Galacturonic Acid Content Research Articles

OPTIMISATION OF PECTIN EXTRACTION ASSISTED BY MICROWAVE FROM BANANA (Musa sapientum L.) FRUIT PEELS USING RESPONSE SURFACE METHODOLOGY

In this study, microwave-assisted extraction (MAE) was used to extract pectin from waste banana (Musa sapientum L. CV. Kluai Namwa) fruit peels. Central composite design (CCD) was used to study and optimise the effects of processing parameters’ variables (microwave irradiation, extraction time, and pH) on the pectin yield, degree of esterification (DE), and galacturonic acid content (GA) of pectins extracted from dried banana fruit peels with hydrochloric acid of 0.05 M. Extraction parameters applied in this study are microwave irradiation (300-600 watt), extraction time (5-15 min), and pH (1-3). The results showed that all the process variables had significant effect on the responses. The optimum conditions for the maximum pectin yield (13.47%), DE (92.45%), and GA (87.99%) were obtained at microwave irradiation of 580 watt, extraction time of 15.86 min, and pH of 1.71. Under the optimal conditions, close agreement between experimental and predicted values was obtained. From the results, second order polynomial model was developed and it adequately explained the data variation and significantly represented the actual relationship between independent variables and the response.

Optimization of Alkali Extraction and Properties of Polysaccharides from Ziziphus jujuba cv. Residue.

Ziziphus jujuba cv. Muzao is a plant widely cultivated in the Yellow River Basin of China. It has nutritional and healthcare functions, in which polysaccharides are the main components of its bio-functions. In order to make effective use of Ziziphus jujuba cv. Muzao residue resources and explore new functional food ingredients, the polysaccharide (ZJRP) from Ziziphus jujuba cv. Muzao residues were extracted by sodium hydroxide, and the optimal extraction conditions of ZJRP were obtained by the response surface method. The basic composition and antioxidant effects of ZJRP were determined. The results showed that ZJRP has significant antioxidant activity, mainly reflected in the high DPPH radical scavenging rate, which may be related to their high content of galacturonic acid and the extraction method. In addition, the rheological and thermal properties of ZJRP were respectively determined by a rheometer and differential scanning calorimetry (DSC), indicating that they have shear thinning properties and good thermal stability. Results showed that the alkaline extraction method can be used as a potential technique for extracting ZJRP with high antioxidant activity, and ZJRP can be further explored as a functional food ingredient.

Pectin extraction from common fig skin by different methods: The physicochemical, rheological, functional, and structural evaluations

Four extraction methods of hot-water (HWE), ultrasound-assisted (UAE), microwave-assisted (MAE), and ultrasound-microwave assisted (UMAE) were utilized to determine the best technique to extract pectin from the common fig (Ficus carica L.) skin. UMAE (11.71%) significantly showed a more extraction yield than MAE (9.26%), UAE (8.74%), and HWE (6.05%). A significant dose-dependent antioxidant capacity for pectins 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging activity was found. The UMAE-pectin with the maximum galacturonic acid content (76.85%) and molecular weight (6.91 × 103 kDa) presented the highest emulsifying activity (61.2–61.3%) and emulsion stability (94.3–95.2%) with a monomodal droplet size distribution at cold and ambient storage temperatures. A non-Newtonian shear-thinning behavior was detected at 1.5–3.0% pectic-solutions. X-ray diffraction (XRD) analysis showed a non-crystalline nature for pectins extracted by UMAE. FTIR spectroscopy and HPLC photodiode array detector revealed that conventional and novel extraction technologies do not change the chemical structure and monosaccharide composition of pectin significantly.

Optimization of Pectin Enzymatic Extraction from Malus domestica 'Fălticeni' Apple Pomace with Celluclast 1.5L.

