Physicochemical,Thermal and Rheological Properties of Pectin Extracted from Sugar Beet Pulp Using Subcritical Water Extraction Process

The objective of this study was to characterize the properties of pectin extracted from sugar beet pulp using subcritical water (SWE) as compared to conventional extraction (CE). The research involved advanced modeling using response surface methodology and optimization of operational parameters. The optimal conditions for maximum yield of pectin for SWE and CE methods were determined by the central composite design. The optimum conditions of CE were the temperature of 90 °C, time of 240 min, pH of 1, and pectin recovery yield of 20.8%. The optimal SWE conditions were liquid-to-solid (L/S) ratio of 30% (v/w) at temperature of 130 °C for 20 min, which resulted in a comparable yield of 20.7%. The effect of obtained pectins on viscoamylograph pasting and DSC thermal parameters of corn starch was evaluated. The contents of galacturonic acid, degree of methylation, acetylation, and ferulic acid content were higher in the pectin extracted by SWE, while the molecular weight was lower. Similar chemical groups were characterized by FTIR in both SWE and CE pectins. Color attributes of both pectins were similar. Solutions of pectins at lower concentrations displayed nearly Newtonian behavior. The addition of both pectins to corn starch decreased pasting and DSC gelatinization parameters, but increased ΔH. The results offered a promising scalable approach to convert the beet waste to pectin as a value-added product using SWE with improved pectin properties.     

Enzymatic Extraction and Characterization of Pectin from Cocoa Pod Husks (Theobroma cacao L.) Using Celluclast® 1.5 L

Cocoa pod husks are a waste generated during the processing of cocoa beans. We aimed to explore the enzymatic extraction of pectin using cellulases. The extraction process was optimized using a central composite design (CCD) and analyzed by response surface methodology (RSM). The parameters optimized were feedstock concentration (%), enzyme dosage (µL/g), and time (h). Three dependent variables were studied: pectin yield (g/100 g dry husk) (R² = 97.02), galacturonic acid content (g/100 g pectin) (R² = 96.90), and galacturonic acid yield (g/100 g feedstock) (R² = 95.35). The optimal parameters were 6.0% feedstock concentration, 40 µL g⁻¹ of enzyme, and 18.54 h, conditions that produced experimentally a pectin yield of 10.20 g/100 g feedstock, 52.06 g galacturonic acid/100 g pectin, and a yield 5.31 g galacturonic acid/100 g feedstock. Using the chemical extraction method, a yield of 8.08 g pectin/100 g feedstock and a galacturonic acid content of 60.97 g/100 g pectin were obtained. Using assisted sonication, a pectin yield of 8.28 g/100 g feedstock and a galacturonic acid content of 42.77 g/100 g pectin were obtained. Enzymatically optimized pectin has rheological and physicochemical features typical of this biomaterial, which provides an interesting alternative for the valorization of cocoa husks.     

β-Transelimination of citrus pectin catalyzed by penicillium italicum pectin lyase in a membrane reactor

Continuous β-transelimination of citrus pectin was achieved using pectin lyase [PNL, poly(methoxygalacturonide)lyase, EC 4.2.2.10] purified fromPenicillium italicum and confined in a membrane reactor. Various operational parameters, such as enzyme and substrate concentrations, filtrate flowrate, and reaction volume were optimized. Kinetic studies indicated that β-transelimination of pectin in the continuous reactor occurred following a first-order reaction with respect to substrate concentration for up to 90 min at 1 mg/mL pectin. This time period could be extended up to 120 min when the reactor was fed with 3–4 mg/mL pectin. During the first 50 h of operation, the system was capable of maintaining a viscosity reduction of 55% below the initial value when it was continuously fed with 4 mg/mL pectin.     

