Pectin Type Research Articles

Innovative modified pectins enriched with galactose: Preparation, characterization, and gel-based properties of curcumin-delivered hydrogel beads

Gelling and thickening are the most important properties of pectin, and these properties are dependent on the molecule's structure. In this study, new types of pectin with varying degrees of modification were prepared by reducing the methyl ester groups on the galacturonic acid residues in pectin to hydroxyl groups using NaBH4, thereby converting methylated galacturonic acid to galactose. The physicochemical properties, rheological behavior, and gelling properties of the modified pectins were investigated. Galacturonic acid levels gradually decreased from 68.98% ± 0.40%–7.49% ± 0.09%, whereas galactose levels increased from 10.29% ± 0.48%–72.26% ± 0.62% with increasing degree of modification. The molecular weight exceeded 500 kDa, and solubility was high. The novel modified pectins underwent gelation without requiring sucrose addition and were calcium and pH sensitive. A higher degree of modification promoted gelation at higher temperatures. Addition of Ca2+ at 60 mg/g caused R-55 to gel at 37 °C and pH 2 but disintegrate at pH 6. Three types of R-55 hydrogel beads encapsulating curcumin were prepared. These beads effectively protected curcumin in the stomach; two allowed for its rapid and slow release in the small intestine, whereas one allowed for its release in the colon. Thus, R-55 can be used as a carrier for the targeted delivery of drugs to the small intestine and colon. The modified pectins are suitable for innovative applications in the food and pharmaceutical fields.

Effect of different types of pectin on the physicochemical, rheology, and sensory properties of low-fat yogurt

Abstract Low-fat yogurt has been defined to contain fat content of not more than 2.0 percent as per The Code of Federal Regulations, FDA, U.S. Nevertheless, the reduced fat content affects the physicochemical properties of yogurt by weakened texture, poor body, syneresis, and sensory quality. This is due to fat globules that govern the protein linkages that are responsible for the yogurt’s texture and firmness. The objectives of this study are to evaluate the physicochemical, rheology properties, and to determine the sensory properties and overall acceptability of low-fat yogurt enriched with different types of pectin. Pectin helps improve the gel characteristics, rheology, and microstructure of set yogurt through interactions with the casein network. Two different types of pectins are used which are low-methoxyl pectin (LMP) and high-methoxyl pectin (HMP). For each type, two different concentrations were used which are 0.5% and 1.0% for both types of pectin. Analysis such as pH measurement, titrable acidity, color measurement, water holding capacity measurement, syneresis measurement, viscosity measurement, microbial analysis, and scanning electron microscopy were conducted. The results from the analysis above were subjected to two-way ANOVA and post hoc Tukey’s test. The addition of LMP (0.5% and 1.0%) showed a positive effect on the quality of yogurt with primary attributes compared to the pectin added with HMP and control sample. In conclusion, the low-fat yogurt had a positive effect due to the enrichment of the pectin. Sample 4 which is the low-fat yogurt with 1.0% of LMP showed better properties compared to other samples.

Influence of Temperature on the Rheological Properties of Selected Mango Products with ‘Saba’ Banana (Musa acuminata x Musa balbisiana BBB Group) Peel Pectin

Saba banana peel pectin (BPP) was applied to mango jelly and mango juice. The rheological characteristics (flow curve, viscosity curve) of mango products at different temperatures (15°C, 25°C, 35°C, 45°C and 55°C) were then evaluated. The rheological data were fitted using the Hershel-Buckley model and the yield stress, consistency index, and flow behavior were identified. Values obtained from BPP mango products were compared to those with commercial low methoxyl pectin (LMP) and high methoxyl pectin (HMP). Results showed that all types of pectin resulted in non-Newtonian mango jelly and mango juice at all temperatures. For both mango jelly and mango juice, the yield stress contributed by BPP was similar to that of HMP. For the consistency, BPP and LMP had same effects on mango jelly while BPP and HMP had the same effects on mango juice at lower temperatures. For the flow behavior, BPP and HMP showed shear thinning effects for most of the temperatures tested.

