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.     

Sustainable production of pectin from lime peel by high hydrostatic pressure treatment

The application of high hydrostatic pressure technology for enzymatic extraction of pectin was evaluated. Cellulase and xylanase under five different combinations (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel. Extraction yield, galacturonic acid (GalA) content, average molecular weight (M_w,ave), intrinsic viscosity [η]_w, and degree of esterification (DE) were compared to those parameters obtained for pectins extracted using acid and aqueous processes. Pressure level, type and concentration of enzyme significantly (p < 0.05) influenced yield and DE of pectin. Enzyme and high pressure extraction resulted in yields which were significantly (p < 0.05) higher than those using acid and aqueous extraction. Although pressure-induced enzymatic treatment improves pectin yield, it does not have any significant effect on M_w,ave and [η]_w of pectin extracts indicating the potential of high pressure treatment for enzymatic pectin production as a novel and sustainable process.     

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。     

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.     

Effect of extraction conditions on the quality characteristics of pectin from passion fruit peel (Passiflora edulis f. flavicarpa L.)

Passion fruit (Passiflora edulis f. flavicarpa L.) yellow variety is composed of 50-55 g peel per 100 g of fresh fruit which is discarded as waste during processing. Utilization of passion fruit peel for pectin extraction was studied. Passion fruit peel obtained after juice extraction was blanched in boiling water for 5 min, dehydrated in a cross flow hot air drier at 60 ± 1 °C to a moisture content of 4 g/100 g of dried peel. The dehydrated passion fruit peel was used for extraction experiments of pectin. The effect of pH, peel to extractant ratio, and number of extractions, extraction time and temperature on the yield and quality characteristics of pectin were investigated. The optimized conditions for extraction of pectin from passion fruit peel yielded 14.8 g/100 g of dried peel. Pectin extracted from the dried peels had a methoxyl content of 9.6 g/100 g, galacturonic acid content of 88.2 g/100 g and jelly grade of 200. Extraction of pectin from dried peels of passion fruit may be considered for effective utilization of passion fruit processing waste.     

酸提工艺对果胶品质的影响

选用福建特产琯溪蜜柚果皮为原料,考察酸提工艺条件对果胶的酯化度、黏均分子质量和半乳糖醛酸含量的影响,设计正交试验L9(34)考察各因素的影响。结果表明:在试验范围内,酸提工艺条件对果胶的酯化度基本无影响,对半乳糖醛酸的含量有明显的影响,对果胶的分子质量影响最显著。9个不同试验条件下,酸提果胶的酯化度63.5%～63.8%,半乳糖醛酸含量74.2%～88.5%,果胶的黏均分子质量101～202ku。     

Preparation of environment‐friendly pectin from sugar beet pulp and assessment of its emulsifying capacity

This study was designed to prepare environment‐friendly pectin from sugar beet pulp (SBP) using subcritical water combined with ultrasonic treatment. Plackett–Burman design based on nineteen different parameters was applied to study the influence of various factors on the characteristics of sugar beet pulp pectin (SBPP). About 29.1% pectin, 62% degree of methylation (DM) and 36% acetylation (DA), and 42.5‐kDa average molecular weight (AMW) were obtained from SBP when using distilled water with solid/liquid ratio of 1:81 for extraction at 110 °C. The yield of SBPP and galacturonic acid (GalA) was mainly affected by solid/liquid (S/L) ratio, water purity and extraction temperature. The ultrasonic temperature, ultrasonic power and extraction temperature were the main factors effecting on neutral sugar content, DM, DA and AMW. Compared with gum arabic (GA), the highest yield SBPP fraction had better emulsifying activity, but poorer emulsion‐stabilizing ability.     

Pectin from low quality ‘Golden Delicious’ apples: Composition and gelling capability

Pectin was acid-extracted from low quality ‘Golden Delicious’ apple fruit, yielding 16% (w pectin/w apple fruit). Composition and some of its physicochemical and functional properties were assessed. The pectin fraction presented a galacturonic acid content of 65% (w/w), an esterification degree of 57%, an intrinsic viscosity, [η], of 307 ml/g and a molecular weight (Mw) of 112 kDa. Pectin gels were obtained in 60% (w/v) fructose and pH 2.7. Pectin gels at 2.0% and 3.0% (w/v) presented hardness values of 10.2 and 20.4 g after 12 h at 4 °C. The gel hardness was greatly affected by aging (20% and 25% decrease in 48 h for gels at 2% and 3%, respectively). The results attained suggest the use of this gum as a potential texturing agent for the food industry.     

