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Emulsion stabilizing properties of pectin
Abstract
Citrus pectin and beet pectin are able to reduce the interfacial tension between an oil phase and a water phase and can be efficient for the preparation of emulsions. Investigations were made to evaluate the effect of various parameters of pectin on its emulsifying capacity. Orange and rapeseed oils emulsions were prepared with pectin as an emulsifier. They were then separated by centrifugation and the pectin fraction remaining in the aqueous phase was analyzed. It was found that the molecular weight, protein and acetyl contents influenced significantly the emulsifying properties. It was observed that for both citrus and beet pectin, the fraction which became associated with the oil contained much more protein than the fraction in the aqueous phase. It is suggested that protein associated with the pectin played a key role in the stabilization of the emulsion. Our experiments indicated that depending on the pectin source, beet or citrus, only a limited quantity is adsorbed on the oil surface. The de-acetylated beet pectin maintained a good emulsifying ability but the chemically acetylated citrus pectin gave better results than the non-acetylated citrus pectin. It was inferred that acetyl groups could also contribute to emulsion stability. It is likely that they act by reducing the calcium bridging flocculation. A model is proposed to explain the emulsifying function of pectin.
... Some natural food hydrocolloids , including pectin, gum arabic, microcrystalline-cellulose, galactomannans and soluble soybean polysaccharides, exhibit emulsifying properties due to the mechanic stabilization effects. This proteinaceous moiety, which is covalently bound to a high weight fraction of the carbohydrate backbone, adsorbs onto the oil–water interface as an anchor (Nakamura et al., 2004; Akhtar et al., 2002; Leroux et al.,2003; Funami et al., 2007). Pectins are semi-flexible polymers of D-galacturonic acid linked together through a-1, 4-glycosidic linkages interrupted by L-rhamnose residues (Akhtar et al., 2002). ...
... Some of the carboxylic groups in the pectin chains are methyl esterified. Depending on the degree of esterification (DE), pectins are divided into two major groups: high methoxyl pectin (HMP) with a DE higher than 50% and low methoxyl pectin (LMP) with a DE lower than 50% (Leroux et al., 2003) Journal of Food Engineering j o u r n a l h o m e p a g e : w w w . e l s e v i e r . ...
... c o m/ l o c a t e / j f o o d e n g the emulsification properties of pectins (Drusch, 2007). According to Leroux et al. (2003), citrus pectin with a low molecular weight and a high degree of methoxylation (>70%) showed a high emulsifying property and was able to stabilize oil in a water emulsion. Protein–polysaccharide interactions have been extensively studied because they appear in most food systems (Benichou et al., 2002). ...
The objective of this study was to apply response surface methodology to estimate the emulsifying capacity and stability of mixtures containing isolated and textured soybean proteins combined with pectin and to evaluate if the extrusion process affects these interfacial properties. A simplex-centroid design was applied to the model emulsifying activity index (EAI), average droplet size (D[4,3]) and creaming inhibition (CI%) of the mixtures. All models were significant and able to explain more than 86% of the variation. The high predictive capacity of the models was also confirmed. The mean values for EAI, D[4,3] and CI% observed in all assays were 0.173 ± 0.015 nm, 19.2 ± 1.0 μm and 53.3 ± 2.6%, respectively. No synergism was observed between the three compounds. This result can be attributed to the low soybean protein solubility at pH 6.2 (<35%). Pectin was the most important variable for improving all responses. The emulsifying capacity of the mixture increased 41% after extrusion. Our results showed that pectin could substitute or improve the emulsifying properties of the soybean proteins and that the extrusion brings additional advantage to interfacial properties of this combination.
... Par ailleurs, plusieurs travaux ont rapporté que le rendement de l'extraction de la pectine dépend également de plusieurs autres paramètres qui varient pour le même agent d'extraction. Il s'agit notamment de la température, du pH, du temps, du rapport solide/liquide et de la granulométrie de la poudre des écorces sèches (Baississe 2009 ;Yapo et al., 2006 ;Leroux et al., 2003). ...
... les résultats de la pectine extraite par l'acide citrique sont comparables avec ceux obtenus par Leroux et al., (2003) et Yapo et al., (2006) qui sont respectivement de 43,2 et de 47,1 % pour la pectine de betteraves, et sont supérieurs à celui trouvé par Yapo et al., (2007) qui est de 30,3 %. ...
... D'après Yapo et al., (2006), Cette activité émulsifiante remarquable des pectines extraites par l'acide citrique peut être due au fait qu'elles sont dotées d'une activité tensioactive qui augmente la viscosité de la phase aqueuse et réduise la tendance à l'émergence des globules d'huile dispersés. Dans le même sens, Dea et Madden (1986), Yapo et al., (2006); cités par Leroux et al., (2003) ont constaté qu'une forte réduction de tension superficielle obtenue avec les pectines de betteraves peut être expliquée par le faibles poids moléculaire. ...
La filière agrumicole a connu, ces dernières années, un développement important grâce aux efforts conjoints des acteurs professionnels et de l'état, en réponse au Plan Maroc Vert. Certes, cette stratégie a permis l‘intensification de la production de cette filière, mais certaines variétés, en l‘occurrence la clémentine, souffre de plusieurs problèmes liés à la surproduction, la fluctuation des prix, la limitation des exportations, la concurrence internationale et l‘absence des voies de transformation maitrisées et adaptées à la qualité de ce fruit. Cette étude vient pour concrétiser l‘un des objectifs principaux de la nouvelle stratégie « Green Génération 2020-2030 » visant la valorisation et la transformation de 70% de la production agricole. Cette thèse de doctorat entre dans le cadre du Mégaprojet de recherche « Agrume » de l‘INRA visant d‘accompagner la stratégie GG par l‘amélioration de la productivité des agrumes et la valorisation technologique de la production par la proposition des voies de transformation adaptées aux caractéristiques des variétés cultivés au Maroc. Ainsi, ce travail de thèse vise la valorisation technologique des clémentines à travers, en premier lieu la caractérisation morphologique, physicochimique et biochimique des variétés cultivées dans la région de Béni-Mellal; ensuite, la mise au point des procédés de transformation du fruit (pulpe et écorce) adaptés à la qualité des variétés cultivés.
Les activités de recherche relatives à la caractérisation ont concerné les fruits (pulpe et écorce) de cinq variétés prélevées au niveau de la région de Béni Mellal. La comparaison de quatre variétés de clémentine (Orograndé, Sidi Aissa, Ain Taoujdat, Nour) et une variété hybride (Nova) de point de vue morphologique, physicochimique et biochimique nous a permis de constater que la variété Sidi Aissa présente
le meilleur rendement en jus ( 64,49%±5,20) et celle de Nova le rendement le plus élevé en écorce. De même l‘écorce de la variété Sidi Aissa était le plus riche en polyphénols totaux (5,18±0,13 g EAG/100g MS) et flavonoïdes (0,07±0,001 g ER/100g MS). L‘étude du pouvoir anti radicalaire par le test de piégeage du radical DPPH a révélé un pourcentage d‘inhibition variant de 19,72±0,97% à 57,65±0,12% pour toutes les variétés étudiées. Par ailleurs, les extraits des écorces de clémentine n‘ont pas montré une activité antibactérienne sur les espèces bactériennes testées à l‘exception l‘extrait de la variété Nour qui a un effet sur E.coli et Listeria monocytogène.
Comme voie de valorisation de ces clémentines, nous avons opté pour l‘extraction des
pectines à partir des écorces et leur utilisation dans la fabrication de la confiture à base de la pulpe. En effet, l‘étude expérimentale de trois protocoles d‘extraction de pectine à partir des écorces de la variété Nova nous ont permis de constater que l‘acide citrique est l‘agent le plus adapté à l‘extraction de la pectine avec un rendement de 21,36 ± 1,37% . Après le choix du procédé d‘extraction par l‘acide citrique, l‘étude d‘optimisation a été réalisée par la méthodologie des plans d‘expérience. Les facteurs les plus influents sur cette extraction sont le pH, la température et la taille des particules. Les résultats d‘optimisation nous ont permis d‘identifier les conditions optimales d‘extraction (pH = 1,5, T = 100°C et taille = 0,1mm) qui nous ont permis d‘avoir un rendement maximal en pectine soit 26,64%.
