Spectroscopy, Fourier Transform Infrared

光谱学,傅里叶变换红外
  • 文章类型: Journal Article
    从废物中提取淀粉也是回收资源和提供新的淀粉来源的有效途径。在这项研究中,从白芸豆渣中分离出淀粉,鹰嘴豆残留物,提取蛋白质或油后的虎坚果粉,观察淀粉颗粒的形态,以确定其理化性质和体外消化率。所有这些分离的淀粉都有独特的性质,其中白芸豆淀粉(KBS)直链淀粉含量高(43.48%),它的结构更有序。扫描电子显微镜显示三种淀粉的不同颗粒形态。KBS和鹰嘴豆淀粉(CHS)是中等颗粒淀粉,而虎子淀粉是一种小颗粒淀粉。傅里叶变换红外光谱分析证实三种淀粉分子之间的官能团和化学键不存在显著差异。体外消化率研究表明,CHS对酶降解的抗性更强。总的来说,这些结果将有助于开发基于从废物中分离非常规淀粉的产品。
    Extraction of starch from waste is also an effective way to recover resources and provide new sources of starch. In this study, starch was isolated from white kidney bean residue, chickpea residue, and tiger nut meal after protein or oil extraction, and the morphology of starch particles was observed to determine their physicochemical properties and in vitro digestibility. All these isolated starches had unique properties, among which white kidney bean starch (KBS) had a high amylose content (43.48%), and its structure was better ordered. Scanning electron microscopy revealed distinct granular morphologies for the three starches. KBS and chickpea starch (CHS) were medium-granular starches, whereas tiger nut starch was a small granular starch. Fourier transform infrared spectroscopy analysis confirmed the absence of significant differences in functional groups and chemical bonds among the three starch molecules. In vitro digestibility studies showed that CHS is more resistant to enzymatic degradation. Overall, these results will facilitate the development of products based on the separation of nonconventional starches from waste.
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  • 文章类型: Journal Article
    阐明乳液中磷脂和乳蛋白之间的相互作用机制对于理解婴儿配方脂肪球的特性至关重要。在这项研究中,采用多光谱方法和分子对接技术探讨磷脂酰胆碱(PC)与乳清分离蛋白(WPI)的关系。观察表明,结合常数,除了热力学参数,随着温度的升高,暗示主要是静态淬火机制。主要是,范德华力和氢键构成了WPI和PC之间的核心相互作用。傅里叶变换红外光谱进一步证实了这一论断,用于验证PC对WPI二级结构的影响。对分子对接的热力学参数的详细评估表明,PC主要粘附于α-乳清蛋白内的特定位点,β-乳球蛋白,和牛血清白蛋白,由疏水相互作用的协同作用推动,氢键,和范德华部队,结合能分别为-5.59、-6.71和-7.85kcal/mol,分别。观察到PC浓度的增加放大了WPI的乳化性质,同时降低了ζ电位。本研究为PC-WPI相互作用机制在食品中的应用奠定了理论基础。
    The elucidation of the interaction mechanism between phospholipids and milk proteins within emulsions is pivotal for comprehending the properties of infant formula fat globules. In this study, multispectral methods and molecular docking were employed to explore the relationship between phosphatidylcholine (PC) and whey protein isolate (WPI). Observations indicate that the binding constant, alongside thermodynamic parameters, diminishes as temperature ascends, hinting at a predominantly static quenching mechanism. Predominantly, van der Waals forces and hydrogen bonds constitute the core interactions between WPI and PC. This assertion is further substantiated by Fourier transform infrared spectroscopy, which verifies PC\'s influence on WPI\'s secondary structure. A detailed assessment of thermodynamic parameters coupled with molecular docking reveals that PC predominantly adheres to specific sites within α-lactalbumin, β-lactoglobulin, and bovine serum albumin, propelled by a synergy of hydrophobic interactions, hydrogen bonding, and van der Waals forces, with binding energies noted at -5.59, -6.71, and -7.85 kcal/mol, respectively. An increment in PC concentration is observed to amplify the emulsification properties of WPI whilst concurrently diminishing the zeta potential. This study establishes a theoretical foundation for applying the PC-WPI interaction mechanism in food.
