Sugar Beet Pectin Research Articles

Enzyme cross-linked pectin microgel particles for use in foods

We report on a new enzyme-based method for producing permanently cross-linked pectin microgels. We investigate the shape, size and rheological properties of these microgel particles making comparisons with the more traditional design of calcium cross-linked pectin microgels. Both sets of microgel particles were prepared via the ‘top-down’ mechanical disruption of parent pectin hydrogels. The first hydrogel was prepared from low methoxyl pectin (LMP) (2 wt% pectin) cross-linked using Ca2+ (8.3 mM CaCl2). The LMP microgels show particle sizes ca. 1–100 μm, but are stable only in [Ca2+] = 8.3 mM or above, swelling and/or dissolving rapidly in pure water. The second type of microgel was prepared from sugar beet pectin (SBP) hydrogels covalently cross-linked via laccase. Gelation kinetics were investigated by small amplitude oscillatory shear rheometry. The SBP microgels resisted dissolution in water for several months. Light scattering measurements suggested that the SBP microgel particle sizes were related to the mechanical properties of the parent hydrogels. Various imaging techniques all suggested that SBP microgels have highly irregular shapes, perhaps due to the top-down technique used for their manufacture and their inherent mechanical properties. Concentrating the SBP microgels (to 35–50 wt% microgel, or 0.6–0.8 wt% overall pectin concentration) resulted in suspensions with rheological properties typical of yield stress fluids. When compared at similar overall SBP concentrations, the SBP microgel suspensions offer distinct advantages as bulk rheology modifiers compared to SBP solutions.

Arabinan side-chains strongly affect the emulsifying properties of acid-extracted sugar beet pectins

Pectins extracted from sugar beet pulp are promising additives for the food and beverage industry due to their good emulsifying properties. However, the relationship between molecular structure and emulsifying properties is still not fully understood; thus, systematic optimization of pectin extraction for a better emulsifying activity is not possible. In this study, we assess the underlying relationship between molecular structure and emulsifying properties by linking relevant structural parameters of 43 acid-extracted sugar beet pectins to their emulsifying properties.Sugar beet pectins with distinct structural characteristics were produced by acid extraction using varying conditions. The extracted polysaccharides were used as emulsifying agents in oil-in-water emulsions. Resulting droplet sizes were measured to correlate molecular characteristics with emulsifying properties. Analyses of protein content, degree of methylation, degree of acetylation, mean molecular weights, and trans-ferulic acid contents showed that these parameters affect the emulsifying properties to some degree, but cannot fully explain the differences observed among all pectins. However, a linear correlation between the proportion of neutral sugar side chains and droplet sizes was observed. The influence of galactose (18–30 mol%) was negligible, but increasing amounts of branched arabinans (up to 57 mol% arabinose) positively affected the emulsification result. Based on these results, it can be concluded that particularly branched arabinan side chains play an important role in the sugar beet pectin-based stabilization of emulsions. Thus, the arabinose content appears to be a suitable indicator to estimate the emulsifying properties of acid-extracted sugar beet pectins.

New pectin derivatives with antimicrobial and emulsification properties via complexation with metal-terpyridines

Pectin is widely used in food and pharmaceutical industries. However, due to its polysaccharide nature it lacks antimicrobial activity. In the current work, new pectin derivatives with interesting optical and antimicrobial properties were prepared via supramolecular chemistry utilizing Fe- or Cu-terpyridine (Tpy-Fe and Tpy-Cu) motifs. To proof derivatization of pectin, ultraviolet-visible spectroscopy (UV–Vis) and Fourier Transform infrared (FTIR) were used. In addition, the prepared pectin derivatives retained the known emulsification activity of the non-modified sugar beet pectin as seen from the particle size analysis of oil-in-water emulsions. The prepared derivatives showed antibacterial activity toward selected Gram-positive and Gram-negative bacteria. In addition, cytotoxicity test showed that the Tpy-Fe-pectin derivative was non-toxic to cells of human hepatocarcinoma, breast adenocarcinoma MCF7, and colorectal carcinoma cells at concentrations up to 100 μg/ml, while Tpy-Cu-pectin had moderate toxicity toward the aforementioned cells at the same concentration levels. The prepared derivatives could have potential applications in emulsions with antibacterial activity.

