Pectin extracted from persimmon peel: A physicochemical characterization and emulsifying properties evaluation

Inhibition effect and mechanism of hydrocolloids on the formation of heterocyclic aromatic amines (HAAs) in meat products: A review

Hydrocolloids are another potential exogenous additive and shows efficient effect in minimizing the formation of toxic by-products during high-temperature processing attribute to their unique structure and high solubility. Therefore, this review provided for the first time comprehensive summary and proposed new insights into the inhibitory effect and mechanism of hydrocolloids on HAAs formation in meat products. Effects of the combined use of hydrocolloids and polyphenols on the HAAs formation inhibitory effects were discussed and highlighted as well. Hydrocolloids, used alone or with polyphenols, can effectively inhibit HAAs formation. Among some common hydrocolloids, carrageenan and chitosan have significant inhibition effect on HAAs formation. Their water retention properties, free radical scavenging ability, and inhibition of Maillard reaction were elucidated as the in-depth mechanism for inhibiting the HAAs formation. This review can provide theoretical reference for hydrocolloids effectively controlling HAAs formation in thermal-processed food, and reducing their harm to human health.

Hypoglycemic and Gut Microbiota-Modulating Effects of Pectin from Citrus aurantium "Changshanhuyou" Residue in Type 2 Diabetes Mellitus Mice

To fully utilize the Citrus aurantium "Changshanhuyou" resource, the hypoglycemic effect and mechanisms of action of pectin from Changshanhuyou residue (HYP) were studied. HYP considerably inhibited α-glucosidase, suggesting its potent in vitro hypoglycemic activity. In streptozotocin-induced type 2 diabetes mellitus (T2DM) mice, HYP significantly increased the body weight, survival rate, hexokinase activity, and glycogen content and decreased fasting blood glucose, oral glucose tolerance, liver weight, and glycated serum protein levels. Furthermore, HYP remarkably improved glycolipid metabolism-related indices in both serum and liver, IL-6 and TNF-α levels in serum, and antioxidant enzyme activities in liver. HYP also modulated mRNA expression of the key factors (e.g., Akt, PI3K, IRS2, InsR, GLUT4, G6 Pase, PEPCK, AMPK, GS, and GSK-3β) and increased short chain fatty acid production and abundance of beneficial bacteria. Thus, the underlying hypoglycemic mechanism of HYP may involve the activation of PI3K/Akt, AMPK, and GS/GSK-3β signaling pathways and modulation of gut microbiota composition.

Construction and dynamic in vitro digestive characteristics of whey protein/chlorogenic acid/high methoxy pectin water-in-oil-in-water emulsion

Chlorogenic acid (CGA), while exhibiting diverse bioactive properties, but poor bioavailability and application stability, encapsulation via emulsion delivery systems represents a promising strategy to enhance its bioavailability and achieve sustained-release kinetics. In this study, bovine whey protein (BWP), CGA and high-methoxyl pectin (PEC) formed the water-in-oil-in-water (W/O/W) emulsion through the two-step emulsification. All W/O/W emulsions showed superior particle size, absolute potential, stability, and antioxidants, especially the W/O/W emulsion of BWP: PEC = 1:5 (0.5 % BWP and 2.5 % PEC) had highest encapsulation efficiency (94.52 ± 0.57 %) of CGA and thermal stability, this is related to the strongest hydrogel properties and grafting degree (16.98 ± 1.17 %). Moreover, in dynamically simulated digestion, the hydrolysis of CGA in continuous gastrointestinal digestion was inhibited, demonstrated remarkable slow-release characteristics; and W/O/W emulsion with high pectin content (BWP: PEC = 1:5) demonstrated prolonged gastric retention (9.9 % residual at 90 min) and reduced proteolytic susceptibility (24.12 % digestibility after 3 h). Consequently, W/O/W emulsions stabilized by BWP-PEC complexes can be applied as a prospective delivery system for enhancing the stability, antioxidant and slow-release properties in vivo of CGA.

Curcumin Microcapsule Formulations for Prolong Persistence in the Photodynamic Inactivation of Aedes aegypti Larvae

Background: Viral diseases including dengue, zika, chikungunya, and yellow fever remain a significant public health challenge, primarily due to the increasing resistance of these vectors, the Aedes aegypti mosquito, to conventional control methods. Objectives: Herein, a microencapsulated curcumin formulation was developed and characterized using spray-drying technology, with D-mannitol and starch as encapsulating agents. After microencapsulation, photolarvicidal tablet formulations (Formulated Curcumin Tablets-FCT) were prepared, varying the proportions of starch and pectin: FCT1 (60% starch), FCT2 (35% pectin and 25% starch), and FCT3 (42.5% pectin and 17.5% starch), while maintaining 10% curcumin and 30% D-mannitol in all formulations. The main goal was to enhance the stability and efficacy of curcumin as a photolarvicidal agent. Methods: The formulation was characterized by UV-Vis spectroscopy, confocal microscopy, thermal analysis (TG and DSC), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and photodegradation assays under fluorescent light. Results: The photodynamic inactivation (PDI) of Ae. aegypti larvae was evaluated under white, fluorescent light exposure, and the formulation exhibited a significantly enhanced larvicidal activity compared to free curcumin, with a 57-fold reduction in LC50 (LC50-24h = 0.27 mg/L). Additionally, the most effective formulation, FCT2, maintained its residual activity for 27 days, reinforcing that curcumin microencapsulation, combined with PDI, can extend vector control. Release studies under different pH conditions confirmed a controlled release mechanism, favoring environmental stability. Conclusions: The results indicate that microencapsulated curcumin has great potential as a sustainable photoinsecticidal agent, offering stability, efficacy, and a promising alternative for managing Ae. aegypti larval populations.