L‘évaluation de la qualité des pectines extraites a été faite à travers leur utilisation dans la fabrication de la confiture et en comparaison avec les pectines commerciales. En effet, six formules de confitures, avec des teneurs variables en pectine (0,4%, 0,6% et 0,8%), ont été testées, trois avec la pectine extraite et trois avec la pectine commerciale. Suite à l‘analyse sensorielle, la formule avec une teneur de 0.4% en pectine a été la plus appréciée aussi bien pour les pectines extraites que celles commerciales. Les confitures à base de pectine extraite et commerciale présentent des propriétés physicochimiques similaires, à l'exception des indices de couleurs qui sont meilleures pour la confiture à base de pectine extraite. Cette dernière est également plus riche de point de vue biochimique notamment en vitamine C. L'analyse sensorielle révèle une différence notable entre les deux types de confiture, le panel de dégustateurs a préféré la confiture à base de la pectine extraite. Par ailleurs, la détermination des critères de qualité de la confiture de clémentine à base de la
pectine extraite a montré qu‘elle est conforme aux exigences de la réglementation en matière de paramètres physicochimiques, biochimiques et microbiologiques. Ces paramètres en fait l‘objet d‘un suivi pour mettre au point la cinétique de dégradation de cette confiture durant le stockage sous différentes températures (4°C, 25°C, 36°C) et durant une période de 60 jours.
Pour les paramètres physicochimiques, nous observons une évolution décroissante en fonction du temps et de la température pour l‘acidité titrable, activité d‘eau et les indices de couleurs (L* et b*) pour les deux types de confitures. Tandis que l‘évolution est croissante pour l‘indice de couleur rouge a*
. L‘étude de la vitesse de dégradation de la vitamine C montre que ce paramètre dépend fortement de la température tandis que les polyphénols évoluent
indépendamment de la température, subissent une dégradation importante dans les quinze premiers jours de stockage, puis restent stables durant le reste du temps du stockage. Par ailleurs, l‘examen microbiologique des deux types de confitures indique une absence totale de développement microbien tout au long de la conservation.
Mots clés : Clémentine, valorisation, extraction, pectine, optimisation, cinétique, dégradation
... As a result, pectin can be absorbed to interface faster and spontaneously than these other polysaccharides. In fact, the surface activity of pectin is mainly originating from protein residues present within the pectin structure, but also to its acetyl groups and molecular weight [6,69]. Furthermore, the molecular weight and packing of these hydrocolloids at air-water interface can explain the differences in the surface excess concentration and the minimum surface area mentioned above for gelatin and polysaccharides. ...
... The standard Gibbs energy of micellization (∆G 0 m ) is calculated using the following equation [35] ∆G 0 m = RT ln CMC (6) The phenomena of adsorption and micellization are frequently evaluated by calculating the free energy of adsorption (∆G 0 Ads ) and the standard Gibbs energy of micellization (∆G 0 m ) in the bulk solution that dictates the equilibrium surface tension of aqueous solutions [69,70]. The negative values in free energy adsorption (∆G 0 Ads ) and standard Gibbs energy of micellization (∆G 0 m ) indicate the feasibility of these process and their spontaneous nature (Table 1) [71,72]. ...
Critical micelle concentration (CMC) is the main physico-chemical parameter to be determined for surfactants due to its impact on surface activity and self-assembled aggregation. The aim of the present study is to determine CMC at 40 °C of gelatin, ι-carrageenan, pectin, gellan gum and xanthan gum by using different analytical techniques, particularly mid-infrared (MIR) spectroscopy as a rapid technique. The CMC values obtained for each hydrocolloid were relatively identical regardless of the applied technique: rheometer, conductimetry and automatic drop tensiometer (tracker). Indeed, CMC values of 55.16 g/L, 14 g/L, 6.04 g/L, 7 g/L and 3.48 g/L were obtained, respectively, for gelatin, ι-carrageenan, pectin, gellan gum and xanthan gum by using the surface tension method (tracker). Similar results were obtained for MIR spectroscopy since CMC values of 70 g/L, 15 g/L, 7 g/L, 5 g/L and 6 g/L were observed, respectively, for gelatin, ι-carrageenan, pectin, gellan gum and xanthan gum. The results presented here clearly demonstrate that it is possible to use MIR spectroscopy as a rapid analytical technique for the CMC determination of the investigated hydrocolloids.
... The EC and ES trend was directly proportional to the molecular weight of the pectins. This aligns with research by Leroux et al. [68], emphasizing the significant impact of molecular weight on viscosity properties and emulsion stabilization. Higher molecular weights alongside longer chains in pectin have been reported to improve emulsion stabilization by better encapsulating and suspending oil droplets in the water phase, preventing coalescence and separation [68]. ...
... This aligns with research by Leroux et al. [68], emphasizing the significant impact of molecular weight on viscosity properties and emulsion stabilization. Higher molecular weights alongside longer chains in pectin have been reported to improve emulsion stabilization by better encapsulating and suspending oil droplets in the water phase, preventing coalescence and separation [68]. Also, the higher viscosity of the continuous phase in the emulsion system can slow down the movement of oil droplets, preventing the aggregation and coalescence of oil droplets [69]. ...
Dragon fruit peel, often discarded, is a valuable source of commercial pectin. This study investigates different extraction methods, including cold-water (CW), hot-water (HW), ultrasound (US), and novel enzyme extraction (xylanase: EZX), to extract pectins from dragon fruit peel and compare their characteristics. The pectin yield ranged from 10.93% to 20.22%, with significant variations in physicochemical properties across methods (p < 0.05). FTIR analysis revealed that extraction methods did not alter the primary structural configuration of the pectins. However, molecular weights (Mws) varied significantly, from 0.84 to 1.21 × 10³ kDa, and the degree of esterification varied from 46.82% to 51.79% (p < 0.05). Monosaccharide analysis identified both homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) pectic configurations in all pectins, predominantly comprising galacturonic acid (77.21–83.12 %mol) and rhamnose (8.11–9.51 %mol), alongside minor side-chain sugars. These properties significantly influenced pectin functionalities. In the aqueous state, a higher Mw impacted viscosity and emulsification performance, while a lower Mw enhanced antioxidant activities and promoted the prebiotic function of pectin (Lactis brevies growth). This study highlights the impact of extraction methods on dragon fruit peel pectin functionalities and their structure–function relationship, providing valuable insights into predicting dragon fruit peel’s potential as a food-grade ingredient in various products.
... The sugar beet pectin has poor gelling capacity compared to the apple and citrus sources due to the high content of acetyl groups and neutral sugars and the higher content of proteinaceous materials bonded covalently to the side chains [64,65]. Pectin from sugar beet is commercially used as a food emulsifier, and its capacity to stabilize oil emulsions was verified by Leroux et al. [66]. They found that the molecular weight, protein, and acetyl contents of the sugar beet pectin significantly influenced the emulsifying properties and were able to reduce the interfacial tension between the oil and water phases. ...
... When combined with high temperature, it will accelerate molecular motion, facilitating the dissolution of pectin in an aqueous medium. When working with low methoxylated pectin (LM), citrates, oxalates, and polyphosphates (named chelators) are added to capture Ca 2+ , allowing the disaggregating of pectin chains [65,66]. Then, the aqueous medium is treated with alcohol to create the pectin precipitate, and filtration is performed to isolate the pectin [65]. ...
Pectin is a versatile polysaccharide produced mainly from natural food sources and agro-industrial wastes, adding value to these by-products. For food applications, it is necessary that pectin first interacts with water for technical purposes. As a food additive, pectin acts as a solution thickener and gelling agent for food formulation, even in concentrations of less than 1 (g/100 mL or g/100 g), and it is sufficient to influence food products’ stability, rheology, texture, and sensory properties. Therefore, this review paper attempts to discuss the versability of pectin use, focusing on food application. It starts by showing the chemical structure, the sources’ potential, thickening, and gelling mechanisms and concludes by showing the main applications to the food sector and its rheological properties.
... Moreover, the acetyl, feruloyl, and protein fractions contribute significantly to the emulsification of pectin (Ngouémazon et al., 2015). In a study, Leroux et al. (2003) found that the fraction associated with oil contained much more protein than the fraction in the aqueous phase for both citrus and beet pectin, and they suggested that pectin-associated protein plays a key role in stabilizing the emulsion. In another study, by comparing the amount of protein in the aqueous phase before and after emulsification using sugar beet pectin, it was possible to assess the role that protein plays in the emulsification process. ...
... work, which results in an increased viscosity. In addition, pectins, in their molecular structure, have hydrophilic (water-loving) and hydrophobic (oil-loving) regions, giving them an effective emulsifying properties (Leroux et al., 2003;Ngouémazong et al., 2015). The high apparent viscosity of mix with PP pectin shows that the stabilizing effect of PP pectin may be more prominent in ice cream compared to WP pectin. ...
