Applications of Microfluidization and High Pressure Processing in Food Industry and the Effect of Them on Food Products

With the development of technology, several new processing techniques are being introduced for the food industry. By applying those novel techniques to food systems, it has been found that the structural and functional properties of food could be altered. Microfluidization which is also known as high pressure homogenization is one of the novel technologies that could be applied in food industry to obtain many beneficial outcomes. High pressure processing is another novel technique that is mainly playing the microbicidal effect. This work is concerned on the possibility of using microfluidization and high pressure processing in food industry based on the experimental findings. These techniques could be used as useful tools in the field of food science and technology.

Structural, Pasting, and Thermal Properties of Ultra-high Pressure-treated Lotus Seed Starch

Lotus seed starch （15%, w/w） was subjected to ultra-high pressure （UHP） at 500 MPa for 10～60 min. The effects of UHP on the structural, pasting, and thermal properties of starch were investigated using solid-state 13C CP/MAS NMR, differential scanning calorimetry （DSC）, HPSEC-MALLS-RI, and a rapid visco analyzer. The 13C CP/MAS NMR results revealed a reduction in the relative crystallinity and peak intensity of the crystalline state with increasing the UHP time. The molecular weight of native starch was 1.433 × 107 Da, which was higher than that of the UHP-treated starch. Viscograms of UHP-treated starch revealed an increase in paste viscosity, peak time, and pasting temperature and a reduction in breakdown and setback viscosity compared to the native starch. Furthermore, the DSC results showed a reduction in gelatinization temperature and gelatinization enthalpy with increasing the UHP time.

Effects of ultra-high hydrostatic pressure on foaming and physical-chemistry properties of egg white

The influences of ultra-high hydrostatic pressure treatment on foaming and physical properties (solubility, hydrophobicity and sulfhydryl content) of egg white were investigated. A pressure range of 0-500 MPa, time range of 0-20 min and pH range of 7.5-8.5 were selected. The foaming property of egg white is improved by 350Mpa and 10min. The treatment resulted in in- crease of sulfhydryl content of egg white, while solubility and hydrophobicity were significantly decreased.

Analysis on performance and test of a new type of ultra-high pressure pipe joint

Analysis as well as application of ultra-high pressure hydraulic system and elements has become a trend. The structure and operation principle of a new type of ultra-high pressure pipe joint is introduced. The structure of the new type of ultra-high pressure pipe joint is simple and is easy to be produced. The finite element model on two working conditions( preload condition with 30 N·m torque and static-loading condition with 70 MPa pressure) is built and computed. The width of contact area,the equivalent stress status,as well as the contact pressure status are plotted and analyzed. According to the national standard,test on air-tightness,blasting,and cyclic endurance is conducted and the results show that the new type of ultra-high pressure pipe joint has the sealability for ultra-high pressure up to 70 MPa,and the DN6 ultra-high pressure pipe joint can provide effective seal under70 MPa fluid pressure. The research can provide a thinking and method on designing ultra-high pressure pipe joint and push forward the development of ultra-high pressure hydraulic system.

Enzymatic Hydrolysis of Hairtail Surimi in an Ultra-High Pressure Bioreactor

Amino acids have been extracted from Hairtail surimi using enzymes in an ultra-high pressure bioreactor. The extraction efficiency of different enzymes including papain, trypsin, and proteases (acid, neutral, alkaline) also has been evaluated, and it has been discovered that neutral protease behaved the best. The amino acids were analyzed using automatic amino acid analyzer, and the enzymatic digestion conditions were optimized. For neutral protease, the optimal condition was 50℃, 250 MPa, pH 7.0. Material to liquid ratio of enzyme is 6%. More than 29 amino acids were detected after 24 hours of hydrolysis;the enzymatic hydrolysis rate can reach 83.29%. The results show that enzymatic digestion under ultra-high-pressure provides a very promising approach to extract amino acids from Hairtail surimi.