Physicochemical properties and in vitro hypolipidemic activities of three different bonding state pectic polysaccharide fractions extracted sequentially from pear pulp

In this study, water-soluble fraction (WSF), chelator-soluble fraction (CSF), and sodium carbonate-soluble fraction (NSF) were sequentially fractionated from pear pulp, of which physicochemical properties and hypolipidemic activities in vitro were evaluated. They showed distinct monosaccharide composition, surface morphology, nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectrums. WSF and NSF were identified as high methyl-esterified pectic polysaccharides with degrees of methyl esterification (DM) of 85.71 % and 66.67 %, respectively, whereas CSF was low methyl-esterified pectic polysaccharides (47.83 %). WSF, CSF, and NSF all demonstrated low molecular weight, desirable rheological, thermal, antioxidant, and hypolipidemic effects in vitro. It was remarkable that WSF displayed the most excellent inhibition capacity of cholesterol micelles (26.63 %), pancreatic lipase (PL) (91.13 %)/cholesterol esterase (CEase) (53.10 %) activity inhibition, attributed to its highest DM and roughest morphology. CSF and NSF exhibited stronger cholate-binding capacity than WSF, inseparable from higher apparent viscosity and gel ability. On these grounds, different bonding state pectic polysaccharide fractions from pear presented some distinctions in their structural characteristics and functional properties, which might endow them with exploitation in health promotion and dietary supplements.

Optimization of hypobaric and ultrasonic processing of persimmon rhamnogalacturonan-I to enhance drug-digestion interactions

The biological activity of polysaccharides used for nutraceuticals/drug excipients has been a neglected area of study. This work deals with the preparation, optimization, characterization, and evaluation of persimmon (Diospyros kaki Thunb.) fruit by-products and the study of the resultant dietary fiber (DF) interaction with other compounds, using acetaminophen as a model. Processing conditions for persimmon by-products were optimized to enhance antioxidant activity, with hypobaric, ultrasonic, and drying conditions tested at three levels of time and pH. The optimized DF was evaluated through in-vitro and ex-vivo release and permeation studies. Optimal conditions included three cycles of vacuum instantaneous expansion coupled with ultrasound waves (USEX), 42 min of ultrasound assisted extraction (UAE), and a pH of 1.5. After treatments, the antioxidant capacity (AC) increased six-fold, and zeta potential (ζ) analysis indicated polysaccharide aggregation at the optimized pH. The optimized polysaccharides, mainly formed by rhamnogalacturonan-I, displayed nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent activity. In-vitro drug-DF interaction studies showed higher acetaminophen release during digestion. Permeation kinetics adhered to the Korsmeyer-Peppas model in both ex-vivo and in-vitro models, suggesting complex permeation mechanisms. Results suggest that the optimized DF enhances the bioavailability and controlled release of acetaminophen, indicating its potential for use in drug delivery systems and nutraceutical applications.

A critical review of persimmon-derived pectin: Innovations in extraction, structural characterization, biological potentials, and health-promoting effects

Persimmon-derived pectin (PP) is a versatile dietary polysaccharide with considerable industrial and biological significance, demonstrating a range of functionalities and health-promoting benefits. This review explores the changes in PP during postharvest and processing, detailing structural alterations and extraction techniques for optimal characteristics. Key functional attributes of PP-such as emulsification, rheology, antioxidant capacity, immunomodulation, and gut microbiota regulation-highlight its potential applications in food, healthcare, pharmaceuticals, and cosmetics. The review also explores methods to enhance the functional properties of PP through synergistic interactions with polyphenols. A strategic roadmap for advancing PP research is proposed, connecting extraction methods, structural characteristics, and functional properties to tailor PP for specific applications in food science and technology. Overall, persimmon-derived pectin is positioned as a valuable food-derived bioactive ingredient with diverse capabilities, poised to drive innovation and advance nutritional science across multiple sectors.

The instability of pectin-based emulsions in the upper digestive tract investigated based on the molecular structure and interfacial properties of pectin

Pectin is a widely used natural emulsifier that is thought to stabilize emulsions in the upper gastrointestinal tract (GIT). However, changes in the structural characteristics and interfacial properties of pectin during its digestive treatment in the upper GIT and the effects on the stability of pectin-based emulsions are still unclear. This study showed that the stability of pectin-based emulsions steadily decreased in the upper GIT. Reductions in the molecular weight of pectin (from 2.74× 105 to 1.61× 105 g/mol) occurred mainly in the stomach, whereas the degree of esterification (from 61.2 % to 42.1 %) decreased throughout the digestive treatment. The change in the structure of pectin reduced its hydrophobicity in the upper GIT, and led to form a cross-linked network with Ca2+ in small intestine rather than adsorbing to the oil-water interface. The behavior was reflected in the increased interfacial tension and the decreases in the interfacial modulus and thickness of pectin. Our insights into the structural characteristics and interfacial properties of pectin and thus into the mechanism of pectin instability in the upper GIT will contribute to the development of more efficient encapsulation methods and improved targeted delivery for active substances or probiotics using pectin-based emulsions.

Effects of different extraction solvents on the compositions, primary structures, and anti-inflammatory activity of pectin from sweet potato processing by-products

To examine the effects of different solvents on the molecular weight, yield, chemical composition, and bioactivity of pectins, four RG-I type pectins were separately extracted from sweet potato residue (SPR) using hot water extraction (HWSP), sodium hydroxide extraction (SHSP), hydrochloric acid extraction (HASP), and chelating agents (CASP). The results showed that the four pectin samples comprised GalUA, Gal, Rha, Ara, Glc, GlcUA, Man, and Xyl components. Among these components, GalA content was the highest in all four pectins. SHSP exhibited relatively higher yield (3.16 %, w/w). Additionally, SHSP exhibited a lower molecular weight (44.49 kDa) and the largest proportion of the RG-I region (75.42 %) compared with other extraction methods. On the contrary, HASP showed relatively lower yield (2.14 %, w/w), and its corresponding prepared pectin had relatively high molecular weight (69.81 kDa) and the minimum range of RG-I region (46.87 %) compared with HWSP, SHSP, and CASP. The anti-inflammation effect of the four SPR pectin samples was investigated using in vitro experiments. Results showed that all of SPR pectin significantly inhibited the levels of IL-1β, IL-6, and TNF-α in lipopolysaccharide (LPS)-treated iBMDM macrophage cells. The preliminary structure-activity relationship between pectin structure and anti-inflammatory activity was also analyzed. SPR pectin can be developed as a potential bioactive ingredient for applications in the food and medicine industries.

