An eco-friendly extraction method to obtain pectin from passion fruit rinds (Passiflora edulis sp.) using subcritical water and pressurized natural deep eutectic solvents

Obtaining value-added products from cashew apple bagasse: A sustainable alternative achieved through a hydrothermal process

The processing of cashew peduncles annually generates approximately 4000 tons of cashew apple bagasse, a biomass rich in value-added products. Pressurized liquid extraction (PLE) was employed to extract bioactive compounds using a Box-Behnken design, with temperature, pH, and solid-liquid ratio as the independent variables. The study evaluated pectin yield, total phenolic compounds (TPC), antioxidant activity (FRAP), sugars, and organic acids. Results were compared to a conventional agitation method (90 °C, 2 h, pH 2.0). Under optimized conditions of 120 °C, pH 2.0, and a solid-to-liquid ratio (S/F) of 15, the PLE method achieved a high pectin yield (23.37 % g g-1), surpassing the conventional method (21.40 % g g-1). Optimal sugar extraction was observed at 100 °C, pH 2.0, and S/F of 10, with a recovery of 90.41 mg per gram of cashew apple bagasse. TPC yields were higher at 120 °C, whereas antioxidant activity peaked at 100 °C. Formic acid concentrations were higher in treatments with low sugar recovery, suggesting compound degradation. Notably, the conventional method produced a higher concentration of formic acid, likely due to the extended extraction time. The kinetic study revealed the formation and recovery patterns of bioactive compounds over time. TPC and FRAP were continuously recovered throughout the studied period, while approximately 80 % of the pectin and sugar yields were achieved within the first 15 min of extraction. Morphological and structural analyses highlighted the impact of the extraction process on the cashew apple bagasse and the resulting pectins. The application of pressure-enhanced porosity in the pectin structure improved thermal stability, significantly reducing the material's hemicellulose fraction. The Ecoscale Environmental Assessment scored 89.75 for pectin extraction and 93 for TPC recovery, surpassing other extraction methods reported in the literature. These findings contribute to the valorization of agro-industrial waste and the development of high-value products from cashew apple bagasse, offering significant potential for the processing industry.

Pioneering polysaccharide extraction with deep eutectic solvents: A review on impacts to extraction yield, physicochemical properties and bioactivities

Deep eutectic solvents (DES) have emerged as promising solvents for polysaccharide extraction from various sources. The DES which is produced by combining hydrogen bond donors and acceptors offers sustainability, low toxicity, a wide range of solubility and tailored properties. This review examines DES features and their effectiveness as extraction media for polysaccharides, highlighting the mechanisms behind their enhanced extraction efficiency compared to classical solvents. Additionally, we discuss the mechanism behind the DES affecting the physicochemical and structural properties of the extracted polysaccharides. The review also explores the antioxidant, antihyperglycemic, antihyperlipidemic and immunomodulatory properties of DES-extracted polysaccharides compared to classical solvents which emphasize structural changes in the polymer complex. This review intends to shed insight into the prospects of green extraction technologies by providing information on the benefits of DES and its potential to modify polysaccharide characteristics and enhance their biological activities, which is covered in depth for the first time here.

Sustainable microwave-based eutectic mixture assisted purification of low-methoxy pectin and its role as an edible emulsifier in carrot jam preparation

An optimized microwave-assisted low methoxyl pectin extraction procedure was described. Six task specific deep eutectic solvents (TDES) were used in the extraction of pectin from bilimbi (LMABP) and pomelo peels (LMCGP). Response surface methodology-based optimization of the parameters like feed-to-solvent ratio, extraction time, and microwave power level results in 72.94 % (w/w) LMABP and 79.3 % (w/w) of LMCGP respectively. Fourier transform infrared (FTIR) analysis shows 20.93 % (w/w) and 20 % (w/w) degree of esterification for LMABP and LMCGP respectively. The stability, particle size, and pH of the extracts were found to be -5.554 mV, 1923 nm, and 2.95 for LMABP, and - 2.34 mV, 3320 nm, and 2.55 for LMCGP respectively. Additionally, the LMP extracts were successfully employed in the preparation of carrot jam with better stability, texture, and lower sugar content. This investigation highlights the synergetic effectiveness of microwave-assisted DES extraction for sustainable LMP extraction.

