Physicochemical properties

物理化学性质
  • 文章类型: Journal Article
    混合酸奶是由牛乳发酵,并通过转谷氨酰胺酶(TG)改性。通过质构特性研究了混合乳和TG对混合酸奶品质特性的影响,流变学(流变仪)和结构(扫描电子显微镜)。研究结果表明,含有50%牛奶的混合酸奶显示出更低的硬度,粘度和一致性。此外,当加入TG时,酸奶表现出更好的流变特性,感官评分和更稳定的微观结构。与未经TG改性的样品相比,改性样品的粘度和粘结性分别提高了10%和100%,分别。牛奶和豆浆的结合改善了酸奶的质地,TG的加入进一步改善了酸奶的理化性质。这一发现为开发具有适宜口感的动植物乳混合酸奶提供了有意义的参考。为混合酸奶在乳品行业的实际应用奠定了基础,这将满足未来消费者对乳制品的要求。
    The mixed yogurt was fermented from Cow-Soy milk and modified by transglutaminase (TG). The effects of mixed milk and TG on the quality characteristics of mixed yogurt were investigated by texture characteristics, rheology (rheometer) and structure (scanning electron microscopy). The findings revealed that the mixed yogurt with 50% cow milk exhibited lower hardness, viscosity and consistency. Furthermore, when TG was added, the yogurt showed better rheological properties, sensory score and a more stable microstructure. Compared with the samples without TG modification, the viscosity and cohesiveness of the modified samples increased by 10% and 100%, respectively. The combination of cow milk and soy milk improved the texture of yogurt, and the TG addition further improved the physicochemical properties of yogurt. This finding provided a meaningful reference for the development of mixed yogurt with a suitable taste from animal and plant milk, and laid a basis for the practical application of mixed yogurt in the dairy industry, which will meet the requirements for dairy products for consumers in future.
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  • 文章类型: Journal Article
    基于植物的蛋白质被认为是可持续的蛋白质来源并且最近需求增加。然而,含有基于植物的蛋白质的产品需要进一步修饰以实现与动物蛋白质产品中存在的那些类似的所需功能。本研究旨在研究酶作为交联剂对以羽扇豆和乳清蛋白为代表的基于植物和动物的杂种蛋白的物理化学和功能特性的影响。分别。使用两种漆酶(漆酶R,来源于白菊和漆酶T,源自杂色Trametes)和转谷氨酰胺酶(TG)。交联实验是通过在pH7,40°C的条件下以1:1的蛋白质含量比例混合羽扇豆粉和乳清蛋白浓缩物粉末的水溶液进行的。在漆酶T的存在下,漆酶R,或TG。将交联的混合物冷冻干燥,并评估获得的粉末的交联模式,颜色,电荷分布(ζ电位),颗粒大小,热稳定性,形态学,溶解度,发泡和乳化性能,和总氨基酸含量。结果表明,与漆酶R交联显著提高了蛋白质的溶解度,混合物的乳化稳定性和起泡能力,而这些官能团在TG处理的混合物中由于广泛的交联而较低。此外,用漆酶T处理的混合物变成褐色,总氨基酸含量下降,这可能是由于酶的氧化交联机制。此外,羽扇豆和乳清混合物中交联的发生通过其他研究参数的变化表明,如粒径,ζ-电位,等。,与对照样品相比。获得的结果表明,酶交联,根据使用的酶的类型,可能会影响基于植物和动物的杂种蛋白质的物理化学和功能特性,有可能影响它们在食品中的应用。
    Plant-based protein is considered a sustainable protein source and has increased in demand recently. However, products containing plant-based proteins require further modification to achieve the desired functionalities akin to those present in animal protein products. This study aimed to investigate the effects of enzymes as cross-linking reagents on the physicochemical and functional properties of hybrid plant- and animal-based proteins in which lupin and whey proteins were chosen as representatives, respectively. They were hybridised through enzymatic cross-linking using two laccases (laccase R, derived from Rhus vernicifera and laccase T, derived from Trametes versicolor) and transglutaminase (TG). The cross-linking experiments were conducted by mixing aqueous solutions of lupin flour and whey protein concentrate powder in a ratio of 1:1 of protein content under the conditions of pH 7, 40 °C for 20 h and in the presence of laccase T, laccase R, or TG. The cross-linked mixtures were freeze-dried, and the powders obtained were assessed for their cross-linking pattern, colour, charge distribution (ζ-potential), particle size, thermal stability, morphology, solubility, foaming and emulsifying properties, and total amino acid content. The findings showed that cross-linking with laccase R significantly improved the protein solubility, emulsion stability and foaming ability of the mixture, whereas these functionalities were lower in the TG-treated mixture due to extensive cross-linking. Furthermore, the mixture treated with laccase T turned brownish in colour and showed a decrease in total amino acid content which could be due to the enzyme\'s oxidative cross-linking mechanism. Also, the occurrence of cross-linking in the lupin and whey mixture was indicated by changes in other investigated parameters such as particle size, ζ-potential, etc., as compared to the control samples. The obtained results suggested that enzymatic cross-linking, depending on the type of enzyme used, could impact the physicochemical and functional properties of hybrid plant- and animal-based proteins, potentially influencing their applications in food.
