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.     

百香果皮果胶提取工艺及其对面团和面包品质的影响

从百香果皮中提取果胶作为面包改良剂,以未添加改良剂和添加豆渣的面团为对比,通过质构仪分析百香果皮果胶对生面团延展性和面包坚韧性的影响。结果显示:百香果皮果胶提取的最佳工艺条件为:质量分数为0.45%的草酸铵、料液比1∶45(g/mL)、50 W超声波辅助提取90 min,果胶提取率为24.79%。质构测试结果表明:添加百香果皮果胶的面团拉丝长度、弹性、粘性和内聚性较大,而硬度较小,其面团品质最好。添加豆渣和百香果皮果胶均使面包的硬度和咀嚼性降低,有效改善面包的质构特性。Kramer感官评定结果表明百香果皮果胶面包最受消费者喜爱。     

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。     

无核黄皮果酱的制备及其理化性质研究

摘要：目的以药食两用的无核黄皮果为原料,研究无核黄皮果酱的最优配方。方法通过单因素试验分别考察糖、柠檬酸、果胶、果皮添加量对感官评分的影响。在单因素实验的基础上,进行正交实验,进一步研究糖、柠檬酸、果皮添加量这3个主要因素对感官评分的影响,以得到感评最佳的配方,并进行正交实验验证实验及相关理化指标的测定。结果无核黄皮果酱的最优配方为果皮添加量15%、糖添加量20%、柠檬酸添加量0.16%、果胶添加量为0.4%,以上均为质量比。 色差为60.13±0.66,可溶性固形物含量为（55.74±0.01）%,有效酸度为2.54±0.02,脱水率为0.00%。结论所制得的无核黄皮果酱酸中带甜,组织状态良好,保型性好,品质较好,为无核黄皮的进一步精深加工和果酱的研制提供参考和借鉴。     

橙皮果胶可食性保鲜膜的应用

利用橙皮提取果胶,检测果胶样品的质量,分析得出该果胶产品符合作为食品添加剂的国家标准。利用橙皮果胶为主要原材料制备的薄膜各项指标为:透光率为87.8%,厚度为0.127 mm,抗拉强度为3.983 MPa,断裂伸长率为24.883%。文中还将果胶标准品膜、提取的果胶样品膜和购买的PE膜进行物理特性的分析对比,并应用于猪肉的保鲜,通过分析汁液渗出量、pH值、挥发性盐基氮和细菌总数4个指标的变化,证明橙皮果胶可食性保鲜膜对冷鲜猪肉的保鲜效果明显优于PE塑料保鲜膜,具有良好的实用价值。     

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.     

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.     

柚类果实提取物生理功能及综合利用研究进展

柚类果形硕大,果皮厚,绝大部分品种的果皮占单果质量的40%～50%。本文从柚果果皮提取物的抗氧化与抑菌作用,精油、黄酮类物质、果胶、膳食纤维、色素、多糖、酚酸的提取工艺,果汁、果酱、果糕、果脯、罐头、果酒、果醋、鲜切柚瓣等柚果加工产品研制,新鲜花、幼果、种子的利用等方面,综述国内外对柚类果实加工及综合利用的研究进展,以期为柚类资源的深度开发利用提供参考。     

Optimisation of pectin acid extraction from passion fruit peel (Passiflora edulis flavicarpa) using response surface methodology

Pectin was extracted from passion fruit peel using three different acids (citric, hydrochloric or nitric) at different temperatures (40–90 °C), pH (1.2–2.6) and extraction times (10–90 min), with and without skins using a 2⁴ factorial design. Temperature, pH and extraction time had highly significant effects on the pectin yield. A central composite design with face centring was used to optimise the extraction process conditions for citric acid without skins. Pectin yields varied from 10% to 70%. The optimal conditions for maximisation of pectin yield were the use of citric acid at 80 °C and pH 1 with an extraction time of 10 min considering model extrapolation.     