A review on pectin-based nanostructures for drug and gene delivery systems

Pectin, a widely available and cost-effective polysaccharide, has garnered considerable attention in biomedical applications, particularly as a matrix for drug and gene delivery systems. Pectin possesses prominent properties such as biocompatibility, biodegradability, and low toxicity, which are desired features for delivery systems. Various pectin-based nanostructures have been applied to encapsulate therapeutic agents, drugs, and genetic materials with the potential of protecting them until selectively transfer to the objective tissue and sustainably release in controlled conditions. Pectin-based nanostructures have been widely used in oral drug delivery systems because of pectin's stability in the gastric and small intestine biological media. Moreover, pectin-based nanostructures have a high potential usage in liver cancer treatment due to the selective targeting of galactose groups of pectin to liver cancer cells' receptors. Despite applying pectin-coated nanocomposites as non-viral vectors of gene delivery, more clinical trials are required to develop such potential carriers in gene therapy. Pectin has unique biological features such as anticancer, antimicrobial, antioxidant, antidiabetic, and anti-cholesterol properties that synergistically enhance the efficiency of the drug/gene delivery system. This review presents an exhaustive investigation of the recent research on pectin-based nanostructures applied in drug/gene delivery systems and other biomedical applications, its advantages, challenges, and future perspectives.

Evaluation of NADES for Pectin Films Reinforced with Oxalic Acid-Modified Chitin Nanowhiskers

The effect of three NADESs as pectin film plasticizers was evaluated at 10%, 30%, and 50% w/w by using the casting method. Two hydrophilic (choline chloride with glycerol or citric acid) and one hydrophobic (thymol-camphor) NADESs were used as replacement for glycerol. Oxalic acid-modified chitin nanowhiskers (oCNWs) at 1% w/w were used to evaluate the effect of the NADESs on the nanofiller. The resulting films using the hydrophobic NADES were difficult to handle and prone to cracking and performed similarly to or worse than pure pectin films. As a result, they were not further evaluated. In contrast, the hydrophilic ones showed characteristics comparable to glycerol. It was found that films containing glycerol and choline chloride-glycerol NADESs showed a decrease in opacity and tensile strength and an increase in WVP, Young's modulus, and maximum elongation. In contrast, those that contained citric acid exhibited a different behavior: opacity was less affected, and a decrease in WVP and an increase in tensile strength and Young's modulus (at 10% and 30% plasticizer) were found. oCNWs tended to decrease WVP and increase Young's modulus but not in a very significant way. Our findings demonstrate that NADESs can be used as plasticizers in pectin films without the need to include glycerol and that the nature of NADESs is relevant to tuning the final properties.

A sustainable extraction approach for recovery of Rhamnogalacturonan I enriched pectin from Amazonian cocoa pod husk

Approximately 16,000 thousand tonnes of cocoa husk are produced annually worldwide during the chocolate production chain, representing considerable potential for pectin extraction. The aim of this study was to investigate a new extraction technique using a binary system composed of carbon dioxide and water (CO2 + H2O) at high pressure and temperature, on cocoa sample from floodplain ecosystem. Temperatures of 393.15 K and 413.15 K and pressures of 20 and 30 MPa were used. Under these combined conditions overall yields ranging from 5.10 % to 10.70 % were obtained. The monosaccharide composition confirmed the extraction of pectic fractions. Uronic acid was identified as the primary monosaccharide (47.2-52.8 %), followed by galactose (19.3-23.6 %) and rhamnose (10.3-13.0 %), which resulted in high percentages of the RG-I region (51.2-44.3 %), which was significantly more prevalent in the extracts obtained with the CO2 + H2O binary system compared to traditional methods. The protein and phenolic contents were lower than found for pectins previously extracted with boiling water from the same raw material. The condition of 413.15 K/20 MPa yielded a pectic fraction with the highest degree of purity (91.05 % ± 0.95 %). The extracted pectins had a low degree of methyl esterification (18.8-22.6 %) and a high degree of acetylation (45.7-52.1 %). The molecular weight of the polysaccharides was in the range of 3.0 × 105 to 5.4 × 105 g/mol. The results demonstrated that the CO2 + H2O binary system is an efficient approach for the sustainable utilization of cocoa pod husk as a source of rhamnogalacturonan I enriched pectins with features that favour the applications as emulsifier agent in the food and pharmaceutical industries.

