Galacturonic Acid Content Research Articles

Effects of enzymatic treatment on the physicochemical properties and antioxidant activity of hawthorn pectin

The effects of enzymatic treatment on the physicochemical properties and antioxidant activity of natural hawthorn pectin (CK) were evaluated using a series of characterization methods. The results indicated that four modified pectin preparations (MPE, MPLE, MPME, and MCE, respectively obtained through treatment with pectinase, pectin lyase, pectin methylesterase, and cellulase) all showed a low methoxy content. MPLE had the highest galacturonic acid (Gal A, 92.01%) content and the highest degradation temperature (135 ℃). MPME had the lowest molecular weight (3.59 kDa) and MCE had the smallest particle size (238.0 nm). Infrared spectroscopy (FTIR) indicated that the enzymatic treatment did not change the primary structure of pectin. Scanning electron micrographs (SEM) showed that the four modified pectin preparations were more fragmented and irregular. Antioxidant activity of the pectin preparations was evaluated by determining their radical scavenging ability (hydroxyl radical and ABTS radical) and reducing power. The IC50 for hydroxyl radical and ABTS radical of all modified pectin preparations was lower than CK. The reducing power of MPE and MPME was higher than that of CK. Different enzymes modification methods played an important role on the characterization of pectin. Enzymatic modification methods offer great promise for the application of hawthorn pectin in functional products.

Effect of Extraction Procedures with Ultrasound and Cellulolytic Enzymes on the Structural and Functional Properties of Citrus grandis Osbeck Seed Mucilage.

The structural and functional properties of Citrus grandis Osbeck (CGO) seed mucilage by different extraction practices, including conventional citrate buffer, ultrasonic-assisted (UAE), enzymatic-assisted extraction (EAE) with cellulase or Celluclast® 1.5 L and various ultrasonic-assisted enzymatic extraction (UAEE) procedures were investigated. It was found that CGO seed from agricultural and processing byproducts is an excellent new source of high methoxyl pectin with quite high intrinsic viscosity (about 108.64 dL/g) and molecular weight (about 1.9 × 106) as compared with other pectin sources. UAEE with Celluclast® 1.5 L enhanced the extraction yield most pronouncedly (about 2.3 times). Moreover, the monosaccharide composition of CGO seed mucilage is least affected by EAE with Celluclast® 1.5 L. In contrast, EAE with cellulase dramatically reduces the galacturonic acid (GalA) content to less than 60 molar%, and increases the glucose (Glc) content pronouncedly (to about 40 molar%), which may be considered as an adverse effect in terms of pectin purity. Though extraction procedures involved with ultrasound and cellulolytic enzymes generally show a decrease in GalA contents, weight average molar mass and intrinsic viscosity, EAE with Celluclast® 1.5 L is least affected, followed by UAE and UAEE with Celluclast® 1.5 L. These features can be leveraged in favor of diversified applications.

Оптимизация условий мицеллярно-ферментативной экстракции пектина из плодов боярышника ( Crataegus monogyna Jacq.)

Introduction. Commercial pectin is usually obtained from apples or citrus fruits. However, some wild fruits, such as hawthorn, are also rich in pectin with valuable nutritional and medical properties. The research objective was to study and improve the process of combined surfactant and enzyme-assisted extraction of pectin from hawthorn fruits.
 Study objects and methods. The study involved a 1% solution of Polysorbate-20 surfactant and a mix of two enzymes, namely cellulase and xylanase, in a ratio of 4:1. The response surface methodology with the Box-Behnken experimental design improved the extraction parameters. The experiment featured three independent variables – temperature, time, and solvent-to-material ratio. They varied at three levels: 20, 40, and 60°C; 120, 180, and 240 min; 15, 30, and 45 mL per g. Their effect on the parameters on the pectin yield was assessed using a quadratic mathematical model based on a second order polynomial equation.
 Results and discussion. The response surface methodology made it possible to derive a second order polynomial regression equation that illustrated the effect of extraction parameters on the yield of polyphenols. The regression coefficient (R2 = 98.14%) and the lack-of-fit test (P > 0.05) showed a good accuracy of the model. The optimal extraction conditions were found as follows: temperature = 41°C, time = 160 min, solvent-to-material ratio = 32 mL per 1 g. Under the optimal conditions, the predicted pectin yield was 14.9%, while the experimental yield was 15.2 ± 0.4%. The content of galacturonic acid in the obtained pectin was 58.5%, while the degree of esterification was 51.5%. The hawthorn pectin demonstrated a good complex-building ability in relation to ions of copper (564 mg Cu2+/g), lead (254 mg Pb2+/g), and cobalt (120 mg Co2+/g).
 Conclusion. Combined surfactant and enzyme-assisted extraction made improved the extraction of pectin from hawthorn fruits. The hawthorn pectin can be used to develop new functional products.

