Characterisation of pectins extracted from banana peels (Musa AAA) under different conditions using an experimental design

An experimental design was used to study the influence of pH (1.5 and 2.0), temperature (80 and 90 °C) and time (1 and 4 h) on extraction of pectin from banana peels (Musa AAA). Yield of extracted pectins, their composition (neutral sugars, galacturonic acid, and degree of esterification) and some macromolecular characteristics (average molecular weight, intrinsic viscosity) were determined. It was found that extraction pH was the most important parameter influencing yield and pectin chemical composition. Lower pH values negatively affected the galacturonic acid content of pectin, but increased the pectin yield. The values of degree of methylation decreased significantly with increasing temperature and time of extraction. The average molecular weight ranged widely from 87 to 248 kDa and was mainly influenced by pH and extraction time.     

Effect of variety and harvest date on pectin extracted from chicory roots (Cichorium intybus L.)

The influence of harvest date on pectin quality and yield of five varieties of chicory is investigated in this work. The pectin is extracted from the raw material with an acidic treatment at 85 °C for an hour after inulin extraction. Main changes due to harvest date are observed in terms of neutral sugar content, average molecular weight, esterification degree and extraction yield. The galacturonic acid content remains relatively constant throughout the harvest period. While no statistically significant differences (p < 0.05) in terms of galacturonic acid content and neutral sugar content are observed between the five cultivars studied, average molecular weight, esterification degree and extraction yield are significantly affected by the cultivar type. Depending on the harvest date, a broad range of pectins can easily be extracted from chicory pulps.     

Isolation and Characterization of Pectin in Sugar-Beet Pulp

Pectin was extracted from sugar-beet pulp by various solvent fractionation procedures. An optimal HCI-extraction method yielded 19.53% pectin from the raw material. The HCl-isolated pectin contained 81.8% galacturonic acid. The sugar-beet pulp pectin obtained from different extraction procedures had a high methoxy content ( 60% degree of methylation). The pectin also contained 10 to 17.5% neutral sugars which were mainly arabinose and galactose as analyzed by gas chromatography. The peak molecular weights (relative to dextrans) of the pectins as determined by gel permeation ranged from 35,500 to 44,700 daltons. The pectin possessed high water-holding capacity and low viscosity.     

干燥方法对柠檬果胶理化性质影响

为探究不同干燥方法对柠檬果胶理化性质的影响,实验以柠檬干渣为原料制备果胶,固定提取和浓缩条件,采用热风干燥、真空干燥、冷冻干燥及喷雾干燥等干燥方法对柠檬果胶进行干燥处理,研究不同干燥方法对柠檬果胶得率、半乳糖醛酸、酯化度、能耗、复水比、凝胶强度及果胶结构的影响,采用变异系数法对各指标加权评分,确定柠檬果胶最佳干燥方法。结果表明:所有干燥后的果胶半乳糖醛酸含量均达到国标65%的要求;酯化度均大于50%,傅立叶红外光谱(Fourier Transform Infrared Spectrometry,FTIR)显示,不同干燥方法干燥后的果胶均具有果胶的特征官能团,说明所用干燥方法不会对果胶结构产生影响。不同干燥方法干燥后的果胶各指标均存在显著性差异(P<0.05),加权综合评分最高的方法是:60℃真空干燥,所得柠檬果胶得率、半乳糖醛酸、酯化度、单位能耗、复水比、凝胶强度分别为17.84%、82.44%、73.16%、28.13 kJ/g、5.36%、149.71 g。真空干燥所需设备简单,且能耗相对较低、产品品质好,对柠檬果胶制备研究具有重要意义。     

炮制法对三叶木通果皮果胶提取及理化性质的影响

为提高三叶木通果皮果胶提取率和质量,探究不同炮制方法对三叶木通果皮果胶提取及其理化性质的影响.以未处理的三叶木通果皮生粉和炒制、砂制、醋制、酒制方法处理的果皮粉为原料,酸法提取得到果胶并进行结构表征,测定其果胶提取率、半乳糖醛酸质量分数、酯化度、乳化活性、乳化稳定性及抗氧化性.结果表明:醋制果胶提取率、半乳糖醛酸质量分...     