PRESSURE FORCE CONTROL FOR FABRICATION OF PLASTIC MICROFLUIDIC CHIPS WITH HOT EMBOSSING METHOD

A pressure force control system for hot embossing of microfluidic chips is designed with a moment motor and a ball bearing lead screw. Based on the numeric PID technique, the algorithm of pulsant integral accelerated PID control is presented and the negative effects of nonlinearity from friction, clearance and saturation are eliminated. In order to improve the quick-resixmse characteristic, independent thread technique is adopted. The method of pressure force control based on pulsant integral accelerated PID control and independent thread technique is applied with satisfactory control performance.

THERMAL MODELLING OF COLLISIONAL OROGENY: IMPLICATIONS FOR THE ULTRA-HIGH PRESSURE METAMORPHISM

The petrological research on the ultra high pressure metamorphism (UHP) of collisional orogen indicates that the upper crustal rocks is subducted to depths exceeding 100 km, and returned to the surface rapidly. In this study, we investigate the thermal structure of collisional orogen as a slab of continental lithosphere being subducted beneath an overriding wedge of continental lithosphere by the 2 D finite element method. The advection heat transfer due to the accretion of orogenic wedge is considered. The wedge is composed of the upper crust materials through the accretion from the down going plate to the upper plate. For identifying the significance of the geometric and/or kinetic factors on the thermal structure of continental subduction, the different combinations of parameters, including dip angle of subduction zone, accretion or erosion rates, and the convergence velocity etc., are used in modelling. The time span of continental subduction in our calculation is less than 30 Ma, according to the short duration of ultra deep subduction of continental slab suggested by the preservation of metastable pre peak low pressure mineralogy assemblage in the garnet of UHP rocks. Therefore, the steep dip angle of down going plate and/or low rate of accretion favour the ultra deep subduction of upper crust materials, especially for the slower down going slab. Meanwhile, taking the erosion rate as the level of exhumation rate of UHP rocks in some orogens (i.e., 1-2 km/Ma or more) does not result in the anatexis melting of crust of the overriding plate, due to the cooling effect of the rapid down going slab. However, the temperature structures of all models are generally cooler than those recovered by thermobarometric studies of the UHP rocks. This implies the significant increase of temperature after the rapid subduction of continental slab. Following the method of Davies and von Blackenburg (1998), we show that the slab breakoff can occur at the depth exceeding 100 km. Thermal modelling on the post subduction stage shows the heating related to the plate breakoff can cause the higher temperature recorded by the exhumed UHP rocks. The higher geotherm during post subduction stage leads to the weak strength of the orogenic wedge, and favours the faster upward movement of the UHP rock slices as ductile agents. The lower temperature gradient of the subduction slab predicted by modelling suggests the cold subducting slab could have transported significant fluids to mantle depth, not released during subduction. Accordingly, the absence of coeval calc alkalic magmatism in UHP orogens might resulted from the lower temperature as well as the fluid free circumstance, both are related to the rapid subduction of cold plate. Therefore, shear heating is not needed for explanation the thermal evolution of UHP orogen. On the other hand, the post collisional or late stage granitic plutonism is closely related to the deep seated heat producing materials of the accretion wedge.

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM resonances.Herein,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors simultaneously.The structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene composites.Then,the result showed that CPP-SS can significantly improve theσof samples.Ultimately,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed.This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

Polyarylacetylene as a novel graphitizable precursor for fabricating high-density C/C composite via ultra-high pressure impregnation and carbonization

High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization(HIPIC)technology,which is time-consuming and expensive.In this study,we report an innovative method utilizing polyarylacetylene(PAA)resin and ultra-high pressure impregnation and carbonization(UHPIC)technology.The extremely high char yield of PAA resin(85 wt.%)and high isotropic pressure of UHPIC(over 200 MPa)promote the densification of the composite.As a result,we achieve a high-density(1.90 g/cm^(3))C/C composite with a high degree of graphitization(81%).This composite exhibits impressive properties,including flexural strength of 146 MPa,compressive strength of 187 MPa,and thermal conductivity of 147 W/(m K).When exposed to oxyacetylene flame at 3000 K for 100 s,it displays minimal linear ablation,with a rate of 1.27×10^(-2)mm/s.This study demonstrates the exceptional graphitizable characteristic of PAA resin,setting it apart from conventional resins.Our time-saving and cost-effective approach holds significant promise for aerospace applications,particularly in harsh aerodynamic heating environments.