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  • 文章类型: Journal Article
    本体外研究的目的是评估三种硅酸钙基密封剂的特定机械和物理化学性能,BioRoot™Flow(BRF),CeraSeal(CRS)和TotalFill®(TF)。制备样品以评价测试的密封剂的不同物理化学和机械性能。这些评估是通过调查pH随时间的变化来完成的,孔隙度,粗糙度,流动属性,抗压强度和润湿性。使用单向方差分析对结果进行统计学评估。从浸入水中1小时到168小时,所有三种密封剂都显示出碱性pH。与CRS和TF相比,在BRF样品中检测到更高的孔隙率和亲水性。在所测试的材料之间在流动性质上没有发现显著差异。与TF和CRS相比,BRF观察到更低的压缩强度值。在PBS中浸渍7天后,在三种材料上检测到不同形状的结构。三种材料在水中浸泡24小时后显示出比3%更高的溶解度(CRS The aim of the present in vitro study was to evaluate specific mechanical and physicochemical properties of three calcium silicate-based sealers, BioRoot™ Flow (BRF), CeraSeal (CRS) and TotalFill® (TF). Samples were prepared to evaluate different physicochemical and mechanical properties of the tested sealers. These evaluations were accomplished by investigating the pH changes over time, porosity, roughness, flow properties, compressive strength and wettability. The results were statistically evaluated using one-way analysis of variance. All three sealers demonstrated an alkaline pH from 1 h of immersion in water to 168 h. A higher porosity and hydrophily were detected in BRF samples compared to CRS and TF. No significant difference was found between the tested materials in the flow properties. Lower compressive strength values were observed for BRF compared to TF and CRS. Differently shaped structures were detected on the three materials after 7 days of immersion in PBS. The three materials demonstrated a higher solubility than 3% after 24 h of immersion in water (CRS < BRF < TF). The novel premixed calcium silicate sealer (BRF) had comparable physicochemical properties to the existing sealers. The lower compressive strength values could facilitate the removal of these materials during retreatment procedures. Further studies should investigate the biological effects of the novel sealer.
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  • 文章类型: Journal Article
    切片和干燥的山楂浆果在储存过程中很容易被昆虫感染。本研究旨在确定昆虫侵染对山楂果实品质的影响,并通过分析理化性质和代谢组学来评估代谢物水平的变化。总共获得了184种共享的差异代谢物,主要包括类黄酮,脂肪酸,羧酸及其衍生物,和含氮化合物。通过接收器工作特性曲线评估,筛选出9个显著差异标记以区分山楂浆果的昆虫侵染。相关分析表明,总有机酸,总酚类物质,总黄酮是昆虫侵染质量评价的有效指标,尿酸和马尿酸可以作为山楂果实贮藏过程中品质劣化的生物标志物。这项研究从宏观和微观角度证明了昆虫侵染会降低山楂浆果的品质。
    The sliced and dried hawthorn berries are easily infested by insects during storage. This study aimed to determine the effect of insect infestation on the quality of hawthorn berries and assess the change at metabolite level by analyzing physicochemical property and metabolomics profiling. A total of 184 shared differential metabolites were obtained, mainly including flavonoids, fatty acids, carboxylic acids and derivatives, and nitrogenous compounds. Through receiver operating characteristic curve assessment, 9 significant differential markers were screened out to distinguish insect infestation of hawthorn berries. Correlation analysis showed that the color, total organic acids, total phenolics, and total flavonoids were effective indicators for quality evaluation of insect infestation, and uric acid and hippuric acid can serve as biomarkers for the quality deterioration of hawthorn berries during storage. This study demonstrated that insect infestation could decrease the quality of hawthorn berries from macro and micro perspectives.