Pectin extraction from watermelon peel (WP) and pomegranate peel (PP) was carried out using three different extraction methods: classical solvent extraction (CSE), ultrasound‐assisted extraction (UAE), and microwave‐assisted extraction (MAE). Extraction parameters (pH, temperature, time, and speed/amplitude/power) were optimized to target maximum crude pectin yield (CPY), while the sample‐to‐solvent ratio (SS) was determined to be fixed at 1:10 w/v at all experiments. CPY was increased by low pH, high temperature, and long time. The pectins obtained at optimum conditions were characterized regarding the physicochemical and rheological properties, and the pectin solutions were found to be typical pseudoplastic fluids. WP pectin extracted with MAE and PP pectin extracted with UAE were determined to have the best emulsifying properties and added to the ice cream formulations. MAE had the maximum CPY of 9.40% for WP (pH = 1.3, 6 min, 596 W) and the best emulsifying properties. UAE had the best emulsifying properties for PP and the CPY was 11.56% in conditions of pH = 1.5, a temperature of 69°C, an extraction time of 29 min, and a 32% amplitude. The use of PP pectin resulted in a significant increase in the apparent viscosity of ice cream mix and also the first dripping time and the hardness of ice cream over commercial emulsifier. Melting properties and hardness values of ice cream with WP pectin were comparatively closer to those of ice cream with commercial emulsifier. On the other hand, the first dripping time and hardness value of ice cream with PP pectin having 60.25 min and 3.84 N, respectively, were higher than those of commercial ice cream having 53.75 min and 2.14 N, respectively.
Practical Application: The utilization of WP and PP, which are good sources for pectin production, benefits both a sustainable environment and a sustainable food industry. Pectin extracted from WP and PP as an emulsifier in ice cream can ensure the production of ice creams with good melting properties. Pectin can be used as a healthy, sustainable, and economical alternative emulsifier in the ice cream industry.
... PE is a linear polysaccharide containing about 300 to 1000 monosaccharide units. The structure of PE is a polymer of α-D-galacturonic acid with 1 → 4 bonds interrupted by segments of rhamnogalacturonan, which combine residues of galacturonic acid and α-L-rhamnopyranose from a 1 → 2 bond that is a partially esterified methyl [34,35]. PE is extracted from apples or citrus peels and is used as a food additive and a gelling and thickening agent [36,37]. ...
The use of edible food packaging by hydrocolloid encapsulation has gained interest as an approach to preserve the physicochemical and sensory properties of food. In this study, pectin (PE) and xanthan gum (XG), naturally occurring hydrocolloids, were utilized with calcium chloride (CaCl2) as a bead-forming agent to develop an extra virgin olive oil-hydrocolloid emulsion encapsulating Bosana extra virgin olive oil (EVOO), a Sardinian monovarietal oil rich in polyphenols and sensory properties. This study investigated the textural evolution of EVOO-beads immersed in Bosana EVOO as a preservative liquid (PL) during 180 days of storage at 20 °C (room temperature) and 40 °C (accelerated shelf-life test). The bead texture was assessed at 30-day intervals along with selected oil quality parameters. Its hardness remained stable, while its springiness, cohesiveness and chewiness significantly decreased with time. Temperature and the interaction time x temperature were significant for cohesiveness. PL showed the expected degradation of polyphenols and α-tocopherol influenced by storage time and temperature. At 20 °C, free acidity and peroxide levels remained within EVOO quality standards, confirming the protective role of encapsulation. Between the PL and oil controls, no effect of the beads was observed. These results highlight the potential of hydrocolloid-based encapsulation to produce EVOO-beads, offering innovative applications as functional food coatings and in preservation technologies.
... Verkempinck et al. (2018) added that citrus pectin is an emulsion stabilizer that enhances the steric, and electrostatic interactions depending on the pectin degree of methyl esterification and pH of the continuous phase in emulsion. The interfacial tension among the water and oil phases can be decreased by citrus pectin, which improves the stability of creaming and emulsions (Leroux et al. 2003). Moreover, emulsion stability depends on many factors such as the particle size, the addition of thickening agents, and the viscosity (Riquelme et al. 2020). ...
In this research work, a mixture design was applied to optimize the encapsulation of capsaicin in oil–water‐nanoemulsion using almond gum, pea protein isolate, and citrus pectin as independent variables. Therefore, results indicated that the cubic, special cubic, and quartic models were the most adequate to describe the variation of responses as a function of independent variables. Therefore, the pea protein isolate showed the highest effect on mean droplet size, polydispersity index, ξ‐potential, and antioxidant activities. However, the almond gum was the most significant component in whiteness and plastic viscosity (p < 0.05). Moreover, the rheological properties of the nanoemulsions demonstrated that are non‐Newtonian fluids with pseudoplastic (shear thinning) behavior and are well‐fitted by the Casson model. Remarkably, all the nanoemulsions exhibited antioxidant activities, in which the almond gum and pea protein isolate combination indicated the highest activities (IC50). Also, the formulated nanoemulsions exhibited more sensitivity to the Gram‐positive bacteria (Listeria monocytogenes and Staphylococcus aureus). Thus, the statistical data revealed that the mixture of almond gum (16.13%), pea protein isolate (73.45%), and citrus pectin (10.42%) was proven to be the optimum condition. Besides, these findings indicated that there are no significant differences between optimal conditions and those obtained in practice (p > 0.05). Under these conditions, the experimental values of mean droplet size, polydispersity index, ξ ‐potential, whiteness index, plastic viscosity, creaming index, encapsulation yield, and the inhibitory concentration at 50% were 3.58 nm, 12.13%, −30.53 mV, 78.65, 0.12 Pa·s, 1.96%, 94.06%, and 23.01 μg/mL, respectively. Furthermore, encapsulated capsaicin was used to Merguez preservation and the results revealed that pH, color parameters, TVB‐N, TBARS amounts, textural properties, and their shelf life were improved over a storage time of 30 days at 4°C. Hence, the findings are encouraging and allow considering the use of capsaicin nanoemulsions based on almond gum for the enrichment of food, cosmetic, and pharmaceutical products.
... It is a natural, mucoadhesive polysaccharide that shows promising potential as a stabilizer for liposomal drug delivery systems [118]. Pectin is capable of forming stable emulsions similar to gum arabic, but at significantly lower concentrations [119]. However, the use of pectin in drug nanosuspensions has not been thoroughly investigated. ...
Poor solubility of many drugs, with ensuing low bioavailability, is a big challenge in pharmaceutical development. Nanosuspensions have emerged as a platform approach for long-acting injectables and solid dosages that enhance drug bioavailability. Despite improvements in nanosuspension preparation methods, ensuring nanosuspension stability remains a critical issue. Conventionally, synthetic and semi-synthetic polymers and surfactants are used in nanosuspension formulations. However, no polymer or surfactant group is universally applicable to all drugs. This fact, as well as their toxicity and side effects, especially if used in excess, have sparked the interest of researchers in the search for novel, natural stabilizers. The objective of this paper is to provide a comprehensive analysis of non-traditional natural stabilizers reported in the literature published over the last decade. First, physical stability and stabilization mechanisms are briefly reviewed. Then, various classes of non-traditional natural stabilizers are introduced, with particular emphasis on their stabilization potential, safety, and pharmaceutical acceptability. Wherever data were available, their performance was compared with the traditional stabilizers. Furthermore, the benefits and limitations of using these stabilizers are examined, concluding with future prospects. This review is expected to serve as a valuable guide for researchers and formulators, offering insights into non-traditional natural stabilizers in drug nanosuspension formulations.
... The presence of hydrophobic groups, including methoxy and acetyl groups, enables polysaccharides to function as efficient emulsifiers in water-in-oil systems, promoting swift adsorption onto the surface of oil droplets [15] . The hydrophilic regions, along with the side chains and main chains of the polysaccharide, protrude into the continuous phase, thereby creating spatial resistance and electrostatic repulsion that hinder or decelerate the aggregation of oil droplets [16] . Consequently, this mechanism maintains the stability of the emulsion [17] . ...
