Gelling Characteristics of Pectin From Sunflower Head Residues

Gelling properties of sunflower head pectin were studied using two instrumental methods: the standard sag method and the Instron textural profile method. For the Instron method, the jellies were formulated with 0-60% sugar content with various amounts of calcium chloride (30 to 90 mg/g pectin) at pHs 5.4 and 6.0. Sunflower pectin had a gel power of 110 compared to 100 for a citrus low-methoxyl pectin and 120 for an amidated low-methoxyl pectin. Sunflower pectin formed jellies under all experimental conditions. Sunflower pectin has a high potential for producing low-caloric foods, particularly when a near-neutral taste is required.     

Sunflower Head Residue Pectin Extraction as Affected by Physical Conditions

Effects of extraction pH, temperature, and time on yield and quality of pectin from sunflower heads (Interstate cultivar) were investigated. The low-methoxyl pectin was extracted, using 0.75% sodium hexametaphosphate at pH 3, 4, and 5 and at 75, 85, and 95°for 20, 40, and 60 min, respectively. Yield, molecular mass, and firmness of jellies of the pectins were determined. Three-way statistical analysis on yield, molecular mass and gel firmness showed strong interactions among pH, temperature and time. Highest yields were obtained at pH 5, 95°for 20 min and pH 4, 85°for 40 min. Pectin extracted for 40 min at pH 3 and 4 and at 85°and 75°C, respectively, had the highest molecular mass. Gel firmness of sunflower pectin prepared at pH 5.4 was higher than that of a commercial citrus pectin.     

正交试验优化向日葵盘果胶的提取和基本分析

研究向日葵盘果胶(SFHP)的提取工艺。通过单因素试验,比较酸化水、0.75%六偏磷酸钠、0.5%乙二胺四乙酸二钠、0.5%草酸-草酸铵、0.5%草酸和0.5%草酸铵6种提取剂的提取效果,确定较优的提取剂种类。选择pH值、提取温度、提取时间和提取固液比为主要工艺参数,通过正交试验,确定较优的提取参数组合:pH3.50、提取时间45min、提取温度85℃、固液比1:30(g/mL)。在此条件下,向日葵盘果胶得率为20.9%(以半乳糖醛酸计)。采用高效尺寸排阻色谱-多角度激光散射检测器(HPSEC-MALLS)和高效阴离子交换色谱-脉冲安培检测器(HPAEC-PAD)测定了向日葵盘果胶的分子质量和单糖组成。结果表明,向日葵盘果胶的分子质量高于柑橘果胶,半乳糖醛酸为最主要单糖成分,占单糖总量的82.1%,鼠李糖为次要成分,仅占单糖总量的9.1%。     

Optimizing Water Washing Process for Sunflower Heads before Pectin Extraction

Most pigment in sunflower heads is water soluble, but is strongly associated with extractable pectin. Washing sunflower heads before pectin extraction is necessary to remove pigment and improve pectin quality. An undesirable side effect is loss of water-soluble pectin. Response Surface Methodology (RSM) was applied to determine effects of variables and to optimize washing conditions for minimum pectin loss with maximum pigment removal. Benchscale washing experiments were carried out at 70-80°C for 10-30 min at water/solid ratios (v/w) of 20:1 to 40: 1, respectively. Both removal of water-soluble pigments and loss of pectin from sunflower tissue increased with increasing temperature, washing time, and water/solid ratio. Optimum conditions were 74.8°C for 25 min at a 25:1 water/solid ratio. This resulted in removal of 56.47% of the pigment, but loss of 2.90% of the pectin, which is practicable for the sunflower pectin industry.     

Cultivar/Location and Processing Methods Affect Yield and Quality of Sunflower Pectin

The influence of cultivar/location of sunflower and grinding, blanching, water washing, and re-extraction of sunflower head residues were studied for yield and quality of pectin. Sunflower head residues from seven varieties/locations were used. The Interstate cultivar from Ardock (North Dakota) and Agri-Pro from Canington (North Dakota) had highest yields (9.14–9.47%). Galacturonic acid content of the pectin did not differ significantly among cultivars. Grinding sunflower heads to particle size <60 mesh did not increase yield or quality of pectin. Peroxidase in head residues was completely inactivated after heat treatment at 75°C for 15 min. Higher shear blending did not increase yield, but decreased molecular mass and firmness of pectin gels. Extracting pectin twice yielded a total 13–14% pectin without lowering pectin quality.     