Research progress on extraction techniques, structure-activity relationship, and biological functional mechanism of berry polysaccharides: A review

In recent years, polysaccharides extracted from berries have received great attention due to their various bioactivities. However, the preparation and application of berry polysaccharides have been greatly limited due to the lack of efficient extraction techniques, unclear structure-activity relationships, and ambiguous functional mechanisms. This review discusses the technological progress in solvent extraction, assisted extraction, critical extraction, and combination extraction. The structure-activity relationship and functional mechanism (antioxidation, hypoglycemic, immunoregulation etc.) of berry polysaccharides are reviewed. After systematic exploration, we believe that industrial production is more suitable for using efficient and low-cost extraction methods, such as ultrasonic assisted extraction and microwave assisted extraction. And some of the bioactivities (antioxidant activity, hypoglycemic activity, etc.) of berry polysaccharides are closely related to their structure (molecular weight, monosaccharide composition, branching structure, etc.). Besides, berry polysaccharides exhibit bioactivities by regulating enzyme activity, cellular metabolism, gene expression, and other pathways to exert their effects on the body. These findings indicate the potential of berry polysaccharides as functional foods and drugs. This paper will contribute to the preparation, bioactivity research, and application of berry polysaccharides.

Optimization of subcritical water extraction for pectin extraction from cocoa pod husks using the response surface methodology

This study optimized subcritical water extraction (SWE) conditions to maximize pectin yield from cocoa pod husk (CPH) and compared the characteristics of CPH pectin extracted through SWE with those of CPH pectin obtained through conventional extraction (CE) with citric acid. The Box-Behnken experimental design was employed to optimize SWE and examine the influence of process parameters, including temperature (100 °C-120 °C), extraction time (10-30 min), and solid:liquid ratio (SLR) (1:30-2:30 g/mL), on pectin yield. The maximum pectin yield of 6.58% was obtained under the optimal extraction conditions of 120 °C for 10 min with 1:15 g/mL SLR and closely corresponded with the predicted value of 7.29%. Compared with CE, SWE generated a higher yield and resulted in a higher degree of esterification, methoxyl content, and anhydrouronic acid value but a lower equivalent weight. The extracted pectin was pure, had low-methoxyl content, and similar melting and degradation temperatures.

Natural Deep Eutectic Solvents Combined with Supercritical Carbon Dioxide for the Extraction of Curcuminoids from Turmeric

BACKGROUND

Curcuminoids, the bioactive compounds found in turmeric, exhibit potent antioxidant, anti-inflammatory, and neuroprotective properties. This study aims to enhance the extraction of curcuminoids from turmeric using environmentally friendly solvents supercritical CO2 (scCO2) combined with natural deep eutectic solvents (NADESs) in one process, and to evaluate the resulting biological activity.

METHODS

A Box-Behnken statistical design was applied to optimize scCO2 extraction conditions-pressure, CO2 volume, and temperature-to maximize curcuminoid yield. Next, the menthol and lactic acid NADESs were selected, and these two solvents were combined into a single turmeric extraction process. The biological activity of the resulting extract was evaluated using antioxidant assays (ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl) and enzyme inhibition assays (acetylcholinesterase, butyrylcholinesterase, and tyrosinase). Toxicity assessments were conducted on the aquatic invertebrates Daphnia pulex, Artemia sp., and Chironomus aprilinus.

RESULTS

The most effective extraction was achieved using a menthol-lactic acid NADES as a cosolvent, integrated at a 1:20 ratio of plant material to NADESs while in combination with scCO2. The optimized scCO2-NADES extraction resulted in a high curcuminoid yield (33.35 mg/g), outperforming scCO2 extraction (234.3 μg/g), NADESs ultrasound-assisted extraction (30.50 mg/g), and alcohol-based solvents (22.95-26.42 mg/g). In biological assays, the extract demonstrated significant antioxidant activity and effective inhibition of enzymes (acetylcholinesterase, butyrylcholinesterase, and tyrosinase). Toxicity studies showed a concentration-dependent response, with EC50 for Chironomus aprilinus at the level of 0.098 μL/mL and Daphnia pulex exhibiting high sensitivity to the extract.

CONCLUSIONS

This study highlights the potential of combining NADESs and scCO2 extraction in one process, demonstrating the effectiveness of scCO2-NADES extraction in maximizing curcuminoid yield and enhancing bioactivity.