Dynamic Compression Behavior of Ultra-high Performance Cement-based Composite with Hybrid Steel Fiber Reinforcements

Ultra-high performance cement-based composites (UHPCC) is promising in construction of concrete structures that suffer impact and explosive loads.In this study,a reference UHPCC mixture with no fiber reinforcement and four mixtures with a single type of fiber reinforcement or hybrid fiber reinforcements of straight smooth and end hook type of steel fibers were prepared.Split Hopkinson pressure bar (SHPB) was performed to investigate the dynamic compression behavior of UHPCC and X-CT test and 3D reconstruction technology were used to indicate the failure process of UHPCC under impact loading.Results show that UHPCC with 1% straight smooth fiber and 2% end hook fiber reinforcements demonstrated the best static and dynamic mechanical properties.When the hybrid steel fiber reinforcements are added in the concrete,it may need more impact energy to break the matrix and to pull out the fiber reinforcements,thus,the mixture with hybrid steel fiber reinforcements demonstrates excellent dynamic compressive performance.

动态高压微射流辅助提取石榴皮多糖工艺优化及其抗氧化活性

以石榴皮为原料,优化动态高压微射流辅助提取石榴皮多糖工艺并探究其抗氧化活性。通过单因素试验分析料液比、微射流压力、提取时间以及提取温度对石榴皮多糖得率的影响。进一步通过响应面试验优化提取工艺,试验结果确定最佳工艺条件为料液比1∶34(g/mL)、微射流压力106 MPa、提取时间2.6 h,在该工艺条件下石榴皮多糖得率为(29.07±0.42)%,与预测值接近,表明模型拟合良好,该优化工艺准确可行。同时提取的石榴皮多糖对DPPH·、·OH及ABTS^(+)·具有较好的清除活性。

高压射流磨在无添加全豆豆乳加工中的应用研究

本文研究了高压射流磨在无添加全豆豆乳中的应用及对全豆豆乳稳定性的影响。通过不同加工工艺下全豆豆乳的显微镜镜检、离心沉淀率、粒径分布、Zeta电位、外观口感、Lumisizer稳定性扫描为指标,明确了高压射流磨可以彻底粉碎全豆组织,降低产品粒径至33μm,且能大幅度提升无添加全豆豆乳的产品口感和货架期稳定性;同时通过考察不同蛋白质含量下全豆豆乳的弹性模量、Lumisizer稳定性扫描结果和Turbiscan扫描发现,蛋白质含量对全豆豆乳的稳定性也有影响,当蛋白质含量达到3.5%,全豆豆乳口感优、稳定性好,属于制备全豆豆乳的优选方案。由此可知:高压射流磨工艺是加工无添加全豆豆乳的关键工艺,对提高该类产品的整体稳定性、改善该类产品的质地口感、提升该类产品的整体品质有显著效果。