Type of pectin affects the functionality of potato protein-pectin conjugates in emulsions

This study investigated the effect of the molecular structure of pectin on conjugate formation and its functionality in plant protein-based emulsions. For this purpose, high-methoxylated, low-methoxylated, amidated citrus pectin and their mixtures with potato protein were vacuum-dried at defined process conditions. The change in free amino groups, colour and molecular weight distribution assessed conjugation. The side reaction, such as pectin degradation, was monitored by the degree of methoxylation, galacturonic acid content and intrinsic viscosity. In addition, FT-IR and hydrophobicity measurements were performed to determine the changes in chemical structure due to the occurring reactions. The ζ-potential, solubility and oil droplet size reflected the functionality of the conjugated samples.The results confirm that, apart from the conjugation of protein and pectin, where the most significant decrease in free amino groups was obtained with an increasing degree of methoxylation or presence of amide groups, undesirable degradation of pectin occurring, resulting in a broad molecular weight distribution of the conjugate samples. The conjugate formation was the highest with amidated pectin. The FT-IR measurements confirmed the formation of Maillard conjugates. The FT-IR spectra showed a decrease in the intensity signals of amide I and amide II and the formation of new C–N bond maxima. In addition, the conjugation caused the shift of the protein's isoelectric point to the acidic environment, resulting in higher solubility and improved emulsion stability at the isoelectric point of the protein.Regarding emulsion stability, the conjugates with amidated pectin performed best and achieved the narrowest oil droplet size distribution over a wider pH range. Emulsion-stabilising properties of conjugates with high- and low-methoxylated pectin differed only slightly. To better understand the underlying mechanisms for emulsion stabilisation, future research will focus on the interfacial properties of the conjugates as determined by interfacial shear rheology and pendant drop analysis.

Effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice

Pectins are dietary fibers that are attributed with several beneficial immunomodulatory effects. Depending on the degree of esterification (DE), pectins can be classified as high methoxyl pectin (HMP) or low methoxyl pectin (LMP).The aim of this study was to investigate the effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice.Supplementation of the diet with LMP or HMP induced changes in the composition of the intestinal microbiota in mice toward Bacteroides, which was mainly promoted by HMP. Metabolome analysis of stool samples from pectin-fed mice showed a different effect of the two types of pectin on the levels of short-chain fatty acids and bile acids, which was consistent with highly efficient in vivo fermentation of LMP. Analysis of serum antibody levels showed a significant increase in IgG and IgA levels by both pectins, while FACS analysis revealed a decrease of infiltrating inflammatory cells in the intestinal lamina propria by HMP.Our study revealed that the structural properties of the investigated pectins determine fermentability, effects on microbial composition, metabolite production, and modulation of immune responses. Consumption of HMP preferentially altered the gut microbiota and suppressed pro-inflammatory immune responses, suggesting a beneficial role in inflammatory diseases.

Understanding structure/rheology relationships of amidated low-methoxyl citrus and apple pectin gels: Implications of sucrose, pectin types and characteristics

In this study, the relationships between structure and rheology (at small and large deformations) of amidated low-methoxyl (LMA) citrus and apple pectin gels were investigated considering how does these relationships can be modulated by soluble solids (sucrose), pectin types and characteristics. For that purpose, various LMA pectins with varying degrees of methyl esterification (DE) and amidation (DA), processed from citrus peels and apple pomace, were used. Scaling models of biopolymer gels have been critically discussed in respect to pectin critical gelling concentration (C0) and their structural variabilities. It was demonstrated that, whatever the types of LMA pectins and their structural variabilities, scalar percolation and quadratic models can be efficiently used for the prediction of the storage modulus G′ and C0 as other biopolymer gels. Fractal approach reveals that the origin of the LMA pectin gel elasticity is more in harmony with an enthalpic network of rod-like filaments with bending rigidity ruling the network's elasticity. The addition of sucrose induced an anticipation of the gelation temperature and an important improvement of the viscoelastic properties of the resulting gels. It was also shown that the most tough gels are obtained for citrus pectins due to the higher level of neutral sugar side chains in apple pectins that can hinder preponderant ca-bridging sites unlike citrus pectins. Finally, it was shown that unlike the firmness and hardness of the gels which appear to be more driven by the amide groups, the deformability of the gels is rather governed by the methyl ester groups.