Pectin was extracted from apple (Malus domestica ‘Fălticeni’) pomace with Celluclast 1.5L, at doses of 20, 40, and 60 µL/g of material. The temperature and time of extraction were varied on three levels—temperature—40, 50, and 60 °C; time—12, 18, and 24 h. For each experiment, the extraction yield (R2 = 0.8905), the galacturonic acid content (R2 = 0.9866), and the degree of esterification (R2 = 0.9520) of pectin was determined. Response surface methodology (RSM) was implemented via a Box–Behnken design, to optimize pectin extraction. In the optimum extraction conditions (temperature of 48.3 °C, extraction time of 18 h 14 min, and enzyme dose of 42.5 µL/g of pomace), the design predicted a 6.76% yield with a galacturonic acid content of 97.46 g/100 g of pectin and a degree of esterification of 96.02%. FT-IR analysis of the pectin sample obtained in these conditions showed a chemical structure similar to that of commercial apple and citrus pectin.

Characteristics of cell wall pectic polysaccharides affect textural properties of instant controlled pressure drop dried carrot chips derived from different tissue zone

To better understanding the role of cell wall pectic polysaccharides (CWPs) on the formation of textural properties of carrot chips dried by instant controlled pressure drop technology (French for Détente Instantanée Contrôlée, DIC), the characteristics of CWPs from ground tissue (GT), junction of ground and vascular tissue (JT), and vascular tissue (VT) of carrot were investigated. Larger expansion volume was obtained in the carrot chips derived from GT, which accompanied with superior textural qualities compared with the chips derived from JT and VT. Remarkable differences were obtained in the amount of pectic fractions, galacturonic acid content, degree of methoxylation, sugar composition and linearity of CWPs that fractionated from different tissue zones of raw carrots. The characteristics of CWPs was confirmed to be a substantial factor that significantly affected the expansion ratio and textural properties of the DIC-dried carrot chips, which providing a mechanistic insight of the relationship between variation in CWPs and the expanding behaviors of DIC-dried fruits and vegetables.

Pectin oligosaccharides from fruit of Actinidia arguta: Structure-activity relationship of prebiotic and antiglycation potentials

Pectin oligosaccharides (POSs) have prebiotic and antiglycation activities in vitro, but the specific structure-activity relationship is unclear. In this study, POSs were obtained by enzymatic and ultrasound-assisted enzymatic degradation of pectin polysaccharide (PPS), respectively. Based on the chemical characterization, the antiglycation in vitro and prebiotic activities of POSs were compared and the structure-activity relationship was studied. The results showed that the antiglycation activity of POSs in vitro was proportional to the galacturonic acid content and GalA:Rha molar ratios except for the low molecular weight POSs (LM-POSs), and inversely proportional to its branching degree, such as Ara:Rha and Gal:Rha molar ratios. In addition, it was also found that the prebiotic activity of POSs was positively correlated with Ara:Rha and Gal:Rha molar ratios in molecule composition and the neutral sugar content, especially galactose and arabinose. The degree of esterification (DE) was less important for both antiglycation and prebiotic activity of POSs. These results provided an important theoretical basis for POSs application in food.

Investigation of cell wall polysaccharides from flour made with waste peel from unripe banana (Musa sapientum) biomass.

The peel from unripe banana biomass is an agroindustrial waste. The present study aimed: (i) to extract pectin from enzymatically-treated waste peel from unripe banana biomass (WPUBB) using a Box-Behnken design to optimize the extraction conditions (temperature, pH and extraction time) and obtain a maximum yield and (ii) to fractionate the polysaccharides from WPUBB employing sequential extractions using different solvents. The optimized product was obtained at 86 °C, pH 2.00, for 6h and it presented a yield of 11.63%. The optimized product had low galacturonic acid content and a high amount of glucose (82.3%), suggesting the presence of starch (as confirmed by the bi-dimensional heteronuclear single quantum coherence NMR spectrum). All of the fractionated polysaccharides had a high glucose content. Low amounts of pectin were found in the water, chelating and diluted alkali-soluble fractions. The fractions extracted using NaOH indicated the presence of glucuronoarabinoxylans. Glucose was the main monosaccharide found in all the fractions extracted from the WPUBB. Although the present study suggests that WPUBB is still not suitable for pectin extraction using current technologies, other compounds, such as resistant starch and glucuronoarabinoxylans, were found, suggesting that WPUBB could be used in the development of food formulations. © 2019 Society of Chemical Industry.

Extraction and characterization of pectin from Premna microphylla Turcz leaves.