The objective of the study was to examine the physicochemical properties and emulsification stability of three different Auricularia auricula polysaccharides (AAP) obtained through hot water extraction (AAP-W), hot acid extraction (AAP-A), and hot alkaline extraction (AAP-AL), respectively. The findings indicated that AAP-W exhibited superior emulsification stability compared to the other two polysaccharides. AAP-W was employed as a natural emulsifier for emulsion preparation, to examine the influence of varying polysaccharide concentrations and oil-water ratios on emulsion stability. Additionally, an investigation was conducted into the stability of the emulsions with respect to pH and salt ion concentration. The findings revealed that the most favorable polysaccharide concentration for the AAP-W emulsion was determined to be 1%, while the volume fraction of the oil phase was established at 0.5. It was also observed that the emulsion exhibited robust stability even in challenging conditions characterized by strong acidic (pH 3−5) or basic environments (pH 9−11), as well as high concentrations of salt ions (0−500 mM). Furthermore, the construction of an AAP-W emulsion system incorporating β-carotene was undertaken to enhance the preservation, bioavailability, and digestive stability of β-carotene, thereby expanding the potential applications of Auricularia auricula polysaccharides. This endeavor also presents a novel approach towards the advancement of novel functional food products.
... Pectin's hydrophobic acetyl groups and protein can function as anchors on the surface of oil particles, reducing surface tension and demonstrating pectin's potential for emulsification and foam stabilization. 21 It has also been used as a viscosity enhancer in lipid digests. 22 It has an emulsifier in oil: water emulsions . ...
In our present paper we have given a comprehensive review of the medical uses, chemistry and other application of pectin. Pectin has many relevant therapeutic uses which is needful for obtaining effective herbal formulation. Pectin is chemically polysaccharide obtained from many fruits and vegetables. It occurs naturally as partial methyl ester of a (1→4) linked (+) - polygalacturonate sequences interrupted with rhamnose residues the neutral sugars. Pectin molecules are namely: galactose, rabinose, xylose and fructose. Common types of pectin are high methoxypectin (HM) and low methoxy pectin (LM). HMP is the common type and labelled as “fast –or rapid-set” and ”slow-set” .fast-set HM is best for chunky jams and slow set HM work well for clear jellies.it is used pharmacologically for regulation of blood cholesterol level and act as antioxidant, antimicrobial and antidiabetic. We have compiled the pharmaceutical, chemical and pharmacological uses of pectin.
... However, when researchers studied pectin from prickly pear peel and xoconostle fruit that possessed a low DM and high DAc, the high content of acetyl did not impede the gelation capabilities of the samples, potentially as a result of their high molecular weight as well as the distribution patterns of their nonmethoxylated GalA residues and acetyl groups [26]. Apart from this, the acetylation of pectin has been thought to contribute to emulsion stability, potentially through the reduction of calcium bridging flocculation [27]. This is particularly evidenced by the notable emulsifying properties of sugar beet pectin, which is highly acetylated [28]. ...
... The emulsifying capacity of sugar beets pectin (Chen et al., 2016;Ma et al., 2013;Schmidt et al., 2015), hawthorn (Cuevas-Bernardino et al., 2016), citrus (Leroux et al., 2003;Schmidt et al. 2017), pumpkin (Cui & Chang 2014) and okra have been demonstrated (Kpodo et al., 2018;Alba et al.,2013;Alba et al., 2016). The emulsifying properties of okra and sugar beets pectins have been attributed generally to either covalently bounded proteins or presence of ferulic acids or high acetyl content (Schmidt et al., 2017;Alba et al., 2013). ...
In chocolate, the primary emulsifier used is soy lecithin. However, soy lecithin is a major allergen to some people and also considered expensive as it is imported. In this study, three different genotypes of okra pectin were extracted and used to replace lecithin in chocolate production as an emulsifier. The okra pectin samples were combined in different ratios and used in different chocolate formulations. The new formulations were evaluated by means proximate analysis and relative preference mapping (RPM). Results showed that there were no significant differences between the moisture content (1.85-2.25 %) and the ash content (2.54-2.82%) for all formulations (p > 0.05). However, there were slight differences among the formulations regarding the fat (30.34-30.99%) and sugar (22.12-31.61%) contents. The RPM results indicated that product F8, F9, F10, F13, F14 and F16 were considered to be similar to the control and liked as much as the control. All these products contain some ratio of Balabi pectin in their formulation except product F10. Product F8 which was the most liked product had fat and sugar contents lower than the control. The study showed that none of the products containing a single pectin variety was found in the area of interest suggesting that combining the pectin varieties gives a better result in the formulation of chocolate compared to using pectin from a single okra genotype.
... As the pH, time, and temperature of extraction increased, the emulsifying activity of the pectin-like material increased. Protein and phenolic compounds co-extracted with many polysaccharides have been linked to emulsion activities [77][78][79]. In the present work, large amounts of phenolic compounds (32.3-52.9 ...
Green peppers are massively produced all over the world; however, substantial quantities of peppers are wasted. Functional polysaccharides can be produced from pepper waste. A conventional acid extraction method was used to obtain pectin-like materials from green bell pepper (GBP). A 23 experimental design (two-level factorials with three factors: temperature, pH, and time) was used to study the relationship between the extraction conditions and the measured physicochemical properties. The extracted polysaccharides were further analysed regarding their physicochemical and functional properties. The yields were in the range of (11.6–20.7%) and the highest yield value was extracted at pH 1. The polysaccharides were classified as “pectin-like”, as the galacturonic acid content was lower than 65%. Glucose and galactose were the major neutral sugars, and their relative amounts were dependent on the extraction conditions. The degree of esterification (DE) of the pectin-like extracts was greater than 50% and they were therefore classified as high methoxyl regardless of the extraction conditions. Also, important levels of phenolic materials (32.3–52.9 mg GAE/g) and proteins (1.5–5.4%) were present in the extract and their amounts varied depending on the extraction conditions. The green bell pepper polysaccharides demonstrated antioxidant and emulsifying activities and could also be used adequately to stabilise oil/water emulsion systems. This finding shows that green bell pepper could be used as an alternative source of antioxidants and an emulsifier/stabilising agent, and furthermore, the extraction conditions could be fine-tunned to produce polysaccharides with the desired quality depending on their application.
... On the other hand, pectin is a polysaccharide that has interfacial activity. Pectin contains protein residues and acetyl groups (4-5%), which help improve its emulsifying ability due to its hydrophobic nature [68]. Hydrophobic sites or chains adsorb on the surface of the oil-water interface. ...
There is a continued need for the advancement of natural emulsifiers to replace synthetic emulsifiers, driven by human health concerns. This study is aimed at producing protein-polysaccharide conjugates through the Maillard reaction and at evaluating its ability as an emulsifier based on its emulsifying properties. The proteins used in this study were bovine milk whey protein and soy protein isolates, while the polysaccharides were maltodextrin and pectin. The protein-polysaccharide conjugation used a Maillard reaction under dry heating conditions. The protein and polysaccharide mass ratios were 1 : 2 and 1 : 3. The results showed that the types of proteins and polysaccharides and their mass affect the surface tension of the conjugate products. Whey protein-pectin conjugates with a mass ratio of 1 : 2 and a concentration of 1% had the lowest surface tension at 43.77 dyne/cm². This conjugate sample also showed the highest emulsifying index at 27.20 m²/g. The conjugate powder containing pectin as a polysaccharide showed better emulsifying activity than that of those containing maltodextrin. However, the smallest droplet size of the emulsion (256.5 nm) resulted from the emulsification process using whey protein-maltodextrin conjugates as an emulsifier. The FTIR and gel electrophoresis (SDS-PAGE) analysis confirmed the conjugation formation. In general, protein-polysaccharide conjugates containing whey protein could potentially act as a natural emulsifier for food.
... Peaks of physical mixture confirmed that drug is present in intact form. The FTIR spectrum of emulgel containing econazole nitrate revealed that there was characteristics peak of fingerprint region of econazole nitrate at 3250 cm-1 which revealed that drug remains intact [38]. ...