Ultrasound modification of pectin and the mechanism of its interaction with cyanidin-3-O-glucoside

The present study investigated water-soluble pectin (WSP), chelating pectin (CSP), sodium carbonate-soluble pectin (NSP), and cyanidin-3-O-glucoside (C3G). Various ultrasonic treatments (688, 1376, 2064, 2431, and 3437 W/cm2, 10 min) were used to modify the three types of pectin, and the structural changes in pectin and the interaction mechanisms between pectin and cyanidin were analysed. The experimental results indicated that ultrasonic (US) modification reduced the molecular weight and degree of methylation (DE) of pectin. The DE values of WSP and CSP decreased by 24.51% and 80.12%, respectively. US modification disrupted the branched structure of pectin and reduces the ratio of rhamnose/galacturonic acid, which caused an increase in the linearity of pectin. US modification enhanced the interaction between the three pectins and anthocyanins, and the US condition of 2064 W/cm2 for 10 min increased the binding rate by 15.71%–46.18%. NSP had the largest binding rate, and US modification had the greatest improvement in WSP binding rate. After US modification, the particle size of the pectin-cyanidin complex decreased, and the zeta potential increased. After heat treatment, the residual mass percentage of the pectin-C3G complex increased, which suggested that the encapsulation of C3G in pectin improved thermal stability. Therefore, US treatment is a versatile processing tool that reduces the DE of pectin and enhances its linearity, which offers a promising approach to promoting pectin-C3G complexes.

Microencapsulation of vitamin E by gelatin-high/low methoxy pectin complex coacervates: Effect of pH, pectin type, and protein/polysaccharide ratio

In this study, gelatin (GA), high-methoxyl pectin (HMP) or low-methoxyl pectin (LMP) were used to prepare complex coacervates, and effect of pectin type, pH, and gelatin-pectin ratio on formation and physiochemical properties of complex coacervates were deeply investigated. Furthermore, vitamin E (VE) was encapsulated using GA-HMP/LMP complex coacervates. The GA-HMP/LMP complex coacervates and GA-HMP/LMP-VE microcapsules were optimized and characterized. At the gelatin-pectin ratios of 2:1 and 3:1 and pH of 4.0, the GA-HMP and GA-LMP had the maximum yield of 54.67 ± 1.82% and 59.33 ± 1.49%, and turbidity of 1.33 ± 0.02 and 1.30 ± 0.04, respectively, and GA-HMP/LMP were close to zero potential at this point, indicating that the strength of electrostatic interaction was strongest. The GA-LMP and GA-HMP displayed spherical and irregular short-rod like appearance, respectively, and more aggregates and denser network were formed at gelatin-pectin ratio of 3:1, especially in GA-HMP3:1. The formation of GA-HMP/LMP complex coacervates was driven by electrostatic interaction, and GA-HMP3:1 had the optimum thermal stability. Except GA-HMP2:1-VE, the prepared and optimized VE mirocapsules by GA-LMP and GA-LMP complex coacervates showed spherical state and uniform particle size. The GA-HMP2:1-VE and GA-HMP3:1-VE possess the highest hygroscopicity and wettability of 109.08 ± 7.66 s and 26.67 ± 0.85 g/100g, respectively. The GA-HMP3:1-VE microcapsules had the highest encapsulation efficiency of 82.67 ± 1.77 %. Results of differential scanning calorimetry and release behavior in hot-water indicated that the microcapsules had excellent thermal stability. Furthermore, the GA-HMP and GA-LMP made VE stable in gastric stages and sustainable release in intestinal stages.