Acid Removal from Sunflower Pectin Gel through Ethanol Washing

Sunflower heads remaining after seed removal is a potential source of low-methoxyl pectin. After extraction and acid precipitation of pectin gel, aqueous ethanol solution was used to purify the pectin. Ethanol washing of nitric acid-precipitated gel in a countercurrent process at 207°C removed acid. Concentration of nitric acid in the ethanol solvent varied depending on washing time, acid concentration in the gel, ethanol in washing solution, and ratio of gel to washing solution. Gel/solvent ratios of 1:2, 1:1.8, and 1:1.5 increased gel pH at the rate of 0.024, 0.022, and 0.018 pH units per min, respectively. Diffusion rate constants of nitric acid from the gel to washing solution were 5.281 × 10^?2, 4.855 × 10^?2, and 4.282 3 10^?2 min^?1, respectively. A cubic regression equation was developed to express the relationship between nitric acid concentrations and pH.     

柠檬皮高酯果胶的分步提取及表征

本研究采用草酸对柠檬皮进行分步提取,得到两种不同性能的高酯果胶(HMP-1、HMP-2),系统地探究了提取条件HMP-1和HMP-2得率和黏度的影响,对HMP-1、HMP-2进行物化性质表征,并通过原子力显微镜(AFM)进行微观结构观察。实验结果表明,在料液比1:20,pH 1.7,70℃1.5 h的反应条件下,HMP-1得率为19.22%,1%溶液的黏度为104.55 mPa·s,分子量为550.4 ku,酯化度为75.22%,胶凝度为218.24°SAG,在酪蛋白等电点附近具有较高的电位绝对值;在料液比1:10,pH 1.7,80℃1.5 h的反应条件下,HMP-2的得率为9.74%,1%溶液的黏度为49.23 mPa·s,分子量为424.7 ku,酯化度为64.34%,胶凝度为171.12°SAG。AFM结果表明,HMP-1呈现较长的线性形态,HMP-2则呈现较为分散、细碎的状态。本研究实现了柠檬皮果胶的分步提取,得到不同类型的果胶,有助于果胶的多元化发展及精准应用。     

不同方法提取的山楂果胶理化性质及体外抗糖化活性的对比

本研究以山楂粉为原料,采用热水浸提、超声辅助热水浸提、酶法辅助热水浸提三种方法提取果胶,探究不同提取方法对果胶得率、总糖含量、总酚含量、半乳糖醛酸含量、酯化度和粘度等理化性质及体外抗糖化活性的影响。结果表明,酶法辅助热水提取果胶的得率最高,达到17.7%,且相应酯化度和粘度最高,但操作过程复杂;热水浸提法果胶得率次之,为10.1%,但总酚含量和酯化度最低;超声辅助热水提取法得率最低,仅有6.4%,但其总糖含量及多聚半乳糖醛酸量最高。体外抗糖化活性分析表明,超声辅助热水法提取的果胶抗糖化活性最强,在BSA-果糖以及BSA-丙酮醛模拟体系中的糖化抑制率分别为82.7%和79.8%,抗糖化活性与半乳糖醛酸酸含量成正比。由此可见,不同提取方法对山楂果胶得率、理化特性以及抗糖化活性均具有很大的影响。     

苹果皮果胶的提取工艺研究

对从新鲜苹果皮中提取果胶的工艺条件进行了研究,经过酸水解提取、酒精沉淀等工艺提取出具有广阔市场前景和丰富营养价值的天然食品添加剂果胶粉。     

微波辅助提取桔皮果胶的优化条件研究

以橘皮为原料,用微波辅助法提取果胶,通过正交试验,得到优化工艺：以盐酸作为萃取剂,pH值为1.5,液料比为10:1(ml/g),微波加热时间为6min,微波处理方式为27%×800W。     