益智酮乙纳米乳液的制备工艺优化及其稳定性

以大豆卵磷脂为乳化剂,菜籽油为油相,制备一种稳定纳米乳液体系包埋益智酮乙。通过单因素试验、响应面试验优化纳米乳液制备条件,运用纳米粒度仪、激光共聚焦显微镜和傅里叶红外光谱仪等测量乳液的粒径、多分散系数(PDI)、Zeta电位、包封率、稳定性、光谱特性等。结果表明:在最佳制备工艺参数(大豆卵磷脂质量浓度18.4g/L、均质压强172.35MPa、均质次数7次和益智酮乙质量浓度7 mg/mL)下,益智酮乙纳米乳液平均粒径为(175.37±4.33)nm,PDI为0.13±0.02,包封率为(91.00±0.03)%;益智酮乙包埋量不影响乳液的粒径和PDI,包埋7 mg/mL益智酮乙的纳米乳液包封率最高;益智酮乙纳米乳液的微观结构为球状,乳液颗粒分布均匀,于4℃贮藏28d时,乳液的粒径、PDI和包封率均无明显变化,乳液系统稳定,添加NaCl浓度≤30 mmol/L时,乳液能维持较为稳定的状态,NaCl浓度≥50 mmol/L时,随着NaCl浓度的升高,乳液的粒径和PDI显著升高,Zeta电位绝对值显著降低,乳液稳定性下降;菜籽油、大豆卵磷脂和益智酮乙之间没有形成共价键,也未发生化学相互作用。

动态超高压微射流技术对红枣酒品质的影响

该研究使用动态超高压微射流技术(DHPM)对红枣酒进行150MPa均质压力处理,以未处理红枣酒为对照,从理化指标、色度、挥发性风味物质和滋味4个方面解析动态超高压微射流处理对红枣酒品质的影响。结果表明,与未处理组相比,动态超高压微射流处理组红枣酒的可溶性固形物含量和酒精度显著降低(p<0.05);L*值(明亮度)显著降低(p<0.05),b*值(黄蓝值)显著增加(p<0.05);醇类和芳香类化合物含量均显著增加(p<0.05);苦味、涩味和后味A的相对强度显著降低(p<0.05),咸味和丰度的相对强度显著增加(p<0.05);经主成分分析(PCA)发现,两者在整体品质结构上存在明显差异。由此可见,动态超高压微射流技术可以有效降低缺陷滋味物质的含量和提升芳香类物质的含量,从而明显改善红枣酒的整体品质。

酶联合动态高压微射流改性豌豆分离蛋白及其在Pickering乳液中的适用性

探究谷氨酰胺转氨酶(transglutaminase,TG)联合动态高压微射流(dynamichigh-pressure microfluidization,DHPM)改性豌豆分离蛋白(pea protein isolate,PPI)的作用机理,明确改性后PPI在Pickering乳液中的适用性。扫描电子显微镜观察和傅里叶变换红外光谱分析结果表明,改性处理后的PPI颗粒形貌更加均匀,且与TG交联程度加强,同时蛋白质分子三级结构发生变化。物性测试结果显示,改性后的PPI表面疏水性与内源荧光性降低,乳化性能提高且平均粒径减小。乳析指数、乳液粒径分布、乳液微观结构和流变性分析结果表明,改性后PPI制备所得Pickering乳液的稳定性和乳化性能改善,且120 MPa处理后乳液稳定性最好。TG联合DHPM改性为PPI在Pickering乳液中的应用提供了可行的方法。本研究为开发高性能的Pickering乳液系统提供了实验基础,对于天然蛋白质的功能性改性研究具有重要的参考价值。

基于高压微流控芯片的水合物相变与气泡演化研究

天然气水合物因其巨大的资源量与高能量密度而被视为一种前景广阔的能源.理解孔隙尺度下天然气水合物生成与分解动力学及气-水-水合物三相分布对优化天然气水合物开采工艺至关重要.文章设计了一种新型的高压微流控可视化实验装置(最高耐压19.0 MPa),可实现孔隙尺度下气体水合物生成和分解相变的直接观测.首先,观测并分析了南海神狐海域温压条件下(压力15.5 MPa)甲烷水合物的成核与生长过程.通过图像识别算法分析了热激法下3种升温速率(0.5,2.0和8.0 K/h)对甲烷水合物分解动力学与气泡演化规律.实验结果表明,孔隙中存在两种不同的甲烷水合物生成机制:(1)甲烷气泡主导生成的气-水-水合物三相共存的疏松多孔型水合物;(2)水中溶解相甲烷主导生成的致密单晶型水合物.其中,单晶型水合物包裹在多孔型水合物周围并呈树突状生长,在接触甲烷气泡时会诱导多孔型水合物的快速成核与生长.水合物分解过程中,气-水-水合物三相共存的多孔型水合物优先分解,单晶型水合物相对稳定,其分解温度高于多孔型水合物约0.3 K.孔隙内水合物分解后产生明显的气泡聚集与融合现象,气泡平均直径为60~100μm.提高升温速率显著加快了水合物分解速率,更有利于气泡融合,造成较大气泡在孔隙内分布.本研究为甲烷水合物在孔隙尺度下生成、分解与微米级气泡演化提供直接实时观测证据,研究结果对深入理解水合物分解动力学与水合物沉积物两相渗流理论提供基础支撑.