An Assessment of Pectin Thiolation parameters: Degree of Esterification, Conjugate and Cross-linking Reagent Concentrations

This study focuses on the optimisation of pectinthiolation using L-cysteine and assesses the impact of the degree ofesterification (DE), polymer to L-cysteine ratio, and concentrations ofconjugating reagents on the total and free thiol content of both highlyesterified (HE) (>50% esterified) and lowly esterified (LE) (<50%esterified) pectin thiomers. The thiolation process was analysed undervariations of four factors - the type of pectin used (HE and LE), the polymer tocysteine ratio, and concentrations of the conjugating reagents 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (EDAC) and N-hydroxysuccinamide (NHS) (0 mM, 25 mM, 50 mM &100 mM). Thiol content was determined using Ellman’s reagent, withspectrophotometric methods. Statistical analysis via multivariant analysis of variation(MANOVA) indicates a significant relationship with respect to total thiolcontent considering DE, polymer to cysteine ratio, and EDAC concentration(P<0.05). Concordantly, MANOVA indicated a significant relationship withrespect to free thiol content considering DE, polymer to cysteine ratio, andboth EDAC and NHS concentrations (P<0.05). Increasing EDAC concentrationcorresponded with increased total and free thiol content in both types ofpectin. In contrast, elevating NHS concentration led to reduced total thiolcontent across most ratios. Thus, the study delineates critical parameters inthe thiolation of pectin using L-cysteine.

Formulations and Technology of Pectin-Containing Drinks Based on Honeysuckle

Solution to the optimization diet issue for people exposed to harmful production factors has a priority importance in the possible metabolic disorders prevention and is one of the most important social tasks of the state. Among the natural intestinal sorbents, pectin and some berries, honeysuckle particularly, obtain synergistic sorption properties related to the industrial xenobiotic detoxification, and merit attention. The research aim is to develop a recipe, study the commodity characteristics and effectiveness of new specialized drinks based on a new type of pectin and honeysuckle for therapeutic and preventive nutrition of workers in mining and rubber industries. Considering the functional properties of the initial ingredients, a man justifies the compound composition of therapeutic and prophylactic drinks based on polysorbovite and honeysuckle, providing the specified consumer properties, and preventive effect in relation to xenobiotics confirmed by clinical trials. The researchers regulated determined nutritional value indicators of the developed beverages.

Characteristics of Interpolyelectrolyte Complexes Based on Different Types of Pectin with Eudragit® EPO as Novel Carriers for Colon-Specific Drug Delivery.

Given that pectin is a well-known substance used for drug delivery, we aimed to obtain and further examine the efficacy of interpolyelectrolyte complexes based on citrus or apple pectin and the Eudragit® EPO for using these carriers in oral drug delivery. To characterize the physicochemical properties of these compounds, turbidity, gravimetry, viscosity, elementary analysis, FTIR spectroscopy, and DSC analysis were utilized. Diffusion transport characteristics were evaluated to assess the swelling ability of the matrices and the release of diclofenac sodium. To examine the release parameters, mathematical modeling was performed by using the Korsmayer-Peppas and Logistic equations as well. During the turbidity study, stoichiometry compositions were selected for the developed IPECs EPO/PecA and EPO/PecC at pH values = 4.0, 5.0, 6.0, and 7.0. The FTIR spectra of the complexes were characterized by an increase in the intensity of the bands at 1610 cm-1 and 1400 cm-1. According to the DSC analysis, IPEC has a certain Tg = 57.3 °C. The highest release rates were obtained for IPEC EPO/PecC_1 and EPO/PecC_4. The mechanism of drug transport from the matrices IPEC EPO/PecC, IPEC EPO/PecA_3, and EPO/PecA_4 can be characterized as Super Case II. Anomalous release (non-Fickian release) is typical for IPEC EPO/PecA_1 and EPO/PecA_2. Thus, the resulting systems can be further used for the effective delivery of the drugs to the colon.

