Conventional Extraction Research Articles

Vermicomposting reduces the antimicrobial resistance in livestock waste

Vermicomposting, a process in which housefly larvae are used to decompose organic waste, has attracted attention as a method for managing antimicrobial-resistant bacteria (ARB) in livestock manure. Vermicomposting effectively reduces antimicrobial resistance genes (ARGs) and residual antimicrobials. However, the evaluation of live bacteria, including ARB, remains scarce. Additionally, conventional DNA extraction methods include DNA from dead bacteria, impeding the accurate evaluation of ARG-associated risk in compost and the microbiome. This study assesses the effectiveness of vermicomposting pig manure against antimicrobial resistance (AMR) by evaluating the ARB, ARGs (focusing on DNA from live bacteria), and microbiome associated with vermicomposting processes. Vermicomposting significantly reduces the abundance of bacteria, including ARB, and decreases the ARG (tetA, tetB, blaTEM, and blaCTX−M) copy number in live bacteria. Bacterial community analysis revealed an increase in the abundance of Gammaproteobacteria. Moreover, the vermicomposted samples effectively cultivated myriad plants. Overall, vermicomposting effectively reduces the ARB and ARGs in pig manure, with potential benefits for plant growth and sustainable waste management. Hence, it can be widely applied to treat livestock manure and other organic wastes to combat AMR.

Microwave-Assisted vs. Conventional Extraction of Moringa oleifera Seed Oil: Process Optimization and Efficiency Comparison.

This study aims to evaluate the effectiveness of microwave-assisted and conventional extraction using ethanol, hexane, and petroleum ether as solvents, and to optimize the process for extracting oil from Moringa oleifera Lam. seeds, with a focus on improving food-grade oil production. Response surface methodology (RSM) was applied to enhance the extraction process of the oil. Central composite rotational design (CCRD) was used to analyze the impact of solid-liquid ratio (x1), power (x2), and temperature (x3) on oil yield. The optimization identified the optimal conditions as a solid/liquid ratio of 1:38, power of 175 W, and temperature of 50 °C, achieving a 42% oil yield. Notably, the microwave-assisted extraction reduced the processing time from 8 h (using conventional Soxhlet extraction) to just 1 h. Conventional extraction with hexane and petroleum ether was also performed for comparison, resulting in similar oil content and fatty acid profiles, predominantly, oleic acid. FTIR analysis confirmed that the microwave-extracted oil contained fatty acids and had similar characteristics to the conventionally extracted oil. Thus, the use of ethanol as a green solvent in the microwave has shown significant improvement in terms of time and energy savings compared to the Soxhlet method with toxic solvents. This study concludes that microwave-assisted extraction with ethanol provides a more energy efficient, environmentally friendly, and time-saving alternative for food-grade oil production, aligning with advancements in food engineering and production.

Conventional and ultrasound-assisted extractions of protein from sacha inchi (Plukenetia volubilis) and their impact on the physicochemical and structural characteristics

This study aimed to evaluate the recovery of proteins from sacha inchi (SI) cake, using two methods: conventional extraction by alkaline solubilization (SIC, pH 10.5, time 60 min, solvent/sample ratio 40/1) and ultrasound-assisted method (SIUS), the latter undergoing optimization using response surface methodology. The protein powder concentrate obtained by SIUS reached a protein content of ∼ 72 % (dry weight, DW), under the optimized conditions of amplitude: 48 %, solvent/sample ratio: 50 mL/g and time: 19 min at pH 10.5, compared to that obtained using the conventional method with ∼77 % (DW). The physicochemical and structural characteristics differentiate both protein concentrates, the SIUS protein presented a slightly darker color, a narrower size particle distribution, a higher specific surface area, and a manifest denaturation as evidenced by the thermal analysis, compared to that obtained for SIC protein. The structural modifications of the proteins were evaluated by FTIR and circular dichroism (CD) spectroscopy, FTIR showed that the total proteins in SIUS had a decrease in β-sheet and an increase in β-turn configuration, whereas the soluble proteins evaluated by CD presented a marked decrease in α-helix and an increase in random coil and β-sheet configurations. The results contribute to offering information for future applications for both protein concentrates from SI cake in the food sector.