Short communication: Stabilization of milk proteins at pH 5.5 using pectic polysaccharides derived from potato tubers

Potato pectin has unique molecular characteristics that differentiate it from commercially available pectins sourced from citrus peels or apple pomace, including a higher degree of branching and a higher acetyl content. The objective of this study was to evaluate the ability of potato pectin to stabilize milk proteins at an acidic pH above their isoelectric point, pH 5.5, at which no citrus- or apple-derived pectins are functional. Potato pectin was extracted from raw potato tubers by heating at pH 4.5 and 120°C for 30 min after removing starch solubilized using a dilute HCl solution adjusted to pH 2. The potato pectin was found to have a galacturonic acid content of 17.31 ± 3.29% (wt/wt) and a degree of acetylation of 20.20 ± 0.12%. A portion of the potato pectin was deacetylated by heating it in an alkaline condition. The deacetylation resulted in a galacturonic acid content of 19.12 ± 4.64% (wt/wt) and a degree of acetylation of 3.03 ± 0.03%. Particle size distributions in acidified milk drink (AMD) samples adjusted to pH 5.5 demonstrated that the acetylated and deacetylated potato pectins were capable of inhibiting the aggregation of milk proteins to the largest degree at a pectin concentration of 1.0 and 0.25% (wt/wt), respectively. Pectin molecules that were not bound to milk proteins in these AMD samples were quantified after centrifugally separating milk proteins and pectin bound to them from the serum. We found that, for the acetylated and deacetylated potato pectins, all or approximately half of the pectin molecules were bound to milk proteins at a pectin concentration of 0.25 or 1.0% (wt/wt), respectively. These results suggest that the presence of acetyl groups is a critical factor that determines how potato pectin molecules bind electrostatically to milk protein surfaces, form 3-dimensional structures there, and function as a stabilizer. The present results demonstrate that potato pectin can stabilize milk proteins at pH 5.5 and potentially enable the development of novel AMD products with improved functionality for casein-containing products with moderately acidic pH profiles.     

Effect of extraction conditions on the yield and chemical properties of pectin from cocoa husks

Different extraction conditions were applied to investigate the effect of temperature, extraction time and substrate–extractant ratio on pectin extraction from cocoa husks. Pectin was extracted from cocoa husks using water, citric acid at pH 2.5 or 4.0, or hydrochloric acid at pH 2.5 or 4.0. Temperature, extraction time and substrate–extractant ratio affected the yields, uronic acid contents, degrees of methylation (DM) and degrees of acetylation (DA) of the extracted pectins using the five extractants differently. The yields and uronic acid contents of the extracted pectins ranged from 3.38–7.62% to 31.19–65.20%, respectively. The DM and DA of the extracted pectins ranged from 7.17–57.86% to 1.01–3.48%, respectively. The highest yield of pectin (7.62%) was obtained using citric acid at pH 2.5 [1:25 (w/v)] at 95 °C for 3.0 h. The highest uronic acid content (65.20%) in the pectin was obtained using water [1:25 (w/v)] at 95 °C for 3.0 h.     

Effect of extraction conditions on the yield and purity of apple pomace pectin precipitated but not washed by alcohol

ABSTRACT:  A study of the influence of extraction conditions (pH: 1.5 to 2; temperature: 80 to 90 °C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of impurities by alcohol washing was carried out. The alcohol precipitate yields varied from 2.9% to 8.9% depending on the pH. At pH 1.5, these yields were higher than those obtained at pH 2 contrary to the galacturonic acid purity (%w/w). Compounds other than pectins were solubilized from the cell walls of apple pomace at pH 1.5, and they were precipitated with alcohol. The apple pectins obtained from the different extraction procedures were highly methylated (54.5% to 79.5%), especially when the conditions (temperature, pH) were drastic. Similar conclusions can be drawn for the neutral sugar content that decreased at pH 1.5 (arabinose, xylose, and galactose) or at the highest temperatures and extraction times (arabinose and galactose). The phenomenon of demethylation and pectin degradation of neutral sugars chains can be observed at acid pH, and for long extraction times. The presence of high quantities of mannose or fructose, glucose, and xylose in the alcohol precipitate showed that pectin precipitation with ethanol was not specific.     