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  • 文章类型: Journal Article
    荞麦淀粉作为一种有价值的原料或食品添加剂在食品工业中引起了全世界的关注。氮(N)和硫(S)是确保谷物品质所必需的两种营养素。本研究调查了氮肥(0、45和90kgNha-1)和S肥(0和45kgSO3ha-1)的化学组成,荞麦淀粉的结构和理化性质.结果表明,增加施肥量降低了直链淀粉含量和淀粉颗粒大小,但增加了透光率,水溶性和膨胀力。吸收峰位置的稳定性和短程有序度的降低表明施肥影响了荞麦淀粉的分子结构。此外,粘度和糊化焓的增加以及糊化温度和动态流变特性的降低表明荞麦基食品的加工特性和产品质量发生了变化。
    Buckwheat starch has attracted worldwide attention in the food industry as a valuable raw material or food additive. Nitrogen (N) and sulfur (S) are two nutrients essential to ensure grain quality. This study investigated the combined application of N fertilizer (0, 45 and 90 kg N ha-1) and S fertilizer (0 and 45 kg SO3 ha-1) on the chemical composition, structure and physicochemical properties of buckwheat starch. The results showed that increasing the fertilizer application decreased amylose content and starch granule size but increased light transmittance, water solubility and swelling power. The stability of the absorption peak positions and the decrease in short-range order degree suggested that fertilization influenced the molecular structure of buckwheat starch. In addition, increases in viscosity and gelatinization enthalpy as well as decreases in gelatinization temperatures and dynamic rheological properties indicated changes in the processing characteristics and product quality of buckwheat-based foods.
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  • 文章类型: Journal Article
    高粱是世界上最古老的农作物之一,是中国北方重要的粮食作物,和白酒酿造行业的主要原料。物理化学性质,烹饪特点,高粱种子的淀粉质量对白酒酿造过程有很大影响。选择适合白酒酿造的高粱,确定不同高粱品种的蒸煮特性和淀粉理化性质,本研究使用了30种高粱,并比较了它们的组成;进一步研究了六种高粱的蒸煮品质和淀粉的理化和糊化特性。采用气相色谱飞行时间质谱分析高粱种子的烹饪香气。此外,扫描电子显微镜,快速粘度分析仪,用差示量热扫描仪分析高粱淀粉的微观结构,淀粉糊化特性,和热力学性质,分别。结果表明,糯高粱的吸水率和糖化力均高于粳型高粱,香气物质差异显著。高粱淀粉具有较高的结晶度,冻融稳定性,和焓,从而表明其结构的稳定性。本研究为今后葡萄酒原料的选择提供了理论依据。
    Sorghum is one of the oldest crops in the world, an important grain crop in northern China, and a major raw material in the liquor-brewing industry. The physicochemical properties, cooking characteristics, and starch quality of sorghum seeds considerably affect the liquor-brewing process.To select suitable sorghums for liquor brewing and to determine the cooking characteristics and starch physicochemical properties of different sorghum varieties, 30 types of sorghum were used in this study, and their compositions were compared; six types of sorghum were further studied for their cooking quality and starch physicochemical and pasting characteristics. Gas chromatography time of flight mass spectrometry was used to analyse the cooking aroma of sorghum seeds. Additionally, scanning electron microscopy, a rapid visco analyser, and a differential calorimetric scanner were used to analyse the microstructure of sorghum starch, starch pasting characteristics, and thermodynamic properties, respectively. The results revealed that the water absorption and saccharification forces of glutinous sorghum were higher than those of japonica sorghum and that the aroma substances were significantly different. Glutinous sorghum starch had high crystallinity, freeze-thaw stability, and enthalpy, thus indicating its structural stability. This study provides a theoretical basis for the selection of wine raw materials in the future.
