Physicochemical properties

物理化学性质
  • 文章类型: Journal Article
    虽然农药制剂广泛用于病虫害防治,这些制剂与佐剂对液滴行为的综合影响,喷涂特性,虫害防治仍需研究。为了阐明它们对液滴行为的影响,喷涂特性,和控制功效,检查了六种啶虫脒的配方和六种佐剂。进行了一系列实验室和现场实验,以分析其理化性质,对棉蚜虫的毒性,液滴沉积特性,和液滴漂移。结果表明,与其他制剂相比,5%啶虫脒微乳液(ME)增强了害虫防治的物理化学特征和有效性。当添加时,农健飞大大提高了所有啶虫脒制剂的效率。在农药制剂中添加选定的助剂可以改善某些理化性质的性能,例如粘度和表面张力,并导致较高的蚜虫死亡率,在本研究中证明了害虫控制的有效性。在现场实验中,啶虫脒制剂和佐剂的组合效果表现出更高的液滴尺寸,覆盖范围,和棉花冠层内的密度。然而,发现5%啶虫脒ME最有效,其次是农健肺。此外,与其他制剂相比,含有佐剂的5%啶虫脒ME减少了液滴漂移并提供了更好的沉积。总的来说,特定配方和佐剂的组合导致改善的物理化学性质,增强的液滴沉积特性,减少喷雾漂移,和增加农药沉积。这些发现强调了选择合适的农药配方和助剂的重要性,并为通过无人机高效喷洒农药奠定了坚实的基础。
    While the pesticide formulations are widely used for pest control, the combined effects of these formulations with adjuvants on droplet behavior, spraying characteristics, and pest control still need to be studied. To clarify their impact on droplet behavior, spraying characteristics, and control efficacy, six formulations of acetamiprid and six adjuvants were examined. A series of laboratory and field experiments were conducted to analyze the physicochemical properties, toxicity against cotton aphids, droplet deposition characteristics, and droplet drift. The results indicated that 5% acetamiprid micro-emulsion (ME) enhanced the physicochemical features and effectiveness in pest control compared to other formulations. The nongjianfei considerably enhanced the efficiency of all acetamiprid formulations when added. The addition of selected adjuvants to pesticide formulations improved the performance of certain physicochemical properties such as viscosity and surface tension and led to higher aphid mortality rates, demonstrating enhanced pest control effectiveness during the present study. In the field experiments, the combination effect of acetamiprid formulations and adjuvants exhibited a higher droplet size, coverage, and density within the cotton canopy. However, 5% acetamiprid ME was found to be most effective followed by nongjianfei. Furthermore, 5% acetamiprid ME with adjuvant reduced the droplet drift and provided better deposition when compared with other formulations. Overall, the combination of specific formulations and adjuvants led to improved physicochemical properties, enhanced droplet deposition characteristics, reduced spray drift, and increased pesticide deposition. These findings highlighted the significance of selecting appropriate pesticide formulations and adjuvants and provided a solid foundation for efficient pesticide spraying through UAVs.
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  • 文章类型: Journal Article
    7天低温贮藏对理化性质的影响,营养成分,研究了猪肉的微观结构。在4°C下冷却7天后,肉表现出颜色恶化和异味的发展。相比之下,-12°C处理显着降低了保水能力和样品颜色的恶化(p<0.05),并防止了pH值的变化。同样,在-12和-18°C的处理有效地保存了肉的嫩度,硫代巴比妥酸反应性物质,蛋白质溶解度,和纹理属性,保持这些品质接近鲜肉(p>0.05)。在-12°C下储存的样品的营养素含量与在-18°C下储存的样品的营养素含量相当(p>0.05)。此外,在-12°C下冷冻被发现可以保护肌肉完整性,促进弹性凝胶网络和均匀的肌肉纤维结构的形成。因此,该研究的结论是,在-12°C下冷冻7天可以减少蛋白质变性并保持猪肉的品质,通常在-18°C的更极端的冷冻条件下获得的结果。
    The effect of 7-day subfreezing storage on the physicochemical properties, nutritional composition, and microstructure of pork was investigated. After 7 days of chilling at 4°C, the meat exhibited color deterioration and the development of off-flavors. In contrast, the -12°C treatment significantly reduced the deterioration in water-holding capacity and color of samples (p < 0.05) and prevented changes in pH value. Similarly, the treatments at -12 and -18°C effectively preserved the meat\'s tenderness, thiobarbituric acid-reactive substances, protein solubility, and textural properties, maintaining these qualities close to those of fresh meat (p > 0.05). The nutrient content of samples stored at -12°C was comparable to those stored at -18°C (p > 0.05). Furthermore, subfreezing at -12°C was found to protect muscle integrity, promoting the formation of an elastic gel network and a homogenous muscle fiber structure. Therefore, the study concludes that 7-day subfreezing storage at -12°C can reduce protein denaturation and maintain thequality of pork, a result that is typically achieved under more extreme freezing conditions at -18°C.