Emulsifying properties and functional compositions of sugar beet pectins extracted under different conditions

Extraction conditions have important effects on the characteristics of sugar beet pectin (SBP). Response surface methodology (RSM) was used to study the impact of different extraction parameters on pectin yield, protein, ferulic acid, and galacturonic acid contents as well as on the emulsifying properties. Results indicated that pH was the main factor influencing pectin yield (ranging from 6.7 to 24.6%). Protein content varied from 0.5 to 6%, while ferulic acid content (ranging from 1.55 to 2.42%) was slightly influenced by the extraction conditions. Droplet sizes of the emulsions stabilized by different SBPs varied from 1.12 to 4.12 µm. Furthermore, according to the correlation analysis, protein content–pectin yield and ferulic acid–pectin yield demonstrated good correlations, respectively. Based on the present study, SBP with different functional components could be extracted as per relevant practical objectives.     

Improvement of paper strength via surface application of sugar beet pectin

The influence of surface-applied original and enzymatically-modified sugar beet pectin on strength properties of fluting, coating base paper, and core board was investigated. The effect was compared with the application of commercial strength-increasing agents. With increasing the polymer uptake, measured strength of paper increased. Original sugar beet pectin increased the strength properties of papers, at the same uptake of polymer, to a higher extent than oxidised potato starch or modified grain flour, while the effect of enzymatically-modified sugar beet pectin was the lowest. For the same increase of paper strength, a several times higher uptake of enzymatically-modified sugar beet pectin was required when compared with the original pectin, oxidised potato starch, or modified grain flour.     

Morphology and structure of hemp fibre after bioscouring

Bioscouring of hemp (Cannabis Sativa L) using pectate lyase (EC 4.2.2.2), Scourzyme L, was performed at 55 degrees C and pH 8.5 in a nonagitated system. The enzyme concentration, treatment time and substrate concentration were varied to obtain the kinetic constants, K(m) and V(m). Greater enzyme concentration and a longer treatment improved the removal of the low methoxy pectin component as indicated by UV spectroscopy. Removal of pectate caused no crystalline transformation in the fibres, except for a slight decline in the crystallinity order index analysed by Fourier Transform infrared spectroscopy and wide angle X-ray diffraction. This corresponded well with the single fibre bundle tensile mechanical properties test. Smooth surfaces and separated fibres observed using SEM images were evidence of successful treatment, supported by weight loss at low temperature of a pectic substance. After treatment, the pectin substance was no longer observed during thermogravimetry. An increase in surface area and pore size after scouring were further evidence of modification.     

Zinc-binding activity of different pectin compounds in aqueous solutions

The zinc-binding activity of different water-soluble pectin compounds varying according to their degree of esterification and of insoluble calcium pectate beads in aqueous solution was studied in a batch sorption system. The zinc uptake by all pectin compounds was highest within the pH range from 4.0 to 7.0. The binding capacities and rates of zinc ions by pectin compounds were evaluated. The Langmuir, Freundlich, and BET sorption models were applied to describe the isotherms and constants. Sorption isotherm data could be well interpreted by the Langmuir equation. The results obtained through the study suggest that pectin compounds are favorable sorbents. The largest number of zinc ions are bound by pectin with the degree of esterification close to zero. Therefore, it can be concluded that low-esterified pectins are more effective substances for elimination of zinc ions from aqueous disposals.     

A colorimetric method for the quantitation of galacturonic acid

A simple, colorimetric assay that is specific for galacturonic acid is presented. The assay uses sulfuric acid, carbazole, a controlled heat water bath, and a spectrophotometer. Galacturonic acid can be detected as free sugar or in polymer forms, such as pectin.     