Assessing the bioactivity, cytotoxicity, and rheological properties of pectin recovered from citrus peels

The recovery of pectin from citrus peel waste for application in the food, nutraceutical, pharmaceutical, and medical industries has attracted much interest. It has been postulated that the presence of polyphenols, sometimes regarded as an impurity, in extracted pectin might confer enhanced biological property. This research study aimed at investigating the physicochemical and biological properties (antioxidant, enzyme inhibitory, and cytotoxic properties) of pectin extracted from the alcohol insoluble residues of the peel waste of grapefruit, lime, and lemon as well as the pectin recovered from untreated peel waste. The rheological behavior of the pectin samples was also evaluated. High methoxyl pectin with galacturonic acid content greater that 60% was recovered from the different raw materials. Pectin obtained from untreated material possessed high phenolic content (19.83–5.94 mg gallic acid equivalent/g sample) and showed higher antioxidant activity. Inhibition against pancreatic cholesterol esterase, pancreatic lipase, and α-glucosidase was observed and pectin enriched with polyphenol showed higher activity. Addition of pectin samples to healthy Vero cells enhanced proliferation and did not show cytotoxic effect. Pectin solutions extracted from untreated lime and untreated grapefruit presented highest viscosity and elastic modulus, which were comparable to those obtained for commercial high-methoxyl pectin. Pectin extracted from lime, lemon, and grapefruit peels possessed interesting biological and viscoelastic properties, which can be exploited for development of novel bioproducts.

Mitigation effects of high methoxyl pectin on acrylamide formation in the Maillard model system

Acrylamide (AA) is a potential carcinogen formed during the process of food heating. Pectin is natural food additive widely presented in fruits and vegetables. This study aimed at investigating the influence of the addition of high methoxyl apple pectin (esterification degree: 82.6%) on AA inhibition in the asparagine (Asn)/glucose (Glc) model system. Results showed that temperature (120–180 °C), pH value (6.0–7.2), pectin addition (0.2–1.0%, w/v), substrate concentration (0.01–0.5 M) and molar ratio of Asn/Glc (5:1–1:10) had significant influence on inhibition of pectin on AA formation. With adding 1.0% (w/v) pectin, the pH value, Glc consumption and Schiff base abundance declined in Asn/Glc model system. Moreover, heating treatment decreased the pH value, molecular weight, esterification degree and galacturonic acid content of pectin. Finally, the pectin degradation product was identified, which might compete with Glc for Asn in Maillard reaction, led to AA reduction. This study provided distinct evidence for controlling AA formation.

EXTRACTION TEMPERATURE AND PH AS DECISIVE FACTORS FOR THE YIELD AND PURITY OF GRAPE POMACE PECTIN

The purpose of this paper is the use of grape pomaces, obtained by processing two different Vitis vinifera varieties (Rară Neagră and Fetească Neagră) from 2019 harvest, cultivated in the Bugeac area, Republic of Moldova, as a source of unconventional pectin. Pectin was extracted under the following conditions, citric acid used as extractant for 3 h of extraction, 125-200 µm of grape pomace particle size and solid to liquid ratio 1:10. The variables which were varied were temperature (70, 80 and 90 °C) and pH (1, 2 and 3). So, pectin yield and galacturonic acid content were determined under the influence of extraction temperature and pH. The obtained results demonstrated that the extraction conditions (temperature and pH) have a significant impact on the yield and purity of pectin from grape pomace. The highest influence on pectin yield was determined by pH 1 (15.54% and 9.96% for Fetească and Rară Neagră grape pomace pectin, respectively) and temperature of 90 °C (7.34% and 7.56% for Fetească and Rară Neagră grape pomace pectin, respectively). The same tendency is observed for galacturonic acid content.