Emulgels have emerged as a promising drug delivery system for enhancing the topical delivery of hydrophobic drugs. The present study was designed to formulate and characterize the emulgels prepared by using pectin for topical delivery of econazole nitrate. For this purpose, pectin, a natural gelling agent, was extracted from Abelmoschus esculentus (okra pods). The extracted pectin was thoroughly characterized for its physicochemical and micromeritic properties. The response surface methodology from Design-Expert was used to optimize the emulgel preparation. The optimized formulations (F1, F2 and F3) were thoroughly characterized through particle size (PS) and zeta potential (ZP) measurements, as well as compatibility assessment of various ingredients and drug release profiles. The zeta potential measurements revealed values of − 16.9 ± 0.467 mV, − 17.9 ± 0.200 mV and − 13.7 ± 0.109 mV for F1, F2 and F3, respectively, indicating good formulation stability. Furthermore, the polydispersity index (PDI) values (0.230 ± 0.005, 0.226 ± 0.002 and 0.075 ± 0.059 for F1, F2 and F3, respectively) indicated uniform and stable formulations with minimal particle size variation. Among the formulations, F3 exhibited superior spreadability (14.954 gm.cm/s), crucial for optimal topical application, while F1 displayed the highest viscosity (1360.151 Pa), ensuring better retention on the skin and prolonged drug release. Regarding drug content (%), F3 achieved the highest value (79.091%), highlighting its potential for delivering a higher dosage of econazole nitrate. Overall, this scientifically stringent study demonstrates the suitability of pectin extracted from okra pods for formulating emulgels with favorable characteristics, providing a solid foundation for further exploration and development of topical drug delivery systems.
... The effects of pectin on consistency and emulsion stability are highly affected from its intrinsic molecular properties (molecular weight, degree of esterification, acetylation, amount of linear homogalacturonan chains, etc.) (Humerez-Flores et al. 2022;Karnik and Wicker, 2018;Niu et al. 2022). The positive roles of covalently bound hydrophobic protein complexes on emulsion stabilizing effect of pectin have also been reported previously (Ngouémazong et al., 2015;Leroux et al. 2003). Moreover, it was recently demonstrated that the presence of phenolic compounds such as ferulic acid enhances the emulsion stabilizing effect of pectins by reducing emulsion droplet size and/or increasing amount of pectin absorbed at oil-water interface of emulsion droplets (Liu et al. 2020). ...
... One of the main natural polymers used for gelation and delivering of molecules of interest is pectin (Mishra, Datt, Pal, & Banthia, 2008). Pectins are anionic plant polysaccharides well known for its gelling (Bemiller, 1986;Willats, Knox, & Mikkelsen, 2006) and emulsifying and emulsion-stabilizing properties (Leroux, Langendorff, Schick, Vaishnav, & Mazoyer, 2003;Ngouémazong, Christiaens, Shpigelman, Van Loey, & Hendrickx, 2015). They are traditionally extracted from citrus peel and apple pomace; however, alternative sources have been extensively studied in the last few decades. ...
Two pectin fractions extracted from coffee pulp, one high-methoxylated (Coffea arabica pectin, CAP) and other low-methoxylated (chelating agent-soluble pectic fraction, CSP), were used for the development of hydrogel beads loaded with coffee roasted and green essential oils (EOs). The aim of the study was to compare the two types of pectin, with or without chitosan, on their encapsulation performance for the delivery of EOs. Systems were analyzed regarding their rheological, morphological, physicochemical and mechanical properties. Association with chitosan reinforced the beads, which showed better mechanical properties and resisted to acidic and basic treatments, influenced by EO type. ATR-FTIRspectroscopy and X-ray diffraction were performed to assess structural characteristics and interactions of the different samples. The analyses showed that alkaline treatment caused more structural modifications than the acidic treatment in the polysaccharide matrix. Swelling ability of CAP was higher than that of CSP, and green coffee oil prevented bead degradation by acids. Controlled release was carried out in fatty food simulant, and the formulations containing CAP and chitosan had the highest release values. DPPH radical scavenging activity showed that coffee essential oils can act as antioxidants, with the roasted coffee oil presenting superior antioxidant activity.
... The emulsifying activity of the extracted pectin (38.46%) is significantly lower than that of the commercial pectin, which has a value of 51%. Our results are comparable with those obtained by Leroux et al. [34] and Yapo et al. [20], which are, respectively, 43.2 and 47.1% for beet pectin. According to Yapo et al. [20], this remarkable emulsifying activity of citric-acid-extracted pectin may be due to the fact that it is endowed with a tension-active activity that increases the viscosity of the aqueous phase and reduces the tendency for the emergence of dispersed oil globules. ...
Citrus peels are considered a rich source of valuable biomolecules. Pectin is a polymer of polysaccharide acid and is composed of galacturonic acid monosaccharides. In this study, response surface methodology was used to optimize pectin extraction from Citrus × clementina Hort. ex Tan. (Rutaceae) peels using citric acid as an extraction solvent. The effect of the parameters conditioning the extraction process and pectin yield (pH level, temperature, extraction time, solid/liquid ratio, and raw material particle size) was investigated using a Box–Behnken design. The quality of the extracted pectin was assessed both chemically (moisture, ash, protein, and carbohydrate content) and functionally (gelling power and emulsifying activity). According to the screening experiment, the pH level, temperature, and particle size were the main factors influencing the pectin yield. The adjusted mathematical model enabled us to plot response surfaces in order to determine the optimal extraction conditions. The highest production yield of pectin (26.6%) was obtained at the optimal conditions of pH = 1.5, temperature = 100 °C, and particle size = 0.1 mm for an extraction time of 30 min. Compared to the predicted value of 26.6%, the experimental extraction yield of C. clementina was about 21.4% of pectin. Concerning the functional properties, the extracted pectin had a high gelling power of 164 ° SAG and an emulsifying activity of 38.5%.
Background: Emulsions are thermodynamically unstable systems, and as storage time increases emulsions will undergo a series of destabilizing processes. The addition of emulsifiers can delay or even prevent these processes through steric hindrance and electrostatic repulsion effects. Compared with small molecule surfactants and proteins, polysaccharides (especially pectins) as emulsifiers have stronger steric hindrance effect and lower sensitivity to the changes in pH, temperature, and salt concentration in the environment.
Scope and approach: This review discusses the factors affecting emulsion stability, structure-emulsification relationships of pectin molecules, and covalent and non-covalent modifications of pectin molecules.
Key findings and conclusions: Large-sized pectin molecules have poor interfacial activity, and the interfacial mechanical properties and emulsification performances of pectin molecules can be improved through acid/alkali hydrolysis, enzyme modification, Maillard reaction, chemical cross-linking and electrostatic bonding, so as to obtain long-term stable emulsions.
This chapter describes the importance of building a sustainable society to develop materials related to low-carbon development and to put into practical use recycling technologies using waste materials as raw materials, since people life growth must be achieved while maintaining a balance between society, the economy, and the environment. For this purpose, economic growth is desired while balancing the construction of a recycling-oriented social structure with the conservation of nature. Specifically, the effective utilization of biomass as a carbon-neutral raw material and environmental remediation and conversion to raw materials are effective measures. Against this current background, this chapter also presents a discussion of the recent status of environmental materials and related technologies, especially upcycling technologies, toward building a sustainable society. Three subsections present the following: (1) Biomass waste reuse and biomass functional materials, (2) Green chemical refineries, and (3) Sustainable green technologies and processes using advanced materials.
The study aims to discuss innovative extraction approaches as compared to available traditional methods to optimize the yield and quality of pectin by eco-friendly techniques and emphasizes purification and analytical techniques for quality toward sustainable development of pectinbased products. Pectin is a complex polysaccharide present in plants, forming a protective barrier and providing mechanical strength to the plant cell. Therefore pectin, a by-product of the food industry, can be an efficient waste valorization product for utilization in the food and pharmaceutical industry as a thickener, stabilizer, and gelling agent. Pectin complex chemistry provides a wide scope for modification of monomers that can alter the properties of pectin and thereby add to the varied applications of pectin enlisted in the review. The review synthesizes findings from meticulously conducted research investigations and authorized scholarly articles. Information retrieval used reputable academic search engines, including PubMed, Elsevier, and Bentham publications with keywords such as “pectin” “chemical modification of pectin”, “drug delivery”, “green methods” and “agro-industrial residues" for a comprehensive exploration. The comprehensive review delves into pectin chemistry and extraction methods, modification, and characterization techniques are discussed along with versatile applications in the food, pharmaceutical, and other industries. Pectin abundantly present in the outer coat or peels of fruits and vegetables has been the best example of a circular economy and has led to zero waste in agricultural industries. The review has elaborated modifications in pectin for its use as an excipient in the pharmaceutical industry, therapeutic use, targeted drug delivery, and food industries.