Purification and Characterization of Alkaline Pectin Lyase from a Newly Isolated Bacillus clausii and Its Application in Elicitation of Plant Disease Resistance

Alkaline pectin lyase (PNL) shows potential as a biological control agent against several plant diseases. We isolated and characterized a new Bacillus clausii strain that can produce 4,180?U/g of PNL using sugar beet pulp as a carbon source and inducer. The PNL was purified to apparent homogeneity using ultrafiltration, ammonium sulfate fractionation, DEAE Sepharose Fast Flow, and Sephadex G-75 gel filtration. The purified PNL was found to be a monomeric protein with a molecular weight of 35?kDa, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). It demonstrated optimal activity with K _m of 0.87?mg/ml at pH?10.0 and 60?°C. The enzyme is stable in the pH range of 8.0?C10.0 and temperature ??40?°C. Ca²⁺ was found to stimulate the enzymatic activity of the PNL by up to 410?%. Mass spectrometric results gave 38?% match coverage with pectate lyase from B. clausii KSM-K16 (gi|56961845). The PNL was found to elicit disease resistance in cucumber seedlings, suggesting that it may have applications in biocontrol and sustainable agriculture.     

Simultaneous capillary GC of acids and sugars as their silyl(oxime) derivatives: Quantitation of chlorogenic acid,raffinose, and pectin substances

Our GC-MS method for the simultaneous quantitation of sugars and acids as their silyl(oxime) derivatives, from one solution by one injection, has been extended to the reproducible determination of high molecular weight compounds sensitive to decomposition yet requiring a high evaporation temperature (e.g. chlorogenic acid and rffinose) and for the quantitation of the decomposition products of pectin (i.e., for the determination of galacturonic acid at low ng levels in the presence of a 10–100 fold excess of glucose eluting just before the acid). The optimized GC procedure has been used for quantitation of the sugar and acid (including chlorogenic acid) composition of potato samples, and for the determination of the increasing amount of the decomposition products of pectin substances in apple pulp after different storage times.     

Pectinases Secretion by Saccharomyces cerevisiae: Optimization in Solid-State Fermentation and Identification by a Shotgun Proteomics Approach

A sequential design strategy was applied to optimize the secretion of pectinases by a Saccharomyces cerevisiae strain, from Brazilian sugarcane liquor vat, on passion fruit residue flour (PFRF), through solid-state fermentation (SSF). A factorial design was performed to determine the influence variables and two rotational central composite designs were executed. The validated experimental result was of 7.1 U mL⁻¹ using 50% PFRF (w/w), pH 5, 30 °C for 24 h, under static SSF. Polygalacturonase, pectin methyl esterase, pectin–lyase and pectate–lyase activities were 3.5; 0.08; 3.1 and 0.8 U mL⁻¹, respectively. Shotgun proteomics analysis of the crude extract enabled the identification of two pectin–lyases, one pectate–lyase and a glucosidase. The crude enzymatic extract maintained at least 80% of its original activity at pH values and temperatures ranging from 2 to 8 and 30 to 80 °C, respectively, over 60 min incubation. Results revealed that PFRF might be a cost-effective and eco-friendly substrate to produce pectinases. Statistical optimization led to fermentation conditions wherein pectin active proteins predominated. To the extent of our knowledge, this is the first study reporting the synthesis of pectate lyase by S. cerevisiae.     

Polysaccharide lyases

Polysaccharide lyases (or eliminases) are a class of enzymes (EC 4.2.2.-) that act to cleave certain activated glycosidic linkages present in acidic polysaccharides. These enzymes act through an eliminase mechanism, rather than through hydrolysis, resulting in unsaturated oligosaccharide products. Acidic polysaccharides are ubiquitous and so are the lyases that degrade them. This review article examines lyases that act on acidic polysaccharides of plant, animal, and microbial origin. These lyases are predominantly of microbial origin and come from a wide variety of both pathogenic and nonpathogenic bacteria and fungi. The lyases discussed include alginate lyase (EC 4.2.2.3), pectin lyase (EC 4.2.2.10), pectate lyase (EC 4.2.2.2), oligogalacturonide lyase (EC 4.2.2.6), exopolygalacturonate lyase (EC 4.2.2.9), chondroitin lyases (EC 4.2.2.4 and EC 4.2.2.5), hyaluronate lyase (EC 4.2.2.1), heparin lyase (EC 4.2.2.7), heparan lyase (EC 4.2.2.8), and other unclassified lyases. This review examines the sources, regulation, purification, and properties of these polysaccharide lyases.     