Effect of glycosylation with sugar beet pectin on the interfacial behaviour and emulsifying ability of coconut protein

The aim of the present study was to investigate the effect of glycosylation with sugar beet pectin (SBP) on the interfacial behaviour and emulsifying ability of coconut protein (CP). The physical stabilities of the emulsions were predicted by transmission variation, droplet distribution and zeta potentials. The results showed that SBP-CP-stabilized emulsions showed better stability during centrifugation than those stabilized by CP because SBP-CP reduced the degree of variation in the CP transmission profile. The adsorption kinetics of all emulsifiers at the oil-water interface were determined to investigate the relationship between the interfacial behaviour and emulsion stability. The presence of SBP considerably reduced the adsorption rate of CP (0.698 mN/m/s1/2) and hampered the development of a highly viscoelastic network at the oil-water interface. The values of the dilatational elastic modulus (Ed = 19.477 mN/m) and dilatational viscous modulus (E = 19.719 mN/m) were approximately equal, indicating that the adsorption process was mainly dominated by elastic behaviour. Additionally, the SBP-CP interaction enhanced the dilatational property of the CP-absorbed layer.

Study on the Relationship between Emulsion Properties and Interfacial Rheology of Sugar Beet Pectin Modified by Different Enzymes.

The contribution of rheological properties and viscoelasticity of the interfacial adsorbed layer to the emulsification mechanism of enzymatic modified sugar beet pectin (SBP) was studied. The component content of each enzymatic modified pectin was lower than that of untreated SBP. Protein and ferulic acid decreased from 5.52% and 1.08% to 0.54% and 0.13%, respectively, resulting in a decrease in thermal stability, apparent viscosity, and molecular weight (Mw). The dynamic interfacial rheological properties showed that the interfacial pressure and modulus (E) decreased significantly with the decrease of functional groups (especially proteins), which also led to the bimodal distribution of particle size. These results indicated that the superior emulsification property of SBP is mainly determined by proteins, followed by ferulic acid, and the existence of other functional groups also promotes the emulsification property of SBP.

Fabrication of food-grade Pickering high internal phase emulsions stabilized by the mixture of β-cyclodextrin and sugar beet pectin

Food-grade Pickering high internal phase emulsions (HIPEs) stabilized by a mixture of β-cyclodextrin (β-CD) and sugar beet pectin (SBP) were fabricated for the first time. The factors affecting the microstructures, mechanical properties, and stabilities of the Pickering HIPEs were systematically investigated. The corresponding hybrid particles were also separated and characterized to reveal the formation mechanism. The results indicated that the mixture could induce the formation of HIPEs with an oil phase volume fraction (φ) of 75% using a one-step high-speed shearing process at room temperature. The composition (the mass ratio of β-CD to SBP, Rc/s) and concentration (W) of the mixture had significant effects on the formation and properties of HIPEs. When W ≥ 1.0% and Rc/s = 2:2 or 3:1, HIPEs had smaller oil droplets, higher gel strengths, better centrifugation stabilities and lutein protection effects. The spectral analysis suggested that SBP could adhere to the surface of β-CD particles to form hybrid particles during the homogenization. Compared with native β-CD particles, these hybrid particles had higher ζ-potential absolute values, and the SBP could also increase the viscosity of the aqueous phase, which contributed to the formation and properties of these HIPEs.

Fate of β-cyclodextrin-sugar beet pectin microcapsules containing garlic essential oil in an acidic food beverage

The health-promoting characteristics of garlic essential oil have been studied for many years. However, the intensive odor has restricted its consumption. The capability of β-cyclodextrin (β-CD) incorporation with sugar beet pectin was evaluated in the garlic oil encapsulation process. The highest encapsulation and production efficiencies were obtained for the samples with 3:6–1:2 and 1:6–1:2 of core:wall material and sugar beet pectin:β-CD ratios, respectively. The scanning electron microscopic images revealed some jags, and especially surface wrinkles on the surface of the samples. The differential scanning calorimetry results showed that the encapsulation process improved the thermal stability of garlic oil. Fourier-transform infrared spectroscopy spectrum showed that the garlic oil was physically entrapped in the β-CD cavity. Applying the sample with the highest level of sulfur content to a gastrointestinal tract model system and an acidic food environment and also studying the physicochemical and release behavior showed the potential of sugar beet pectin as a wall material for garlic essential oil in acidic systems.