Pectin Extraction from Lemon By-Product with Acidified Date Juice: Effect of Extraction Conditions on Chemical Composition of Pectins

Mixtures of date and lemon pectins were extracted from lemon by-product with acidified date juice under different conditions of temperature, pH and time. Individual pectins from date and lemon, respectively, were also extracted using the same experimental conditions, then analysed and compared to pectin mixtures. It was found that the use of extreme conditions resulted in higher galacturonic acid content, lower degree of methylation, lower neutral sugar content, lower molecular weight and darker colour pectins. Examination of the individual neutral sugars showed that the main ones were galactose (1.6–5.4%), arabinose (1.6–4.2%) and rhamnose (0.5–0.8%). The Gal A/Rha molar ratios varied from ∼53 to ∼149. Moreover, mixture of pectin extracted at the optimal extraction conditions (84.34 °C, pH 2.8 during 3 h 34 min) had interesting properties, with a high galacturonic acid content (63.4%), low degree of methylation (∼35%) and a mass molecular weight of about 243 kg/mol.     

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.     

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.     

超声-酶法提取的豆腐柴低酯果胶理化性质及结构表征

以豆腐柴为原料,采用超声-酶法提取低酯果胶,并探究其理化性质、结构特征、抗氧化活性以及流变特性。结果表明,超声-酶法提取的果胶得率达35.53%,相比传统酸法提取提高17.28%,属于低酯果胶(酯化度为16.80%),颜色呈现淡黄色,其总糖醛酸含量达到81.17%(质量分数)。通过高效液相色谱法对果胶分子质量进行测定,其重均分子质量(M w)为27.24 kDa,数均分子质量(M n)为15.30 kDa,M w/M n为1.78,表明豆腐柴果胶分子质量较低,且较为均一。单糖组成分析发现,半乳糖醛酸、葡萄糖、鼠李糖、半乳糖等是主要组分,其结构线性度较低,主要结构为短侧链的RG-Ⅰ型。红外光谱扫描特征峰证实其含有果胶成分;扫描电镜显示其表面粗糙,含有较多孔隙结构;X射线衍射表明豆腐柴果胶具有一定的结晶度;差示量热扫描、热重分析显示豆腐柴果胶在259.3℃发生降解,热稳定性较好;流变学分析结果表明不同浓度豆腐柴果胶溶液均出现剪切变稀现象,为非牛顿流体,10 g/L的果胶溶液储能模量(G′)高于损耗模量(G″),表现出较好的弹性;抗氧化活性测定显示豆腐柴果胶清除DPPH自由基、ABTS阳离子自由基的IC 50分别为0.37、0.34 g/L。研究结果为豆腐柴低酯果胶的开发及综合利用提供理论依据。     

Isolation and characterisation of pectic substances from murta (Ugni molinae Turcz) fruits

Cell walls polysaccharides from murta fruit (Ugni molinae Turcz), an endemic Chilean species with relevant food uses, were fractionated by water, ammonium oxalate, hot diluted HCl and cold diluted NaOH extractions. The polysaccharide fractions were analysed for monosaccharide composition and physicochemical properties. Pectic substances were found in all extracts, but mainly in the oxalate and acid soluble fractions, in which they appear as homogalacturonan polymers. Murta pectin was further extracted by hot diluted acid treatment using industrial conditions, yielding 30% by weight of dry fruit. The polymer showed similar composition and physicochemical properties to those of commercial citrus pectin, presenting a galacturonic acid content of 70.9% (w/w), a molecular weight of 597 kDa, and a methoxylation degree of 57%. The FT-IR spectrum of murta pectin suggests the presence of ferulic acid residues on its structure and the NMR analysis confirmed the structure of this polysaccharide. It is concluded that murta fruit can be considered as a valuable source of high quality pectin.     

山楂生、炒品果胶结构表征和体外降脂作用研究

目的 明确山楂生品果胶(raw hawthorn pectin, RHP)和炒品果胶(fried hawthorn pectin, FHP)的结构与其体外降脂作用的关系。方法 通过测定酯化度、半乳糖醛酸含量、分子量、特性黏度、黏均分子量、中性糖组成和比例,用扫描电镜观察微观形态,来表征RHP和FHP的结构。通过果胶对胆固醇胶束和胆酸盐的结合能力等体外实验评价其降脂作用。结果 RHP酯化度为52.19%,属于高酯果胶; FHP酯化度为31.95%,属于低酯果胶。RHP分子量有4个级分(217904、16907、8933、5104 Da),FHP分子量有4个级分(238813、16662、8770、5063 Da)。RHP特性黏度和黏均分子量分别为0.10 dL/g和2.75×10⁴ g/moL, FHP特性黏度和黏均分子量分别为0.16 dL/g和4.71×10⁴ g/moL。RHP、FHP均含有葡萄糖、鼠李糖、半乳糖、果糖和木糖等中性糖,但各糖的分子摩尔比不同。微观形态中, RHP分子间交联良好; FHP分子之间交联较少。在体外降脂实验中,R...     