Tyramine-assisted fluorescent labeling of polysaccharides: Characterization, and interfacial properties

Fluorescence labeling has been widely used in various fields, including fluorescent sensors, biochemistry, medical and chemical research. This study proposed an efficient strategy for the detection and microanalysis of polysaccharides. Soy hull polysaccharide (SHP) was successfully labeled with fluorescein isothiocyanate (FITC) via an amination reaction using tyramine as a linker. The labeled polysaccharide (FTSHP) was characterized by fluorescence, UV-visible, flourier transform infrared (FT-IR), 1H NMR, differential scanning calorimetry (DSC) and interfacial tension. The results indicated that the labeling efficiency of FTSHP with different concentration of FITC (0.20-0.35 wt%) was 1.51 %, 1.58 %, 1.63 %, and 1.67 %, respectively, with fluorescence intensity increasing as FITC concentration increased. Moreover, the interfacial adsorption capacity and thermal stability of FTSHP were significantly improved compared to SHP. This labeling method offers a promising approach for detection and analysis of polysaccharides, providing new insights into the study of other natural polysaccharides.

Unlocking the potential of persimmons: A comprehensive review on emerging technologies for post-harvest challenges, processing innovations, and prospective applications

Persimmons are widely acknowledged as a valuable source of both medicinal and nutritional components, providing a diverse spectrum of nutrients and phytochemicals. Despite these benefits, biases against persimmons persists due to their characteristic astringent flavor that sets them apart from other fruits. Although several studies have explored various aspects of persimmons, a comprehensive review that addresses post-harvest challenges, processing innovations, and potential applications is notably absent in the literature. This review aims to fill this gap by discussing a range of topics, including emerging preservation technologies, methods for detecting and eliminating astringency, identification of functional elements, health-promoting prospects, and advancements in processed persimmon products. The primary objective is to enhance the utilization of persimmons and promote the development of diverse, customized products, thereby fostering the emergence of functional and futuristic foods.

An in-depth review: Unraveling the extraction, structure, bio-functionalities, target molecules, and applications of pectic polysaccharides

Pectic polysaccharides have long been a challenging subject of research in the field of macromolecular science, given their complex structures and wide range of biological effects. However, the extensive exploration of pectic polysaccharides has been limited due to the intricacy of their structures. In this comprehensive review, we aim to provide a thorough summary of the existing knowledge on pectic polysaccharides, with a particular focus on aspects such as classification, extraction methodologies, structural analysis, elucidation of biological activities, and exploration of target molecules and signaling pathways. By conducting a comprehensive analysis of existing literature and research achievements, we strive to establish a comprehensive and systematic framework that can serve as a reference and guide for further investigations into pectic polysaccharides. Furthermore, this review delves into the applications of pectic polysaccharides beyond their fundamental attributes and characteristics, exploring their potential in fields such as materials, food, and pharmaceuticals. We pay special attention to the promising opportunities for pectic polysaccharides in the pharmaceutical domain and provide an overview of related drug development research. The aim of this review is to facilitate a holistic understanding of pectic polysaccharides by incorporating multifaceted research, providing valuable insights for further in-depth investigations into this significant polymer.

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.

Pectin-based cinnamon essential oil Pickering emulsion film with two-sided differential wettability: A major role in the spatial distribution of microdroplets

Pickering emulsions have attracted much attention as a novel emulsifying technology. This research to explore Zein-Citrus pectin nanoparticles stabilized cinnamon essential oil (CEO) Pickering emulsion (ZCCPEs) for constructing Pickering emulsion edible film (PEF). Unlike traditional research, which focuses on antibacterial and antioxidant activities, our research examined the physical properties of PEF, specifically changes in wettability. The results show that PEF has better transparency and tensile strength than the pectin alone direct emulsion film (PAEF), and the spatial distribution of Pickering emulsion droplets gives different wettability on both sides of PEF. The partially hydrophobic upside has important application value in food packaging. At the same time, the PEF is biodegradable and environmentally non-polluting. The edible film loaded with essential oils, developed based on the Pickering stabilization mechanism in this study, possesses several desirable characteristics for potential used as bioactive packaging films in food applications.

An investigation of a strengthening polysaccharide interfacial membrane strategy utilizing an anionic polysaccharide-alkaline ligand interfacial assembly for all-liquid printing

The applications of polysaccharides as emulsifiers are limited due to the lack of hydrophobicity. However, traditional hydrophobic modification methods used for polysaccharides are complicated and involve significant mechanical and thermal losses. In this study, soy hull polysaccharide (SHP) and terminally aminopropylated polydimethylsiloxane (NPN) were selected to investigate the feasibility of a simple and green interfacial membrane strengthening strategy based on the interfacial polymerization of anionic polysaccharides and fat-soluble alkaline ligands. Our results show that deprotonated SHP and protonated NPN can be complexed at the water/oil (W/O) interface, reduce interfacial tension, and form a strong membrane structure. Moreover, they can quickly form a membrane at the W/O interface upon the moment of contact to produce stable all-liquid printing products with complex patterns. However, the molecular weight of NPN affects the complexation reaction. Consequently, this study has long-term implications to expanding the areas of application for anionic polysaccharides.

Physicochemical, structural and functional properties of low methoxyl pectin‑iron (III) complex and its effect on rats with iron deficiency anemia

Iron deficiency anemia (IDA) is the most common nutritional disease worldwide. In this study, a low methoxyl pectin (LMP)‑iron(III) complex was prepared. The physicochemical and structural properties were characterized by HPSEC, HPIC, CV, FTIR, 1H NMR, XRD, SEM and CD. The results showed that iron increased the molecular weight of the LMP‑iron(III) from 11.50 ± 0.32 to 12.70 ± 0.45 kDa and improved its crystallinity. Moreover, the findings demonstrated that -OH and -COOH groups in LMP coordinate with Fe3+ to form β-FeOOH. The water-holding capacity, emulsion stability, and antioxidant activities of the LMP‑iron(III) were lower than those of LMP. Furthermore, the therapeutic effects of LMP‑iron(III) on IDA were investigated in rats. Following LMP‑iron(III) supplementation, compared with the model group, the administration of LMP‑iron(III) significantly increased the body weight, hemoglobin concentration, and serum iron concentration as well as decreased free erythrocyte protoporphyrin concentration. Therefore, the LMP‑iron(III) can potentially treat IDA in rats experiments, providing a theoretical basis for the development of a promising iron supplement.