Enzyme- and acid-extracted sugar beet pectin as green corrosion inhibitors for mild steel in hydrochloric acid solution

Pectin extracted from sugar beet pulp using enzymatic or acid hydrolysis was evaluated as corrosion inhibitor for mild steel under acidic conditions. Effect of pectin concentration on corrosion rate and efficiency was studied via weight loss and electrochemical measurements. The effect of temperature on corrosion inhibition was studied in temperature range from 298 to 333 K. The thermodynamic parameters of corrosion process such as activation energy, equilibrium constant of adsorption (Kads), and standard free energy of adsorption (ΔGads) were also calculated. Scanning electron microscopy (SEM) coupled with Energy Dispersive X-Ray analysis (EDX) was used to examine the surface of mild steel after corrosion test. The results showed dependence of corrosion efficiency on method of pectin extraction. Enzymatic-extracted pectin showed moderately higher inhibition efficiency than the acid-extracted pectin. Polarization curves indicated that both types of pectin acted as mixed-type inhibitors with predominant inhibition at the cathodic site.

Impact of Type of Sugar Beet Pectin-Sodium Caseinate Interaction on Emulsion Properties at pH 4.5 and pH 7.

Equal parts of sugar beet pectin and sodium caseinate were interacted through electrostatic attraction, enzymatic crosslinking, and the Maillard reaction to prepare three oil-in-water emulsifier systems. Oil-in-water emulsions (10%) were processed via high shear overhead mixing at the natural pH of the emulsifier systems, followed by pH adjustment to pH 4.5 and pH 7. The emulsions were stable against coalescence, except for a slight increase in the mean droplet size for the enzymatic cross-liked emulsion at pH 4.5 over a 14-day storage period. This emulsion also showed the lowest absolute zeta (ζ)-potential value of near 30 mV. The Maillard interaction emulsifier system resulted in larger droplet sizes compared to the other two emulsifier systems. Small deformation oscillatory shear rheology assessment of the emulsion cream phases revealed an impact of the emulsifier system design at pH 4.5.

Investigation of the Formation Mechanism and Curcumin Bioaccessibility of Emulsion Gels Based on Sugar Beet Pectin and Laccase Catalysis.

In this study, modified whey protein hydrolysates (WPH) were obtained after succinic anhydride succinylation and linear dextrin glycation, and emulsion gels were prepared on the basis of unmodified/modified WPH stabilized emulsions with sugar beet pectin (SBP) addition and laccase-catalyzed cross-linking. The influences of emulsifier types and SBP contents on the texture of emulsion gels were estimated. The texture and rheological properties of emulsion gels were characterized. An ideal gel emulsion was formed when the SBP content was 3% (w/w). A uniform network was observed in emulsion gels stabilized by W-L, W-L-S, and W-S-L. In addition, the effect of the emulsifier type on the bioaccessibility of curcumin encapsulated in emulsion gels was investigated and the W-S-L stabilized emulsion gel exhibited the highest curcumin bioaccessibility (65.57%). This study provides a theoretical basis for the development of emulsion gels with different textures by SBP addition and laccase cross-linking as encapsulation delivery systems.

Fabrication of polysaccharide-based high internal phase emulsion gels: Enhancement of curcumin stability and bioaccessibility

A simple approach was developed to formulate polysaccharide-based high internal phase emulsions (HIPEs) using complexes of sugar beet pectin (SBP), tannic acid (TA), and chitosan (CS) to stabilize the system. The ability of pectin to stabilize the HIPEs was significantly improved after it formed complexes with TA, which were likely held together by hydrogen bonding. The stability of the HIPEs was further improved by adding CS, which was attributed to the formation of a 3D biopolymer network around and between the oil droplets. The impact of TA concentration, CS concentration, and pH on the oil droplet size, microstructure, and rheology of the HIPEs was investigated. Compared with SBP/TA complexes, the SBP/TA/CS complexes facilitated the formation of stable HIPEs with a gel-like texture and good stability to centrifugation, dilution, thermal treatment, and ultraviolet light. HIPEs prepared from SBP/TA/CS complexes were shown to delay lipid digestion and improve curcumin bioaccessibility. These findings provide a useful approach for designing HIPE-based soft solids from natural ingredients that can be used in foods and other commercial products.