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  • 文章类型: Journal Article
    利用新型活性成分对壳聚糖纳米制剂进行功能改性已引起全球关注。在这项研究中,壳聚糖已通过组氨酸功能化,以使用离子凝胶法制备新型壳聚糖-组氨酸纳米制剂(C-HNF)。C-HNF表现出优良的物理生化特性,影响番茄生理生化动态。这些优良的特性包括均匀尺寸的纳米颗粒(314.4nm),较低的PDI(0.218),粘度(1.43Cps),较高的zeta电位(11.2mV),纳米粒子浓度/ml(3.53×108),电导率(0.046mS/cm),封装效率(53%),装载能力(24%)和产量(32.17%)。FTIR光谱显示组氨酸与C-HNF,而SEM和TEM暴露了其多孔结构。通过种子处理和叶面喷雾将C-HNF应用于番茄幼苗和盆栽植物,对生长参数产生积极影响。抗氧化防御酶活性,活性氧(ROS)含量,叶绿素和氮含量。我们声称组氨酸官能化的壳聚糖纳米制剂增强了物理生化特性,强调其提高番茄植物生化和生理过程的潜力。
    The use of novel active ingredients for the functional modification of chitosan nanoformulations has attracted global attention. In this study, chitosan has been functionalized via histidine to craft novel chitosan-histidine nanoformulation (C-H NF) using ionic gelation method. C-H NF exhibited elite physico-biochemical properties, influencing physiological and biochemical dynamics in Tomato. These elite properties include homogenous-sized nanoparticles (314.4 nm), lower PDI (0.218), viscosity (1.43 Cps), higher zeta potential (11.2 mV), nanoparticle concentration/ml (3.53 × 108), conductivity (0.046 mS/cm), encapsulation efficiency (53%), loading capacity (24%) and yield (32.17%). FTIR spectroscopy revealed histidine interaction with C-H NF, while SEM and TEM exposed its porous structure. Application of C-H NF to Tomato seedling and potted plants through seed treatment and foliar spray positively impacts growth parameters, antioxidant-defense enzyme activities, reactive oxygen species (ROS) content, and chlorophyll and nitrogen content. We claim that the histidine-functionalized chitosan nanoformulation enhances physico-biochemical properties, highlighting its potential to elevate biochemical and physiological processes of Tomato plant.
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  • 文章类型: Journal Article
    海冰微藻是极地海洋食物网能量和营养供应的关键来源,尤其是在春天,在开放水域浮游植物开花之前。作为食物来源的微藻的营养质量取决于它们的生物分子(脂质:蛋白质:碳水化合物)组成。在这项研究中,我们使用基于同步加速器的傅里叶变换红外显微光谱(s-FTIR)来测量主要海冰分类群的生物分子含量,Nitzschiafrigida,来自整个北极春季的自然陆地快速冰群落。从内部(相对稳定)和外部(相对动态)峡湾位置重复采样六周,显示生物分子含量的高特异性内变异性,阐明N.frigida的可塑性,以适应动态的海冰和水条件。环境触发因素表明冰中生产力的结束和冰融化的开始,包括氮限制和水温升高,推动了脂质和脂肪酸储存的增加,蛋白质和碳水化合物含量下降。在气候变化和北极大西洋化预测的背景下,动态混合和突然变暖的水平流可以截断这些重要的季末环境变化,使藻类在足够的脂质储存之前从冰上释放,影响通过极地海洋系统的碳转移。
    Sea-ice microalgae are a key source of energy and nutrient supply to polar marine food webs, particularly during spring, prior to open-water phytoplankton blooms. The nutritional quality of microalgae as a food source depends on their biomolecular (lipid:protein:carbohydrate) composition. In this study, we used synchrotron-based Fourier transform infra-red microspectroscopy (s-FTIR) to measure the biomolecular content of a dominant sea-ice taxa, Nitzschia frigida, from natural land-fast ice communities throughout the Arctic spring season. Repeated sampling over six weeks from an inner (relatively stable) and an outer (relatively dynamic) fjord site revealed high intra-specific variability in biomolecular content, elucidating the plasticity of N. frigida to adjust to the dynamic sea ice and water conditions. Environmental triggers indicating the end of productivity in the ice and onset of ice melt, including nitrogen limitation and increased water temperature, drove an increase in lipid and fatty acids stores, and a decline in protein and carbohydrate content. In the context of climate change and the predicted Atlantification of the Arctic, dynamic mixing and abrupt warmer water advection could truncate these important end-of-season environmental shifts, causing the algae to be released from the ice prior to adequate lipid storage, influencing carbon transfer through the polar marine system.