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  • 文章类型: Journal Article
    在这项研究中,比较研究干热处理(DHT)和退火(ANN)对多结构的影响,研究了黑青麦(BHB)淀粉的理化性质和体外消化率。结果表明,DHT和ANN均不影响BHB淀粉的“A”型结晶模式和FT-IR光谱,但是改变了形态,提高吸水能力和降低粘度。与天然淀粉相比,DHT和ANN修饰的样品在直链淀粉含量方面具有完全相反的变化趋势,颜色特征,吸油能力,糊化参数和糊化温度。这些变化与DHT改性淀粉的处理温度和时间呈正相关,而这取决于ANN改性淀粉的治疗持续时间。DHT后淀粉中的总体外水解速率和快速消化淀粉含量显着提高,而缓慢消化的淀粉和RS水平下降。然而,随着处理时间的延长,ANN显著提高了水解稳定性,尤其是RS含量增加和RDS水平降低。因此,这项研究确定DHT和ANN是改变BHB淀粉性质的有效方法,更重要的是,它们通过不同的机制产生了不同的影响,这将提醒用户根据不同的应用目的选择合适的方法进行物理淀粉改性。
    In this study, comparative investigation on the effect of dry heating treatment (DHT) and annealing (ANN) on multi-structure, physicochemical properties and in vitro digestibility of black highland barley (BHB) starch was done. Results revealed that both DHT and ANN did not affect the \"A\"-type crystalline pattern and FT-IR spectroscopy of BHB starch, but changed the morphology, raised water absorption capacity and lowered viscosities. Compared to native starch, DHT- and ANN-modified samples had totally opposite alteration trends in amylose content, color characteristics, oil absorption capacity, gelatinization parameters and pasting temperature. These changes were positively related to treatment temperature and time for DHT-modified starches, while which were dependant on treatment duration for ANN-modified starches. Total in vitro hydrolysis rate and rapidly digestive starch content in starch markedly raised after DHT, whereas slowly digestive starch and RS levels decreased. Nevertheless, ANN significantly improved the hydrolyzation stability with treatment time prolonging, especially increased RS content and lowered RDS level. Therefore, this study identified both DHT and ANN were effective methods to alter the properties of BHB starch, and more importantly, they had distinguishing influence by different mechanisms, which would remind user to select appropriate means for physical starch modification based on different application purposes.
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  • 文章类型: Journal Article
    本研究旨在揭示细菌动力学对烤肉(Larou)品质和生物胺(BA)积累的影响。物理化学参数,游离氨基酸,BAs,氨基酸脱羧酶,并确定了微生物概况,在Larou成熟和储存过程中探索了它们的关系。结果表明,在拉罗成熟期,水分和亚硝酸钠显著降低(p<0.05),而pH值,NaCl,TBARS,挥发性碱性氮总量显著增加(p<0.05)。BAs主要在Larou的干熟和储存阶段形成,可能存在酪胺和苯乙胺中毒的风险。厚壁菌和放线菌是主要的门,优势属是葡萄球菌属,棒状杆菌和乳球菌。相关性分析显示棒状杆菌,短杆菌,乳酸菌,四球菌和葡萄球菌属。在确定Larou的质量和安全性方面发挥了至关重要的作用。
    在线版本包含补充材料,可在10.1007/s10068-023-01472-1获得。
    This study aimed to reveal the impact of bacterial dynamics on the quality and biogenic amine (BA) accumulation of dry-cured Chinese bacon (Larou). Physicochemical parameters, free amino acids, BAs, amino acid decarboxylase, and microbial profiles were determined, and their relationships were explored during Larou ripening and storage. The results showed that moisture and sodium nitrite decreased significantly during the Larou ripening stage (p < 0.05), while pH, NaCl, TBARS, and total volatile basic nitrogen considerably increased (p < 0.05). BAs were mainly formed during the stages of dry-ripening and storage of Larou and may present a risk of tyramine and phenylethylamine poisoning. Firmicutes and Actinobacteriota were the predominant phyla, and the dominant genera were Staphylococcus, Corynebacterium and Lactococcus. Correlation analysis showed Corynebacterium, Brevibacterium, Lactobacillus, Tetragenococcus and Staphylococci spp. played a crucial role in determining the quality and safety of Larou.