贮藏期间芦荟果胶含量变化及影响果胶粘度因素的研究

果胶作为由植物中提取的天然添加剂,具有良好的胶凝化和稳定化作用。从具有保健作用和药用价值的芦荟中提取果胶已广泛应用于食品工业、化妆品、医药等领域。本文对贮藏期间芦荟果胶含量态变化进行研究,并确定影响果胶粘度的因素,对芦荟果胶提取具有指导意义。本文采用酸水解醇析法提取芦荟中的果胶,确定提取果胶醇析过程中的最优pH和温度,并明确贮藏0～60d芦荟中果胶含量,此外还确定各种影响因素对果胶成品粘度的影响。结果表明,醇析过程中的最佳pH3.5,最佳温度为50℃。果胶成品的pH2.79（符合国标）,甲氧基含量为8.518%,属于高甲氧基果胶。贮藏0～60d库拉索芦荟中的果胶含量在贮藏10d时达到峰值。而后果胶含量随贮藏时间的延长而降低,并且在20d之后明显下降。因此,最适宜芦荟果胶提取和加工的时间为0～20d。所得芦荟果胶粘度与温度、柠檬酸和氯化钠添加量呈负相关,而与果胶浓度和蔗糖添加量呈正相关。     

柚子黄酮、果胶的提取及保健饮料的研制

以沙田柚为材料,采用单因素试验和正交试验,对柚皮中黄酮和果胶的提取工艺条件进行了优化,并将柚汁、黄酮和果胶等通过调配、均质、杀菌等工艺制成保健饮料。结果表明:黄酮的最佳提取条件为乙醇浓度90%,料液比1︰40,提取时间50 min,超声波提取温度30℃,黄酮得率为0.612 3%;果胶的最佳提取工艺条件为pH1.4,料液比1︰110,超声波提取温度50℃,时间6 min,乙醇浓度90%,果胶得率为11.90%;保健饮料的最佳配方是柚汁15%,柠檬酸0.2%,黄酮0.06%,果胶0.08%,β-环状糊精0.3%,该饮料口感良好,风味独特,具有丰富的营养和一定的保健功能。本研究为保健饮料行业增添了新品种,为柚子的精深加工提供了新思路。     

Processing and Quality Evaluation of a Low-Calorie Christophene Jam (Sechium edule (Jacq.) Swartz

ABSTRACT: Effects of high methoxyl pectin (2% HM) and low methoxyl pectin (1.0,2.0% LM) and carrageenan (0.03, 0.06, 0.09%) on gel set and texture were investigated in the production of a low-calorie (13g /1tbsp jam of < 10 calories) christophene ( Sechium edule (Jacq.) jam. Inclusion of aspartame, saccharin with aspartame, and sucralose in jam provided sweetness and bulkiness while saccharin contributed to sweetness. Pectin had no effect ( P > 0.05) on texture but provided gel set ( P < 0.05). A jam of 12°Brix, pH 3.62, 2% HM pectin, 0.03% carrageenan, with 1.9% sucralose was "liked moderately" to "very much". Based on ranking, sucralose was most preferred ( P < 0.05) over other sweeteners. Sensory texture of jam improved on storage at 7 °C but with loss ( P < 0.05) of total soluble solids and significant fading ( P < 0.05) of color by day 35.     

Rheological,textural, micro-structural and sensory properties of mango jam

Mango jam behaved as pseudoplastic fluid exhibiting yield stress. The Herschel–Bulkley (HB) model described adequately the steady-state rheological behavior of jam. Temperature dependence of the consistency index followed Arrhenius relationship. Time dependent structural breakdown characteristics of mango jam followed Hahn model. Hardness of mango jam increased with pectin concentration and acidity. Hardness increased up to 60% sugar concentration but decreased with further increase in sugar concentration at all pH and pectin levels. Stickiness, work of shear, and adhesion did not show any systematic trend with pH, pectin, and sugar concentration. The overall acceptability was rated highest for mango jam prepared with 65% sugar, 1% pectin at pH 3.4. Principal component analysis (PCA) revealed that hardness and work of shear are the most relevant among all the characteristics (physicochemical, sensory, textural, rheological, and compositional) studied for mango jam. Microstructure of mango jam was found to be composed of network regions with large pores as well as dense, compact regions with small pores.     