Effects of dynamic ultra-high pressure homogenization on the structure and functional properties of casein

Dynamic ultra-high pressure homogenization(UHPH)is a novel high-pressure processing technique.In this study,the effects of dynamic UHPH on the structure and functional properties of casein were systematically investigated.It was found that the functional properties of casein changed with dynamic UHPH treatment,and the treatment at 150 MPa could significantly improve casein aqueous solubility,foaming and emulsifying properties.These functional improvements could be attributed to its structural changes,since the dynamic UHPH treatment could change the secondary structure,promote the interchange reaction between the disulfide bond and the sulfhydryl group,and increase the surface hydrophobicity.The obtained results could broaden the application of casein and provide ideas for the non-thermal processing of proteins.

ULTRA-HIGH PRESSURE DIFFERENTIAL THERMAL DETERMINATION OF DIASPORITE

Water plays an important role in the evolution history of the earth and the water in the deep earth mainly exists in minerals and magma melt. The study on ultra-high pressure differential thermal determination ofhydroites and their stability and mechanism of dehydration-dehydroxylation are significant for the understanding of the heat evolution history

Grain-refining fabrication of nanocrystalline(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)high-entropy ceramics by ultra-high pressure sintering

As an important A_(2)B_(2)O_(7)-type ceramic,(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)high-entropy pyrochlore pos-sesses promising properties such as high melting point,high chemical durability,and low thermal conductivity.However,the low sintering ability limits its application in thermal barrier coating and radioactive waste immobilization.It usually needs long-term high-temperature soaking to achieve full density,but with inevitable grain growth.In this work,dense and grain-refined nanocrystalline(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)ceramics were prepared with ultra-high pressure sintering(UHPS)method under 10 GPa at a low temperature of 800℃.The densification behavior,microstructure evo-lution,and properties of the UHPS-ed samples were then investigated.The grain size of as-prepared(La_(0.2)Nd_(0.2)Sm_(0.2)Gd_(0.2)Eu_(0.2))_(2)Zr_(2)O_(7)ceramic was only 151 nm,which is 40%smaller than that of raw pow-der.In addition,it exhibited advantageous properties including both high hardness and aqueous durabil-ity.Plastic deformation under ultra-high pressure was believed as the dominant densification mechanism responsible for grain refinement and property improvement.

Application of adaptive pressure-driven microfluidic chip in thyroid function measurement

The improvement in accuracy of in vitro diagnosis has always been the focus of early screening of thyroid dysfunction.We constructed a microfluidic chip based on a polystyrene polymer substrate.Total triiodothyronine(TT3),total thyroxine(TT4),free triiodothyronine(FT3),free thyroxine(FT4),and thyrotropin(TSH) in human whole blood samples were analysed by fluorescence immunoassay to evaluate thyroid function.The results indicate that the microfluidic chip shows a good linear relationship in the detection of TT3,TT4,FT3,FT4,and TS H standards,and the correlation coefficient(r) is not less than0.9900.In addition,the chip also has strong anti-interference(RSD%≤5%) and good repeatability(CV≤8%),and its inter-batch differences are small(CV ≤15%).The results of practical application in clinical thyroid function mea surement indicated its high accuracy(r≥0.9900).It provides a new method for the determination of thyroid function and lays a foundation for subsequent clinical application.