    UNASSIGNED: The online version contains supplementary material available at 10.1007/s10068-023-01472-1.
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  • 文章类型: Journal Article
    在这项研究中,比较了四种不同类型的复合营养米(米粉加其他粗粮,豆类,土豆,和其他粉末,挤压为人造米粒)和普通大米。我们发现,复合营养大米的蛋白质和表观直链淀粉含量高于普通大米,分别高达9.775%和19.45%。γ-氨基丁酸(GABA)和抗性淀粉含量远低于普通水稻,膳食纤维含量与普通大米没有差异。傅里叶变换红外光谱(FTIR)和X射线衍射(XRD)分析结果表明,复合营养大米的淀粉性质和结构因高温高压加工而发生变化。特别是,淀粉的晶体结构变成V形。此外,人工品尝和品尝仪的结果表明,复合营养大米的味道普遍不如普通大米。总之,复合营养米存在营养不平衡、口感差等问题。复合营养米的口感品质还有很大的提升空间。因此,未来复合营养米的发展应注重营养平衡和口感改善。本文的研究结果也为此提供了一定的理论基础。
    In this study, it was compared the physicochemical properties and cooking taste quality between four different types of compound nutritional rice (rice flour with the addition of other coarse grains, legumes, potatoes, and other powders, extruded as artificial rice grains) and common rice. We found that the protein and apparent amylose contents of compound nutritional rice were higher than that of common rice, up to 9.775% and 19.45% respectively. The γ-aminobutyric acid (GABA) and resistant starch contents were much lower than in common rice, and the dietary fiber content did not differ from that in common rice. The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis revealed that the starch properties and structure of the compound nutritional rice changed due to high temperature and high pressure processing. In particular, the crystalline structures of starch became V-shaped. In addition, the results of artificial tasting and tasting meter showed that the taste of compound nutritional rice was generally inferior to that of common rice. In summary, compound nutritional rice had problems such as nutritional imbalance and poor taste. There was still a lot of room for improving the taste quality of compound nutritional rice. Therefore, the future development of compound nutritional rice should focus on both nutritional balance and taste improvement. The results of this paper also provided a certain theoretical basis for this.
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  • 文章类型: Journal Article
    干分馏代表了从牛脂中分离各种级分的重要技术。这项研究的目的是对物理化学性质的变化进行系统的调查,结晶行为,热性能,和在牛脂干分馏过程中产生的风味化合物。在40、30和15°C下产生的固体组分为44.88%,33.72%,和13.04%,15°C时液体含量为8.36%,这符合饱和脂肪酸含量的特点。X射线衍射清楚地揭示了干分馏过程中的β-β'转化。差示扫描量热曲线显示放热和吸热峰的变化,以及焓。电子鼻识别短链化合物,醛类,酮,和含氮物质作为风味化合物。挥发性化合物使用HS-SPME-GC-MS定量。总的来说,干分馏产生具有不同物理化学性质和芳香活性物质的牛脂分馏化合物,从而扩大其潜在的利用率。
    Dry fractionation represents a significant technique for separation of diverse fractions from beef tallow. The objective of this study was to undertake a systematic investigation of alterations in physicochemical properties, crystallization behavior, thermal properties, and flavor compounds that occur during the beef tallow dry fractionation process. The solid component yielded at 40, 30, and 15 °C were 44.88%, 33.72%, and 13.04% respectively, with an 8.36% liquid content at 15 °C, which was consistent with the characteristics of saturated fatty acids content. The β - β\' transformation in the dry fractionation process was clearly revealed by X-ray diffraction. Differential scanning calorimetry curves exhibited alterations in exothermic and endothermic peak, as well as enthalpy. Electronic nose identified short-chain compounds, aldehydes, ketones, and nitrogen-containing substances as flavor compounds. Volatile compounds were quantified using HS-SPME-GC-MS. Overall, dry fractionation produces beef tallow fractionated compounds with diverse physicochemical properties and aromatic-active substances, thereby expanding its potential utilization.