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...     

响应面优化微波加热法提取橘皮果胶

以橘皮为原料,采用微波加热法提取橘皮果胶。探讨了微波功率、液固比、提取时间及提取液pH对果胶提取率的影响。采用响应面法建立二次回归模型,并对提取工艺进行了优化。结果表明,当微波功率509 W,液固比25∶1(g/g),提取时间6.6 min及提取液pH2.4时,果胶的提取率可达到17.81%。比相同条件下常规水浴法的果胶提取率高4.4%。     

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.     

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。     

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%。     

Prediction of Pectin Yield and Quality by FTIR and Carbohydrate Microarray Analysis

Pectin production is complex, and final product quality assessment is generally accomplished at the end of the process using time-consuming off-line laboratory analysis. In this study, pectin was extracted from lime peel either by acid or by enzymes. Fourier transform infrared spectroscopy and carbohydrate microarray analysis were performed directly on the crude lime peel extracts during the time course of the extractions. Multivariate analysis of the data was carried out to predict final pectin yields. Fourier transform infrared spectroscopy (FTIR) was found applicable for determining the optimal extraction time for the enzymatic and acidic extraction processes, respectively. The combined results of FTIR and carbohydrate microarray analysis suggested major differences in the crude pectin extracts obtained by enzymatic and acid extraction, respectively. Enzymatically extracted pectin, thus, showed a higher degree of esterification (DE 82 %) than pectin extracted by acid (DE 67 %) and was moreover found to be more heterogeneously esterified when probed with the monoclonal antibodies JIM5, JIM7, and LM20. The data infer that enzymatic pectin extraction allows for extraction of complex, high DE pectin, and that FTIR and carbohydrate microarray analysis have potential to be developed into online process analysis tools for prediction of pectin extraction yields and pectin features from measurements on crude pectin extracts.     

Characterisation of dragon fruit peel pectin extracted with natural deep eutectic solvent and sequential microwave-ultrasound-assisted approach

In this research, the physicochemical characteristics (proximate and chemical compositions, monosaccharides profiles, chemical structures, antioxidant activities and rheological properties) of dragon fruit peel pectin extracted with the solvent system of choline chloride-glucose-water (5:2:5) and sequential microwave-ultrasound-assisted approach (PC-MUAE), were evaluated, and then compared with those of the commercial pectin and other products from various extraction methods. No remarkable differences in the FTIR spectra of the commercial and extracted samples were observed, leading to the fact that the derived polysaccharides were pectin. The commercial pectin possessed a bright-yellow colour, while extracted pectin was yellow to brownish. Moreover, the facade of the latter under SEM was rough with miniature heterogeneous fragments. PC-MUAE was categorised as high methoxyl pectin with the degree of esterification of 59.76% and as a pseudoplastic substance with neutral pH (6.42), average level of solubility (73.90%), high equivalent weight (680.6 g mol⁻¹), high molecular weight (5.05 × 10⁵ Da), high antioxidant activities (total phenolic content of 8.14 mg of gallic acid equivalent/g pectin and 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging capacity of 2.41 µmol Trolox equivalent/g pectin) and high viscosity at all tested domains of shear rate as compared with those of the commercial product and others from various methods. The anhydrouronic acid content of PC-MUAE was 64.28%, approximately to the minimum level (65%) proposed by FAO and EU. There were arabinose, galactose, glucose, mannose, rhamnose and xylose detected in extracted pectin. Consequently, PC-MUAE has the potential characteristics of high methoxyl pectin for the food industries.