Recently, there has been an increasing research interest in the development of Pickering emulsions stabilized with naturally derived biopolymeric particles. In this regard, plant gums, obtained as plant exudates or from plant seeds, are considered promising candidates for the development of non-toxic, biocompatible, biodegradable and eco-friendly Pickering stabilizers. The main objective of this review article is to provide a detailed overview and assess the latest advances in the formulation of Pickering emulsions stabilized with plant gum-based particles. The plant gum sources, types and properties are outlined. Besides, the current methodologies used in the production of plant gum particles formed solely of plant gums, or through interactions of plant gums with proteins or other polysaccharides are highlighted and discussed. Furthermore, the work compiles and assesses the innovative applications of plant gum-based Pickering emulsions in areas such as encapsulation and delivery of drugs and active agents, along with the utilization of these Pickering emulsions in the development of active packaging films, plant-based products and low-fat food formulations. The last part of the review presents potential future research trends that are expected to motivate and direct research to areas related to other novel food applications, as well as tissue engineering and environmental applications.
Pectin's physicochemical, structural, and functional characteristics vary widely depending on the source of extraction. In this study, pectins were extracted from seedless quince and pomegranate peel, and their physicochemical, structural, and functional properties were investigated. A Box-Behnken Design with three factors and three levels was applied to optimize the pectin extraction yield from each matrix. As a result, the best extraction yields for quince pectin (QP) and pomegranate peel pectin (PPP) were 11.44 and 12.08 % (w/w), respectively. Both extracted pectins exhibit a linear structure, with the homogalacturonan domain dominating the rhamnogalacturonan I. Both pectins are highly methyl-esterified (DM > 69 %) with a higher degree of acetylation for PPP than QP, with 12 and 8 %, respectively. Unlike QP, PPP has a narrow, homogenous distribution and greater molecular weight (120 kDa). Regarding functionality, 1 g of QP could retain 4.92 g of water, and both pectin emulsions were more stable at room temperature than at 4 °C. When the concentration of QP is increased, rheological measurements demonstrate that it exhibits pseudoplastic behavior. Finally, QP can be used as a thickener, whereas PPP can be utilized as starting material for chemical changes to create multifunctional pectins.
The relationship between the properties of wall material and spray-dried microcapsules was investigated. Soybean oil was encapsulated with various concentrations of maltodextrin (10 and 20% w / w ) and sugar beet pectin (0.5, 1, 2, 3, and 4% w / w ) solution via spray drying with a three-fluid nozzle (3FN). The rheological properties of the wall material solution were characterized using a controlled strain rheometer before spray drying and were found to fit the power-law model. The rheological properties of a wall material within the range of the samples tested had a limited impact on the morphology of the microcapsules. Most spray-dried samples had a wrinkled surface with some microcapsules having a spherical shape with a hollow core. As the consistency index of the wall material solution increased, the particle size distribution of microcapsules became wider. The surface oil content of the microcapsules was between 1.3 and 3.4%, generally increasing as the consistency index of the wall material solution increased. The encapsulation efficiency (EE) was between 74.7 and 91.2%. When compared with the sample produced with a two-fluid nozzle (2FN), 3FN microcapsules were larger and had higher effective EE and higher oil loading than 2FN microcapsules. This study revealed that oil could be encapsulated by wall materials, without the preparation of an emulsion, with a 3FN, which will save time and energy for the encapsulation process.
The emulsion forming and stabilizing capacities of water-soluble biopolymers originating from the aqueous (serum) phase of heat-treated and high pressure homogenized purées were investigated. The serum biopolymers were characterized and then utilized as emulsifier/stabilizer in simple oil-in-water emulsions. The resulting emulsions were stored at 4 °C and monitored for 2 weeks. Results revealed that carrot and tomato sera contained higher amounts of pectin and lower protein compared to broccoli. The serum pectic biopolymers exhibited distinct molecular structures, depending on the vegetable origin. Given these natural biopolymer composition and characteristics, emulsions with small droplet sizes were observed at pH 3.5. However, emulsions at pH 6.0 showed large mean droplet sizes, except for the emulsion formulated with carrot serum. Regardless of the pH, emulsions containing carrot serum biopolymers exhibited high capacity to form fine emulsions that were stable during the 2-week storage period at low temperature. This study clearly shows the capacity of natural water-soluble biopolymers isolated from the serum phase of vegetable purées to form fine emulsion droplets and maintain its stability during storage, especially in the case of carrot serum biopolymers.
The effect of high methoxy pectin on the behaviour of model acid milk drinks has been investigated using viscometry, laser diffraction size measurement and microelectrophoresis. The results of these different tests are interpreted using the theory of colloidal stability. With increasing pectin concentration, the behaviour changes from flocculated with few particles below 0.2µm diameter and shear thinning, time-dependent rheology to non-flocculated, many sub 0.2µm particles and low viscosity with Newtonian rheology. With even higher pectin concentrations, the acid milk drink remains non- flocculated, but with increasing viscosity and close to Newtonian rheology.
It is shown that pectin adsorbs to the surface of the casein aggregates and acts as a dispersing agent. Its stabilising effect cannot be explained by electrostatic repulsion, but presumably by steric stabilisation. The pectin is probably anchored to the casein surface by electrostatic attraction
Primary cell walls from exponentially growing cell-suspension cultures of spinach contained ferulic acid and p-coumaric acid esterified with galactopyranose and arabinopyranose residues of polysaccharides. The feruloylated polysaccharides behaved in exactly the same way as total cell-wall pectin with respect to (1) extraction with chelating agents, (2) extraction by trans-elimination degradation, (3) extraction with mild acid, and (4) electrophoretic separation into acidic and neutral species. Partial digestion of cell walls with Driselase, under conditions which specifically inhibited galactanase and galactosidases yielded galactose-containing feruloyl tri- to pentasaccharides, in all of which the feruloyl group was on the non-reducing terminus. Larger feruloyl oligosaccharides were also found, some of which were acidic. Partial acid-hydrolysis of cell walls gave a homologous series of feruloyl oligosaccharides, probably with the structure Feruloyl-arabinopyranose-(arabinofuranose)n-arabinose where n=0-7. Evidence is presented that the arabinose chain was unbranched, with the feruloyl group on the nonreducing terminus. It is suggested that acidic and neutral pectins carry ferulic acid on the non-reducing termini of the neutral arabinose- and/or galactose-containing domains. The pectins carry approximately one feruloyl residue per 60 sugar residues. Possible rôles of feruloyl pectin in the regulation of cell expansion, in disease resistance, and in the initiation of lignification are discussed.
This chapter provides an overview on the main groups of plant polysaccharide other than those, such as starch and fructans. Plant polysaccharides fall into a number of well-defined structural families. The availability of modern techniques has made possible the development of a new and powerful complementary approach to the study of plant cell polysaccharides. Biologically homogeneous primary cell walls are readily obtained from undifferentiated cells grown in suspension culture. The methylation technique is then applied to the total mixture of polysaccharides present in the cell wall and to fractions derived there from by the use of purified hydrolytic enzymes. In addition to cellulose, two other β-D-glucans are of widespread although not abundant occurrence in plants, namely, those containing 1–3 linkages only and those containing both 1–3 and 1–4 linkages. In contrast to cellulose and callose, the mixed glucans are generally rather soluble in aqueous solvents. Some β -D-glucans are only isolated by extraction with alkali, and evidence shows that these glucans are cell wall components and are probably covalently linked to other macro-molecules.
Gum from Acacia senegal has been fractionated using hydrophobic affinity chromatography. Characterization, including identification of sugars and determination of protein and amino acid contents, has been undertaken for each fraction together with measurements of molecular mass and molecular mass distribution using laser light scattering and gel permeation chromatography. The results have indicated that the gum consists of three distinct components. Fraction 1. which represents 88.4% of the total, is an arabinogalactan with molecular mass 2.79 x 10(5) and is deficient in protein. Fraction 2, which represents 10.4% of the total. is an arabinogalactan-protein complex with a molecular mass of 1.45 x 10(6), containing similar to 50% of the total protein. It is envisaged that on average each molecule of fraction 2 consists of five carbohydrate blocks of molecular mass similar to 2.8 x 10(5) covalently linked through a chain of amino acid residues. Fraction 3 represents only 1.24% of the total gum but contains similar to 25% of the total protein and has been shown to consist of one or more glyeoproteins. Whereas the proteinaceous components of fractions 1 and 2 contain predominantly hydroxyproline and serine. this is not the case for fraction 3.
An experimental design was constructed to study the influence of different parameters of acidic extraction on yield, chemical composition and intrinsic viscosity of pectins from fresh sugar-beet roots. pH, and, to a lower extent, time and temperature of extraction, affected greatly the yield and features of extracted pectins whereas the type of acid had no effect. Influences of extraction conditions on pectins characteristics were quantified and second order models were built.