Impacts of microwaves on the pectin extraction from apple pomace: Technological properties in structuring of hydrogels

The valorization of by-products eliminates the risks of economic barriers and reduces the overall amount of pollution and the carbon footprint of the products. In this context, conventional heating extraction (CE) and microwave-assisted extraction (MAE) were compared to extract pectin from apple pomace. The effects of temperature on MAE were evaluated based on the resulting properties obtained in subsequent pectin hydrogels. A pectin yield of 10.6 ± 0.3% was obtained by MAE with 5 min extraction, while CE showed a yield of 9.5 ± 0.3% after 2 h. The pectin extracted by both methods had a low methoxyl content, indicating a low degree of esterification. The galacturonic acid content was greater than 60% for most samples. Zeta potential analysis indicated the ability of the pectin to form stable gels. According to the X-ray diffractograms, increasing the extraction temperature led to a decrease in the crystallinity of the pectin structure. Rheological tests showed increased storage modulus as the temperature increased by MAE from 80 to 100 °C for the pectin-based hydrogel. The water holding capacity was greater than 50% for all hydrogels. Furthermore, an analysis of electrical consumption and energy costs highlighted the economic advantage of using microwave heating technology to extract pectin.

PH shift extraction technique for plant proteins: A promising technique for sustainable development

With the recognition of animal-derived foods as unhealthy and their association with climate change, researchers are increasingly focusing on plant-based protein as a sustainable alternative. Plant proteins offer versatile functional and dietary benefits, making them suitable for various food applications. This study investigates the influence of alkaline and acidic pH conditions on the extraction yield and the functional and nutritional properties of plant-based proteins. The primary sources of plant protein include cereals, legumes, and oilseeds, which can be used to address essential amino acid deficiencies through blending. Several methods have been employed for protein extraction from plant sources, such as salt extraction, microwave-assisted extraction, ultrasound-assisted extraction, and micellar precipitation. Among these techniques, the pH shift method stands out due to its non-thermal nature, sustainability, and cost-effectiveness. In this method, proteins are solubilized at alkaline pH and then precipitated at their isoelectric point, resulting in a collection of protein precipitate. It is crucial to optimize extraction techniques based on qualitative and quantitative analysis to enhance protein yield, characteristics, and nutritional value. Most conventional protein extraction methods require a large quantity of chemicals, which imposes the issue of safe disposal, compromising environmental sustainability. Traditional methods also produce protein with non-proteinaceous constituents, adding another purification step and resulting in increased overall cost. However, the pH shift method utilizes comparatively less harsh chemicals and has a high protein extraction yield, which makes it comparatively more environmentally and economically sustainable. The sustainable extraction of plant-based proteins addresses the health and environmental concerns associated with animal-derived foods and offers a promising solution to promote sustainability in the food industry.

Numerical investigation of centrifugal passive mixing in Omega shaped microchannel and comparison with fixed platform

The extraction of DNA from isolated cells is crucial for diagnosing and treating various diseases, including cancer, which has become a leading cause of death in recent years. Circulating tumor cells (CTCs) in the blood can be separated from other blood cells, allowing for DNA extraction and analysis for further research. Microfluidic methods are more cost-effective than conventional DNA extraction techniques and have significant potential for high-throughput mixing in lab-on-a-chip (LOC) and lab-on-a-disk (LOD) devices without damaging DNA. Chemical methods for cell lysis, where the mixing of reagents is essential, are particularly efficient on these platforms due to the generation of secondary flows. This is especially true in microchannels with a serpentine design, which enhances mixing quality—a critical parameter for cell lysis efficiency. This study presents and compares the mixing capabilities of the two microchannel platforms (LOC and LOD). Additionally, we introduce a new Omega-shaped serpentine microchannel that combines features of both straight and curved serpentine channels. The mixing quality across all geometries and both platforms has been investigated. Our findings indicate that the centrifugal platform is the most effective for mixing at low inlet velocities. Furthermore, we examine the number of stages in the Omega channel and conclude that 7 Ω stages are sufficient for achieving high mixing quality (∼100 %).