Polysaccharide-Based Micro/Nanomotors for Active Ingredient Delivery in Food

Micro/nanomotors (MNMs) are miniature devices that can generate energy through chemical reactions or physical processes, utilizing this energy for movement. By virtue of their small size, self-propulsion, precise positioning within a small range, and ability to access microenvironments, MNMs have been applied in various fields including sensing, biomedical applications, and pollutant adsorption. However, the development of food-grade MNMs and their application in food delivery systems have been scarcely reported. Currently, there are various issues with the decomposition, oxidation, or inability to maintain the activity of some nutrients or bioactive substances, such as the limited application of curcumin (Cur) in food. Compared to traditional delivery systems, MNMs can adjust the transport speed and direction as needed, effectively protecting bioactive substances during delivery and achieving efficient transportation. Therefore, this study utilizes polysaccharides as the substrate, employing a simple, rapid, and pollution-free template method to prepare polysaccharide-based microtubes (PMTs) and polysaccharide-based micro/nanomotors (PMNMs). PMNMs can achieve multifunctional propulsion by modifying ferrosoferric oxide (Fe3O4), platinum (Pt), and glucose oxidase (GOx). Fe-PMNMs and Pt-PMNMs exhibit excellent photothermal conversion performance, showing promise for applications in photothermal therapy. Moreover, PMNMs can effectively deliver curcumin, achieving the effective delivery of nutrients and exerting the anti-inflammatory performance of the system.

Effect of Organic Acid-Aided Extraction on Characteristics and Functional Properties of Pectin from Cannabis sativa L

The extraction of cannabinoids from the inflorescence and leaves of Cannabis sativa L. is gaining interest from researchers, in addition to addressing the under-utilization of the by-products in the stems and roots of the trees. The present study investigated the recovery of pectin from the left-over parts of hemp tress using an eco-friendly method with the aid of organic acids. Different cannabis cultivars-Chalotte's Angels (CHA) and Hang-Krarog (HKR)-were used as plant materials. The stems of both cannabis cultivars contained more pectin than the roots, and tartaric acid-aided extraction provided higher yields than from citric acid. Extracting the acid solution affected some characteristics, thereby differentiating the functional properties of the derived pectin. Extraction using tartaric acid provided pectin with a higher galacturonic acid content, whereas pectin with a higher methylation degree could be prepared using citric acid. The pectin samples extracted from the stems of CHA (P-CHA) and HKR (P-HKR) had low methoxyl pectin. P-CHA had better free radical scavenging capability, whereas P-HKR showed more potent reducibility. Considering the functional properties, P-CHA showed greater emulsion formability and foaming activity, whereas P-HKR possessed a better thickening effect. The present work suggests the feasible utilization of P-CHA and P-HKR as food additives with bioactivity.

Structural and flow rheological properties of pumpkin pectic polysaccharide extracted by citric acid

The present study aimed to investigate the structural and physicochemical characteristics of acid-extracted pumpkin pectic polysaccharide (AcPP) and to evaluate their flow rheological properties. AcPP was extracted from pumpkin pulp using the citric acid extraction method. The physicochemical and structural properties were analyzed by chemical methods and instrumental analyses. The obtained results showed that AcPP consisted predominantly of GalA (85.99 %) and small amounts of Rha, Gal, and Ara, with the ratio of HG/RG-I being 81.39/16.75. In addition, AcPP had medium DE (45.34 %) and contained four macromolecular populations with different Mw of 106.03 (main), 10.15, 4.99, and 2.90 kDa. The NMR analysis further confirmed that AcPP contained a linear backbone consisting of α-1,4-linked GalA residues, some of which were partially methyl-esterified. Furthermore, AcPP was amorphous in nature and had favorable thermal stability. The effects of extrinsic factors on the flow rheological properties of AcPP were evaluated. In particular, the high concentrations of CaCl2 (8 mM) and MgCl2 (10 mM) were effective in enhancing the viscosity and non-Newtonian shear-thinning behavior of the AcPP solution. This study elucidates the unique molecular structure of AcPP and suggests the potential of AcPP as a rheology modifier in low-viscous and mineral-reinforced beverages.

Extraction of pectins from renewable grapefruit (Citrus paradisi) peels using deep eutectic solvents and analysis of their structural and physicochemical properties

This study presents an innovative attempt to extract high-quality pectins from grapefruit (Citrus paradisi) peels by using deep eutectic solvents (DESs) as extraction agents. The maximum yield of betaine-citric acid (BC)-extracted pectin (BC-P) reached 36.47 % under the optimum process conditions: an L/S ratio of 25 mL/g, a pH of 2.0, and a temperature of 85 °C for 120 min. The yield of BC-P was significantly higher than HCl-extracted pectin (HCl-P, 8.76 %) under a pH of 2.0. In addition, the structural, physicochemical, and emulsifying properties of the purified pectins (BC-P and HCl-P) and commercial pectin (CP) were comparatively analyzed. Results showed that BC-P exhibited higher RG-I value, more arabinan side-chains, bigger Mw and Mn value than HCl-P. Moreover, the viscosity, G' and G'' of BC-P were significantly higher than those of HCl-P and CP. More importantly, BC-P demonstrated better emulsifying activity and stability compared to HCl-P and CP. When the concentration of BC-P was increased to 1.50 %, a stable emulsion containing a 50 % soybean oil fraction could be obtained. Our results confirmed that DESs can be considered as high-effective agents for pectin extraction. Pectins extracted from grapefruit peels can be as a promising natural emulsifiers that can be used in the food industry.

New insight into pectic fractions of cell wall: Impact of extraction on pectin structure and in vitro gut fermentation

Pectic polysaccharides modulate gut fermentation ability, which is determined by structural characteristics. In this work, apple pectins were extracted by HCl (HAEP), NaOH (AEP), cellulase (EAEP), and in parallel cell wall pectic fractions were sequentially extracted by water (WEP), chelator (CEP) and NaOH (NEP). The aim is to comprehensively compare the impact of extraction on pectin structure and gut fermentation behavior. Results showed that high content of galacturonic acid (90.65 mol%) and large molecular weight (675 kg/mol) were detected in the HAEP. Molecular morphology of the HAEP presented high linearity, while AEP, EAEP and WEP exhibited compact filamentous structures with highly branched patterns. The AEP was characterized by high yield (33.1 g/100 g d.b.), moderate molecular weight (304 kg/mol) and large extent of rhamnogalacturonan-I region (24.88 %) with low degree of branching (1.77). After in vitro simulated gut fermentation for 24 h, total content of short-chain fatty acid (SCFA) generated with the AEP supplement increased to 36.8 mmol/L, followed by EAEP, HAEP and WEP (25.2, 24.2 and 20.3 mmol/L, respectively). Meanwhile, WEP simultaneously produced the highest ammonia content (22.4 mmol/L). This investigation suggests that the fermentation of AEP produces more beneficial SCFA and less ammonia, thus indicating a better gut fermentation property.