Component analysis and free radicals scavenging activity of Cicer arietinum L. husk pectin

A pectin (CAP) was extracted from the husk of Cicer arietinum L. Monosaccharide analysis of CAP revealed the dominance of galacturonic acid and smaller amounts of galactose, arabinose, rhamnose, glucose, xylose and mannose. Viscosimetric analysis showed that the intrinsic viscosity ([η]) and the molecular weight (MW) of CAP were 296 mL/g and 105 kDa, respectively. The degree of esterification (DE = 10%) was determined by FTIR spectroscopy. CAP exhibited a dose-dependent free radical scavenging activity, as shown by its DPPH radical inhibition. At 1.0 mg/mL CAP exhibited a scavenging rate of 29% on DPPH radicals. The evaluation of antioxidant activity suggested that CAP had good potential for DPPH radical scavenging activity and should be explored as a novel potential antioxidant.     

Monosaccharide composition and hydrodynamic properties of industrial pectin substances

A study of the monosaccharide composition and hydrodynamic characteristics of pectin substances has made it possible to judge their structure and evaluate the quality of the desired product obtained in industry. The results of the investigation show that, depending on the method of extraction, it is possible to obtain both a homogalacturonan and also a graft copolymer consisting of residues of galacturonic acid and rhamnose with branches formed through the neutral sugars.V. I. Nikitin Institute of Chemistry, Academy of Sciences of the Tadzh SSR, Dushanbe. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 455–460, July–August, 1990.     

Isolation and structural characterization of a pectin homo and ramnogalacturonan

With a purpose to achieve an individual components of the pectins there was purified and separated the acidic components of the apple pectin and its chemical structure was studied using (13)C-NMR-Spectroscopy. The apple pectin was consecutively subjected to processing with hydrochloric acid and ethanol mixture, ultracentrifuging at 7000 and 40 000 rpm, ultrafiltration, fractionation on cellulose (DEAE-52) ion exchanger, eluting by the phosphate buffer. The contents of the acidic and neutral polysaccharides in an initial pectin and in the selected fractions controlled by narrow-band filter - spectroscopically in relation to E(q)=E(298)/E(315). In the (13)C-NMR-spectrums of the pectins before purifications on the ion exchanges besides the signals characteristic for homogalacturon, resonances are observed at 105.8, 79.01, 76.3, 73.9, 70.0 and 18.32 m.d., appropriate to the ramnogalacturonan residues. Resonance lines of acidic fraction in the field of 69.8, 70.6, 72.3, 80.6, 100.6 and 176.6 m.d. are referred to homogalacturonan residues and signals at 55.9, 73.3, 80.8, 101.6 and 172.6 m.d. to their methoxyl group. Minor resonance at 18.32 originated from C-6 rhamnose residues, substituted or unsubsituted with galactosyl-chains. Hence it has been shown that the apple pectin consist mainly of linear homogalacturonan and branched ramnogalacturonan macromolecules.     

Assignment of acetyl groups to O-2 and/or O-3 of pectic oligogalacturonides using negative electrospray ionization ion trap mass spectrometry

Partially acetylated and methylated oligogalacturonides produced by enzymatic hydrolysis of sugar beet pectin were analysed by negative electrospray ionization ion trap mass spectrometry (ESI-ITMS). The (18)O labelling of the oligomer reducing end allowed the precise assignment of the fragments resulting from glycosidic bond and cross-ring cleavages. The collisional-induced dissociation of the C(i) and Z(j) fragment ions through sequential MS(n) experiments always displayed (0, 2)A-type cross-ring cleavage ions which were related to C(2)H(4)O(2) losses. These (0, 2)A ions appeared to be highly diagnostic ions allowing the precise location of the acetyl groups to the O-2 and/or O-3 of the acetylated galacturonic acid residues.     