EXTRACTION AND OPTIMIZATION OF PECTIN FROM COFFEE ROBUSTA PULP AND ITS APPLICATION IN THE FOOD PRODUCT

Coffee is one of the paramount agricultural commodities and the most consumed beverages in the world. A serious problem with the coffee industry now-a-days is huge amount of coffee pulp gets wasted once the coffee beans were separated from its cherries. It is found essentially rich with carbohydrates, proteins, minerals, fat and contains a sufficient level of minor compounds such as pectin, caffeine, tannins, polyphenols. Pectin was extracted by two different methods such as acid hydrolysis and enzymatic extraction at different pH and temperature. Pectin was evaluated for its proximate analysis and physio-chemical analysis such as ash content, moisture content, pectin yield, methoxyl content, equivalent weight, anhydrouronic acid content, degree of esterification, gel forming ability, viscosity & galacturonic acid content. The project was carried out with extraction and optimization of pectin and to incorporate in to the food product. The pectin act as thickening agent and gelling agent and it is incorporated with jam to study its characteristics with commercial food grade.

The The Effect of Concentration of Citric Acid Solution on Extraction of Pectin from Watermelon Albedo

Watermelon albedo or the white flesh of watermelon rind contains pectin with high enough content. In this study was conducted the extraction of pectin from watermelon albedo by the liquid-solid extraction method. The citric acid solution was used as a solvent with concentrations varied by 4%, 7%, and 10%. The research steps include the pretreatment of raw material, the extraction, the posttreatment of extraction, and the analysis of pectin. The pretreatment aimed to reduce water content and reduce the size of raw material. The extraction process was the main process in which pectin dissolution occurred in the citric acid solvent. Furthermore, the posttreatment of extraction aimed to obtain pectin solid with the addition of ethanol. The final step was the analysis, including pectin yield, moisture content, methoxyl content, galacturonic acid content, and pectin functional group. Based on research obtained, an increase in the concentration of citric acid increased pectin yield, methoxyl content, and galacturonic acid content. The moisture content of pectin decreased with the increasing concentration of citric acid. Pectin yield, moisture content, methoxyl content, galacturonic acid content resulted from 10% concentration of citric acid solvent are 8.356%, 19.748%, 7.029%, and 69.048%, respectively. Based on FTIR analysis, the functional groups contained in pectin are hydroxyl group, methyl group, carbonyl group, and ether group. This functional groups are main constituents of pectin structure.

Increasing RG-I content and lipase inhibitory activity of pectic polysaccharides extracted from goji berry and raspberry by high-pressure processing

The impact of high-pressure processing (HPP) extraction on the structural, rheological, and functional properties of goji berry and raspberry pectic polysaccharides were investigated under acidic and alkaline conditions. These properties were compared with those of pectic polysaccharides extracted by conventional hot-acid and cold-alkali methods. Extraction yield, molecular weight, rheological behavior, and antioxidant activity of pectic extracts depended on the source materials of extraction. The solvent pH was the driving factor for the degree of esterification, as revealed by NMR and FTIR analysis. Monosaccharide composition was the primary variable between the extracts. The hot-acid extraction led to the highest galacturonic acid (GalA) contents, 46.9% for goji berry and 65.2% for raspberry, indicating the prevalence of homogalacturonans (HG) regions. HPP-assisted acidic/alkaline extractions gave rise to higher rhamnogalacturonan-I (RG-I) regions, pointing to the prevalence of hairy regions. The antioxidant activity of raspberry extracts was significantly (P ≤ 0.05) higher than goji berry extracts. The higher amount of RG-I may determine the higher antioxidant activity of raspberry pectic polysaccharides. The correlation between structural parameters and the lipase inhibitory activity also revealed that the higher lipase inhibitory activity of pectic polysaccharides is mostly correlated with the higher content of RG-I (r = 0.9259, P = 0.00033). Thus, HPP-assisted extraction may intensify the lipase inhibitory activity of pectic polysaccharides by increasing their RG-I content.

Profiling the water soluble pectin in clear red raspberry (Rubus idaeus L. cv. Heritage) juice: Impact of high hydrostatic pressure and high-temperature short-time processing on the pectin properties