Excipient emulsion prepared with pectin and sodium caseinate to improve the bioaccessibility of carotenoids in mandarin juice: The effect of emulsifier and polymer concentration

Excipient emulsions were prepared using different emulsifiers (pectin and sodium caseinate, individually or compositely) to study the emulsifying properties and their co-digested effects on the retention and bioaccessibility of carotenoids in mandarin juice, which is a good source of carotenoids in people's diet. Results showed that both pectin (PC) and pectin-sodium caseinate (PC-SC) emulsion significantly increased the carotenoids retention and bioaccessibility of mandarin juice, with the effects depending on both emulsifiers and polymer concentration. Whether for PC or PC-SC emulsion, lower pectin content accompanied with lower viscosity showed higher carotenoids bioaccessibility. And for the complexed emulsions, appropriate sodium caseinate addition could be more beneficial in improving carotenoids bioaccessibility. It had been found that the viscosity comparing with particle size seemed to play a more important role in affecting carotenoid bioaccessibility during the co-digestion. This study could provide a basis for improving the carotenoids bioaccessibility in the real system of fruits and vegetables with excipient emulsions.

Pectin-rich dragon fruit peel extracts: An environmentally friendly emulsifier of natural origin

Pectin extraction is generally an energy-intensive industrial process, while on the other hand their extraction methods vary from different sources. Starting with that perspective, pectin (WSP) containing ultra-low degree of methylation (31.08 ± 1.27%) from dragon fruit peel (DFP) was extracted by using pure water at room temperature. WSP, dominant in DFP (17.13 ± 1.01%), showed both a high molecular weight and a wide molecular weight distribution, while the yield of the rest acid-soluble pectin (HAP) from DFP residue was only 5.22 ± 0.76%. Furthermore, WSP can stabilize emulsions over a wide range of concentrations and oil phases, especially HIPE. Therefore, the hypothesis was verified that the pectin-rich extract from dragon fruit peel with excellent emulsifying properties could be simply extracted by pure water. This environmentally-friendly and energy-saving extraction method provides a new insight to increase the additional value of dragon fruit peel produced in food processing.

Comparisons of pulsed ultrasound-assisted and hot-acid extraction methods for pectin extraction under dual acid mixtures from onion (Allium cepa L.) waste

The aim of this study is to compare the physicochemical properties and yields of pectins extracted from onion waste under hot acid (HAE) and pulsed ultrasound-assisted extraction (PUAE) methods using different organic-inorganic acids, their mixtures, and pure water. The extraction temperature for experiments carried out under HAE was kept at 90°C for 90 min, whereas PUAE experiments were accomplished at RT in 15 min. In general, HAE gave better pectin yields compared with PUAE due to the significance of the increasing extraction temperature for the release of pectin from the plant matrix. While the maximum pectin yield from onion waste was 16.22% for HAE, the highest yield for PUAE was 9.83%. PUAE provides less time- and energy-consuming extraction of pectin within 15 min and thus seems to be more economic compared with the HAE. According to the physicochemical properties (equivalent weight (EW), degree of esterification (DE), methoxyl (MeO), and galacturonic acid (Gal-A) contents) of obtained pectins, extracted pectins were mostly high methoxy pectin. While the DE and MeO values of pectins extracted in organic acid conditions under HAE were higher, these values were found to be higher for pectins extracted in inorganic acids under PUAE. For acid mixtures, the DE and MeO values of pectins under HAE were mostly found to be lower than those under PUAE. Sequential PUAE and HAE methods for the extraction of pectin from onion waste were also found to be useful in terms of obtaining higher yields and better physicochemical properties. The highest pectin yield was 20.32% for the sequential PUAE and HAE methods. FT-IR analyses of the extracted pectins by both HAE and PUAE methods showed similar vibration bands compared with those of commercial citrus pectin.

NADES assisted integrated biorefinery concept for pectin recovery from kinnow (Citrus reticulate) peel and strategic conversion of residual biomass to L(+) lactic acid

The present study aims to establish an integrated strategy for valorization of kinnow peel waste. A total of ten natural deep eutectic solvents (NADESs) were exploited for extraction of pectin. The highest yield of pectin enriched material was reported 35.66 % w/dw using choline chloride-Maltose based NADES. The extraction process parameters and chemical composition of NADES influenced the yield and different associated physico-chemical attributes of the pectin enriched material. All the recovered pectin enriched materials found to be composed of low methoxy pectin (degree of methylation: 18.41-40.26 %) and galacturonic acid (GalA) content was in range of 67.56-78.22 %. The Principal Component Analysis (PCA) was used to categorise isolated pectin enriched materials based on similarities and differences. The liquid fraction upon pectin extraction presented a considerable amount of fermentable sugar which was further utilized for lactic acid production by microbial intervention. The microbial strain Lactobacillus amylophilus GV6 was exploited for lactic acid fermentation where the highest yield reached 55.59 g/L. A sustainable and straight-forward biorefinery concept was developed for extraction of pectin enriched material and lactic acid production from kinnow peel waste with potential application in food and biotechnological sectors.

Structural characteristics, functional properties, antioxidant and hypoglycemic activities of pectins from feijoa (Acca sellowiana) peel

The structure characteristics, functional properties, antioxidant and hypoglycemic activities of pectins extracted from feijoa peel with water (FP-W), acid (FP-A) and alkali (FP-B) were investigated. Results showed that the feijoa peel pectins (FPs) were mainly composed of galacturonic acid, arabinose, galactose and rhamnose. FP-W and FP-A had higher proportion of homogalacturonan domain, degree of esterification and molecular weight (for main component) than FP-B; FP-B owned the highest yield, protein and polyphenol contents. FP-W had a compact and smooth surface morphology unlike FP-A and FP-B. FP-W and FP-A had better thermal stability than FP-B. The rheological analysis suggested that the FPs exhibited pseudoplastic fluid behavior, and the elastic characteristics were dominant. Results showed that FP-W and FP-B had superior antioxidant and hypoglycemic activities than FP-A. According to correlation analysis, monosaccharide composition, sugar ratios and degree of acetylation were chief factors affecting the functional properties, antioxidant and hypoglycemic activities of the FPs.