Effect of extraction conditions on the yield, purity and surface properties of sugar beet pulp pectin extracts

The extraction of pectins from sugar beet pulp was carried out in an aqueous acid medium under different conditions using a full two-state experimental design for three extraction parameters (pH, temperature and time). The yields of the extracted pectins ranged from 4.1% to 16.2%. Their contents in pectin constituents were 35.2–76.3% galacturonic acid, 6.8–32.9% neutral sugars, 2.0–4.2% methoxy groups, 0.8–3.8% acetyl groups, and 0.1–0.7% ferulic acid. Moreover, protein residues were present in all the extracts within the range of 0.9–6.8% and varied with the extraction conditions. On high performance size exclusion chromatography, the elution pattern of the acid-extracted pectins showed a wide molar mass distribution consisted of two relatively broad peaks. Their weight-average molar mass values determined by HPSEC-RALLS ranged widely from 20,200 to 90,100 g/mol. Most of the extracted pectins were surface-active, and some of them were quite able to produce and stabilize with effectiveness oil-in-water emulsions. Thus, it was inferred that yield, physico-chemical characteristics and surface properties of acid extracted pectins from sugar beet pulp were influenced by the extraction conditions.     

Structural Characteristics of Pumpkin Pectin Extracted by Microwave Heating

Abstract: To improve extraction yield of pumpkin pectin, microwave heating was adopted in this study. Using hot acid extraction, pumpkin pectin yield decreased from 5.7% to 1.0% as pH increased from pH 1.0 to 2.0. At pH 2.5, no pectin was recovered from pumpkin flesh powder. After a pretreatment at pH 1.0 and 25 °C for 1 h, pumpkin powder was microwave‐extracted at 120 °C for 3 min resulting in 10.5% of pectin yield. However, premicrowave treatment at 60 °C for 20 min did not improve extraction yield. When microwave heating at 80 °C for 10 min was applied after premicrowave treatment, final pectin yield increased to 11.3%. When pH was adjusted to 2.0, the yield dropped to 7.7% under the same extraction conditions. Molecular shape and properties as well as chemical composition of pumpkin pectin were significantly affected depending on extraction methods. Galacturonic acid content (51% to 58%) of pumpkin pectin was lower than that detected in commercial acid‐extracted citrus pectin, while higher content of neutral sugars and acetyl esters existed in pumpkin pectin structure. Molecular weight (M_w) and intrinsic viscosity (η_w) determined for microwave‐extracted pumpkin pectins were substantially lower than acid‐extracted pectin, whereas polydispersity was greater. However, microwave‐extracted pectin at pH 2.0 had more than 5 times greater M_w than did the pectin extracted at pH 1.0. The η_w of microwave‐extracted pectin produced at pH 2.0 was almost twice that of other microwave‐extracted pectins, which were comparable to that of acid‐extracted pectin. These results indicate that extraction yield of pumpkin pectin would be improved by microwave extraction and different pectin structure and properties can be obtained compared to acid extraction. Practical Application: Pumpkin is a promising alternative source for pectin material. Pumpkin pectin has a unique chemical structure and physical properties, presumably providing different functional properties compared to conventional commercial pectin sources. Depending on the conditions to produce pumpkin pectin, diverse molecular structures can be obtained and utilized in various food applications.     

酸法提取苹果渣中的果胶及其性质分析

采用酸法提取苹果渣中的果胶,并以单因素试验为基础,通过响应面法优化其提取工艺条件。结果表明,酸法提取苹果渣果胶的最佳工艺条件为：盐酸调节pH值1.5,温度100 ℃,时间2 h,固液比1∶14（g∶mL）。在上述最佳条件下,苹果渣中粗果胶得率为33.12%,果胶提取率为19.65%。4个因素对粗果胶得率的影响顺序为：pH值＞温度＞时间＞固液比。酸法提取果胶的分子质量主要分布在165.92 kDa、5.83 kDa与0.45 kDa范围;酯化度为60.90%,属于高酯果胶;半乳糖醛酸含量为70.48%,所提取的果胶纯度相对较高。     

Physicochemical properties and partial structural features of haw pectin

Haw pectin obtained by cold-water extraction displayed higher viscosity than that of commercially available lemon pectin. After hydrolysis using purified polygalacturonase, haw and lemon pectins yielded polygalacturonase-resistant fractions (CP1-1 and LP1-1, respectively) in the high-molecular-weight region. Anion-exchange chromatography of the resistant fractions yielded additional three fractions (Hf1, Hf2, Hf3) for CP1-1 and 2 fractions (Lf1, Lf3) for LP1-1. The acidic fractions Hf3 and Lf3 were similar in structure; however, the sugar content of the neutral fractions Hf1 and Lf1 differed. The structural differences in the fractions Hf1 and Lf1, and the presence or absence of the acidic fraction Hf2 in the pectin molecule might be associated with the difference in viscosity between haw and lemon pectins. Structural analysis revealed that fraction Hf2 was a polysaccharide in which approximately one-third of the main chain was composed of α-1,4-linked GalA, and no α-1,4-linked GalA was present in the remaining two-thirds pectolyase-resistant region. Furthermore, the constituent sugars Gal and Man existed quantitatively in the pectolyase sensitive region of Hf2.     