Water soluble pectin (WSP), inherently present in the particle and serum phase of processed red raspberries, largely contributes to their overall structure organization. Nevertheless, pectin losses were preliminarily observed in hydrostatic pressure (HHP)-, and high-temperature short-time (HTST)-processed clear red raspberry juice. This study therefore aims to elucidate the process-induced pectin loss and conversion by profiling the WSP and its subdomains (homogalacturonan, HG; rhamnogalacturonan I, RG I) from differently processed red raspberry juice. First, pectin content and pectin-related enzymes (polygalacturonase [PG], pectin methyl esterase [PME], pectate lyase [PL], and β-galactosidase) in fresh, HHP-, and HTST-processed juice were analyzed. Results suggested that the pectin loss in HHP-processed juice was attributed to the residual activities of endogenous HG-modifying enzymes (PG, PME, and PL), whereas that in HTST-processed juice was due to the nonenzymatic depolymerization. Subsequently, WSP, RG I -, and HG-rich fractions were selectively isolated from differently processed juice. These fractions ranged in molecular weight (Mw, 34.03–83.69 kDa), D-(+)-galacturonic acid (GalA) content (32.22%–88.32%), and degree of esterification (3.10%–38.71%). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectra confirmed the low esterified GalA-rich backbone. X-ray diffraction (XRD) patterns indicated an amorphous structure. Notably, monosaccharides composition and microscopic observations demonstrated the presence of side branches in HG-rich fractions. Differences in Mw, monosaccharides composition, and XRD revealed process-induced depolymerization occurred in the HG subdomain of WSP. However, the HG-rich fractions from processed juice showed higher thermostability. These basic findings provided novel insights into the pectin loss and conversion in processed red raspberries.

Assisted ohmic heating extraction of pectin from pomegranate peel

Pomegranate peel is rich in various compounds such as pectin. The aim of this study was to first, find the optimal conditions for extracting pomegranate pectin by ohmic heating method and then, to compare the properties of this pectin with pectin extracted under optimal conditions by conventional acidic method. With conventional acidic method, the optimal extractor acid, pH and solid to solvent ratio were determined, they were hydrochloric acid, 1.5 and 1:40, respectively, and these results were generalized to ohmic heating extraction condition. Then, the effects of voltage gradient and time, during ohmic heating on the yield and galacturonic acid, were studied using the response surface methodology (RSM). According to the findings, the optimal conditions for the voltage gradient and time were 10 V/cm and 18 min, respectively. Extraction yield and galacturonic acid percentage were 8.16% and 82.86% in ohmic method and 8.93% and 73.84% in conventional method, respectively. As it can be seen, the galacturonic acid content of the pectin extracted under ohmic heating were significantly higher. The study on different pomegranate peel size showed that in ohmic heating even with bigger size of particle, the yield remained constant.

RENDEMEN AND CHARACTERISTICS OF PEKTINS RED DRAGON FRUIT LEATHER (Hylocereus costaricensis) WITH THE DIFFERENCE IN EXTRACTION METHOD AND TIME

This study aims to determine the effect of the method and time of extraction on the yield and characteristics of pektin red dragon fruit leather according to the SNI pektin (01-2238-1991) and the International Pektin Producers Association (IPPA) 2003. The experimentals design was a Completely Randomized Design with 2 factors. The first factor was the extraction method used, namely (M1 = conventional method, M2 = ultrasonik method). The second factor was extraction time (W1 = 15 minutes, W2 = 30 minutes, W3 = 60 minutes, and W4 = 90 minutes. The results showed that the extraction method had a significant effect on yield, equivalent weight, galacturonic acid content, degree of esterification, water content and ash content, but had no significant effect on methoxyl content. Extraction time significantly affected yield, equivalent weight, methoxyl content, galacturonic acid content, degree of esterification, water content and ash content. While the interaction of the two treatments had a significant effect on yield, equivalent weight, and water content. The highest yield was obtained using the ultrasonik method for 60 minutes with a value of 13.57%. The equivalent weight that meets IPPA (2003) and SNI pektin standards (01-2238-1991) is found in conventional and ultrasonik methods at 30 and 60 minutes.

Rheological and gelling properties of Nicandra physalodes (Linn.) Gaertn. pectin in acidic media

Nicandra physalodes (Linn.) Gaertn. polysaccharide (NPGP) was previously recognized as a pectic polysaccharide, with a high galacturonic acid content (87.8%) and a low methoxylation degree (28%). In the present study, it was found that NPGP can form self-supporting gels when cooling its heated solutions (2.0%, w/v) acidified by citric acid. It was demonstrated that the decrease in pH led to the suppression in electrostatic repulsions between the pectin chains, thereby promoting pectin chain-chain association mainly through hydrogen bonding. As the pH decreased from 3.2 to 2.4, the gel strength and gel thermal stability were continuously increased. Moreover, it was shown that sucrose addition slightly promoted the gelation and gel thermal stability of NPGP, but the effect of monovalent ions (Na+) and divalent ions (Ca2+) was not significant. Conclusively, our results indicate that NPGP is a new gelling polysaccharide that shows great potential in formulation of acidic gel foods.

Isolation, Chemical Characterization and Antioxidant Activity of Pectic Polysaccharides of Fireweed (Epilobium angustifolium L.).