Physicochemical properties and Pb2+ adsorption capacity of freeze-dried hawthorn pectin fractions by gradient ethanol precipitation

Three fractions of FHP20, FHP40 and FHP60 were obtained from freeze-dried hawthorn pectin by gradient ethanol precipitation (20-60 %), and their physicochemical properties and adsorption performance on Pb²⁺ were investigated. It was found that the content of galacturonic acid (GalA) and esterification of FHP fractions gradually reduced with the increase of ethanol concentration. FHP60 had the lowest molecular weight (60.69 × 10³ Da), and the composition and proportion of monosaccharides were significantly different. The experimental results of Pb²⁺ adsorption showed that the adsorption process fitted well with the Langmuir monolayer adsorption and the pseudo-second-order models. Our findings suggested that pectin fractions with good homogeneity of molecular weight and chemical construction can be obtained by gradient ethanol precipitation, and hawthorn pectin could be developed as a potential adsorbent for Pb²⁺ removal.

A pectin-based photoactivated bactericide nanosystem for achieving an improved utilization rate, photostability and targeted delivery of hematoporphyrin

Photoactivated pesticides have many advantages, such as high activity, low toxicity, and no drug resistance. However, poor photostability and a low utilization rate limit their practical application. Herein, the photosensitizer hematoporphyrin (HP) was used as a photoactivated pesticide, covalently linked with pectin (PEC) via ester bonds, to prepare an amphiphilic polymer pro-bactericide, and subsequently self-assembled in aqueous solutions to obtain an esterase-triggered nanobactericide delivery system. The fluorescence quenching effect due to the aggregation of HP in nanoparticles (NPs) enabled the inhibition of photodegradation of HP in this system. Esterase stimulation could trigger HP release and increase its photodynamic activity. Antibacterial assays have shown that the NPs had potent antibacterial capacity, almost completely inactivating bacteria after 60 min of exposure to light. The NPs had good adherence to the leaves. Safety assessment indicated that the NPs have no obvious toxic effects on plants. Antibacterial studies on plants have shown that the NPs have excellent antibacterial effects on infected plants. These results provide a new strategy for obtaining a photoactivated bactericide nanosystem with a high utilization rate and good photostability and targeting ability.

Eco-friendly simultaneous extraction of pectins and phenolics from passion fruit (Passiflora edulis Sims) peel: Process optimization, physicochemical properties, and antioxidant activity

The objective of this study was to simultaneously extract passion fruit (Passiflora edulis) peel pectins and phenolics using deep eutectic solvents, to evaluate their physicochemical properties and antioxidant activity. By taking L-proline: citric acid (Pro-CA) as the optimal solvent, the effect of extraction parameters on the yields of extracted passion fruit peel pectins (PFPP) and total phenolic content (TPC) was. and the highest TPC (9.68 mg GAE/g DW) were attained under 90 °C, extraction solvent pH = 2, extraction time of 120 min and L/S ratio of 20 mL/g. In addition, Pro-CA-extracted pectins (Pro-CA-PFPP) and HCl-extracted pectins (HCl-PFPP) were subjected to high performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), thermogram analysis (TG/DTG) and rheological measurements. Results verified that the Mw and thermal stability of Pro-CA-PFPP were higher than those of HCl-PFPP. The PFPP solutions featured a non-Newtonian behavior, and compared with commercially pectin solution, PFPP solution exhibited a stronger antioxidant activity. Additionally, passion fruit peel extract (PFPE) exhibited stronger antioxidant effects than PFPP. The results of ultra-performance liquid chromatography hybrid triple quadrupole-linear ion trap mass spectrometry (UPLC-Qtrap-MS) and high performance liquid chromatography (HPLC) analysis showed that (-)-epigallocatechin, gallic acid, epicatechin, kaempferol-3-O-rutin and myricetin were the main phenolic compounds in PFPE and PFPP. Our results suggest that Pro-CA can be considered as an eco-friendly solvent for high-efficient extraction of high-value compounds from agricultural by-products.

Antioxidant activity and semi-solid emulsification of a polysaccharide from coffee cherry peel

In order to further improve the economic benefits of the coffee industry chain, we carried out the following systematic research on processing by-products. In this research, the obtained coffee cherry peel polysaccharide (CCP) which was removed from the coffee cherry peel by hot acid method had a galacturonic acid content of 20.50 % and a molecular weight of 3.05 kg/mol. According to the results of monosaccharide analysis, Fourier transform infrared spectroscopy, molecular weight distribution, and thermal analysis, CCP was a typical high methoxy polysaccharide. In vitro antioxidant results showed that CCP had better antioxidant capacity than commercial citrus polysaccharide (APC). When it came to emulsification performance, the water-oil bonding ability and disturbance resistance to the fluid of CCP were also significantly higher than that of APC. Specially, we found that 0.50 % (wt%) CCP could form a solid-liquid gel with very high plasticity at low oil phase fraction. In conclusion, the coffee cherry peel could be used as a natural source of a novel emulsifier, providing a promising alternative for polysaccharide in the food industry.

Characterization of hawthorn pectin gained via different ethanol concentrations

Pectin is identified as an effective delivery material due to its excellent gel-forming ability, low immunogenic properties, biocompatibility, and biodegradability. These excellent properties depend on the preparation method of pectin. In the study, four pectin fractions (named: CAHP30, CAHP40, CAHP50, and CAHP60, respectively) were obtained by different ethanol precipitations (30%, 40%, 50%, and 60%). Physicochemical properties, antioxidant activity, and emulsifying ability of HP were investigated and analyzed. Results showed that the surface structure of pectin was changed by ethanol fractional precipitation, and four fractions were low methoxy pectin. They had different monosaccharide compositions, but all rich in GalA. The Mw/Mn of CAHP30, CAHP40, CAHP50, and CAHP60 were 3.29, 2.57, 2.66, and 2.77, respectively. CAHP30 and CAHP60 had excellent emulsifying ability; moreover, CAHP60 was endowed with additional lipid antioxidant capacity and had the best thermal stability. E-CAHP40 exhibited a property between the entangled network structure. Overall, pectin with specific properties could be obtained by different ethanol concentrations.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 → and →4)-α-GalpA-6-O-methyl-(1→, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