Polysaccharide Conjugates' contribution to mellow and thick taste of Pu-erh ripe tea, besides Theabrownin

Mellow and thick taste (MTT) is considered to be a typical taste characteristic of high-quality Pu-erh ripe tea. However, the role of polysaccharide conjugates remains unclear. In this study, the infusion of different grades of Pu-erh ripe tea was isolated to fractions by sensory-guided ultrafiltration technology and the key taste substances of MTT in Pu-erh ripe tea were identified and confirmed in the sensory reconstruction experiment. Further separation, purification and structural identification of the polysaccharide conjugates were carried out. Involving in aggregation morphology, the ultrafiltration fraction exhibited obvious MTT than other fractions. The main MTT compound (PRTPS-5), mainly composed of the rhamnose, galactose, arabinose and mannose, had a molecular weight of 22.93 kDa. The main chain of PRTPS-5 comprised α-L-Araf-(1→, →2,4)-α-L-Rhap-(1→, →2)-α-L-Rhap-(1→, α-D-Galp-(1→, →4)-α-D-GalpA-6-OMe-(1→, →4)-α-D-Manp-(1→, →3,6)-β-D-Galp-(1 → and →5)-α-L-Araf-(1 → and contained multiple pectic characteristic peaks. This result had scientific guiding significance for the quality enhancement of Pu-erh ripe tea.

A Comprehensive Review on Advanced Extraction Techniques for Retrieving Bioactive Components from Natural Sources

The extraction of bioactive components from natural sources has gained significant attention in recent years due to increasing demand for natural and functional constituents in various industries, including pharmaceuticals, food, and cosmetics. This review paper aims to provide a comprehensive overview of the studies on extracting bioactive components from natural sources using different advanced extraction techniques. It highlights the need for efficient extraction methods to preserve these components' integrity and bioactivity. Various extraction techniques as supercritical-fluid extraction, microwave-assisted extraction, ultrasound-assisted extraction, subcritical solvent extraction, and solid-phase microextraction are explored in detail, highlighting their principles, advantages, and limitations. The review further examines the impact of different factors on the extraction process, including solvent selection, extraction time, temperature, ultrasonication-amplitude, etc. Additionally, emerging techniques, such as green extraction methods and nanotechnology-based approaches, are discussed, emphasizing their potential to enhance the extraction efficiency and sustainability of the process. Furthermore, the review presents case studies and experimental results from recent research articles, providing insights into applying different extraction techniques for specific bioactive components, such as phenolics, flavonoids, alkaloids, and essential oils. It discusses the extraction yield, bioactivity, and potential utilization of the extracted components in various industries. Overall, this review paper is valuable for researchers, scientists, and industry professionals interested in extracting bioactive components from natural sources. It consolidates the current knowledge on different advanced extraction techniques, their optimization parameters, and their potential applications, facilitating further advancements in the field and the development of innovative extraction methods for bioactive component extraction from natural sources.

Novel films of pectin extracted from ambarella fruit peel and jackfruit seed slimy sheath: Effect of ionic crosslinking on the properties of pectin film

Here, we prepared ionically crosslinked films using pectin extracted from agro-wastes, specifically ambarella peels (AFP) and jackfruit seed slimy sheath (JFS). Physiochemical properties of pectins, including moisture content, molecular weight (Mw), degree of esterification (DE), and galacturonic acid (GA), were analyzed. Optimal extraction was determined, i.e., citric acid concentration 0.3 M, time 60 min, solid/liquid ratio 1:25, and temperature 90 °C for AFP or 85 °C for JFS. Pectin yields under these conditions were 29.67 % ± 0.35 % and 29.93 ± 0.49 %, respectively. AFP pectin revealed Mw, DE, and GA values of 533.20 kDa, 67.08 % ± 0.68 %, and 75.39 ± 0.82 %, while JFS pectin exhibited values of 859.94 kDa, 63.04 % ± 0.47 %, and 78.63 % ± 0.71 %, respectively. The pectin films crosslinked with Ca2+, Cu2+, Fe3+, or Zn2+ exhibited enhanced tensile strength and Young's modulus, along with reduced elongation at break, moisture content, water solubility, water vapor permeability, and oxygen permeability. Structural analyses indicated metal ions were effectively crosslinked with carboxyl groups of pectin. Notably, the Cu2+-crosslinked film demonstrated superior water resistance, mechanical properties, and exhibited the highest antioxidant and antibacterial activities among all tested films. Therefore, the pectin films represent a promising avenue to produce eco-friendly food packaging materials with excellent properties.