Emulsifying properties of depolymerized citrus pectin of 70% esterification and differing molecular weights in the range 48–146kgmol−1 have been investigated in systems containing rapeseed oil (RSO) and D-limonene at pH values 4.7 and 7. Emulsion stability was followed by determining changes in average droplet size and extent of serum separation with time, with gum arabic chosen as the reference emulsifier. At pH 4.7, it has been found that a relatively low concentration (4wt%) of pectin of molecular weight 70kgmol−1 give fine RSO emulsions (20vol% oil) with excellent long-term stability. Emulsion stability was reduced: (a) at pH 7, (b) with pectin of higher or lower molecular weight and (c) in the presence of added ionic calcium. Changes in particle-size distribution on storage were inferred to arise, at least in part, from droplet flocculation by pectin bridging. Analysis of the aqueous serum layer after centrifugation indicated that only about 25% of the pectin becomes associated with the oil droplets, and that this adsorbed material contains almost all the protein fraction present in the hydrocolloid. The fraction remaining in the serum phase was found not to be effective for subsequent emulsification.
The emulsification properties of 14 hydrocolloid gums (propylene glycol alginate, gellan, carrageenan, pectin, methylcellulose, microcrystalline cellulose, gum arabic, locust bean gum, guar, xanthan, mustard, flaxseed, fenugreek, oat) were investigated. Gum dispersions were prepared in water (0.5%) and emulsified with 40% oil using a Polytron homogenizer. Emulsion stability was determined by centrifugation and storage time, surface and interfacial tension by Du Nouy ring, particle size by integrated light scattering and overall morphology by light microscopy. When compared to the other gums in this study, fenugreek produced a very stable emulsion. Fenugreek was more efficient than other gums in lowering the interfacial free energy, its emulsion was composed of very small oil droplets (70%
Gum from Acacia senegal has been fractionated using hydrophobic affinity chromatography. Characterization, including identification of sugars and determination of protein and amino acid contents, has been undertaken for each fraction together with measurements of molecular mass and molecular mass distribution using laser light scattering and gel permeation chromatography. The results have indicated that the gum consists of three distinct components. Fraction 1, which represents 88.4% of the total, is an arabinogalactan with molecular mass 2.79 × 105 and is deficient in protein. Fraction 2, which represents 10.4% of the total, is an arabinogalactan—protein complex with a molecular mass of 1.45 × 106, containing ~50% of the total protein. It is envisaged that on average each molecule of fraction 2 consists of five carbohydrate blocks of molecular mass ~2.8 × 105 covalently linked through a chain of amino acid residues. Fraction 3 represents only 1.24% of the total gum but contains ~25% of the total protein and has been shown to consist of one or more glycoproteins. Whereas the proteinaceous components of fractions 1 and 2 contain predominantly hydroxyproline and serine, this is not the case for fraction 3.
Physico-chemical factors relevant to the emulsifying and stabilizing properties of gum arabic are discussed. Experimental information is presented relating to (i) the effect of extensive dilution of the aqueous phase on the surface viscosity at the planar oil—water interface and (ii) the effect of non-adsorbing polysaccharide on the emulsion stability. We conclude that the surface rheology of gum arabic films is relatively insensitive to dilution of the aqueous phase, although clear evidence is found for a small but significant reduction in the surface viscosity over a time-scale of the order of 100 h. We observe that addition of dextran to gum arabic emulsions at high ionic strength leads to enhanced instability with respect to creaming; the effect is attributed to depletion flocculation.
VARIOUS investigators have given evidence for the presence of protein in the cell walls of higher plants1–6. We give evidence here for the occurrence of protein in the walls of sycamore (Acer pseudoplatanus L.), and bean (Phaseolus vulgaris). This protein contained hydroxyproline, and differed in this respect from the protein of the cell contents. Hydroxyproline has been found by Steward and Thompson7 to occur in the protein of tissue cultures of carrot and potato, and Pollard and Steward8 showed that the protein containing this imino-acid was stable in the growing cells and was not metabolized.
The reaction of the ester groups in pectin with alkaline hydroxylamine at room temperature produces hydroxamic acids. Pectin hydroxamic acid forms with ferric ions an insoluble complex and acetohydroxamic acid, produced from secondary acetyl groups of pectin, forms a soluble red complex. These reactions, applied to pectic substances, serve as the basis for a specific and rapid colorimetric method for the determination of up to 450 γ of acetyl per sample, with an accuracy within about ±2%. These reactions apply also to the quantitative determination of acetyl in acetylated carbohydrate polymers.
Pectins have been extracted from sugar-beet cossettes by a sequential treatment with water, oxalate, hot dilute acid and cold dilute alkali, and from pulp with different conditions of pH and temperature. All these samples have been chemically characterised and tested for their gelling capacity with persulphate. Pectins from cossettes have characteristics very close to those previously extracted in the same way but are not able to give gels by addition of persulphate. On the other hand, some, but not all, of the pectins from pulp can gel under these conditions. No simple relationship was found between the gelling ability and the chemical characteristics of the pectins.
An experimental design was used to study the influence of different parameters (pH, temperature, time, and type of acid) on extraction of pectins from fresh sugar beet. The extraction conditions have important effects on the features of extracted pectins. Their composition (neutral and acidic sugars, degrees of esterification, amounts of ferulic and diferulic acids) and some physicochemical properties (molar mass, intrinsic viscosity) were determined. The type of acid used (HCl or HNO3) had no effect on the characteristics of extracted pectins. Different kinds of pectins can be obtained with good yields at pH 1. Galacturonic acid amounts of the extracted pectins were nearly constant whatever the extraction conditions, whereas the degrees of methylation and acetylation showed large variations. At pH 1, the extracts were particularly rich in rhamnogalacturonan regions, the nature and the quantity of side chains differing according to extraction conditions. The molar masses of extracted pectins were higher than those obtained from sugar beet pulp; beside the sole impact of raw material, possible cross-linking of pectic molecules through diferulic bridges is discussed.
Hop pectins were extracted from spent hops using acid extraction conditions and were characterized chemically. The acid extraction of spent hops resulted in a yield of 2%, containing 59% of polysaccharides. The hop pectins under investigation had a relatively high molecular weight and an intrinsic viscosity comparable to that of commercially available apple and citrus pectins. The low degree of methyl esterification of these pectins implicates that they are mainly suitable for use in calcium gels. The degree of acetylation and the neutral sugar content were relatively high.A high molecular weight fraction which contained arabinogalactan-proteins was shown to be present in the hop pectin extract after preparative size-exclusion chromatography. Additionally, a fraction with a lower molecular weight was present containing mainly homogalacturonans. The arabinogalactans in the high molecular weight population consisted of (1→3)- and (1→3,6)-linked galactans highly branched with arabinose and galactose side-chains. The protein part of the arabinogalactan-protein (13%) was found to be rich in cystein, threonin, serinin, alanin, and hydroxyprolin. The molecular weight distribution of the hop pectin after degradation with the enzymes endopolygalacturonase plus pectin methyl esterase suggested that the arabinogalactan-protein present in the hop pectin extract was linked to the pectin and that the arabinogalactan-protein itself had a fairly low molecular weight.
The chemical composition of three industrial ‘rapid-set’ pectin samples, one from apple and two from lemon, has been extensively investigated. The socalled ‘ballast’ that has been removed by copper precipitation appears to be mainly constituted of neutral polysaccharides and, to a less extent, of proteins and phenolic compounds. Purified pectin molecules are composed of galacturonic acid and neutral-sugar residues and also carry some phenolic and proteinaceous material. Pectin molecules of industrial apple and citrus preparations are very similar to those extracted under mild conditions from similar sources but carry fewer neutral sugars. All three pectins have been found to be slightly acetylated (DAc 1·5 and 5·0% for lemon and apple pectins, respectively). The pectin extracted from apple contains more neutral sugars and more phenolics but fewer proteins than the two lemon pectins, which are very close to each other. However, one of the lemon pectins contains a pectin fraction that appears to be less esterified. The same lemon pectin also differs from the other pectin samples by its higher calcium-ion content. Both structural and analytical consequences are discussed.