Green Technologies for Persimmon By-Products Revalorisation as Sustainable Sources of Dietary Fibre and Antioxidants for Functional Beverages Development

The use of green technologies such as ultrasound and natural deep eutectic solvents (NADES) for revalorisation of food and agricultural by-products represents a sustainable way to tackle waste and promote a healthier environment while delivering much-needed functional food ingredients for an increasingly unhealthy population. The processing of persimmon (Diospyros kaki Thunb.) generates large amounts of by-products rich in fibre-bound bioactive phytochemicals. This paper assessed the extractability of bioactive compounds through NADES and the functional properties of the persimmon polysaccharide-rich by-products to evaluate their suitability to be used as functional ingredients in commercial beverages. Although higher amounts of carotenoids and polyphenols were extracted after eutectic treatment vs. conventional extraction (p < 0.05), the fibre-bound bioactives remained abundant (p < 0.001) in the resulting persimmon pulp by-product (PPBP) and persimmon pulp dietary fibre (PPDF), showing also a strong antioxidant activity (DPPH^•, ABTS^•+ assays) and an improved digestibility and fibre fermentability. The main structural components of PPBP and PPDF are cellulose, hemicellulose and pectin. PPDF-added dairy-based drink showed more than 50% of preference over the control among panellists and similar acceptability scores to the commercial ones. Persimmon pulp by-products represent sustainable source of dietary fibre and bioactives and are suitable candidates to develop functional ingredients for food industry applications.

Optimization of Mopan Persimmon Wine Fermentation with Pectinase and Analysis of Its Mechanism of Action

Due to the high sugar content of Mopan persimmon, which has an annual output of more than 0.5 million tons in China, it can be processed to make fruit wine. In this study, a strain of yeast screened from different persimmon samples was used for persimmon wine fermentation. The optimal conditions of persimmon wine fermentation were determined through single-factor experiments as follows: Yeast addition of 0.08 g/kg; a fermentation temperature of 28 °C; sucrose addition of 18%; and pectinase addition of 0.01%. Under these conditions, the alcohol content of persimmon wine reached 12.9%. The addition of pectinase during persimmon wine fermentation was found to decompose pectin at high speed, reduce the viscosity of the fermentation liquid, increase the dissolved oxygen content in the fermentation liquid, promote the growth and reproduction of yeast, and effectively convert the sugars into alcohol. After fermentation, alcohol, residual sugars, and total phenolic content with or without pectinase treatment were 12.9 and 4.4%, 2.2 and 13.4 g/L, and 738.7 and 302 µg/mL, respectively. Scanning electron microscopy (SEM) results showed that compared with the mash without pectinase treatment, the mash with pectinase had a larger network structure and more pores and yeasts.

Physicochemical and functional properties of RG-I enriched pectin extracted from thinned-young apples

The demand for obtaining pectin from new sources has been continuously increasing. The abundant but underutilized thinned-young apple is a potential source of pectin. In this study, an organic acid (i.e., citric acid) and two inorganic acids (i.e., hydrochloric acid and nitric acid) commonly used in commercial pectin production were applied to extract pectin from three varieties of thinned-young apples. The physicochemical and functional properties of the thinned-young apple pectin were comprehensively characterized. The highest pectin yield (8.88 %) was obtained from Fuji apple using citric acid extraction. All pectin was high methoxy pectin (HMP) and rich in RG-I regions (>56 %). The citric acid extracted pectin had the highest molecular weight (Mw) and lowest degree of esterification (DE) values, and exhibited great thermal stability and shear-thinning property. Furthermore, Fuji-apple pectin possessed significantly better emulsifying properties compared to pectin obtained from the other two varieties of apples. Thus, pectin extracted with citric acid from Fuji thinned-young apples has great potential to be applied in the food industry as a natural thickener and emulsifier.

Rheological Assessment of Oil-Xanthan Emulsions in Terms of Complex, Storage, and Loss Moduli

This experimental assessment was carried out to study the viscoelastic performance of crude oil-xanthan emulsions employing a RheoStress RS100 rheometer. Crude oil with a concentration range of 0−75% by volume was used to prepare the oil-gum emulsions. Two xanthan gums of Sigma and Kelzan were added in the emulsions with concentration ranges of 0−104 ppm. The linear viscoelastic ranges of all the tested oil-gum emulsions were found in the range of 0.1−10 Pa. Thus, the experimental tests were completed within the linear viscoelastic range of 1 Pa. The complex modulus increased gradually and steadily with frequency and gum concentration for all the examined emulsions. The addition of crude oil into the lighter xanthan concentration of <103 ppm provided almost the same behavior as the xanthan solution, whereas the presence of crude oil within the higher xanthan concentrations significantly stimulated the measured values of the complex modulus. For lower gum concentrations of up to 1000 ppm, oil concentration displayed no effect on both the storage and loss moduli, whereas for gum concentrations higher than 1000 ppm, both moduli increased gradually with crude oil concentration.

Purification, structural characterization and antioxidant activities of two neutral polysaccharides from persimmon peel

Two neutral polysaccharides (PPP1-1 and PPP1-2) were purified from persimmon peel. PPP1-1 (21.84 kDa) was mainly composed of arabinose (22.92 %), galactose (21.09 %), glucose (35.13 %), and xylose (19.09 %), while PPP1-2 (10.42 kDa) mainly contained arabinose (32.98 %), galactose (20.81 %), glucose (26.86 %), xylose (10.46 %), and mannose (7.63 %). Methylation and NMR spectra analysis demonstrated that the backbone of PPP1-1 appeared to be →6)-α-D-Glcp-(1→, →2,6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Manp-(1→, and α-L-Araf-(1 → residues. The main chain of PPP1-2 was composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,5)-α-L-Araf-(1 → residues with branches consisting of →3)-α-L-Araf-(1→, →1,2)-α-D-Glcp-(6→, →4)-α-D-Glcp-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →4)-β-D-Xylp-(1→, →4,6)-α-D-Glcp-(1→, and →4)-β-D-Manp-(1 → residues and terminal of α-L-Araf-(1 → residue. PPP1-2 exhibited stronger antioxidant activities and better thermal stability than PPP1-1. Our results provided the foundation for further investigating the structure and biological activities of persimmon peel polysaccharides and highlighted their potential to become potential antioxidants in functional food.