The impact of supercritical carbon dioxide processing on the aroma and physicochemical properties of soybean flour

Soybeans are rich in protein but have limited food applications due to their undesirable volatile compounds, negatively affecting their flavor and consumer acceptance. This study aimed to extract lipids and volatile compounds from soybean flour using supercritical carbon dioxide (SC-CO2) and investigate the impact of extraction conditions on the properties of soybean flour, including particle size distribution, composition, color, and rheological and textural qualities. Similar lipid extraction yields (∼20%) were obtained with SC-CO2 and conventional hexane extractions. The volatile compound concentration of the soybean flour was reduced after SC-CO2 extraction (0.63-1.00 µg/g) as compared to hexane extraction (1.44-1.68 µg/g). The results showed that SC-CO2-treated soybean flour showed smaller particle sizes (<250 µm, ∼70%), improved protein purity upon protein extraction, and brighter color as compared to hexane-extracted flour. Additionally, in comparison to untreated soybean flour, SEM images revealed a more disrupted and rough structure in defatted soybean flour. Overall, the presented SC-CO2 approach can improve the aroma of soybean flour while achieving similar lipid extraction yields with conventional hexane extraction, all without the use of toxic organic solvents.

Unleashing the potential of castor oil as extraction solvent of carotenoids from tomatoes

Adding carotenoids to cosmetic formulations aligns with the industry’s growing ethos of producing safer, more sustainable, and nature-inspired products. While synthetic compounds still have their place in cosmetics, the shift towards natural ingredients such as carotenoids reflects a more significant commitment across the industry to satisfy consumer preferences and contribute to a greener future. Castor oil is a well-known natural oil used in several cosmetic formulations because it reduces moisture loss and enhances skin hydration. However, it’s only added to cosmetics simultaneously with all the other components, including natural extracts. Thus, this work goes behind literature and classic downstream approaches. A simplification of cosmetics formulations is intended by using castor oil directly as the extraction solvent of natural bioactive compounds, such as carotenoids from tomatoes. A comparison of its extraction performance with conventional extraction solvents was made, and all the process operating conditions were optimized (SLR = 0.06 gbiomass.mLsolvent-1, percentage of castor oil = 50 % (v/v), and time of extraction = 90 min) to achieve a maximum recovery of 3.2 ± 0.2 mgCar.gbiomass-1. Additionally, its capacity as a preservative of carotenoids degradation was also tested against a conventional solvent to enhance natural pigments’ shelf life showcasing increased stability (especially at 75 °C), a current problem of their application in industry. The environmental performance of the process proposed was analyzed based on the carbon footprint, with electricity consumption identified as the most significant contributor. This impact could be greatly reduced by utilizing photovoltaic energy. Lastly, a conceptual process design has been proposed to envision its practical application in an industrial setting.

Uncovering condition information loss in medical text extraction: The challenge of non-contiguous spans

We investigated the limitations of conventional named entity recognition (NER) and entity linking (EL) methods in accurately extracting patient condition information from medical texts, focusing on the challenges posed by non-contiguous spans and the potential information loss. We utilized a corpus with entity-relation annotations, analyzing the frequency and nature of non-contiguous spans that include irrelevant entities within gaps. The corpus was further analyzed to pinpoint the types of entity representations predominantly linked with peripheral spans—those not encompassing central symptom-describing terms—with a focus on items, body parts, and clinical tests. Our analysis revealed that 18.6 % of patient condition expressions were non-contiguous spans containing irrelevant entities, suggesting an accuracy ceiling of 81.4 % for conventional NER and EL approaches in the worst-case scenario. The study highlights the importance of entity types such as items, body parts, and clinical tests in these expressions, indicating that conventional extraction methods incur considerable information loss. The findings underscore the need for more sophisticated information extraction techniques capable of handling the complexities of medical texts, including non-contiguous spans. Adapting methods that allow gaps within entities or employing graph-based term assignments can enhance the accuracy and comprehensiveness of medical text annotation.