In this work, response surface methodology (RSM) and microwave pretreatment were used to extract pectin from Premna microphylla Turcz leaves (PMTL). The process variables were optimized by the isovariant central composite design to improve the pectin extraction yield. The optimum conditions obtained were as follows, extraction time 2 h, temperature 90 °C, pH 2 and liquid-solid (LS) ratio 50 mL/g. The extraction yield was 18.25% under these conditions, which was close to the predicted value (17.60%). Then the pectin was characterized by gas chromatographic (GC), spectrophotometric (UV-visible Spectroscopy) and spectroscopic (Fourier transform infrared) methods. The galacturonic acid content was 82.75%, and on this basis, the other monosaccharide composition analysis illustrated that pectin from PMTL was also composed of rhamnose, arabinose, mannose, glucose and galactose in a ratio of 2.96:1.17:1.04:8.07:2.05. The pectin of PMTL had an esterification degree of 62.50% and it showed good antioxidant activity. Taken together, the pectin of PMTL could be used as potential additive in food industry.

Influence of mechanical and thermal treatment on particle structure, leaching of alcohol insoluble substances and water binding properties of pectin-rich orange fibre

Mechanical and thermal processings may affect the composition and the techno-functional properties of dietary fibre as a part of a complex food system. The aim of this study was to investigate the impact of a mechanical and thermal treatment alone or in combination on alcohol insoluble substance (AIS), the content of galacturonic acid (GalA), the water retention capacity (WRC) and the microstructure by scanning electron microscopy (SEM). Two samples of orange fibre with different particle size (coarse and fine) were investigated in an experimental design and evaluated with regard to particle size (d50) after treatment and their impact on network formation. Our study highlights a more pronounced susceptibility of the coarse fibre towards mechanical stress compared to the fine fibre with regard to particle size reduction. High-pressure homogenization (HPH) represents the crucial step regarding AIS release and the increase of WRC for both fibres. A mechanical treatment with additional thermal treatment maximises AIS release. GalA, as a marker for pectin in AIS, was detected in various amounts depending on the intensity of the treatment. Highest values for WRC were achieved for the coarse fibre as a consequence of both, particle size reduction and the formation of a stable network on a microstructural level.

Efficient extraction and characterization of pectin from orange peel by a combined surfactant and microwave assisted process

Surfactant and microwave assisted extraction (S-MAE) was used for pectin extraction from orange peel. First, we optimized the conditions of microwave assisted extraction (MAE), e.g., irradiation time, liquid-to-solid ratio (LSR), and pH on pectin yield (PY), galacturonic acid (GA) content, and degree of esterification (DE) using a Box-Behnken design. Under optimal conditions (pH 1.2, 7.0 min, and 21.5 v/w LSR), we obtained a PY of 28.0 ± 0.5%, which was close to the predicted value (31.1%). Second, we analyzed the effect of surfactant on microwave extraction of pectin. Among the surfactants investigated, Tween-80 (8 g/L, w/v) increased PY by 17.0%. Compared with conventional solvent extraction, S-MAE is a novel and efficient method for pectin extraction, which generated a higher (p < 0.05) PY (32.8%), GA content (78.1%), DE (69.8%), and Mw (286.3 kDa).

Cellulase-Assisted Extraction, Characterization, and Bioactivity against Rheumatoid Arthritis of Astragalus Polysaccharides

This study investigated the effect of cellulase on the isolation of crude Astragalus polysaccharide (APS), analyzed the monosaccharide component of deproteinized APS, detected the molecular weights of purified APS, and examined the biological activities and the preliminary mechanism against rheumatoid arthritis (RA). Compared with water extraction method, cellulase-assisted extraction increased the yield of crude APS to 154% and polysaccharide contents to 121%. Crude APS was then purified by ethanol precipitation, Sevag deproteinization, and high-performance liquid chromatography (HPLC) analysis; monosaccharide contents of APS were different after cellulase-assisted method, especially galacturonic acid content which significantly increased. DEAE-52 cellulose column chromatography isolated three polysaccharide fractions, including a neutral polysaccharide (APS-water) and two acidic polysaccharides (APS-NaCl1 and APS-NaCl2). Using high-performance gel permeation chromatography (HPGPC), the molecular weights of APS-water, APS-NaCl1, and APS-NaCl2 were identified as 67.7 kDa, 234.1 kDa, and 189.4 kDa, respectively. Then their therapeutic effects and possible mechanism against RA were explored using type II collagen-induced arthritis (CIA) rat model. APS could significantly reduce paw swelling, serum concentration of IL-1β and TNF-α, and the expression levels of NF-κB-p65 and IκBα in synovial membranes in CIA rats. Our study indicated that cellulase significantly increases the yield and polysaccharide contents of crude APS, improves the product quality, and preserves the biological features against RA in CIA rats.