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  • 文章类型: Journal Article
    本研究检查了不同浓度的丁基化羟基甲苯(BHT)抑制剂对转化动力学的影响,聚合收缩应力,以及实验树脂复合材料(ERC)的其他相关物理化学性能。用含有0.5重量%樟脑醌和1重量%胺的75重量%填料配制模型复合材料,BHT浓度为0.01重量%(BHT-0.01);0.1重量%(BHT-0.1);0.25重量%(BHT-0.25);0.5重量%(BHT-0.5);1重量%(BHT-1),和对照(无BHT)。它们在聚合收缩应力(PSS;n=5)上进行了测试,转换度(DC;n=3),最大聚合速率(RpMAX;n=5),吸水率(Wsp;n=0),和溶解度(Wsl;n=10),弯曲强度(FS;n=10),弯曲模量(FM;n=10),努普显微硬度(KH;n=10),和显微硬度降低(HR;n=10)。有关这些测试的数据提交单因素方差分析和Tukey检验(α=0.05;β=0.2)。BHT-0.25,BHT-0.5和BHT-1显示PSS逐渐显着降低(p=0.037);然而,BHT-1表现出测试的物理化学性质的降低。因此,在这项研究的局限性内,可以得出结论,0.25和0.5重量%之间的BHT浓度对于降低收缩应力是最佳的,而不影响ERC的其他物理化学性质。
    The present study examined different concentrations of the butylated hydroxytoluene (BHT) inhibitor on the kinetics of conversion, polymerization shrinkage stress, and other correlated physicochemical properties of experimental resin composites (ERC). A model composite was formulated with 75 wt% filler containing 0.5 wt% camphorquinone and 1 wt% amine with BHT concentrations of 0.01 wt% (BHT-0.01); 0.1 wt% (BHT-0.1); 0.25 wt% (BHT-0.25); 0.5 wt% (BHT-0.5); 1 wt% (BHT-1), and control (no BHT). They were tested on polymerization shrinkage stress (PSS; n = 5), degree of conversion (DC; n = 3), maximum polymerization rate (RpMAX; n = 5), water sorption (Wsp; n = 0), and solubility (Wsl; n = 10), flexural strength (FS; n = 10), flexural modulus (FM; n = 10), Knoop microhardness (KH; n = 10), and microhardness reduction (HR; n = 10). Data concerning these tests were submitted to one-way ANOVA and Tukey\'s test (α = 0.05; β = 0.2). BHT-0.25, BHT-0.5, and BHT-1 showed a gradually significant decrease in PSS (p = 0.037); however, BHT-1 demonstrated a decrease in the physicochemical properties tested. Thus, within the limitations of this study, it was possible to conclude that BHT concentrations between 0.25 and 0.5 wt% are optimal for reducing shrinkage stress without affecting other physicochemical properties of ERCs.