Effects of pH and temperature on the structure, rheological and gel-forming properties of sugar beet pectins

Sugar beet pectin (SBP) was modified by alkaline at both 25 °C and 3 °C to produce gel-type pectins. The structure, rheological and gelation properties of series modified SBPs were then assessed. The results showed that low temperature effectively inhibited the β-elimination of SBP during alkali treatment, and the average molecular weight (Mw) and galacturonic acid (GalA) content of the resulting SBP were much higher than that of the alkali-treated SBP at 25 °C. Due to the low degree of methylation (DM) (≦ 21.2) and degree of acetylation (DA) (≦ 14.6), SBP treated under pH 11 and 12 at 3 °C could successfully form stable elastic gels, and these gels were further confirmed to be frequency-independent through rheological analysis. The SEM and TG/DTG results showed that the corresponding gel of SBP treated under pH 12 at 3 °C for 120 min had the most uniform micro-network structure and the best thermal stability. This work for the first time demonstrated the effect of a wide pH range on the chemical structure, rheological and physical gelation properties of SBP, especially under alkaline conditions at a low temperature (3 °C). Findings from this work suggest that alkali treatment at low-temperature allows SBP to have the potential to become a gel-type commercial pectin.

Mechanical, thermal stability and microstructural properties of emulsion-filled gels: Effect of sugar beet pectin/soy protein isolate ratio

The current study focused on how matrix ratio affected the gel properties and microstructures of sugar beet pectin (SBP)/soy protein isolate (SPI)-based gels with and without emulsion. Roles of emulsion stabilized by Tween 20 and different ratios of matrices in gelation induced by laccase and heat treatment were evaluated. The textural, rheological and thermal stability properties of either gels or gels containing emulsion were enhanced with increasing level of SBP and weakened with increasing concentration of SPI. With the increase of SBP concentration, the emulsion addition showed no significant influence on the textural parameters of gels. However, the thermal stability of gel was weakened because of the emulsion addition. The E/P212 showed improved textural and rheological properties compared with the gel without emulsion. All gels exhibited a frequency-independent behavior, and the water holding capacity of each gel was about 90%. Moreover, microstructure analysis indicated that the well-filled honeycomb gel was formed in E/P212. The gelation behavior was mainly dominant by SBP, and the underlying gelation mechanism was that the SBP was cross-linked to promote the gelatinization reaction and rate of SPI.

Influence of cations, pH and dispersed phases on pectin emulsification properties

The cooperativity of six cations (Ca2+, Mg2+, Zn2+, Al3+, Cr3+ and Fe3+), three pectins (sugar beet, high and low methyl esterified), three dispersed phases (medium chain triglycerides (MCT), orange oil and hexadecane), time (30 days) and pH (2.0 and 6.0) has been investigated in the formation and stability against coarsening of oil-in-water emulsions. Cations generally influenced emulsion stability in the following order (most stable) Ca2+ ​> ​Mg2+ ​> ​Al3+ ​> ​Cr3+ ​> ​Zn2+ ​> ​Fe3+ (least stable). This order largely coincided with that of the strength of pectin-cation interactions showing that the higher the affinity of cation for pectin the less stable the emulsion. More stable emulsions were formed with sugar beet pectin, which was also unresponsive to the presence of cations, followed by high- and then low-methyl esterified samples. At pH 2.0 all pectins showed their best emulsification performance whereas shifting pH to 6.0 severely impaired emulsification capacity and longer term stability against droplet growth. Smaller droplets were created with hexadecane under all conditions studied followed by MCT and orange oil in agreement with their aqueous solubilities. The present results advance our understanding of the stabilisation of emulsions using pectin and allow us to tailor their functionality for applications in food, pharmaceutical and biomedical industries.