Properties of plant-derived soluble dietary fibers for fiber-enriched foods: A comparative evaluation

Plant-derived soluble dietary fibers (SDF) have many important physiological functions and the applications of SDF vary based on their properties, which are worth further investigating for fiber-enriched food production. In this study, SDF derived from konjac, apple, chicory, flaxseed, orange, psyllium seed, soybean and oat were purified, and their structural, physicochemical and functional properties were systematically evaluated. Monosaccharide composition analysis showed that these SDF belonged to heteropolysaccharides, of which konjac, psyllium seed, apple, soybean and oat SDF were glucomannan, arabinoxylan, pectin, arabinogalactan and glucan, respectively. The molecular weight of konjac glucomannan (KGM, 5.22 × 10⁶ Da) was the highest, and inulin, soybean arabinogalactan (SA) and oat glucan (OG) had higher water solubility. Moreover, KGM, apple pectin (AP), flaxseed SDF (FS) and psyllium seed arabinoxylan (PA) exhibited better water-holding capacity, swelling capacity, emulsifying activity and stability. Rheological studies and texture profile analysis suggested that KGM had the best viscosity and gelation ability. In addition, AP and orange SDF (OS) showed better α-amylase inhibitory activity, while OS and KGM had higher pancreatic lipase inhibitory activity. Also, KGM and FS displayed fine cholesterol absorption capacity. To summary, these functional properties illustrated the feasibility of SDF to regulate blood sugar and blood lipid levels.

Jabuticaba (Plinia sp.) Peel as a Source of Pectin: Characterization and Effect of Different Extraction Methods

The peel of jabuticaba, a small fruit native to Brazil, has been shown to be a potential source of antioxidants and soluble dietary fibers. In this study, flours prepared from these peels were evaluated as a source of pectin. Different extraction methods were employed: ultrasound (US) extraction followed by low temperature heating (40 °C); in a microwave (MW) without (method 1) or with cellulase (method 2) or hemicellulase (method 3); or in a water bath (method 4). Pectin yields ranged from approximately 18% for methods 1 and 4 up to 22% for enzyme-assisted extractions (methods 2 and 3). Methods that did not employ enzymes resulted in low amounts of methoxyl pectins, as opposed to high amounts of methoxyl pectins obtained after enzyme treatment. Cyanidin-3-O-glucoside (C3G) and ellagic acid were the main phenolic compounds found in jabuticaba peel pectins, with higher C3G levels obtained with enzyme-free extraction (methods 1 and 4). All pectins from jabuticaba peel presented a reddish tone, good emulsifying properties and high swelling capacity. The pectin extracted using US+MW+cellulase (method 2) presented better emulsifying performance (higher values of emulsifying activity and emulsion stability), more effective than commercially available citrus pectin.

Extraction of Pectin from Passion Fruit Peel: Composition, Structural Characterization and Emulsion Stability

Extraction methods directly affect pectin extraction yield and physicochemical and structural characteristics. The effects of acid extraction (AE), ultrasonic-assisted acid extraction (UA), steam explosion pretreatment combined with acid extraction (SEA) and ultrasonic-assisted SEA (USEA) on the yield, structure, and properties of passion fruit pectin were studied. The pectin yield of UA was 6.5%, equivalent to that of AE at 60 min (5.3%), but the emulsion stability of UA pectin was poor. The pectin obtained by USEA improved emulsion stability. Compared with UA, it had higher protein content (0.62%), rhamnogalacturonan I (18.44%) and lower molecular weight (0.72 × 10⁵ Da). In addition, SEA and USEA had high pectin extraction yields (9.9% and 10.7%) and the pectin obtained from them had lower degrees of esterification (59.3% and 68.5%), but poor thermal stability. The results showed that ultrasonic-assisted steam explosion pretreatment combined with acid extraction is a high-efficiency and high-yield method. This method obtains pectin with good emulsifying stability from passion fruit peel.

Pectin extracted from dragon fruit Peel: An exploration as a natural emulsifier

As a potential source of pectin, the peel of dragon fruit is a by-product of fruit processing and will bring considerable economic benefits. In this study, pectin (DFP) was extracted from dragon fruit peel by using a hot-acid method, and two commercial pectins were used as controls to correlate structural differences with physical and chemical properties through systematic evaluation. The galacturonic acid (GalA) content, degree of esterification (DM) and molecular weight (Mw) of DFP were 87.02 ± 0.89 %, 37.26 ± 1.37 % and 1181.75 ± 11.21 kDa, respectively. The FTIR and XRD analysis also confirmed that DFP is ultra-low methoxylated pectin and also contains characteristic functional groups naturally present in pectin. Compared to APA140 and LMP, DFP showed excellent emulsification at low concentrations. In particular, the extraordinary antioxidant activity of DFP may be attributed to polyphenols in free or bound form. Overall, DFP can be considered as a promising emulsifier and the results of the study provide an alternative to natural sources of emulsifiers in the food industry.

Extraction optimization and characterization of persimmon peel pectin extracted by subcritical water

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Persimmon peel pectin (PPP) was extracted by subcritical water.

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PPP had low M_w of 21.79 kDa and its degree of esterification was 40.61 %.

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PPP attributed to a degradation temperature of 228.05 ℃.

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The IC₅₀ of PPP to ABTS•+ was 9.8-times that of commercial citrus pectin in vitro.

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PPP altered microbial intestinal communities in mice.

Persimmon peel pectin (PPP) was extracted by subcritical water via the response surface methodology. The optimal crude PPP extraction yield of 7.62 ± 0.7 % was found at 138 °C, 2.84 min, and liquid–solid ratio of 1:10.02. After treatment of deproteinization and decolorization with papain and hydrogen peroxide, 83.19 % of protein and 78.56 % of the colour in crude PPP were removed, respectively. PPP owned the M_w of 21.79 kDa and its uronic acids content was 64.03 %. PPP was further affirmed by fourier transform infrared, X-ray diffractometer and ¹H NMR analysis. Moreover, the degradation temperature (228.05 ℃) of PPP was verified via differential scanning calorimetry. Then, the IC₅₀ of PPP to ABTS•+ was 9.8 times that of commercial citrus pectin. Moreover, PPP could change microbial communities and selectively enrich Bacteroides, Cetobacterium, Erysipelatoclostridium, Parabacteroides and Phocaeicola sartorii. This study demonstrated that subcritical water was practicable for extraction of persimmon peel pectin.