Gelation behavior between Nicandra physalodes (Linn.) Gaertn. pectin and Ca2+ is governed by degree and pattern of methylesterification

Nicandra physalodes (Linn.) Gaertn. Pectin (NPGP) is a new type of natural low methoxy pectin (LMP), however, the relatively poor gelling capacity of NPGP and neutral calcium limits its applicability in the food industry. In this study, we improved the gelling capacity of NPGP, and the impact of the degree and pattern of methyl esterification on NPGP gelation behavior triggered by neutral calcium was investigated. To achieve this goal, NPGP was treated with pectin methyl esterase (PME, 30 °C, pH 4.5) for various time. This modification decreased the degree of methyl esterification (DM) and generated different patterns of methyl ester distribution, quantified as the degree of blockiness (DB). The obtained PME-NPGPs possess the ability to form self-supporting gels in the presence of CaCl2, with the highest gel hardness being 331.98 g. By estimating the DM and quantifying the DB of PME-NPGP, the DB value of PME-NPGP was increased from 17.74% to 31.84% with DM decreasing from 33.09% to 17.37%, indicating a shift toward a more blockwise distribution of nonmethylated GalA in NPGP. Additionally, adsorption isotherms for Ca2+ on de-esterified NPGP were determined, enabling the quantification of its cation binding capacity and interaction energy. Reducing DM and increasing DB of NPGP were found to enhance NPGP's binding capacity to Ca2+. This research provides an important foundation for NPGP food processing, and the obtained PME-NPGP can be promising in the fields of food gel and drug delivery.

Effect of temperature and extraction time on quality of pectin from arabica coffee pulp

Coffee is one of the largest commodities in the world. With coffee production more industrialized, waste generated a huge environmental problem. Coffee pulp is the main by-product of coffee processing. One of the components of coffee pulp is pectin. Pectin production from coffee pulp and its characteristics should be studied since extraction conditions used in production vary depending on raw material, desired type of pectin, and process economics. This research aimed to study the characteristics of pectin from coffee pulp extracted using oxalic acid under different times (80 and 90 minutes) and temperatures (100oC and 120oC). The parameters analyzed were yield, equivalent weight, water content, ash content, methoxyl, galacturonic acid, and degree of esterification. The result showed that extraction time and temperature affect the characteristics of pectin. The highest yield was obtained by extraction at 90oC for 90 minutes. The coffee pectin has colored light brown and is categorized as low methoxyl pectin. Overall pectin coffee pulp produced in this study has met the quality requirements of dried pectin by the International Pectin Producer Association (IPPA) standard

Novel edible films fabricated with HG-type pectin extracted from different types of hybrid citrus peels: Effects of pectin composition on film properties

This study investigated the valorization of novel HG-type hybrid citrus pectins derived from three cultivars: Setoka (ST), Kanpei (KP), and Shiranui (SH), and their application as packaging materials. The physicochemical properties of these pectins and their corresponding films were evaluated and compared to commercial citrus pectin. Significant variations were observed in pectin yield (18.15–24.12 %) and other physicochemical characteristics, such as degree of esterification (DE), degree of methoxylation (DM), and monosaccharide composition, among the different cultivars. All hybrid citrus pectins were classified as high-methoxy pectin types (66.67–72.89 %) with typical structural configurations like commercial citrus pectin. However, hybrid citrus pectin films exhibited superior physical properties, including higher mechanical strength, flexibility, and lower water solubility than commercial citrus pectin film, while maintaining similar transparency and moisture content. Additionally, the films displayed smooth and uniform surface morphology, confirming their excellent film-forming properties. Correlation analysis revealed that DE positively influenced mechanical properties (r = 1.0). Furthermore, the monosaccharide composition of pectins showed strong relationships (r = 0.8–1.0) with the film's mechanical and barrier properties. These findings highlight the potential of hybrid citrus pectin as potential packaging material, and the knowledge of the structure-function relationship obtained in this study could be useful for the tailored modification of citrus pectin-based packages.