Chitinase and proteinase K treatments enhance the DNA yield of microsporidium Ecytonucleospora hepatopenaei spores

Microsporidium Ecytonucleospora hepatopenaei (EHP) spores were purified from the hepatopancreas of Penaeus vannamei infected with EHP by percoll density gradient centrifugation and differential centrifugation. The EHP spores contain a thick chitin wall and might not rupture using the routine DNA extraction protocol. In this study, three enzymes were used, including chitinase, proteinase K, and DNase I. Chitinase or proteinase K digestions caused weakened fluorescence of chitin showing by a blurred edge of EHP spores stained with calcofluor white under a fluorescence microscope. Different combinations of these enzymes followed by DNA extraction with phenol–chloroform from EHP spores showed significant increases in the copy number of the EHP SSU gene per spore. The combination of the chitinase and proteinase K treatments resulted 4.46 ± 1.07 copies/spore detected, which is 31.6 ± 20.7 folds of no treatment groups, accounting to (55.7 ± 13.4)% of the total copies of the gene in the spore. The additional treatment with chitinase to the conventional extraction protocol with a proteinase K digestion step for feces and hepatopancreas samples of P. vannamei resulted in a significant difference in EHP copies in the DNA of (83.8 ± 64.1)% and (55.3 ± 88.0)% increases. The study proved that chitinase and proteinase K treatment enhance the DNA extraction from microsporidian spores resulting in high yield.

Sequential extraction of hawthorn pectin: An attempt to reveal their original mode of being in plants and functional properties

Hawthorn is rich in pectin, which is much higher than most cultivated fruits, but conventional extraction methods do not meet the requirements of low energy consumption and green production. Pectin in hawthorn is divided into soluble and insoluble parts, and with the ripening of hawthorn, the original pectin is converted into soluble pectin and pectic acid under the action of enzymes. Therefore, based on the characteristics of hawthorn pectin, this study sequentially extracted hawthorn pectin using water-soluble pectin (WSP) and hot acid-soluble pectin (HAP) method, verifying the feasibility of extracting hawthorn pectin with pure water at room temperature, and systematically analyzing and comparing the physicochemical properties and functional characteristics of the two methods. The combination of texture analysis and gel rheology revealed that WSP formed a more uniform and dense network structure during the gelation process. Additionally, microscopic observations and emulsification index results indicated that the emulsion prepared with WSP (WSE) had a smaller particle size and better stability. This indicates that hawthorn pectin is suitable for extraction with pure water at room temperature, which can maintain its good physical properties while reducing energy consumption, providing a new approach for the large-scale extraction of pectin in the food industry.

Anthocyanin Extraction from Roselle (Hibiscus sabdariffa L.) Calyces: A Microwave-Assisted Approach Using Box-Behnken Design

Roselle (Hibiscus sabdariffa L.) is a widely consumed edible flower, often utilized as a natural coloring agent. The bright red color of roselle is due to its anthocyanin content. Beyond their role as colorants, anthocyanins are known for their potent antioxidant properties, which have drawn significant interest for their potential health benefits. To fully harness the advantages of roselle's anthocyanins, developing a reliable extraction method is crucial. This study aimed to establish a fast, efficient, and environmentally friendly extraction technique using microwave-assisted extraction (MAE). Key factors, such as temperature (30, 65, and 100 °C), solvent concentration (30%, 50%, and 70% ethanol in water), and solvent-to-solid ratio (10:1, 25:1, 40:1), were optimized using the Box-Behnken design combined with response surface methodology. The extraction time (5-30 minutes) was also evaluated to maximize anthocyanin recovery. Two major anthocyanins, delphinidin-3-sambubioside and cyanidin-3-sambubioside, were identified using UHPLC-PDA-QToF-MS and quantified using a cyanidin-3-glucoside calibration curve. The optimal extraction conditions were found to be 72 °C, using 70% ethanol in water with a 40:1 solvent-to-solid ratio for 15 minutes. This method was validated with high accuracy (>98% recovery) and precision (CV <6%). It was successfully applied to quantify the anthocyanin content in both purple and red roselle varieties. This rapid and effective MAE method offers a more sustainable, energy-efficient, and time-saving alternative to conventional extraction methods, benefiting industries that rely on natural colorants and antioxidants.