Structural, gelation properties and microstructure of rice glutelin/sugar beet pectin composite gels: Effects of ionic strengths

In this study, the rice glutelin (RG)/sugar beet pectin (SBP) composite gels were prepared by laccase induced cross-linking and subsequent heat treatment, and the effects of different calcium ion concentrations (0–400 mM) on the gelation, structural properties and microstructure of the RG/SBP composite gels were investigated. The results showed that the addition of 200 mM calcium ion could improve the rheological, textural properties and water holding capacity of the RG/SBP composite gels. The addition of SBP and calcium ions enhanced the hydrophobic interaction between RG molecules, thereby increased the gel properties of RG. The changes in Raman spectroscopy reflected the positive effect of the addition of SBP and calcium ions on the formation of a denser and more homogeneous protein gel, as evidenced by the results of scanning electron microscopy. Overall, SBP and calcium ions could be applied to the plant protein gel systems as gel-strengthening agents.

Molecular characterization of the interacting and reacting systems formed by α-lactalbumin and sugar beet pectin

We investigated the molecular properties of interacting complexes and conjugates formed between α-lactalbumin (αLA) and SBP using a multi-detection (UV, dRI, MALLS, and DPV) HPSEC. Dry-heating reactions were conducted at the mass ratios 1:0, 5:1, 3:1, 2:1, 1:1, and 0:1 αLA:SBP under controlled conditions (60 °C, 79% RH, 72 h). The in-depth physicochemical analysis showed that the association levels were 32, 37, 47, and 61% αLA and 18, 24, 30, and 42% SBP for 5:1, 3:1, 2:1, and 1:1 αLA:SBP, respectively. The stoichiometry was estimated to be 233, 121, 90, and 45 αLA per SBP. Studies of the solution mixtures (3:1) demonstrated that αLA formed complexes with all sized SBP at pH ~ 6.50 through local charge-charge and hydrophobic interactions with stoichiometry ~110:1. Furthermore, the complexes and conjugates did not change the conformation of SBP considerably, i.e., compact spheres, random coils, and rigid rods but increased the molecular chains' stiffness.

Interpenetrating polymer network hydrogels of soy protein isolate and sugar beet pectin as a potential carrier for probiotics

In present study, a combination of biopolymers soy protein isolate (SPI) and sugar beet pectin (SBP) has been used to prepare an interpenetrating polymer network (IPN) hydrogel by enzymatic method. The obtained results showed that the rheological properties, textural properties and swelling properties could be tuned by regulating the concentrations of SPI and SBP as well as the amount of laccase. Moreover, the incorporation of probiotic Lactobacillus paracasei LS14 resulted in a decrease of storage modulus (G′) and hardness of SPI/SBP IPN gels. The reason might be that the addition of probiotics caused the exposure of tryptophan-containing extension regions within SPI molecules to a more polar environment. In addition, the occurrence of steric-hindrance effect of probiotic cells during the gelation of IPN hydrogels retarded the formation of covalent cross-links or physical interactions between biopolymer molecules. Scanning electron microscopy (SEM) observation confirmed that the presence of probiotics slightly disrupted the ordered microstructure of the IPN hydrogel. Under simulated gastrointestinal conditions, the SPI/SBP IPN gel showed its advantage in protection of Lb. paracasei LS14 since it had higher viabilities of probiotic cells as compared to free cells. In addition, lyophilized gels exhibited better storage stability but lower probiotic viability in comparison to wet gels. Overall, this study explored a novel method for the production of SPI/SBP IPN gel as a delivery system for probiotics, which would have great potential for development of probiotic-containing foods.

Characterization of two extracellular arabinanases in Lactobacillus crispatus.