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  • 文章类型: Journal Article
    离子液体(IL)是具有广泛的工业和科学应用的令人感兴趣的化合物。它们有非凡的性能,例如它们许多物理性质的可调性,因此,他们的活动;以及合成方法的简易性。因此,它们成为催化的重要组成部分,提取,电化学,分析,生物技术,等。本研究通过最小抑制浓度(MIC)估算方法确定了各种基于咪唑鎓的离子液体对酿酒酵母的抗真菌活性。增加连接到咪唑鎓阳离子的烷基的长度,增强了IL的抗真菌活性,以及它们破坏细胞膜完整性的能力。在用IL处理的酿酒酵母细胞上进行的FTIR研究揭示了这些细胞的生化组成的改变。有趣的是,在连接的烷基的长度增加时,脂肪酸含量的变化与分子活性的增加同时发生。统计分析和机器学习方法证实了这一趋势。根据酿酒酵母细胞的FTIR光谱对抗真菌活性进行分类,预测准确率为83%,这表明制药和医药行业可以从机器学习方法中受益。此外,合成的离子化合物在药物和医学应用中表现出巨大的潜力。
    Ionic liquids (ILs) are interesting chemical compounds that have a wide range of industrial and scientific applications. They have extraordinary properties, such as the tunability of many of their physical properties and, accordingly, their activities; and the ease of synthesis methods. Hence, they became important building blocks in catalysis, extraction, electrochemistry, analytics, biotechnology, etc. This study determined antifungal activities of various imidazolium-based ionic liquids against yeast Saccharomyces cerevisiae via minimum inhibitory concentration (MIC) estimation method. Increasing the length of the alkyl group attached to the imidazolium cation, enhanced the antifungal activity of the ILs, as well as their ability of the disruption of the cell membrane integrity. FTIR studies performed on the S. cerevisiae cells treated with the ILs revealed alterations in the biochemical composition of these cells. Interestingly, the alterations in fatty acid content occurred in parallel with the increase in the activity of the molecules upon the increase in the length of the attached alkyl group. This trend was confirmed by statistical analysis and machine learning methodology. The classification of antifungal activities based on FTIR spectra of S. cerevisiae cells yielded a prediction accuracy of 83%, indicating the pharmacy and medicine industries could benefit from machine learning methodology. Furthermore, synthesized ionic compounds exhibit significant potential for pharmaceutical and medical applications.
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  • 文章类型: Journal Article
    在乳制品中,添加的透明质酸钠可以与蛋白质形成复合物,从而影响产品性能。在本研究中,在不同温度(25℃,65℃,90℃和121℃)研究了蛋白质/SH比和pH对复合物形成的影响。SH的添加降低了WPI/WPH的粒径,增加了系统中的电位值,随着处理温度的升高而变化较大。研究了配合物的结构性质。与SH的结合降低了游离氨基和游离巯基的含量,以及荧光强度和表面疏水性。FTIR结果和褐变强度测量证明了美拉德反应产物的形成。此外,SH的附着提高了WPI/WPH的热稳定性,降低了其抗原性。
    In dairy products, the added sodium hyaluronate may form complexes with proteins, thereby affecting product properties. In the present study, the interaction between whey protein isolate (WPI)/ whey protein hydrolysate (WPH) and sodium hyaluronate (SH) was characterized under thermal treatment at different temperatures (25 ℃, 65 ℃, 90 ℃ and 121 ℃) after studying effects of protein/SH ratio and pH on complex formation. The addition of SH reduced the particle size of WPI/WPH and increased potential value in the system, with greater variation with increasing treatment temperature. The structural properties of complexes were studied. The binding with SH decreased the contents of free amino group and free thiol group, as well as the fluorescence intensity and surface hydrophobicity. FTIR results and browning intensity measurement demonstrated the formation of Maillard reaction products. Moreover, the attachment of SH improved the thermal stability of WPI/WPH and decreased their antigenicity.
