction (UAE) of sinapine thiocyanate (ST) from black mustard seed (BMS). The NADES consisting of choline chloride and ethylene glycol (EG) was screened as the extraction solvent and single-factor experiments were carried out. In addition, compared with the conventional extraction solvents and extraction methods. The optimized extraction conditions were described below: NADES synthesized by ChCl and EG was used as an extractant with a water content of 20 %, and the solid–liquid ratio was 1:30 g∙mL−1. The mixture was extracted under the ultrasonic parameters of 60 ℃ and 200 W for 75 min. The extraction rate obtained using this method was higher than traditional solvents such as methanol, ethanol and water, and the time consumed was also greatly reduced compared to heated reflux extraction. A variety of instruments were used to characterize the experimental materials and further elucidate the extraction mechanism. Meanwhile, the antioxidant capacity of the ChCl/EG extract of BMS was determined by ultraviolet–visible spectrophotometry. The green evaluation of the method was carried out by the complex green analytical procedure index (ComplexGAPI). This work provides a green technique for valid extraction of ST from BMS, which is expected to be expanded to pharmaceutical, food and other related industries.

Pulsed electric field‐assisted extraction of mushroom ß‐glucan from Pleurotus pulmonarius by‐product and study of prebiotic properties

SummaryPleurotus pulmonarius is one of the most widely consumed mushrooms containing low calories and fat. This study aimed to extract polysaccharides mainly ß‐glucan from P. pulmonarius by‐products including cap and stem using pulsed electric field (PEF) and study their prebiotic properties. The by‐products were subjected to PEF at a field strength of 5, 7.5 and 10 kV cm−1, a frequency of 15 Hz and a number of pulses of 12 000; then, the ß‐glucan content was determined with K‐YBGL assay test kit compared with a conventional extraction method using hot water at 100 °C for 6 h. In raw materials, crude carbohydrate contents in the cap and stem were 50.42% and 68.78%, respectively, and the ß‐glucan contents were 34.03% and 50.22%, respectively. After treated with PEF at 7.5 kV cm−1, the highest yield of 4.18% with ß‐glucan content of 14.10% was achieved. And the stem treated at 10 kV cm−1 showed the highest yield of 2.34% with ß‐glucan content of 21.39%. Comparatively lower yield and ß‐glucan contents were found in the samples treated with hot water. Scanning electron micrographs suggested that PEF caused severe damage to both samples. Additionally, the study of the prebiotic properties revealed that both products exhibited the ability to stimulate the growth of target lactic acid bacteria and the production of short‐chain fatty acid. This study suggested that PEF could enhance the extraction efficiency of β‐glucan with prebiotic potential from P. pulmonarius by‐products.

Review on Advancements in the Production of Artificial Aggregates from Industrial Byproducts: A Sustainable Solution for Infrastructure Development

This review paper explores the burgeoning interest in artificial aggregates as sustainable alternatives to traditional construction materials, driven by concerns over resource depletion and environmental degradation. It comprehensively examines recent advancements, challenges, and future prospects in this field. Beginning with an overview of the imperative for alternative aggregates in construction, the paper discusses various types of artificial aggregates sourced from industrial by-products, recycled materials, and innovative manufacturing processes. It delves into their mechanical, physical, and environmental properties, contrasting them with natural aggregates, and evaluates the impact of production techniques like sintering, foaming, and chemical activation on their performance. Environmental sustainability aspects, including carbon footprint reduction and waste management, are rigorously analyzed, underscoring the potential of artificial aggregates to mitigate ecological impacts associated with conventional extraction and processing methods. Addressing hurdles to widespread adoption, such as technological barriers and economic viability, the review proposes strategies for overcoming these challenges and outlines future research directions to optimize artificial aggregates' properties and applications. In conclusion, this review offers valuable insights into the state-of-the-art developments in artificial aggregate technology, highlighting their pivotal role in advancing sustainability and resilience within the construction sector. Key Word: Artificial aggregates, Sustainable construction materials, Environmental impact, Recycling, Waste utilization.