超声辅助提取佛手废渣果胶的工艺优化

目的：对佛手废渣果胶提取工艺进行优化。方法：分别通过响应面试验和正交试验对果胶的超声辅助酸提和乙醇沉析工艺进行优化。结果：响应面试验优化后的超声辅助酸提工艺条件为浸提时间37min、浸提温度63℃、超声功率395W、pH1.6。正交试验优化后的醇析条件为浓缩比1:4、醇析温度15℃、醇析时间1.5h、醇析液pH2.0、醇析液乙醇体积分数70%。结论：经验证在最佳工艺条件下,果胶提取得率22.1%,果胶醇析得率85.7%。     

Box-Behnken法优化提取荔枝渣中果胶工艺

以荔枝渣为材料,采用超声波辅助酸法提取工艺,运用Box-Behnken试验设计方案获得超声波预处理时间、功率和料液比等因素对果胶得率的影响规律,并结合质构仪分析果胶硬度、黏度、酯化度等指标。结果表明：超声波预处理荔枝渣提取果胶最佳工艺为超声时间14.8 min、超声功率300 W、料液比1∶10.7,在此基础上选择pH 2的盐酸溶液提取,乙醇沉淀时液-液体积比1∶1.5,沉淀时间90 min,果胶理论得率17.86%,实测得率为17.38%。所得果胶黏度为55.8×10－3 Pa·s,酯化度为40.7%,质构特性分析表明所得荔枝渣果胶硬度平均值为40.400 g,弹性平均值为55.51%,黏性绝对平均值为12.880 g,果胶样品色泽较好,胶凝度高。     

甜菜压粕中果胶的提取工艺研究

探讨了料液比、提取温度、提取液pH值以及提取时间对酸提醇析法提取甜菜压粕中果胶得率的影响,结果表明,甜菜压粕中果胶的最佳提取工艺为:料液比1∶20,浸提温度90℃,提取液pH 1.0,提取时间3.5 h;在最佳条件下,果胶平均得率为27.10％,用咔唑比色法测定半乳糖醛酸的含量为17.82％,果胶纯度为65.76％.     

超声辅助酶法提取咖啡果皮果胶工艺的优化及其理化特性分析

为研究咖啡果皮中果胶的提取工艺和理化特性,以云南小粒咖啡果皮为原材料,在单因素实验的基础上采用响应面设计优化果胶的超声辅助酶法提取工艺,采用傅里叶红外光谱（Fourier Transform Infrared Spectroscopy,FT-IR）检测粗果胶的官能团组成;通过AB-8大孔树脂、Sevage法脱色脱蛋白纯化粗果胶,并比较纯化前后果胶理化特性的差异。结果表明,最佳提取条件为：纤维素酶添加量1.49%,酶解时间45.78 min,超声时间19.30 min,得率为16.42%。FT-IR结果显示咖啡粗果胶含有典型的多糖结构。纯化后,果胶总糖含量增加了17.51%,多酚、蛋白质含量、酯化度和乙酰化度分别减少了72.41%、23.53%、77.43%和91.16%。与粗果胶相比,纯化可增加果胶持水性（20.05 g/g）、持油性（8.13 g/g）、乳化性（48.06%）和乳化稳定性（45.59%）,分别增加了470%、52.25%、26.31%和9.64%,但是降低了咖啡果胶的起泡性和泡沫稳定性。该研究为云南小粒咖啡果皮果胶的开发利用提供了试验基础。     

香蕉皮果胶萃取及果胶保鲜膜制备的研究

采用4种不同的方法萃取果胶,分析果胶结构,研究成膜因素对制备膜性能影响,探索制备膜的最佳工艺。结果表明,各种方法萃取的产品都为果胶,酸解盐析法萃取果胶效果最好,萃取率达1.311%;果胶底物浓度和变性淀粉用量影响制备膜的抗拉强度和断裂伸长率;影响制备膜抗拉强度的因素主要顺序为成膜助剂用量 >果胶浓度> 变性淀粉用量,但果胶+助膜剂+交联淀粉制备的膜其结构、抗拉强度都为最好,最佳制备膜的工艺参数为果胶底物浓度2.4%、助膜剂用量0.5%、变性淀粉用量1.0%。     

