Extraction and characterisation of pectin polysaccharide from soybean dreg and its dispersion stability in acidified milk drink

In this study, pectin polysaccharide (SDPP) was obtained from soybean dreg (26.2% yield), and characteristics of SDPP were compared with those of soybean soluble polysaccharides (SSPS) and citrus pectin (HMP). The galacturonic acid and molecular weight of SSPS, SDPP or HMP were 11.8%, 40.6% or 70.2% and 112, 446, or 440 kDa. SDPP had similar viscosity and protein content to SSPS, and functional groups and linear structure to HMP. SSPS, SDPP or HMP differed in particle size of 260, 467 or 1195 nm and ζ–potential of −5.8, −14.6 or −23.5 mV at pH 4.0. The precipitation of acidified milk drink (AMD) was 6.31% without stabiliser or below 1.75% with 0.4% SDPP at pH 3.6–4.6. These results suggested that SDPP combines the structure and characteristic of HMP and SSPS, and AMD with SDPP had great stabilising behaviour at wider pH range (pH 3.6–4.6).     

山楂果胶低聚半乳糖醛酸提取物对中波紫外线辐射HaCaT细胞氧化损伤和光老化的保护作用

探讨了山楂果胶低聚半乳糖醛酸提取物对中波紫外线(ultraviolet B,UVB)辐射后人永生化表皮角质形成细胞(HaCaT)的氧化损伤和光老化的保护作用。体外培养HaCaT细胞,分为对照组(HaCaT细胞不照射UVB,不给予山楂果胶低聚半乳糖醛酸提取物处理)、UVB辐射组(30 mJ/cm~2)、低剂量(5μg/mL)山楂果胶低聚半乳糖醛酸+30 mJ/cm~2 UVB辐射组、高剂量(10μg/mL)山楂果胶低聚半乳糖醛酸+30 mJ/cm~2 UVB辐射组。以噻唑蓝比色法检测细胞活力,采用试剂盒检测超氧化物歧化酶(superoxide dismulase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、过氧化氢酶(catalase,CAT)和乳酸脱氢酶(lactate dehydrogenase,LDH)活力,丙二醛(malondialdehyde,MDA)含量,羟脯氨酸(hydroxyproline,Hyp)质量浓度和活性氧(reactive oxygen species,ROS)水平。采用酶联免疫吸附测定实验检测肿瘤坏死因子-α(tumor necrosis factor alpha,TNF-α)、白细胞介素-6(interleukin-6,IL-6)质量浓度和基质金属蛋白酶-1(matrix metalloproteinase 1,MMP-1)含量。结果表明,经UVB照射后,Ha Ca T细胞活力明显降低。低、高剂量的山楂果胶低聚半乳糖醛酸提取物对经UVB辐射的HaCaT细胞具有显著的增殖作用(P0.05);SOD、GSH-Px、CAT活力增加;LDH活力、ROS水平和MDA含量下降;Hyp质量浓度增加;MMP-1含量和TNF-α、IL-6质量浓度下降,且与辐射组比较均具有显著或极显著差异(P0.05或P0.01)。实时荧光定量聚合酶链式反应检测MMP-1、TNF-α及IL-6 m RNA表达水平与其含量或质量浓度检测结果一致。因此,山楂果胶低聚半乳糖醛酸对UVB辐射Ha Ca T细胞的氧化损伤及光老化具有保护作用。     

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。     

Pectin: A Long-Neglected Broad-Spectrum Antibacterial

First reported in the late 1930s and partly explained in 1970, the antibacterial activity of pectin remained almost ignored until the late 1990s. The concomitant emergence of research on natural antibacterials and new usages of pectin polysaccharides, including those in medicine widely researched in Russia, has led to a renaissance of research into the physiological properties of this uniquely versatile polysaccharide ubiquitous in plants and fruits. By collecting scattered information, this study provides an updated overview of the subtle factors affecting the behaviour of pectin as an antimicrobial. Less-degraded pectin extracted by acid-free routes, we argue in the conclusions, will soon find applications from new treatments for polymicrobial infections to use as an implantable biomaterial in tissue and bone engineering.     

果胶提取技术及对品质影响研究进展

果胶是一种天然、功能型的食品添加剂,具有凝胶、增稠、乳化等作用,现已广泛应用于食品、药品及化妆品等领域。该文着重介绍了近年来国内外果胶提取技术及其对果胶品质的影响,简单阐述果胶的结构和应用,此外,该文对果胶今后研究的重点和提取技术的发展趋势进行分析展望,为果胶提取的研究和发展提供参考。     

四种多糖代替明矾改善红薯粉的品质特性

以阿拉伯胶、海藻酸钠、黄原胶、果胶四种天然多糖代替传统红薯粉生产中的明矾，研究了4种添加剂对红薯粉品质的影响。以添加剂种类为因素，添加剂量为水平，通过单因素和复配实验对红薯粉相关品质进行了测试。实验表明4种多糖对红薯粉品质有着不同的影响，其中阿拉伯胶对样品断条率影响较大，当阿拉伯胶添加量为0.1%时，样品断条率最低，为23.51%；海藻酸钠主要影响红薯淀粉流变性质，当添加水平为0.5%时，相应的应力、黏度和法向应力分别为76.97 Pa、3.85 Pa?s、-12.53 Pa；黄原胶对红薯粉的硬度性影响较大，当添加水平为0.2%时，其硬度达到18.83 N；果胶主要影响样品的内聚性、咀嚼性，当添加水平为0.3%和0.1%时，样品的内聚性和咀嚼性分别达到0.70 Ratio和20.51 mJ；而使用0.1%阿拉伯胶、0.4%海藻酸钠、0.4%黄原胶、0.3%果胶与0.2%阿拉伯胶、0.3%海藻酸钠、0.4%黄原胶、0.1%果胶复配而成的复合添加剂，其样品拉伸力分别达到0.60 N、0.62 N，断条率分别为23.25%、24.66%，能够显著提升红薯粉的各项性质，改善红薯粉的品质。结果表明可以通过天然多糖复配的方法有效替代红薯粉上产中有害的明矾。     

马铃薯渣综合利用研究现状及进展

马铃薯渣是马铃薯淀粉加工产业的一种副产物,常被作为垃圾废弃掉,造成资源浪费和环境污染。实际上,马铃薯渣中含有许多有价值的成分,具有被开发利用的潜力。目前,马铃薯渣的综合利用主要集中在以下几方面:提取膳食纤维和果胶;制备高蛋白高能量饲料;制备新型黏合剂、胶黏剂和吸附材料;制备燃料酒精、生物质混合燃料和能量气体;制备种曲、醋、酱油及可食性膜等。综述了马铃薯渣目前综合利用的研究现状及进展。