Extracellular glycosyl hydrolases are uncommon in lactobacilli and include amylases and fructosidases mediating starch and fructan utilization, respectively. Extracellular arabinanases have not been described in lactobacilli. This study is aimed at identifying the function of an arabinan utilization operon in Lactobacillus crispatus DSM29598 and at characterizing two putative extracellular arabinanases that are located on that operon. The arabinan utilization operon of L. crispatus DSM29598 encodes enzymes for degradation of arabinan, α-galactosidases, β-galactosidases, and enzymes and for utilization of arabinose including phosphoketolase. The two putative extracellular arabinanases, AbnA and AbnB, are homologous to family GH43 endo-arabinanases. In Lactobacillaceae, homologs of these enzymes were identified exclusively in vertebrate-adapted species of the genus Lactobacillus. L. crispatus grew with arabinan from sugar beet pectin as sole carbon source, indicating extracellular arabinanase activity, and produced lactate and acetate, indicating metabolism via the phosphoketolase pathway. The two arabinanases AbnA and AbnB were heterologously expressed and purified by affinity chromatography. AbnA hydrolyzed linear and branched arabinan, while AbnB hydrolyzed only linear arabinan. The optimum pH for AbnA and AbnB was 6 and 7.5, respectively; 40°C was the optimum temperature for both enzymes. The application of arabinan degrading L. crispatus as probiotic or as synbiotic with pectins may improve the production of short-chain fatty acids from pectin to benefit host health. KEY POINTS: • An arabinan utilization operon in L. crispatus encodes two extracellular arabinanases. • The same operon also encodes metabolic genes for arabinose conversion. • In Lactobacillaceae, extracellular arabinanases are exclusive to Lactobacillus species.

Microencapsulation of hemp seed oil by pea protein isolate−sugar beet pectin complex coacervation: Influence of coacervation pH and wall/core ratio

The objective of this study was to investigate the impact of coacervation formation pH (3.5 and 2.5) and wall/core ratio (1:1, 2:1 and 4:1) on physicochemical properties of spray-dried hemp seed oil (HSO) microcapsules by means of pea protein isolate (PPI)–sugar beet pectin (SBP) complex coacervates. In general, both phase behaviors and viscoelastic properties of PPI−SBP coacervates were affected by the wall/core ratio. The coacervates structures were highly dependent on the coacervation formation pH, which greatly impacted the spray drying efficiency (PY), encapsulation efficiency (EE), oil distributions in microcapsules and oxidative stability of HSO. At the pHopt (3.5), PPI−SBP complex coacervates possess denser structure owing to the greater electrostatic interaction, whereas softer structure was formed at pH 2.5 as evidenced by rheological properties and FTIR. Because of the homogeneous large pore size and smooth inner surface of liquid coacervates formed at pH 2.5, spray-dried microcapsules had a remarkable higher EE than that formed at pH 3.5. However, the oxidative stability of HSO in PPI−SBP microcapsules prepared at pH 2.5 was significantly shortened due to the weaker electrostatic interaction strength between PPI−SBP, resulting in the partially broken PPI−SBP network caused by the spray drying process. As such, some hollow particle and incomplete particle shape was observed in SEM and CLSM image, which promoted the lipid oxidation of encapsulated HSO. In terms of wall/core ratio, the lower wall/core ratio had lower EE, higher percentage of surface oil on microcapsules, and lower oxidative stability of HSO.

Sugar beet pectin extracted by ultrasound or conventional heating: a comparison.

The yield and quality of sugar beet pulp pectin obtained by ultrasound-assisted extraction (UAE) were compared to those obtained by conventional heating. Extraction temperature (70-90)°C, extraction time (2-4) h and pH (1-1.5) were considered as the variables for the conventional extraction while ultrasound frequency (20-60) kHz, time (10-30) min and amplitude (60-100%) were considered as the variables for UAE. The optimal conditions for maximum yield of pectin for conventionally and ultrasonically extracted pectin were determined by the central composite design and the Box Behnken design, respectively. The optimum conditions of conventional extraction were the temperature of 90°C, time of 4h and pH of 1. The optimum conditions of UAE were ultrasound frequency of 20kHz, time of 10min, and ultrasound amplitude of 96%. Extraction using the optimized conditions of conventional heating and UAE achieved the best yield of 20.75% and 20.85%, respectively. The degree of methyl esterification, ferulic acid content and molecular weight of UAE pectin were higher than conventionally extracted pectin but the content of galacturonic acid in UAE pectin was lower than that of conventionally extracted pectin. The infrared spectra of both pectins revealed the occurrence of polysaccharide component. The pectin achieved by UAE had higher lightness value than conventionally extracted pectin, confirming its application in different products partially in bright food products. The UAE pectin possessed higher viscosity than conventionally extracted pectin. The addition of UAE pectin increased all of the DSC gelatinization parameters. Overall, UAE could be a promising scalable and economical approach to obtain pectin with unique characteristics.