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  • 文章类型: Journal Article
    Cerrado是世界上生物多样性最丰富的生物群落之一,其特点是丰富的具有独特营养特征的本地水果。在这个意义上,社会,经济,充分利用食物的环境重要性得到广泛认可。因此,通常被认为是废物,果壳可以转化为具有高附加值的副产品。这项工作的目的是对理化性质进行全面评估,碳水化合物和脂肪酸谱,植物化学化合物,酚醛型材,以及在natura中回收的buriti(毛里求斯flexuosa)壳提取物的抗氧化潜力,并在55°C(面粉)下脱水。此外,通过热重分析(TGA)验证了功能性能,扫描电子显微镜(SEM),和傅里叶变换红外光谱(FTIR)从buriti贝壳粉。结果表明,在55°C下处理的样品的纤维含量和能量值高(58.95g/100g和378.91kcal/100g,分别)和低脂和蛋白质含量(1.03g/100g和1.39g/100g,分别)。不管分析的样本,麦芽糖是大多数糖(37.33-281.01g/100g)。检测到的主要脂肪酸是油酸(61.33-62.08%),其次是棕榈酸(33.91-34.40%)。对矿物剖面的分析表明,样品之间没有显着差异,表明干燥过程不会干扰获得的结果(p≤0.05)。对单个酚类物质的分析可以鉴定出buriti壳中的六种酚类化合物。然而,可以观察到干燥方法对酚分布有积极和显著的影响(p≤0.05),与绿原酸(2.63-8.27毫克/100克)和三角碱(1.06-41.52毫克/100克),大多数化合物。另一方面,重要的是要强调的是,贝壳的类胡萝卜素含量很高,主要是β-胡萝卜素(27.18-62.94µg/100g)和α-胡萝卜素(18.23-60.28µg/100g),也受到55°C干燥过程的积极影响(p≤0.05)。基于所测试的不同方法,干燥的壳显示出高含量的植物化学化合物和高抗氧化活性。结果表明,布瑞提贝壳粉可以得到充分利用,具有营养和化学方面,可以应用于开发新的可持续,营养丰富,和功能性食品配方。
    The Cerrado is one of the most biodiverse biomes in the world, characterized by a wealth of native fruits with unique nutritional characteristics. In this sense, the social, economic, and environmental importance of fully utilizing food is widely recognized. Therefore, generally considered waste, fruit shells can be transformed into a coproduct with high added value. The objective of this work was to carry out a comprehensive assessment of the physicochemical properties, carbohydrate and fatty acid profile, phytochemical compounds, phenolic profile, and antioxidant potential of the recovered extracts of buriti (Mauritia flexuosa) shells in natura and dehydrated at 55 °C (flour). In addition, the functional properties were verified by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) from buriti shell flour. The results indicated high fiber content and energy value for the sample processed at 55 °C (58.95 g/100 g and 378.91 kcal/100 g, respectively) and low lipid and protein content (1.03 g/100 g and 1.39 g/100 g, respectively). Regardless of the sample analyzed, maltose was the majority sugar (37.33 - 281.01 g/100 g). The main fatty acids detected were oleic acid (61.33 - 62.08 %) followed by palmitic acid (33.91 - 34.40 %). The analysis of the mineral profile demonstrated that the samples did not differ significantly from each other, showing that the drying process did not interfere with the results obtained (p ≤ 0.05). The analysis of individual phenolics allowed the identification of six phenolic compounds in buriti shells. However, it is possible to observe that the drying method had a positive and significant influence on the phenolic profile (p ≤ 0.05), with chlorogenic acid (2.63 - 8.27 mg/100 g) and trigonelline (1.06 - 41.52 mg/100 g), the majority compounds. On the other hand, it is important to highlight that buriti shells have a high content of carotenoids, mainly β-carotene (27.18 - 62.94 µg/100 g) and α-carotene (18.23 - 60.28 µg/100 g), also being positively influenced by the drying process at 55 °C (p ≤ 0.05). The dried shells showed a high content of phytochemical compounds and high antioxidant activity based on the different methods tested. The results show that buriti shell flour can be fully utilized and has nutritional and chemical aspects that can be applied to develop new sustainable, nutritious, and functional food formulations.
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  • 文章类型: Journal Article
    研究了不同比例(w/w)的红茶天然芳香提取物(NAEBT)预乳化对猪肉面糊保水性(WHC)的影响。添加NAEBT可显著降低猪肉面糊的蒸煮损失(CL),从23.95%降至18.30%(P<0.05)。此外,预乳化的NAEBT显著提高了颜色稳定性,增加了弹性(P<0.05)。TBARS和羰基的结果表明,NAEBT预乳化显著减轻了蛋白质的氧化损伤(P<0.05)。导致β折叠水平增加(P<0.05),如FT-IR分析所证实。因此,猪肉面糊的水分流动性受到限制(P<0.05),导致储能模量增加(P<0.05)和孔径减小。总之,NAEBT的抗氧化作用提高了猪肉面糊的WHC。
    The effect of varying proportions (w/w) of natural aromatic extract of black tea (NAEBT) with pre-emulsification on the water-holding capacity (WHC) of pork meat batter was investigated. The addition of NAEBT significantly reduced the cooking loss (CL) of pork meat batter from 23.95 % to 18.30 % (P < 0.05). Furthermore, NAEBT with pre-emulsification significantly improved the color stability and increased the springiness (P < 0.05). The results of TBARS and carbonyls indicated that NAEBT with pre-emulsification significantly alleviated oxidative damage to proteins (P < 0.05), resulting in an increased level of β-sheet (P < 0.05), as confirmed by FT-IR analysis. As a result, the water mobility of pork meat batter was restricted (P < 0.05), resulting in an increase in the energy storage modulus (P < 0.05) and a decrease in the pore size. In summary, the WHC of pork meat batter was improved by the antioxidant effect of the NAEBT.