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。     

不同部位柚子果胶提取率与理化特性相关性研究

采用酸处理乙醇沉淀法从柚子黄皮、白皮、囊衣、果肉中提取果胶,计算提取率,对提取的柚子果胶进行pH、半乳糖醛酸、酯化度、溶解度、黏度等理化特性的测定,并分析果胶液的热稳定性、提取率与理化特性的相关性。结果表明,柚子不同部位果胶的提取率表现为：果肉>白皮>囊衣>黄皮,pH为：黄皮>囊衣>白皮>果肉,半乳糖醛酸含量：白皮>黄皮>囊衣>果肉,酯化度：囊衣>白皮>果肉>黄皮,溶解度：果肉>白皮>囊衣>黄皮;各部位提取率、半乳糖醛酸、酯化度均存在极显著差异（p <0.01）,黄皮、囊衣、白皮果胶之间pH差异不显著（p> 0.05）;柚子果胶提取率与pH呈显著负相关（r=-0.973,p<0.05）;柚子各部位果胶的黏度均优于市售果胶,但高温降低了柚子果胶的热稳定性。     

Optimization of extraction process of crude polysaccharides from boat-fruited sterculia seeds by response surface methodology

Response surface methodology (RSM) was applied to optimize the extraction of crude polysaccharides from boat-fruited sterculia seeds. A central composite design was used for experimental design and analysis of the results to obtain the optimal extraction conditions. Extraction temperature, pH, extraction time and water to seed ratio were found to have a significant influence on the yield and purity of the extracted crude polysaccharides, while the three other factors except the water to seed ratio also significantly affected the relative viscosity. Based on the RSM analysis, optimum conditions were: temperature 60–65 °C, time 2.3–3.1 h, pH at 7.0 and water to seed ratio at 75:1. Under the optimized conditions, the experimental values were in close agreement with values predicted by the model. The crude polysaccharides prepared under optimum conditions contained 58.2% total carbohydrates (including uronic acids), 20% proteins, 9% moisture and 4.5% ash. The crude polysaccharides consisted of glucose (22.6%), rhamnose (10.0%), arabinose (7.9%), galactose (5.0%), xylose (0.8%) and galacturonic acid (11.8%).     

柿果胶提取工艺优化及理化性质研究

为了开发柿深加工产品,以脱涩柿果为原料,利用Box-Behnken方法设计,通过响应面分析法对柿果胶的酸提醇沉法提取工艺进行优化,并研究提取的柿果胶的理化性质。结果表明,柿果胶最佳提取条件为0.1 mmol/L HCl提取液pH4.00,液料比为23:1 (g/g),提取时间107 min,提取温度92 ℃,在此条件下柿果胶得率为7.31%。对上述条件下柿果胶的理化性质研究发现,柿果胶的亮度为L* 30.74,彩度为C* 13.04,色度角为h° 44.07,酯化度为98.88%;高效液相测其分子量为405.3 kDa,且单糖组成是岩藻糖、阿拉伯糖、半乳糖、葡萄糖、木糖、果糖和半乳糖醛酸。可为柿果胶的提取和应用提供重要的理论基础和技术支持。     

菊苣粕果胶的微波辅助提取工艺研究

提取是菊苣果胶生产技术的关键单元操作。本文以菊苣粕为原料,比较微波辅助提取法(Microwave-assisted extraction,MAE)及传统热酸法(Conventional heating extraction,CHE)对果胶得率、化学组成和分子量的影响。研究结果表明:两种提取方法对菊苣果胶的半乳糖醛酸、甲酯化度和乙酰化度等结构指标没有显著的影响;延长传统热酸法的提取时间有助于提高果胶得率,但会导致果胶分子链发生一定程度的降解;微波处理时间与果胶得率、重均分子量(Mw)间存在显著的正相关性;微波处理时间为120 s时,果胶得率(12.7%)与重均分子量(321 ku)均最高,且果胶分子结构降解程度较低。与传统热酸法相比,微波辅助提取法具有效率高和降解程度低等优点,是提取菊苣果胶的理想方法。