Functionality and yield of pectin extracted from Palmyra palm (Borassus aethiopum Mart) fruit

Large numbers of fruits from Palmyra palm (Borassus aethiopum Mart), a common, native tree of tropical regions, are underutilized and left to spoil. This work was conducted to assess pectin content of Palmyra palm fruit, and to develop a reliable protocol for pectin extraction. Yield and galacturonic acid content of Palmyra palm fruit soluble solids were investigated at various pH (natural pH of 5.2–5.5, 2.5, 7), time (30–120 min) and temperature (70 °C, 80 °C, 90 °C). Yield and galacturonic acid content of extracted soluble solids were strongly dependent (p < 0.0001) on temperature, time and pH of extraction and ranged from 47 to 149 g kg⁻¹ and 682 to 880 g kg⁻¹ dry weight, respectively. High galacturonic acid (808–852 g kg⁻¹) were obtained at 70 °C and 90 °C under natural pH; at 70 °C pH 7 and pH 2.5 at all temperatures studied. Analysis of pectin extracted at natural pH (30 min, 90 °C) revealed highly esterified pectin with good gelling and emulsifying properties. Production of galacturonic acid of more than 650 g kg⁻¹ dry weight indicates that Palmyra palm fruit could serve as an excellent raw material for industrial pectin production.     

Extraction of pectin from passion fruit peel using moderate electric field and conventional heating extraction methods

Yellow passion fruit peel contains a high level of pectin that can be extracted from cell walls of plants. Direct boiling is a conventional method of extraction, which takes around 2 h to obtain a good yield of pectin. The long period of heating can produce degradation in the pectin, when the conventional heating is used to extract the pectin a lot of time and energy is spent. The purpose of this study was to explore the conventional and the moderate electric field extractions of pectin from passion fruit peel. The comparison of galacturonic acid content and esterification degree of the pectin obtained by different extraction methods indicated that similar values were obtained. Furthermore, moderate electric field is an efficient, timesaving, and eco-friendly method for the extraction of pectin from passion fruit peel, especially for pectin with a high esterification degree and galacturonic acid content higher than 65%.Industrial relevanceThis information is important for food industry since direct boiling, that is a conventional method of extraction, takes around 2 h to obtain a good yield of pectin and uses strong acid solutions. Also, today, this information which shows much interest in the food industry.     

Rheological and high gelling properties of mango (Mangifera indica) and ambarella (Spondias cytherea) peel pectins

Ambarella and mango peels are good sources of pectins (15–20%), with high degree of methylation (60–78%) and high molar masses. Ambarella and mango ( Améliorée and Mango varieties) peel pectins were extracted using HCl or oxalic acid/ammonium oxalate (OAAO). Purified pectins were analysed for their flow behaviour and phase diagrams were established at pH 3 as sucrose vs. pectin concentration. The gelation kinetics and mechanical spectra of these pectin gels were studied and compared to those of commercial citrus (lime) pectins. At a concentration of 1% (w/v), all pectic solutions had a shear thinning behaviour but at 0.6% (w/v), only OAAO-extracted pectins exhibited such behaviour. Phase diagrams showed that at pH 3, gelation of OAAO mango extracted pectins was possible at low polymer concentration (0.2%; w/w) for a sucrose concentration of 60% (w/w). OAAO-extracted pectins exhibited a higher gelling ability than HCl-extracted ones. Sucrose (45–50%) and pectin (0.2–0.6%) concentration had a deep impact on the gel strength. Our results enable to conclude that the OAAO extraction from mango and ambarella peels allowed the recovery of pectins that exhibit high gelling properties.     