Juice related water-soluble pectin characteristics and bioaccessibility of bioactive compounds in oil and emulsion incorporated mixed juice processed by high pressure homogenization

Aim of this study was to investigate the juice related water-soluble pectin (WSP) characteristics, total carotenoid bioaccessibility (TCB) and total polyphenolic bioaccessibility (TPB) in oil and emulsion incorporated high pressure homogenized mixed juices. Five mixed juices were prepared with carrot puree, clear apple juice and peach juice at ratios of 50:30:20, 40:40:20, 30:50:20, 40:30:30 and 30:40:30, and subjected to homogenization at 140 MPa and 25 °C for 1 pass. Galacturonic acid (GalA) content, degree of methylesterification (DM), neutral sugars and molecular weight (Mw) were analyzed. Bioaccessibility of carotenoids and polyphenolics was evaluated by using either corn oil or corn oil emulsion. As the results indicated, distinct particle and WSP characteristics were observed among different juice ratios of homogenized mixed juices. Small intestinal digesta showed varied particle and rheological properties. Besides, TCB was significantly higher when added with oil or emulsion than no oil added. Nevertheless, the ratio at 30:40:30 of carrot, apple and peach exhibited the highest TCB, WSP content and DM value, while the ratio at 30:50:20 showed the highest TPB. Results highlighted the potential of manipulating juice ratio to enhance TCB and TPB. Moreover, bioaccessibility of bioactive compounds exhibited significant correlations with particle properties and WSP characteristics respectively. TCB showed upward polynomial correlations with volume-mean and area-mean diameters of digesta respectively, while exhibited downward polynomial correlations with WSP content and DM, respectively. Meanwhile, TPB showed upward polynomial correlations with WSP content and DM, respectively.

Utilization of by-products of Hibiscus sabdariffa L. as alternative sources for the extraction of high-quality pectin.

The by-products of Hibiscus sabdariffa L. (HsL), obtained after soaking or decoction of the calyces of Colima and Sudan cultivars, were used for pectin extraction. After soaking, the wastes of both cultivars gave higher yields of pectin than those obtained by decoction. The pectin of the wastes by soaking presented high methoxyl groups, galacturonic acid content, viscosity and gelling capacity. Pectin of this treatment also exhibited bands in the regions of 1750cm-1 and 1630cm-1 that represents the C=O stretching vibrations of methyl ester and the amounts and degree of esterification of the HsL pectin. Interestingly, the pectin retained the typical red color of fresh HsL calyces. The amounts of anthocyanins and ascorbic acid of pectin did not show effects against pathogenic microorganisms. Nonetheless, pectin of the Sudan HsL wastes obtained by soaking, exhibited higher properties than those of the citric pectin, thus, demonstrating its potential for industrial applications.

Extraction Optimization, Physicochemical Characteristics, and Antioxidant Activities of Polysaccharides from Kiwifruit (Actinidia chinensis Planch.).

In order to evaluate effects of extraction techniques on the physicochemical characteristics and antioxidant activities of kiwifruit polysaccharides (KPS), and further explore KPS as functional food ingredients, both microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) were optimized for the extraction of KPS. Furthermore, the physicochemical structures and antioxidant activities of KPS extracted by different techniques were investigated. The optimal extraction conditions of UAE and MAE for the extraction of KPS were obtained by response surface methodology. Different extraction techniques significantly affected the contents of uronic acids, molecular weights, molar ratios of constituent monosaccharides, and the degree of esterification of KPS. Results showed that KPS exhibited remarkable DPPH and ABTS radical scavenging activities, and reducing power. The high antioxidant activities observed in KPS extracted by the MAE method (KPS-M) might be partially attributed to its low molecular weight and high content of unmethylated galacturonic acid. Results suggested that the MAE method could be a good potential technique for the extraction of KPS with high antioxidant activity, and KPS could be further explored as functional food ingredients.