The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively. EA-4.0 and EA-0.8 were found to scavenge the DPPH radical in a concentration-dependent manner at 17–133 μg/mL, whereas commercial apple pectin scavenged at 0.5–2 mg/mL. The antioxidant activity of EA-4.0 was the highest and exceeded the activity of EA-0.8 and a commercial apple pectin by 2 and 39 times (IC50—0.050, 0.109 and 1.961 mg/mL), respectively. Pectins EA-4.0 and EA-0.8 were found to possess superoxide radical scavenging activity, with IC50s equal to 0.27 and 0.97 mg/mL, respectively. Correlation analysis of the composition and activity of 32 polysaccharide fractions obtained by enzyme hydrolysis and anionic exchange chromatography revealed that the antioxidant capacity of fireweed pectins is mainly due to phenolics and is partially associated with xylogalacturonan chains. The data obtained demonstrate that pectic polysaccharides appeared to be bioactive components of fireweed leaves with high antioxidant activity, which depend on pH at their extraction.

Structure Characterization of Polysaccharide from Chinese Yam (Dioscorea opposite Thunb.) and Its Growth-Promoting Effects on Streptococcus thermophilus.

To clarify the mechanisms underlying the growth-promoting effects of yam polysaccharide on Streptococcus thermophilus (S. thermophilus), the yam polysaccharide was extracted using a deep eutectic solvents (DESs) method and separated into four fractions by DEAE-cellulose 52. These fractions were used as the alternative carbon source to substitute lactose to compare their growth-promoting effects on S. thermophilus. Furthermore, their molecular weight, monosaccharide and functional groups’ composition, microscopic forms and other basic structure characterizations were analyzed. The results showed that all the fractions could significantly promote S. thermophilus growth, and fractions exhibited significantly different growth-promoting effects, whose viable count increased by 6.14, 6.03, 11.48 and 11.29%, respectively, relative to those in the M17 broth medium. Structure-activity relationship analysis revealed that the high growth-promoting activity of yam polysaccharide might be more dependent on the higher molecular weight, the higher galacturonic acid content and its complex spatial configuration, and the existence of β-glycosides would make the yam polysaccharide have a better growth-promoting effect on S. thermophilus.

Application of an eco-friendly sodium acetate/urea deep eutectic solvent in the valorization of melon by-products

An eco-friendly sodium acetate/urea (NaOAc:urea:water) deep eutectic solvent (DES) was evaluated for the extraction of bioactive compounds from melon peels. Melon peels were first extracted with water to separate the water-insoluble solids (WIS) from free sugars, and the WIS were subsequently extracted with the DES. The extracts were analyzed for oligosaccharides and protein as well as total phenolic content and antioxidant activities. The influence of extraction parameters (time, temperature, DES molar ratio, water content and solid consistency) on the composition of the extracts was evaluated. At the selected conditions (NaOAc:urea:water with molar ratio 1:3:1.6 (10% (w/w) water), with a consistency of 2% (w/w), at 90 °C for 10 min), the total oligosaccharide yield was 8.84 g oligosaccharides/100 g WIS, of which 90% were oligogalacturonides, and the total phenolic content and protein content were 4.35 mg GAE/g WIS and 2.87 g/100 g WIS, respectively. Pectin enriched in branched rhamnose units with a low degree of methyl esterification was recovered by precipitation, with a yield of 7.95 g/100 g WIS and a galacturonic acid content of 49.44%.

Utilization of stalk waste separated during processing of sun-dried figs (Ficus carica) as a source of pectin: Extraction and determination of molecular and functional properties

This study aimed the utilization of fig stalk waste as an alternative pectin source. For this purpose, the characteristics of extracted stalk waste pectin (SP) were compared with those of citrus pectin (CP) and pectin extracted from defected substandard whole sun-dried figs (FP). The SP had a higher extraction yield (11.7%) than FP (9.4%). The galacturonic acid content and degree of esterification of SP (32.3 and 50.1%) were higher than those of FP (19.9 and 38.8%), but lower than those of CP (79.3 and 56.2%), respectively. The SP and CP had different sugar compositions (d-glucose, l-rhamnose, d-galactose and l-arabinose) and weight average molecular weights, but similar FTIR profiles. The SP showed almost 1.9 and 1.6-fold higher Trolox equivalent antioxidant capacity (TEAC), and 2.7 and 2.0-fold higher water absorption capacity than CP and FP, respectively. SP at 3% (w/w) showed the second highest viscosity after CP and the highest emulsion stability. Gels of SP and CP at 1.75–3% range had similar firmness, but SP formed more fracturable gels than CP. Sun-dried fig stalk waste is a better source of pectin than defected substandard whole sun-dried figs. The SP could be utilized to develop functional food with alternative textural and rheological properties.