西兰花茎果胶的提取及理化性质研究

以西兰花废弃茎为原料,探究其果胶提取工艺和理化性质。通过单因素试验和正交试验优化果胶提取工艺,以商品橘子皮果胶（commercial orange pectin,COR）为对照,通过西兰花果胶（Brassica oleracea L.pectin,BOP）酯化度、溶解度、半乳糖醛酸含量等指标来评价其理化性质,采用扫描电镜和傅里叶红外光谱表征其结构。结果表明,BOP提取最佳条件为pH值1.5,料液比1∶25（g/mL）,提取温度90℃,提取时间80 min,该条件下验证试验的平均得率为9.42% ;与COR相比,BOP中半乳糖醛酸含量为70.34% ,酯化度为46.7% ,西兰花果胶属于低酯果胶、溶解度为74% ,果胶灰分含量为7.56% ,果胶酸不溶物含量为3.85% ,果胶pH值为3.05。BOP和COR的表观颗粒形态存在较大差异,BOP颗粒直径较COR的大,呈清晰片状,排列不紧密,有较多的孔隙。     

微波辅助萃取柠檬皮中果胶动力学及热力学研究

采用离子液体氯化1- 丁基-3- 甲基咪唑水溶液为萃取剂,对微波辅助萃取柠檬皮中果胶的动力学及热力学进行研究。以Fick 扩散第二定律为理论基础,采用分离变量法建立果胶提取动力学方程,并推算出速率常数k、活化能Ea、焓变ΔH0、熵变ΔS0 和自由能变ΔG0 等动力学和热力学函数值。     

南瓜果胶不同提取方法的研究

以南瓜果肉为材料,采用咔唑比色的方法,通过正交试验,分别研究超声波法、纤维素酶法和离子交换树脂法提取南瓜果胶的最佳提取条件。结果表明：超声波法的最佳提取工艺条件为：超声波功率400W,时间35min,液料比10:1(ml/g),果胶得率5.98%;纤维素酶法提取果胶的最佳工艺条件为：酶解时间2.0h,pH4.5,酶解温度55℃,加酶量0.5%,果胶得率9.56%;离子交换树脂法提取果胶的最佳工艺条件为：树脂用量15%,料液比为1:20(g/ml),pH2.5,时间2.0h,温度80℃,果胶得率7.62%。三种提取方法进行比较,纤维素酶法果胶得率最高,为南瓜果胶的最佳提取工艺。     

柿皮果胶纤维素酶法提取工艺

采用纤维素酶法辅助提取柿皮中的果胶,探讨提取过程中各因素对果胶提取率的影响。结果表明:柿皮果胶纤维素酶法提取的最佳工艺条件为提取温度45℃、加酶量3.0mg/g、提取液pH4.0、料液比1:35、提取时间2h,测得果胶的提取率为8.87%。该方法简便、快捷,可用于柿皮果胶的提取和测定。     

果胶提取工艺数学模型的建立

运用Design Expert7.0 软件技术,采用响应曲面分析法,研究果胶提取影响因素对果胶提取得率的影响,建立果胶提取工艺数学模型。单因素试验结果表明,果胶提取得率最高的各影响因素值分别为：提取液pH2.2 左右,提取温度85℃,提取时间1.4h,液料比为3:1,盐析温度70℃。正交试验结果表明,提取液pH1.5、提取温度90℃、提取时间2.0h、盐析温度65℃、提取率最高为1.14%。果胶提取工艺数学模型为Y(%)＝－ 36.9 ＋1.39X1 ＋ 0.785X2 － 1.95X3 ＋ 0.142X4 － 0.0192X1X2 － 0.0151X1X3 － 0.0198X1X4+0.0289X2X3 － 0.0004X2X4 ＋ 0.0237X3X4＋ 0.386X1 － 0.0045X2 － 0.696X3 － 0.0008X4。