Canola meal extract as a low-cost substrate in Mortierella alpina culture for the production of arachidonic acid

The demand for high-quality and cost-effective raw materials is growing across various industries. Canola meal (CM), a low-cost by-product of canola processing facilities, boasts an impressive nutritional profile comprising protein, carbohydrates, vitamins, and minerals, making it a potential candidate for microbial culture media. Saskatchewan leads globally in canola production and plans to expand its canola processing facilities. Commercial valorization of CM could not only optimize the management of this by-product but also offer additional incentives and financial returns to regional canola stakeholders. Efficient utilization of canola meal extract (CME) in producing polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA), holds promise as valuable ingredients or base chemicals for the food, feed, and nutraceutical industries. This study focused on incorporating pH 10.5 treated alkaline extract (AE) and temperature 160°C treated subcritical extract (SE) of CM into the culture medium of Mortierella alpina, an oleaginous fungus, by replacing conventional yeast extract (YE). Trials investigated the effect of aeration levels ranging from 0.5 to 2.0 vvm and revealed that increasing oxygen supply significantly boosted fungal growth rate and ARA content in biomass up to 0.39 day⁻¹ and 21.86 %, respectively. ARA production correlated positively with biomass accumulation and lipid content. Replacing YE with CME resulted in less significant differences (P < 0.05) in biomass and lipid accumulation. Additionally, AE- and SE-supplemented media exhibited higher ARA accumulation of 144.91 mg/L and 165.8 mg/L, respectively, compared to standard media (124.87 mg/L). Therefore, this study introduces canola meal extract (CME) as a novel nitrogen source in microbial media, with comparative demonstrations showing its efficiency to be similar to that of conventional extracts.

Integrated Seismic Attributes as a Tool to Delineate the Oligocene Channels Architecture, Baltim Field, Offshore Central Nile Delta, Egypt

The hydrocarbons in the Nile Delta area are produced from both clastic and non-clastic reservoirs, with ages ranging from the Early Cretaceous to the Plio-Pleistocene. The study area is situated in Baltim field offshore, Central Nile Delta, approximately 10 kilometers off the Egyptian coast (Fig. 1). The main producing reservoir in Baltim field is Abu Madi Formation (Miocene age) as there were many discoveries in the last decades resulting in most of the area had been considered as a brown field. Nowadays, the Oligocene section is considered as the hope for new hydrocarbon potentiality in the deep section (below Miocene). Among the drilled sedimentary sequence in the Nile Delta, Tineh Formation (Oligocene age) contains multiple levels of reservoir rocks with high-quality reservoirs including: Satis-1, Satis-3, Notus-1, Tineh-1, Atoll-1 &amp; Salamat-1 (Fig. 2). This work's objective is to delineate the different channels of the Oligocene section in trial to add more reserves to the field. One of the main challenges for the exploration of these deep reservoirs is to delineate the reservoir geometry itself. A strong tool for improving bed thickness imaging and mapping, geologic discontinuities and channel delineation is the spectral decomposition technique providing more details than the conventional amplitude extractions. So, in this work, we applied the spectral decomposition tool to track the geometric dimensions of the Oligocene channels. RGB color blending performed from 10, 16, and 20 Hz represents the most significant geological features to get a better picture of the channel’s geometry. After determining the channel’s boundary by using the RGB blending, the channel geo-body was extracted. This technique helps in reducing the uncertainties of hydrocarbon exploration. Consequently to the integration between RMS amplitude maps and the channel geo-body that was extracted from the spectral decomposition, Oligocene channels became clearer and the boundaries well defined.