Effect of Ultrasound-Assisted,Microwave-Assisted and Ultrasound-Microwave-Assisted Extraction on Pectin Extraction from Industrial Tomato Waste

This work aimed to study the effect of ultrasound-assisted (UAE), microwave-assisted (MAE), and ultrasound-microwave-assisted (UMAE) methods for pectin extraction from industrial tomato waste. The overall performance index from the fuzzy analytical method with three criteria, pectin yield, galacturonic acid, and lycopene content, was applied to evaluate the best extraction conditions by using the weight of 75, 20, and 5, respectively. The UAE conditions was performed at a temperature of 80 °C for 20 min with the variations in the extraction pH and the solid liquid (SL) ratio. The best UAE conditions with high pectin yield, and high total carboxyl group, as well as a lycopene content, was the pH of 1.5 and the SL ratio of 1:30. The MAE conditions was performed with variations in the microwave powers and times. The results showed that the best MAE conditions were 300 W for 10 min, which gave high pectin yield with high galacturonic acid and lycopene content. Various conditions of UMAE at the best conditions of MAE and UAE were performed and exhibited that the UAE had more positively affected the pectin yield. However, the FTIR spectra of obtained pectins from different extraction techniques showed a similar pectin structure.     

酶解-离子色谱法测定烟草中的果胶

建立了一种测定烟草中果胶含量的酶解-离子色谱法,并对酶解条件进行了优化.即样品经快速溶剂萃取仪用80%乙醇除糖后,在47℃、pH4条件下用果胶酶酶解2 h,用离子色谱测定酶解液中的半乳糖醛酸含量.该法的线性相关系数为0.999 3,回收率98.3%～100.8%,RSD为3.43%.     

Derivation of hydroxamic acid from pectin and its applications in colorimetric determination

A hydroxamic acid (HX) derivative of pectin was prepared, and its potential application to simple colorimetric determination of polysaccharides was investigated. The coupling reaction between pectin and hydroxylamine (HA) progresses in the presence of 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluenesulfonate (CMEC). The calibration curve for pectin showed good agreement and the lower limit of detection was 0.5 mg. This is a very simple and rapid determination method, which does not require tedious pre-treatment, for polysaccharides containing carboxyl groups.     

Characterisation of natural polysaccharides (plant gums) used as binding media for artistic and historic works by capillary zone electrophoresis

The monosaccharide constituents of plant gums were separated by capillary electrophoresis at pH 12.1 and detected with indirect UV absorbance. The plant gums investigated were gum arabic, gum acacia, gum tragacanth, cherry gum and locust bean gum (carob gum). The monosaccharides obtained after hydrolysis with 2M trifluoroacetic acid and lyophilisation of the hydrolysate were arabinose, galactose, mannose, rhamnose, xylose, fucose, and glucose, and the two sugar acids galacturonic and glucuronic acid, in accordance with the literature. They were separated in a background electrolyte consisting of NaOH to adjust the pH, 20 mM 2,6-pyridinedicarboxylic acid as chromophore for detection and 0.5 mM cetyltrimethylammonium bromide as additive to reverse the electroosmotic flow. Based on their electropherograms, the plant gums could be identified by their typical composition (depicted in a decision scheme) as follows: a peak of glucuronic acid, together with that of rhamnose, is indicative for gum arabic. Peaks of galacturonic acid and fucose point to gum tragacanth. Locust bean gum shows a major peak for mannose (with the concomitant galactose peak in ratio 4-1), whereas a glucuronic acid and a mannose peak together with a prominent arabinose peak indicates cherry gum. The method was applied to identify the plant gums in samples like watercolours and in several paint layers like gum tempera or those with egg white or drying oils as additives. Artificial aging experiments of thin layers of gum arabic on paper or glass carried out with UV-A radiation (366 nm) did not result in changes of the saccharide patterns, in contrast to the simultaneously conducted aging of a drying oil layer.