CTAB DNA Extraction Method Optimization for Quantification of Lard Content in Cheese and Butter Using Real-Time PCR

ABSTRACT Porcine adulteration in dairy products for economic purposes has been tackled mostly by protein- and lipid-based porcine detection methods. In this study, a DNA-based approach was used to determine the presence of porcine DNA in dairy products, especially butter and cheese. DNA was extracted by optimizing the conventional CTAB extraction method followed by an assessment of DNA fragmentation by real-time PCR assays targeting different sizes of amplicon. Butter and cheese DNA samples were analyzed using both endogenous and porcine-specific real-time PCR assays and the lard content was estimated based on the linear regression analysis of a series of different percentages of lard-adulterated butter and cheese DNA samples. Even though the optimization steps did not improve the DNA yield, the successful amplification of the 200 bp amplicon depicted high DNA quality. Approximately 1% lard was able to be quantified exhibiting high potential of the assay in quantifying porcine content in lard-adulterated highly processed food products.

ULTRASOUND-ASSISTED EXTRACTION OF NATURAL ANTIOXIDANTS FROM THE HAZELNUT SKIN: OPTIMIZATION AND COMPARISION WITH CONVENTIONAL METHOD

This study focused on extracting antioxidants from hazelnut skin, an industrial food waste, using two different methods: conventional extraction (CE) and ultrasound-assisted extraction (UAE). The Response Surface Methodology (RSM) has been utilized using the total phenolic content (TPC) and antioxidant capacity (AC) results as responses in optimizing both method conditions. The independent variables and their levels for the optimal experimental design were adjusted as follows: temperature (50-90°C), time (2-62 min), and loading capacity (5-15%) for CE; and temperature (25-50°C), time (1-30 min), loading capacity (5-15%), and ultrasonic amplitude (20-50%) for UAE. The optimum conditions were determined to be 90°C for 35 min with a 5% loading capacity for CE, and 50°C for 27 min with a 5% loading capacity and 50% amplitude for UAE. The TPC of the extracts were found to be 142.62 mg GAE/g and 129.69 mg GAE/g, while the AC values were 127.02 μmol TE/g and 116.00 μmol TE/g for CE and UAE methods, respectively. In conclusion, it has been demonstrated that hazelnut skin extracts obtained by optimizing CE and UAE methods can serve as natural antioxidant alternatives in food products and may hold significant potential for further applications.

Optimization of Ultrasonic-Assisted Extraction of Antioxidants in Apple Pomace (var. Belorusskoje malinovoje) Using Response Surface Methodology: Scope and Opportunity to Develop as a Potential Feed Supplement or Feed Ingredient

Apple pomace represents an underexploited source of bioactive compounds. This study examines the optimization of total phenolic content (TPC) and antioxidant extraction yield of apple pomace (variety: Belorusskoje malinovoje) using response surface methodology. The green extraction technique used was ultrasound-assisted extraction, and it was compared with conventional solvent extraction. The impact of extraction time and amplitude of ultrasound-assisted extraction on the yield of polyphenols and antioxidants has been evaluated. Total phenolic content was determined using an established TPC assay. The antioxidant activity of the apple pomace was determined using established assays 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+). Furthermore, the potential of apple pomace as a feed material was explored by assessing its nutritional composition, vitamins, minerals, fatty acids, and amino acid content. The extraction of antioxidants and phenolic compounds was efficiently optimized using RSM. The optimal conditions for TPC and DPPH• analyses were achieved with an extraction time of 17.5 min and an ultrasound-assisted extraction amplitude of 20%. Optimal conditions for ABTS•+ were 5 min extraction time and 20% amplitude. Conventional and ultrasound-assisted extraction methods yielded comparable results. Moreover, apple pomace exhibits potential as a feed ingredient despite its modest protein content. This study contributes to the utilization of apple pomace by providing additional information on its antioxidant content and nutritional composition, thus contributing to its sustainable utilization in various industries, especially the livestock feed sector.