Acetylated pectin has been isolated from whole sugar beet tissue and from sugar beet pulp. A variety of extraction sequences and fractionation procedures were employed; all the extracts were of the pectin polysaccharide type containing 44–60% uronate, 12–22% neutral sugars, 4–6% methoxyl and 2–9% acetyl groups. The neutral sugars rhamnose, arabinose and galactose were present in all the extracts, and were covalently linked to the acidic polymer. Many of the extracts were surface active, and possessed foaming and emulsifying properties. Typically, foam volumes of 20–50% with t½ of 120–180 min were obtained. The extracts were used to emulsify a model oil-in-water system containing 10% (v/v) groundnut oil. Oil droplet sizes of ~1 μm were obtained, considerably less than those obtained with commercial pectins, and the emulsions were stable for at least 36 h at 4°C. No correlations could be found between the foaming/emulsifying properties of the acetylated pectin fractions and their chemical structure.
Gum arabic has been separated into five molecular mass fractions using gel permeation chromatography. Each fraction was shown to be present in varying proportions. A high proportion of the proteinaceous material (60%) is associated with one high molecular mass component, which constitutes <10% of the total gum. This fraction can be degraded enzymically to give products with similar molecular masses to the other fractions. Although gum arabic solutions of >12% (w/w) were required to give stable 20% (w/w) orange oil emulsions of small droplet size, it was demonstrated that only 1–2% of the gum actually adsorbed at the oil-water interface. Further investigation revealed that it was the high molecular mass, protein-rich fraction which predominantly adsorbed and hence is responsible for the gum's emulsifying ability. Stable emulsions could not be produced using enzyme-degraded gum arabic.
The influence of the nature of the oil phase on the emulsifying behaviour of gum arabic has been investigated at neutral pH. Time-dependent droplet-size distributions are reported for oil-in-water emulsions (1% wt gum, 10% vol. oil) made with n-hexadecane, d-limonene and orange oil. Three different gum samples of known analytical composition have been compared, and it is found that the gum giving the most rapid lowering of the tension at the n-hexadecane-water interface also gives the most stable n-hexadecane-in-water emulsions as well as the smallest droplets with all three oils. On the other hand, the same gum gives the poorest stability of the d-limonene-in-water and orange oil-in-water emulsions.
Galactomannans are considered to be predominantly hydrophilic carbohydrate polymers (gums) with a rigid backbone. The gums are not expected to have significant surface activity nor to form primary adsorbed layers on oil—water interfaces. However, it was found that commercial, native LBG and guar gum reduce surface tension of water to ~55 mN/m, and adsorb/precipitate on oil—water interfaces, reducing their interfacial tensions. The surface activity of purified guar, where levels of proteins were reduced to a minimum of 0.8% wt, was not inferior to that of the crude gum, unlike gum arabic. Oil-in-water emulsions of various oils with LBG or guar were prepared. The oil droplets were covered with precipitated gum layers exhibiting strong birefringency, indicating formation of organized gum layers on the interface. The adsorption capacity and surface load have been evaluated. Coalescence and flocculation have been minimized by establishing the best gum/oil ratios for full droplets coverage.
A pectic fraction, retained by ultrafiltration of the juice from enzyme treated apple tissue and resistant to further enzymic degradation, was isolated and characterized using chemical and enzymic methods. The fraction was termed MHR (modified hairy regions) and this fraction was characterized by a high arabinose content, next to a high rhamnose to galacturonic acid ratio and a high acetyl content and smaller proportions of xylose and galactose.Rhamnogalacturonase (RGase), an enzyme able to hydrolyze galacturonic acid-(1→2)-rhamnosyl linkages within the rhamnogalacturonan backbone of MHR was used to obtain both oligomeric and polymeric degradation products. These RGase-oligomers consist of a tetrameric or hexameric backbone of alternating rhamnose and galacturonic acid residues with a galactose residue substituted at C-4 of part of the rhamnose moieties.Next to the subunit from which these oligomers were released, two other subunits were recognized: a highly methyl esterified xylogalacturonan segment and residual stubs of the backbone rich in branched arabinose side chains.Comparison of the MHR with non-modified pectic hairy regions of apple cell wall, isolated in a mild and defined way, revealed great resemblance indicating that the modifications of the MHR during enzymic liquefaction were only minor. Analogous MHR fractions could be isolated from potato fibre, pear, carrot, leek, and onion tissue.Finally, an adapted model is presented for the prevailing population of apple MHR having the highest molecular weight. The universal validity of this model for pectic hairy regions from other plant sources is discussed.
Viscometric measurements were carried out on well-characterized apple, citrus, sugar-beet pectins in order to analyse the effect of the nature and the amount of substituents (methyl, amide, acetyl groups) and of the rhamnose content on the flexibility of the polymeric backbone. Through the dependence of the intrinsic viscosity with the ionic strength the flexibility parameter B was determined. B values between 0.072 and 0.017 indicate that pectins are relatively stiff molecules. However, an increase in flexibility is noticeable with the rise of the rhamnose content and of the amount of amide groups of the pectic acids. The flexibility is also sensitive to the degree of methylation.
Improved methods of isolation and analysis of cell walls from a range of plant tissues have shed new light on the structure of the constituent polymers, and have also helped to clarify some of the conflicting opinions on their mode of occurrence and association within the walls. The chemistry (and biochemistry) of pectic and hemicellulosic polymers in different types of plant organs is outlined, with particular emphasis on parenchymatous and immature tissues. The following aspects are discussed: the mode of occurrence of arabinans, galactans and arabinogalactans, and the possible association of some of them with proteins; the structural features of the esterified rhamnogalacturonans and associated neutral sugar residues in the pectic substances of middle lamellae and primary cell walls; the occurrence of acidic xylans, acidic arabinoxylans, and acidic arabinoxylans in association with other polymers in the cell walls of cambial, suspension-cultured and parenchymatous tissues of dicotyledons; evidence for the occurrence of small but significant amounts of xyloglucans in association with other polymers, and the occurrence of a range of xyloglucans in parenchymatous tissues; evidence for the occurrence of phenolic ester and phenolic cross-linkages between the cell wall polymers of parenchymatous tissues of both dicotyledons and monocotyledons, particularly the association of hydroxycinnamic acids with some pectic substances; the occurrence of proteoglycans and proteoglycan-polyphenol complexes and their relationship to the traditional hemicelluloses; and some aspects of the non-cellulosic polymers of non-endospermic and endospermic seeds.
Pectin is a family of complex polysaccharides present in all plant primary cell walls. The complicated structure of the pectic polysaccharides, and the retention by plants of the large number of genes required to synthesize pectin, suggests that pectins have multiple functions in plant growth and development. In this review we summarize the current level of understanding of pectin primary and tertiary structure, and describe new methods that may be useful to study localized pectin structure in the plant cell wall. We also discuss progress in our understanding of how pectin is biosynthesized and review the biological activities and possible modes of action of pectic oligosaccharides referred to as oligogalacturonides. We present our view of critical questions regarding pectin structure, biosynthesis, and function that need to be addressed in the coming decade. As the plant community works towards understanding the functions of the tens of thousands of genes expressed by plants, a large number of those genes are likely to be involved in the synthesis, turnover, biological activity, and restructuring of pectin. A combination of genetic, molecular, biochemical and chemical approaches will be necessary to fully understand the function and biosynthesis of pectin.
Pectin is an emulsifying agent, comparative efficiencies of pectin, tragacanth, karaya and acacia
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New uses of fruit pectin. The Fruit Products Journal and American Vinegar Industry Complex pectin: structure elucidation using enzymes
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Rooker, W. A. (1927). New uses of fruit pectin. The Fruit Products Journal and American Vinegar Industry, 7(1), 11. Schols, H. A., & Voragen, A. G. J. (1996). Complex pectin: structure elucidation using enzymes. In J. Visser, & A. G. J. Voragen (Eds.), Pectins and Pectinases (Vol. 14) (pp. 3–19). Progress in Biotechnol-ogy, Amsterdam: Elsevier.
New uses of fruit pectin
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Rooker, W. A. (1927). New uses of fruit pectin. The Fruit Products Journal
and American Vinegar Industry, 7(1), 11.
Particle size distribution profiles of emulsions made with orange oil 10% and 10% ester gum in 2% w/w beet pectin (dashed line, D½4; 3 ¼ mm)
- Fig
Fig. 6. Particle size distribution profiles of emulsions made with orange oil
10% and 10% ester gum in 2% w/w beet pectin (dashed line, D½4; 3 ¼ mm)
and de-calcified (full line, D½4; 3 ¼ mm).
Emulsifying behaviour of gum arabic
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Emulsifying behaviour of gum arabic
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Automatisation du dosage des substances pectiques par la méthode au méta-hydroxydiphenyl
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Emulsion stabilisation of depolymerised pectin
- Akhtar