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  • 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
    已知一些氨基酸通过人和单胃动物的肠道微生物群代谢介导免疫应答。然而,通过饮食,大多数游离氨基酸在小肠中被吸收,只有少量到达富含微生物群的结肠。为了增强氨基酸的微生物代谢及其潜在的健康益处,为了保护和递送至结肠,开发了包封策略。到目前为止,氨基酸的主要封装系统是基于固体脂质颗粒,但是它们在消化道中的命运从未得到完全澄清。在这项研究中,我们研究了各种氨基酸(支链氨基酸混合物,或者赖氨酸,或色氨酸)在模仿仔猪的体外口胃肠消化过程中负载在固体脂质颗粒中。负载的固体脂质颗粒被完全表征其组成,热行为,分子结构,结晶状态,表面形态,和粒度分布。此外,我们通过将固体脂质颗粒筛分成两个不重叠的尺寸部分来研究颗粒尺寸的影响。我们发现在胃部消化阶段氨基酸释放量很高,主要由物理参数控制,即粒度和结晶状态,包括表面形态。大粒度和/或平滑有序颗粒确实导致更慢和更低的释放。尽管在消化的肠道阶段脂质水解是显著的,在没有酶的情况下也观察到结晶状态和表面形态的影响,指向通过这些多孔固体脂质颗粒的主要水/溶质扩散机制。
    Some amino acids are known to mediate immune responses through gut microbiota metabolism in both humans and monogastric animals. However, through the diet, most free amino acids are absorbed in the small intestine and only a small quantity reaches the microbiota-rich colon. To enhance microbial metabolism of amino acids and their potential health benefits, encapsulation strategies are developed for their protection and delivery to the colon. So far, the main encapsulation systems for amino acids are based on solid lipid particles, but their fate within the digestive tract has never been fully clarified. In this study, we investigated the release of various amino acids (branched-chain amino acid mixture, or lysine, or tryptophan) loaded in solid lipid particles during in vitro oro-gastrointestinal digestion mimicking the piglet. The loaded solid lipid particles were fully characterized for their composition, thermal behavior, molecular structure, crystalline state, surface morphology, and particle size distribution. Moreover, we investigated the effect of particle size by sieving solid lipid particles into two non-overlapping size fractions. We found that amino acid release was high during the gastric phase of digestion, mainly controlled by physical parameters, namely particle size and crystalline state including surface morphology. Large particle size and/or smooth ordered particle indeed led to slower and lower release. Although lipid hydrolysis was significant during the intestinal phase of digestion, the impact of the crystalline state and surface morphology was also observed in the absence of enzymes, pointing to a dominant water/solute diffusion mechanism through these porous solid lipid particles.
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  • 文章类型: Journal Article
    这项工作是研究四种益生元糖阿拉伯树胶(GA)的作用,低聚果糖(FOS),魔芋葡甘聚糖(KGM),和菊粉(INU)掺入对包封效率(EE)的影响,物理化学稳定性,和尿石素A-负载脂质体(UroA-LP)的体外消化。还通过体外结肠发酵研究了脂质体对肠道菌群的调节。结果表明,用GA包被的脂质体表现出最佳的EE,生物可及性,储存和热稳定性,生物可及性是UroA-LP的1.67倍。用FOS涂覆的UroA-LP显示出最佳的冻融稳定性和转化。同时,糖的添加显著提高了拟杆菌的相对丰度,降低了变形杆菌和放线菌的丰度。涂有FOS的UroA-LP,INU,和GA表现出最高的副杆菌属有益菌丰度,Monoglobus,和结核分枝杆菌,分别。FOS还可以降低有害细菌Collinsella和肠球菌的丰度,增加乙酸的含量,丁酸和异丁酸。因此,益生元糖可以改善EE,物理化学稳定性,UroA-LP的肠道菌群调节,并促进UroA的生物可利用性,但是效率因糖类类型而异,这为UroA在食品工业中的应用和提高其生物活性奠定了基础。
    This work was to investigate the effect of four prebiotic saccharides gum arabic (GA), fructooligosaccharide (FOS), konjac glucomannan (KGM), and inulin (INU) incorporation on the encapsulation efficiency (EE), physicochemical stability, and in vitro digestion of urolithin A-loaded liposomes (UroA-LPs). The regulation of liposomes on gut microbiota was also investigated by in vitro colonic fermentation. Results indicated that liposomes coated with GA showed the best EE, bioaccessibility, storage and thermal stability, the bioaccessibility was 1.67 times of that of UroA-LPs. The UroA-LPs coated with FOS showed the best freeze-thaw stability and transformation. Meanwhile, saccharides addition remarkably improved the relative abundance of Bacteroidota, reduced the abundances of Proteobacteria and Actinobacteria. The UroA-LPs coated with FOS, INU, and GA exhibited the highest beneficial bacteria abundance of Parabacteroides, Monoglobus, and Phascolarctobacterium, respectively. FOS could also decrease the abundance of harmful bacteria Collinsella and Enterococcus, and increase the levels of acetic acid, butyric acid and iso-butyric acid. Consequently, prebiotic saccharides can improve the EE, physicochemical stability, gut microbiota regulation of UroA-LPs, and promote the bioaccessibility of UroA, but the efficiency varied based on saccharides types, which can lay a foundation for the application of UroA in foods industry and for the enhancement of its bio-activities.
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