Sugarcane molasses-induced gelation of low-methoxy pectin

Sugarcane molasses (SCM), a byproduct generated from sucrose manufacturing, has attracted considerable interest due to its high sugar content, polyphenolic compounds, and calcium ions. The objective of this study was to fabricate a type of low methoxy pectin (LMP)-based gel crosslinked by endogenous calcium ions found in SCM. Gel was formed by adding SCM into a 1 wt% LMP solution, which resulted in a Ca2+ concentration of 2–6 mmol/L. Rheological and textural measurements confirmed the formation of SCM-LMP gels. Compared to LMP gels induced by CaCl2, SCM-LMP gels exhibited weak storage modulus and gel strength, probably due to the presence of metal ions and small molecular sugars from SCM, which impede the formation of effective junction zones required for building a calcium-pectin network. The polyphenolic compounds from SCM were encapsulated within the SCM-LMP gel, enhancing its antioxidant capacity. Overall, this research explores the effectiveness of SCM in inducing LMP gelation for the first time. The findings of this study demonstrate a strategy for preparing LMP gels with antioxidant properties.

Type of pectin determines structuring potential of soy proteins into meat analogue applications

The addition of pectin to soy protein isolate (SPI) is a route to create fibrous products using shear cell technology. In this study, we investigated pectins derived from soybean, sugar beets, and citrus (two variants) that vary in sugar composition, degree of methylation and acetylation. The objective was to examine how these different pectins impact the functional properties of the SPI dispersions. The SPI-pectin blends were shear structured and their visual appearance, microstructural, rheological, and mechanical properties were analyzed. The addition of pectins from citrus (the highly methyl-esterified form) and soybean resulted in fibrous products when mixed with SPI. The addition of the low methyl-esterified pectin derived from citrus led to less pronounced fibrous product, and pectin from sugar beet did not lead to fibrous products. To explain the effect, several properties of the blends and products were tested. It was found that the fibrous products contained more air (i.e. higher void fraction) than products that were not fibrous, and that air bubbles were deformed in the shear direction. The rheological measurements of the blends revealed that the pectins lowered the yield and flow point of SPI, and the flow transition index. The blend with the highest elasticity after heating also had the highest deformation of air bubbles. Based on all results it was concluded that pectin influenced the structure formation in two ways: 1) affecting the ability to facilitate air inclusion and 2) influencing the storage modulus and elasticity of the matrix.

Reinforcement of urea formaldehyde resins with pectins derived from orange peel residues for the production of wood-based panels

Pectin is a high molecular weight carbohydrate polymer that can be utilized in various applications in many sectors. The current study involved extracting pectin samples from orange peel residues and utilizing them as additives in water-based adhesive systems for producing composite wood panels. Three pectin types were used, named Pectin-A (extracted from orange peels with HCl), pectin-B (extracted from orange peels with H2SO4) and a commercial pectin called Pectin-C. The aim of the study was to examine the possibility of enhancing the efficacy of wood-based panels, such as particleboard, by strengthening amino resins like urea-formaldehyde resin (UF) using pectin samples. Three methods were utilized to incorporate the pectins into the adhesive systems: pectin 0.1% w/w dry/liquid resin added during the initial (1) and final (2) stage of the resin’s synthesis and pectin 0.1% w/w dry/liquid resin was incorporated into the glue mixture (3), which was then sprayed onto wood particles for the production of particleboard (PB) panels. It was found that pectins improve the performance of the final particleboards, especially when added during the UF resin synthesis. In addition, they may provide the adhesive and wood panel producers with a more environmentally friendly bio-additive for their products.

High methoxyl pectin can improve the extrusion characteristics and increase the dietary fiber content of starch-cellulose extrudates.