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  • 文章类型: Journal Article
    抗糖尿病肽(ADP),具有潜在抗糖尿病活性的肽,在糖尿病的治疗和控制中具有重要意义。尽管它们具有治疗潜力,由于数据有限,ADP的发现和预测仍然具有挑战性,肽功能的复杂性,以及传统湿式实验室实验的昂贵和耗时的性质。本研究旨在通过探索使用先进的深度学习技术发现和预测ADP的方法来解决这些挑战。具体来说,我们开发了两种模型:单通道CNN和三通道神经网络(CNN+RNN+Bi-LSTM)。ADP主要来自BioDADPep数据库,除了数以千计的来自抗癌的非ADP,抗菌,和抗病毒肽数据集。随后,使用进化尺度模型(ESM-2)进行数据预处理,然后通过10倍交叉验证进行模型训练和评估。此外,这项工作通过文献综述收集了一系列新出版的ADP作为独立的测试集,并发现CNN模型在预测独立测试集时达到了最高的准确率(90.48%),超越现有的ADP预测工具。最后,考虑了模型的应用。SeqGAN用于生成新的候选ADP,然后用构建的CNN模型进行筛选。然后使用物理化学性质预测和药物潜力的结构预测来评估所选肽。总之,本研究不仅建立了稳健的ADP预测模型,而且利用这些模型筛选了一批潜在的ADP,解决了基于肽的抗糖尿病研究领域的关键需求。
    Antidiabetic peptides (ADPs), peptides with potential antidiabetic activity, hold significant importance in the treatment and control of diabetes. Despite their therapeutic potential, the discovery and prediction of ADPs remain challenging due to limited data, the complex nature of peptide functions, and the expensive and time-consuming nature of traditional wet lab experiments. This study aims to address these challenges by exploring methods for the discovery and prediction of ADPs using advanced deep learning techniques. Specifically, we developed two models: a single-channel CNN and a three-channel neural network (CNN + RNN + Bi-LSTM). ADPs were primarily gathered from the BioDADPep database, alongside thousands of non-ADPs sourced from anticancer, antibacterial, and antiviral peptide datasets. Subsequently, data preprocessing was performed with the evolutionary scale model (ESM-2), followed by model training and evaluation through 10-fold cross-validation. Furthermore, this work collected a series of newly published ADPs as an independent test set through literature review, and found that the CNN model achieved the highest accuracy (90.48 %) in predicting the independent test set, surpassing existing ADP prediction tools. Finally, the application of the model was considered. SeqGAN was used to generate new candidate ADPs, followed by screening with the constructed CNN model. Selected peptides were then evaluated using physicochemical property prediction and structural forecasts for pharmaceutical potential. In summary, this study not only established robust ADP prediction models but also employed these models to screen a batch of potential ADPs, addressing a critical need in the field of peptide-based antidiabetic research.
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  • 文章类型: Journal Article
    开发了具有比色pH指示剂特性的智能指示剂膜,掺入黑大豆种皮花青素(BA),纤维素纳米晶体(CNC),和海藻酸钠(SA)监测肉类新鲜度。不同的CNC添加对微观结构的影响,薄膜的防水性能,和BA释放动力学进行了全面的研究。结果表明,随着CNC添加量的增加,提高了SA/BA/CNC薄膜的力学性能,水接触角从51.6°增加到69°。此外,水溶性,蒸汽吸附,渗透率显著下降,表明增强的水阻隔性能。释放动力学结果表明,BA在72h内迅速释放,此后缓慢释放。Fick\的模型描述了它的发布过程。具有7%和10%CNC的膜具有较低的BA扩散系数。它们的扩散被表述为线性回归方程(y=nx+a),其中R2>0.80,n<0.50。结构表征表明,CNC固定化BA主要通过氢键,用SA和BA形成紧密的网络微结构。肉新鲜度监测结果表明,含有7%CNC的薄膜随着总挥发性碱性氮和pH值的增加而显示出可见的颜色变化,随着低BA释放,高水阻隔性和机械性能。因此,CNC在改善指示膜的物理化学性能方面具有巨大潜力,智能比色指示剂膜可应用于各种食品。
    Intelligent indicator films with colorimetric pH indicator properties were developed, incorporating black soybean seed coat anthocyanin (BA), cellulose nanocrystals (CNC), and sodium alginate (SA) to monitor meat freshness. The effect of different CNC additions on the microstructure, water barrier properties of the films, and BA release kinetics were comprehensively investigated. The results showed that with the increasement of CNC addition, the mechanical properties of SA/BA/CNC films were improved, the water contact angle significantly increased from 51.6° to 69°. Moreover, water solubility, vapor adsorption, and permeability significantly decreased, indicating enhanced water barrier properties. The release kinetic results showed that BA was released rapidly within 72 h and slowly thereafter, and its release process was described by Fick\'s model. Films with 7 % and 10 % CNC had lower BA diffusion coefficients. Their diffusions were formulated as linear regression equations (y = nx + a), where R2 was >0.80 and n was <0.50. Structural characterization showed that CNC immobilized BA mainly through hydrogen bonding, forming compact network microstructures with SA and BA. Meat freshness monitoring results showed that the film containing 7 % CNC showed visible color changes with increasing total volatile basic nitrogen and pH, along with low BA release, high water barrier and mechanical properties. Therefore, CNC has great potential for improving the physicochemical properties of indicator films, and the intelligent colorimetric indicator film could be applied to various food product.