Green Approaches to Extractive Metallurgy: A Novel Synthesis of Sustainable Practices

The realm of extractive metallurgy, a cornerstone for diverse industrial applications, has traditionally grappled with environmental challenges stemming from conventional extraction methods. This thorough literature review delves into the realm of innovative green approaches within extractive metallurgy, with the overarching goal of synthesizing sustainable practices. The introduction casts a spotlight on the environmental quandaries associated with traditional metallurgical practices, underscoring the imperative for ecologically friendly alternatives. The research methodology meticulously entails a comprehensive review of peer-reviewed literature, applying stringent criteria to handpick studies that delve into sustainable metallurgical practices. The results and discussion section intricately categorizes and dissects an array of green approaches in metal extraction, including bioleaching, ionic liquids, supercritical fluid extraction, green hydrometallurgy, electrochemical methods, and hybrid processes, providing nuanced insights into their efficacy and sustainability. Through the lens of case studies, the study sheds light on recent strides made by industries that have wholeheartedly embraced these sustainable practices, with a keen focus on unraveling their consequential environmental and economic impacts. Moreover, the study conscientiously addresses the challenges encountered in the adoption of green metallurgy and adeptly identifies latent opportunities for further development in this transformative field. The findings resonate with a resounding call for the widespread adoption of sustainable practices within extractive metallurgy, emphasizing their profound implications for both industrial application and the trajectory of future research endeavors. This expanded exploration underscores the pivotal role of environmentally conscious approaches in reshaping the landscape of extractive metallurgy, paving the way for a more sustainable and responsible future.

Ultrasonic-assisted extraction of polyphenolics from Schrebera swietenioides Roxb.: An optimization using response surface methodology

Schrebera swietenioides Roxb is an important medicinal plant used for the treatment of various diseases by the indigenous communities. However, this plant is still underexplored in the modern scientific era. Specifically, the leaves of the plant are reported to contain various medicinal properties such as antioxidant, antimicrobial, anti-inflammatory, and antipyretic activity. Herewith, the present work demonstrates and optimizes the extraction process usingan ultrasonic system and comopared the results with conventional extraction methods. Optimization was performed by combining first and second-order polynomial designs at different levels using Plackett-Burman and Central-Composite designs. A total of 31 experiments were conducted at different levels, including ultrasonic power (10–40 %), solvent-to-sample ratio (20–50 mL/g), solvent concentration (50–80 %), and HCl normality (0.2–1 N). The findings of the study suggest a significant (p<0.05) influence of extraction parameters on the extraction yield of the response variables, including total phenol (TPC), total flavonoid (TFC), total tannin (TTC), and the antioxidants activity. Further, the predicted values demonstrated good agreement with the experimental values, exhibiting a high (R2>95%) coefficient of determination and a non-significant lack of fit. At the optimized condition, the experimental values of TPC, TFC, TTC and antioxidants (DPPH, ABTS, FRAP) activity were found near the model predicted values. The HPLC-PDA analysis identified ten polyphenolic compounds, among which rutin hydrate (12.991±0.003 mg/g DW), followed by phloridzin (6.660±0.001 mg/g DW), and chlorogenic acid (3.380±0.008 mg/g DW) were the most prominent compounds. Furthermore, the optimized extract showed effective antibacterial activity against Bacillus subtillis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus species. In conclusion, the obtained results indicate that the proposed optimization strategy can be utilized to enhance the yield of polyphenolics from the target species with possibility of its application in therapeutics values.

Simulation data-driven adaptive frequency filtering focal network for rolling bearing fault diagnosis

The scarcity of well-labeled samples severely limits the application of deep learning-based fault diagnosis methods. To address this issue, this paper proposes a novel domain-adaptive intelligent diagnostic method, termed a simulation data-driven adaptive frequency filtering focal network, which transfers knowledge from dynamic simulation data to unlabeled measured data. First, a dynamic simulation model is established to simulate the coupled behavior of rolling bearings and generate substantial labeled simulation data. Subsequently, an adaptive frequency filter is introduced to suppress random interference components in the frequency domain, complementing conventional time-domain feature extraction methods, thereby reducing the distribution discrepancy between simulation and measured data. Finally, a domain-aware weighted focusing strategy is proposed to adjust sample weights based on predicted domain labels, helping the model focus on difficult samples with significant distribution discrepancies and reduce misclassification. Experimental results demonstrate that the proposed method effectively integrates simulation and measured data, achieving high-accuracy fault diagnosis of rolling bearings in unlabeled measured data. The proposed approach offers a promising fault diagnosis solution in scenarios where obtaining labeled samples is challenging or impractical.