Extraction and characterization of pectins from cocoa husks: A preliminary study

Cocoa husks, a by-product of cocoa processing, were investigated as a source of pectins. Preliminary results of pectin recovery and characterization are shown; they constitute the first part of a study for the optimization of pectin extraction from this by-product. Husks of two different origins (Ghana and Venezuela) were used whole or minced and pectins were extracted under various conditions (pH 7.0, 4.0, 2.5, 1.5 and 1.0; extraction periods 1–3 h): the highest yield is obtained with minced husks after 1 h of extraction at pH 2.5. A preliminary characterization of pectins, in terms of methyl and acetyl ester contents, was also carried out in order to investigate the influence of different extraction conditions on the chemical composition of the extracts.     

Optimisation of acid extraction of pectin from sweet potato residues by response surface methodology and its antiproliferation effect on cancer cells

The response surface methodology was employed to study the acid extraction of pectin from sweet potato residues. The effects of extraction temperature, extraction time, solution pH and liquid/solid ratio on yield and galacturonic acid content of pectin were investigated. Experimental data were fitted to quadratic polynomial models and analysed using appropriate statistical methods. The determined optimum conditions were extraction temperature 93 °C, extraction time 2.2 h, solution pH 1.7 and liquid/solid ratio (v/w) 30:1. Under these conditions, the experimental extraction yield and galacturonic acid content of pectin were 5.09% and 70.03% (w/w), which were in good agreement with predicted values, 5.08% and 69.40%, respectively. In addition, sweet potato pectin exhibited remarkable antiproliferation effects on human colon cancer cells HT‐29 and human breast cancer cells Bcap‐37 by 46.64% and 42.64% at 1.00 mg mL^?1 separately, indicating that it could potentially be used as a natural supplement in functional foods.     

响应面法优化籽瓜皮中高纯度果胶的提取工艺

利用响应面法优化籽瓜皮中高纯度果胶的提取工艺条件,以半乳糖醛酸的含量为果胶纯度的评价指标,采用咔唑-硫酸比色法测定果胶中半乳糖醛酸含量。在单因素试验的基础上,选择提取温度、提取时间和提取液pH值等因素进行响应面试验设计。结果表明,果胶提取最佳工艺条件为提取时间150 min、提取温度88 ℃、提取液pH值为1.6、料液比为23∶1(g∶L)。优化工艺所提取果胶中半乳糖醛酸含量理论值为78.03%,实测值为76.65%,实际测定值与理论计算值基本吻合。     

Extraction and characterization of pectin from cacao pod husks (Theobroma cacao L.) with citric acid

Variables that influence the citric-acid extraction of pectins from cacao pod husk were examined. A screening study tested the main parameters influencing pectin yield and uronic acid content by a factorial fractional 3^3?1 design. Further, response surface methodology was applied using a central composite design to examine the effect of a greater region of variable values on pectin yield and uronic acid content. The yield was optimized by increasing the temperature and time. None of the variables had a significant effect on the uronic acid content, and there was lack of fit of the model to the uronic acid content. From the fitted model, extraction conditions with aqueous citric acid at pH 3.0 for 95 min at 95 °C provided a predicted yield of approximately 9.0 g/100 g dry cacao pod husks. The obtained experimental value for the yield was 10.1 ± 0.3 g/100 g dry cacao pod husks, with the pectins containing 65.1 ± 0.8 g uronic acid/100 g fraction, DE 40.3% and DA 15.9%. At 5 g/100 g aqueous solution, the fraction behaved as a concentrated solution and presented a non-Newtonian shear-thinning behavior, well described by Cross Model. Additionally, the fraction formed gels at acidic pH and high sucrose content.     

Characterization of pectin extracted from banana peels of different varieties

Pectins were extracted from banana peels of five different varieties using citric acid solution. The chemical characteristics of banana peel pectins were investigated and compared with citrus peel and apple pomace pectins which were extracted under the same extraction conditions to assess the potential of banana peels as an alternative source of commercial pectin. The yield of banana peel pectins ranged from 15.89 to 24.08%. The extracted banana peel pectins were categorized as high methoxyl pectin with the degree of esterification between 63.15 and 72.03% comparable to those of conventional pectin sources from citrus peel (62.83%) and apple pomace (58.44%). The anhydrouronic acid (AUA) content of banana peel pectins varied from 34.56 to 66.67%. Among various banana varieties being studied, pectin from Kluai Nam Wa variety had the highest AUA content (66.67%) which met the criteria for food additive pectin indicating its commercial significance as an alternative pectin source.