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  • 文章类型: Journal Article
    氮肥的使用是提高作物产量和质量的重要农艺实践。本研究调查了五种施氮量(0、60、135、210和285kgN/hm2)对谷子(FM)淀粉理化性质的影响。最佳施氮量(210kgN/hm2)显着增加L*,a*,和b*值,水和油的吸收能力,水溶性,和膨胀的力量。小淀粉颗粒的数量随着施氮量的增加而增加,但是颗粒形态和典型的A型模式在处理之间没有改变。施氮增加了相对结晶度和有序结构,导致较高的糊化焓。与对照组(7.02J/g)相比,焓增加了21.94%,66.38%,73.50%,和103.28%的氮施用量下,分别。此外,施氮量大大提高了A和B3链的百分比,同时降低了直链淀粉的表观含量,峰值粘度,和最终粘度。210和285kgN/hm2处理对水溶性和溶胀力的影响,水和油的吸收,与60和135kgN/hm2处理相比,淀粉的透光率更高。这些结果表明,氮肥显着影响FM淀粉的理化性质。
    The use of nitrogen fertilizer is a crucial agronomic practice to increase crop output and quality. This study investigated the impact of five nitrogen application levels (0, 60, 135, 210, and 285 kg N/hm2) on the physicochemical properties of foxtail millet (FM) starch. Optimal nitrogen application (210 kg N/hm2) significantly increased L*, a*, and b* values, water and oil absorption capacity, water solubility, and swelling power of starch. The number of small starch granules increased as the nitrogen application rate increased, but the granule morphology and typical A-type pattern did not change among the treatments. Nitrogen application increased the relative crystallinity and ordered structure, resulting in a higher gelatinization enthalpy. Compared to the control group (7.02 J/g), the enthalpy increased by 21.94 %, 66.38 %, 73.50 %, and 103.28 % under the nitrogen application rates, respectively. Moreover, nitrogen application greatly increased the percentage of A and B3 chains while it lowered the apparent amylose content, peak viscosity, and final viscosity. The effects of 210 and 285 kg N/hm2 treatments on the water solubility and swelling power, water and oil absorption, and light transmission of starch were greater compared to the 60 and 135 kg N/hm2 treatments. These results indicate that nitrogen fertilization significantly affects the physicochemical properties of FM starch.
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  • 文章类型: Journal Article
    低共熔溶剂(DES)是一种通过混合氢键供体和氢键受体制备的溶剂,并因其低毒性和可持续性而成为生态文明建设的热门话题。其优异的性能,如挥发性低,热稳定性和生物降解性使其在众多有机溶剂中脱颖而出,并广泛应用于医药等领域,化学工业和农业,具有广阔的发展前景。近年来,DES在食品领域的应用主要集中在小分子物质的提取,关于DES在大分子物质中的应用,目前还很少有综述。在这次审查中,我们介绍了合成,DES的分类和性质,综述了DES在食品工业中高分子物质的应用,包括提取大分子物质,如壳聚糖和果胶,以及相关高分子基底膜的制备。同时,我们分析了DES的特点及其在应用中的优势和局限性,并为未来的发展提供了前景。
    Deep eutectic solvent (DES) is a kind of solvent prepared by mixing hydrogen bond donors and hydrogen bond acceptors, and have become a hot topic in ecological civilization construction due to its low toxicity and sustainability. Its excellent properties such as low volatility, thermal stability and biodegradability make it stand out among many organic solvents and widely used in fields including medicine, chemical industry and agriculture, with broad development prospects. In recent years, the application of DES in the food field has mostly focused on the extraction of small molecular substances, and there are few summaries on the application of DES in macromolecular substances. In this review, we introduced the synthesis, classification and properties of DES, and summarized the application of DES in the food industry for macromolecular substances, including the extraction of macromolecular substances such as chitosan and pectin, as well as the preparation of related macromolecular substrate films. At the same time, we analyzed the characteristics of DES and its advantages and limitations in application, and provided prospects for future development.
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