Pectinase hydrolysis of guava pulp: effect on the physicochemical characteristics of its juice

The objective of this research is to assess the effect of enzymatic treatment of guava puree on the physicochemical parameters of the juice. Pectinases from Aspergillus niger were applied to the puree at 43 ± 3 °C under constant stirring. Enzyme concentrations used were: 0.033 % (w/w), 0.055% (w/w), 0.078 % (w/w) and 0.1 % (w/w). For each enzyme concentration, the treatment times were varied from 3 – 90 min. Physicochemical parameters of raw puree and enzymatically treated juice were determined. These were: viscosity, pH, electric conductivity, protein and polyphenol content, galacturonic acid content, color, TSS, and antioxidant capacity. Particle distribution, homogeneity of raw puree and juice samples dried extracts were assessed using a Field Emission Scanning Electron Microscopy (FESEM). A 91% viscosity decrease was recorded for each enzyme concentration after 3 min of enzyme reaction. That drecrase was accompanied by an increase in galacturonic acid content with increasing depectinization factors. Enzyme treatment of guava puree led to a decrease in pH, protein and polyphenol contents and an increase in conductivity and color. Analysis of FESEM images of guava samples bestowed a decrease in particle size, a scattering of particles in the medium, an increase in continuous phase proportion and an improvement of sample homogeneity with increasing values of processing parameters, due to the breaking-down of bigger particles and the solubilization during depectinization.

Ferulated Pectins from Sugar Beet Bioethanol Solids: Extraction, Macromolecular Characteristics, and Enzymatic Gelling Properties

Pectin from sugar beet (Beta vulgaris L.) (SBP) was extracted from a sugar beet waste (SBW) registering a 4.4% (w/w) yield. SBP presented a weight-average molar mass of 459 kDa, galacturonic acid content of 52.2%, and a low esterification degree (30%). The macromolecular characteristics of SBP revealed a flexible and extended coil chain conformation. The main neutral sugars in SBP were galactose (20.7%), mannose (5.0%), and arabinose (3.60%) while ferulic acid (FA) content was 2.1 µg·mg−1 sample. FA remained in the SBP chain mainly in RG I region even after suffering both, industrial processing and harsh weathering conditions. Consequently, SBP formed covalent gels induced by laccase. Covalent cross-linking content (dimers and trimer of FA) was 0.97 mg·g−1 SBP. The 8-5′, 5-5′, and 8-O-4′ dimers of FA isomers proportions were 75, 17, and 8%, respectively. SBP gels at 4% (w/v ) registered storage (G′) and loss (G″) moduli final values of 44 and 0.66 Pa, respectively. SBP gels were soft and adhesive according to texture profile analysis. Scanning electron microscopy analysis of SBP lyophilized gels revealed an imperfect honeycomb-like structure with 4.5 ± 1.4 µm average cavities diameter.

Pectin from butternut squash (Cucurbita moschata) – The effect of enzyme-assisted extractions on fiber characteristics and properties

The effect of the application of enzymes in procedure for pectin extraction from butternut squash (Cucurbita moschata) on characteristics and properties of isolated fiber was studied. Combination of cellulase and xylanase with subsequent acidic extraction step enabled the highest achieved yield of pectin fiber, 81.0 ± 3.6 mg/gDW. Applied enzymes showed considerable potential to influence characteristics and properties of pectin fiber. Enzymatic and enzyme aided acidic extractions delivered pectin molecules greatly enriched in content of galacturonic acid, 72.2% and 68.1%, w/w, respectively, and with higher molecular weights of dominant polysaccharide fractions in comparison to acidic extraction. Sole enzymatic procedure enabled the extraction of pectin fiber without accompanying extraction of starch. Viscosities of solutions of pectin fibers extracted with the aid of enzymes were greatly lower than that of acid extracted fiber while their water solubility was significantly improved. Pectin fiber from enzymatic extraction exhibited the highest antioxidant capacity of 1729.81 μM TE/100 gDW and more than 16 times higher content of phenolic acids comparing to fibers from extraction protocols that included acidic step. Results revealed that isolation of pectin fiber with favorable characteristics was enabled by green protocol that involved cellulase and xylanase, and no acid.