Structural and Rheological Properties of Pectins Extracted from Industrial Sugar Beet By-Products.

In this work, the efficient extraction of pectin from sugar beet by-products (pressed, ensiled and dried pulp), by using an acid method or a commercial cellulose, is accomplished. The extraction method had an impact on the pectin monomeric composition, mainly in xylose, arabinose, and galacturonic acid content, as determined by GC-FID. FTIR and SEC analyses allowed the determination of similar degrees of methoxylation and molecular weights, respectively, in the extracted pectins. The acid extraction of pectin in the ensiled by-product led to the highest yield (19%) with a galacturonic acid content of 46%, whereas the application of the enzymatic extraction method resulted in a lower yield (13%) but higher galacturonic acid content (72%). Moreover, the stability in aqueous solution as well as the emulsifying activity index was higher for pectin extracted by the acid method, whereas the viscosity was higher in pectin extracted by the enzymatic method. To the best of our knowledge, this is the first study analyzing the physicochemical properties and exploring the potential reuse of ensiled and dried by-products from sugar beet industry for the extraction of pectin to be further used in the food and pharmaceutical areas.

Advances in Studies Using Vegetable Wastes to Obtain Pectic Substances: A Review

Vegetable waste represents a serious environmental problem for industries; however, it is also a valuable source of pectic substances. This paper aims to highlight the advances that have been made through studies regarding pectic substances from vegetable wastes, as well as providing an overview of the chemical structure of pectin, extraction and characterisation techniques, and potential applications for pectin in relation to the areas of food and health. Pectin is mainly composed of galacturonic acid and it is one of the most complex polysaccharides in nature. A wide range of vegetable wastes contain a high pectin yield that can be industrially utilised. However, factors such as the type of raw material, the maturation stage of that raw material, and the extraction techniques that are used, affect the structural and functional properties of the pectin, as well as influencing its potential application. This study outlines the different environmentally-friendly techniques that are used to extract pectin, such as microwave, ultrasound, enzymatic and other methods, highlighting their advantages and disadvantages compared with the conventional extraction method. Some techniques are advantageous for industrial use; however, it is necessary to optimise the extraction conditions and to make a financial investment in order to obtain a high yield of pectin in a short amount of time. Characteristics such as galacturonic acid content, the degree of methyl esterification, the degree of acetylation, molar mass and the chemical structure are essential parameters required to define possible applications of pectic substances. In vitro and in vivo studies regarding the properties of pectic substances have shown that these substances can be beneficial to health, with antimicrobial, antitumoral, anti-inflammatory and analgesic effects. Nevertheless, further studies are required to examine the mechanisms of action for these effects to be applied in humans. Consequently, greater understanding about the chemical structure of pectin and its extraction techniques are crucial for the development of new foods and drug formulations.

Pectin oligosaccharides from hawthorn (Crataegus pinnatifida Bunge. Var. major) inhibit the formation of advanced glycation end products in infant formula milk powder.

Pectin oligosaccharides (POSs) can not only be used as prebiotics to promote the growth of beneficial bacteria in the intestine but also can be used as natural food-borne antiglycation agents to inhibit the formation of advanced glycation end products (AGEs) in vitro, which is related to their structure, including molecular weight and galacturonic acid content. In this study, haw polysaccharides (HPSs) were isolated and purified, and POSs with high antiglycation activity in vitro were prepared. On this basis, the inhibitory effect of POSs on the formation of AGEs in infant formula milk powder was investigated. The results showed that no obvious inhibitory effect of POSs was found on the formation of AGEs in infant formula milk powder under accelerated storage at 25 °C and 45 °C. But, POSs showed a strong inhibitory effect on the formation of furosine, Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL) and the total AGEs in infant formula milk powder under accelerated storage at 65 °C. In addition, POSs also had a strong inhibitory effect on the formation of lipid oxidation products but did not affect the formation of protein degradation products. Simultaneously, the cytotoxicity experiments using human umbilical vein endothelial cells showed that the infant formula milk powder supplemented with POSs had the lowest cytotoxicity compared to the blank control (BC) and GOS/FOS supplementation milk powder under accelerated storage at 65 °C, which may be related to the inhibitory effect of POSs on the formation of AGEs in infant formula milk powder. Furthermore, the in vitro fermentation experiments showed that the antiglycation process did not affect the prebiotic activity of POSs in infant formula milk powder.