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  • 文章类型: Journal Article
    研究了使用碱性和自由基介导的方法(AM和FRM)结合超声处理合成的乳清-槲皮素和乳清水解物-槲皮素缀合物的结构和功能特性。FTIR显示在3000-3500cm-1(N-H拉伸区域)和具有缀合物的1000-1100cm-1区域的新峰。共轭增加了无规卷曲和α-螺旋含量,同时减少了β-折叠和转弯。它还增加了颗粒尺寸和表面疏水性,其在AM中显著高于(p<0.05)FRM缀合物。与FRM缀合物相比,AM缀合物具有更高的自由基清除活性,但槲皮素含量较低。总的来说,乳清-槲皮素偶联物的功能特性优于乳清水解物-槲皮素偶联物。然而,无论生产方法如何,水解产物缀合物具有显著更高的变性温度。超声处理提高了FRM缀合物的自由基清除活性和槲皮素含量,而AM缀合物的两者均降低。该研究表明,乳清-槲皮素缀合物通常具有比乳清水解物缀合物更好的质量,并且超声处理倾向于进一步改善这些性质。这项研究强调了使用骆驼乳清或乳清水解物-槲皮素结合物来增强食品工业中食品的功能特性的潜力。
    The structural and functional properties of whey-quercetin and whey hydrolysate-quercetin conjugates synthesized using alkaline and free radical-mediated methods (AM and FRM) coupled with sonication were studied. FTIR showed new peaks at 3000-3500 cm-1 (N-H stretching regions) and the 1000-1100 cm-1 region with the conjugates. Conjugation increased the random coils and α-helix content while decreasing the β-sheets and turns. It also increased the particle size and surface hydrophobicity which was significantly (p < 0.05) higher in AM than FRM conjugates. AM conjugates had higher radical scavenging activity but lower quercetin content than FRM conjugates. Overall, the functional properties of whey-quercetin conjugates were better than whey hydrolysate-quercetin conjugates. However, hydrolysate conjugates had significantly higher denaturation temperatures irrespective of the method of production. Sonication improved the radical scavenging activity and quercetin content of FRM conjugates while it decreased both for AM conjugates. This study suggested that whey-quercetin conjugates generally had better quality than whey hydrolysate conjugates and sonication tended to further improve these properties. This study highlights the potential for using camel whey or whey hydrolysate-quercetin conjugates to enhance the functional properties of food products in the food industry.
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  • 文章类型: Journal Article
    有毒重金属对水污染的增加,特别是六价铬,已经成为一个重大的环境问题。本研究探索了白蚁加工生物质的热解,特别是湿地松刨花板及其白蚁粪便(TD),制备生物炭及其对铬(Ⅵ)吸附的应用。白蚁粪便,富含木质素,和刨花板,富含纤维素,在各种温度下热解以评估生物质组成对生物炭性质的影响。研究发现,与富含纤维素的刨花板生物炭相比,富含木质素的白蚁粪便产生的生物炭具有更高的固定碳含量和比表面积。FTIR和拉曼光谱揭示了热解过程中分子结构的显著变化,这影响了生物炭的吸附能力。吸附实验表明,TD生物炭表现出较高的铬(VI)吸附能力,归因于其独特的化学组成和由于较高的木质素含量而增强的表面特性。这些发现强调了木质素在生产用于重金属吸附的高效生物炭中的关键作用,强调白蚁处理生物质在净水技术中的实际适用性。
    The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the pyrolysis of termite-processed biomass, specifically Pinus elliottii particleboard and its termite droppings (TDs), to produce biochar and its application for chromium (VI) adsorption. Termite droppings, rich in lignin, and particleboard, rich in cellulose, were pyrolyzed at various temperatures to assess the effect of biomass composition on biochar properties. The study found that lignin-rich termite droppings produced biochar with higher fixed carbon content and specific surface area than cellulose-rich particleboard biochar. FTIR and Raman spectroscopy revealed significant molecular structure changes during pyrolysis, which influenced the adsorption capabilities of the biochar. Adsorption experiments demonstrated that TD biochar exhibited significantly higher chromium (VI) adsorption capacity, attributed to its distinct chemical composition and enhanced surface properties due to higher lignin content. These findings underscore the crucial role of lignin in producing efficient biochar for heavy metal adsorption, highlighting the practical applicability of termite-processed biomass in water purification technologies.
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