Direct Extraction of Lipids, β-Carotene, and Polyphenolic Compounds from Wet Microalga Dunaliella salina by Liquefied Dimethyl Ether.

Extraction of lipids and high-value products from highly wet microalgae requires significant energy for the drying pretreatment. In this study, we examined the direct extraction of lipids, β-carotene, and polyphenolic compounds from wet Dunaliella salina using liquefied dimethyl ether (DME), which is effective in lipid extraction for biofuel production. The amount of DME-extracted β-carotene was 7.0 mg/g, which was higher than that obtained from the chloroform-methanol extraction. Moreover, the total phenolic content extracted with DME and its antioxidant capacity were slightly higher than those extracted with chloroform-methanol. DME removed almost all the water and extracted 29.2 wt% of total lipids and 9.7 wt% of fatty acids. More lipids were extracted from wet samples by liquefied DME than by chloroform-methanol extraction. The C/N ratio of lipids extracted with DME was 112.0, higher than that of chloroform-methanol. The high C/N ratio suggests that nitrogen-containing phosphatidylcholines may be less easily extracted by liquefied DME and may be highly selective. However, the ratio of saturated fatty acids was 34.8%, lower than that of chloroform-methanol. Na+ and Mg2+ in the culture medium were not extracted using DME. Thus, using the extract with DME has both advantages and disadvantages compared to using the extract with chloroform-methanol; however, it has satisfactory extraction properties. DME is expected to be an environment-friendly alternative solvent because it does not require drying, which is necessary for conventional extraction solvents.

Phycocyanin-Loaded Alginate-Based Hydrogel Synthesis and Characterization.

Phycocyanin was extracted from Spirulina platensis using conventional extraction (CE), direct ultrasonic-assisted extraction (direct UAE), indirect ultrasonic-assisted extraction (indirect UAE), and microwave-assisted extraction (MAE) methods at different temperatures, extraction intervals, stirring rate, and power intensities while maintaining the same algae to solvent ratio (1:15 w/v). The optimization of the extraction parameters indicated that the direct UAE yielded the highest phycocyanin concentration (29.31 ± 0.33 mg/mL) and antioxidant activity (23.6 ± 0.56 mg TE/g algae), while MAE achieved the highest purity (Rp = 0.5 ± 0.002). Based on the RP value, phycocyanin extract obtained by MAE (1:15 w/v algae to solvent ratio, 40 min, 40 °C, and 900 rpm) was selected as active compound in an alginate-based hydrogel formulation designed as potential wound dressings. Phycocyanin extracts and loaded hydrogels were characterized by FT-IR analysis. SEM analysis confirmed a porous structure for both blank and phycocyanin loaded hydrogels, while the mechanical properties remained approximately unchanged in the presence of phycocyanin. Phycocyanin release kinetics was investigated at two pH values using Zero-order, First-order, Higuchi, and Korsmeyer-Peppas kinetics models. The Higuchi model best fitted the experimental results. The R2 value at higher pH was nearly 1, indicating a superior fit compared with lower pH values.

Red Seaweed (Rhodophyta) Phycocolloids: A Road from the Species to the Industry Application.

Seaweed polysaccharides are versatile both in their functions in seaweed physiology and in their practical applications in society. However, their content and quality vary greatly. This review discusses the main factors that influence the yield and quality of polysaccharides, specifically carrageenans and agars (sulfated galactans) found in red algae species (Rhodophyta). In addition, its historical, current, and emerging applications are also discussed. Carrageenan has been influenced mainly by photosynthetically active radiation (PAR) and nitrogen, while its relationship with temperature has not yet been replicated by recent studies. Agar's seasonal trend has also been found to be more ambiguous than stated before, with light, temperature, nutrients, and pH being influencing factors. In this review, it is also shown that, depending on the compound type, seaweed polysaccharides are influenced by very different key factors, which can be crucial in seaweed aquaculture to promote a high yield and quality of polysaccharides. Additionally, factors like the extraction method and storage of polysaccharides also influence the yield and quality of these compounds. This review also highlights the drawbacks and inadequacy inherent from the conventional (or current) extraction technology approaches.