Improving total dietary fiber content while maintaining the texture/expansion of extruded products is a challenge. Pectin has a dual function; it is a source of dietary fiber and it also functions as a hydrocolloid, which could improve the texture of high-fiber extruded foods. The objective of this study was to evaluate the impacts of pectin types from citrus peel on the expansion characteristics of starch-cellulose extrudates. High and low methoxyl pectin (HMP and LMP) was added to the starch-cellulose mixtures and extruded using a twin-screw extruder. The pasting properties of raw mixtures, extrusion properties, microstructure, and dietary fiber contents of the extrudates were studied. The inclusion of HMP in raw materialimproved the peak viscosity (629.7±8.1 to 754.7±80.1 mPa s) and maintained the final viscosity compared to the control (starch-cellulose mixture alone), unlike LMP. HMP relatively maintained the extrusion process parameters such as torque, back pressure, and specific mechanical energy as the control. Interestingly, the addition of 7% of HMP had a similar expansion ratio (3.41±0.08 to 2.35±0.06) compared to the control (3.46±0.08 to 2.32±0.09) under the extrusion conditions studied. The total dietary fiber content improved from 12.22±0.01% to 18.26±0.63% (w/w). HMP maintained the expansion characteristic of starch-cellulose extrudates and improved its total dietary fiber content relative to LMP. Adding HMP to the mixtures improved the extensibility of the melt, favoring bubble growth and expansion of the starch-cellulose extrudates. Fourier transform infrared spectroscopy data suggested that there could be intermolecular interactions between starch, cellulose, and pectin, but the nature of these interactions needs further investigation. PRACTICAL APPLICATION: The study provides practical information on the influence of the addition of high and low methoxyl pectin on starch-cellulose extrudates. The results can help the industry to produce snack products that are more nutritious but are still well accepted by the consumers.

Pectin conformation influences the bioaccessibility of cherry laurel polyphenols and gut microbiota distribution following in vitro gastrointestinal digestion and fermentation

Interactions between dietary fiber and phenolic compounds in foods can influence their gastrointestinal fate. This study aimed to examine the effect of four types of pectin on the polyphenols of cherry laurel puree and human gut microbiota during a simulated in vitro gastrointestinal digestion and large intestine fermentation. Results revealed that the combined addition of different pectins and pectinase to cherry laurel puree significantly affected the content and bioaccessibility of phenolics. The addition of pectins and pectinase distinctively impacted the phenolic subclasses in both raw and post-digested/fermented cherry laurel puree, suggesting differential interactions due to structural features. Both pectins and pectinase modulated the composition of fecal microbiota after in vitro fermentation, increasing bacterial diversity following pectinase treatment. The combined addition of pectins followed by pectinase had differential impacts on polyphenol bioaccessibility and gut microbiome diversity, hence having a potential outcome in terms of human health.

Effects of phytosanitary irradiation treatment and refrigerated storage on the physicochemical properties of three pectin types isolated from mandarin pulp

The impact of fruit exposure to ionizing energy as phytosanitary treatment on pectin properties has received little attention, especially on that from the flesh of citrus fruit other than oranges. In this study, hot-water, chelating agent and alkali soluble pectins (HWSP, CASP and ASSP) were extracted from juiced segments of mandarins that were treated with γ-irradiation (0, 0.15, 0.4 and 1 kGy) and stored (3 wks at 6 °C + 1 wk at 20 °C). Irradiation increased the recovery of HWSP and CASP and decreased the molecular weight (MW), the degree of methyl esterification (DME) and the protein content of the pectins. Storage further enhanced the recovery and the reduction of DME and MW of all tested pectins. The sum of the contents of arabinose, galactose, mannose and xylose was always lower in pectin from stored fruit as compared to pectin from non-stored fruit, independent of irradiation. Irradiation influenced the viscosity of the tested pectins from non-stored fruit. It did not impact the viscosity of pectins from stored fruit, which had a lower viscosity than that of pectins from non-stored fruit. Irradiation increased the hysteresis of pectins, independent of storage. Overall, irradiation and storage impacted the physicochemical properties of the pectins, negatively affecting their functionality.