Citrus pectin obtained by ultrasound-assisted extraction: Physicochemical, structural, rheological and functional properties

ABSTRACTTangerine (Citrus reticulata. CRP) and grapefruit (Citrus paradisi. CPP) pectins obtained by ultrasound-assisted extraction (UAE) and conventional extraction (CE) using citric acid were characterized to establish their potential uses as an alternative source of commercial pectin. The pectins obtained by UAE and CE presented a pseudoplastic fluid characteristic with shear thinning behavior, a high esterification degree (CRP 82.30–71.81% and CPP 84.25–72.15%) and were of commercial quality based on galacturonic acid content (CRP 76.03% and CPP 76.03–71.01%). CPP presented greater viscosimetric molecular weight than CRP. Meanwhile, CRP presented greater polyphenol and protein content with respect CPP. The functional properties were influenced by citrus source and extraction method. UAE favored greater yields in a shorter time (CPP: 26.05%, 30 min; CRP: 13.46%, 15 min) compared to CE. UAE combined with the use of citric acid offers an effective alternative for obtaining high-quality pectins with lower polluting effluent, time and energy requirements.

Extraction of Pectin from Ripe Plantain Peel, Fabrication and Characterization of Composite (Pectin/PVA/Glycerol) Films Produced from the Extracted Pectin

High methoxyl pectin (DE = 59.53%) was extracted from plantain peel using acid extraction method. Pectin yield was 40.5%; moisture content was 87.56%; equivalent weight was 1000 g/ml, and galacturonic acid content was 2.89 mg/ml. Composite polymer films incorporating the extracted pectin manifest their best mechanical properties; tensile strength and % elongation of 5.51 MPa and 5.75% respectively with 10 ml glycerol/1g pectin. Raman spectra peaks at 2930 cm1, 1750 cm–1 and 820 cm–1 indicated CH-stretch, C=O ester group of pectin and COH ring in pectin respectively. Films containing pectin sourced from waste are considered potential alternative sources of environmentally benign packaging materials.

Effect of long term cold storage and microwave extraction time on the physical and chemical properties of citrus pectin

Pectin, acid-extracted by microwave heating under pressure from orange and lime albedo, was cold (−20 °C) stored for 14 years and the physical and chemical properties were compared to the properties of the original microwave-extracted pectin prior to cold storage. The pectin physical and chemical properties were measured by using multi-detector high performance size exclusion chromatography (HPSEC), atomic force microscopy (AFM), amino acid, monosaccharide and degree of esterification compositional analysis following cold storage. The weight average molar mass (Mw), intrinsic viscosity (ηw) and radius of gyration (Rgz) changed following cold storage depending on the time of microwave extraction, but all three parameters decreased with extraction time for both orange and lime pectin, regardless of whether they were analyzed before or after cold storage. All pectin samples had little or no appreciable difference in galacturonic acid content following cold storage, yet the degree of esterification decreased by approximately 50% and total sugar content increased following cold storage for both orange and lime pectin. Homogalacturonan (HG) was the major cold-stored pectin component with lower amounts of rhamnogalacturonan I (RG I) containing arabinogalactan side chains present in pectins extracted for shorter times. Amino acid analysis indicated that protein associated with pectin was enriched in aspartic acid/asparagine, glutamic acid/asparagine, leucine and lysine with UV absorbing phenylalanine and tyrosine also present in cold-stored pectin. UV detection in HPSEC chromatograms for both orange and lime pectins following cold storage, revealed that more protein was associated with higher molar mass pectin at 2.5 min of extraction time. By 10 min of extraction time, there was a larger breakdown of high molar mass pectin and protein shifted to a lower molar mass distribution weight fraction. AFM images showed that small spherical molecules, segmented rods and kinked rods were present in both orange and lime pectin following cold storage.