The study investigated the interactions between high-methoxyl pectin (HMP) and milk fat globules or membrane (MFGs/MFGM) ingredients. Mixtures of raw milk and HMP at concentration of 0.20 %, 0.30 %, and 0.40 % (w/ w) (designated as 0.20 pectin (Pec), 0.30 Pec, and 0.40 Pec, respectively) underwent cream separation and ultra- centrifugation to enrich the MFGs/MFGM materials, with raw milk without HMP serving as a control. The control and 0.20 Pec exhibited multimodal particle sizes distributions with the additional peaks within the range 0.01-0.10 mu m. HMP at 0.20 % level enhanced system stability of MFGs/MFGM, indicated by a higher zeta-potential and a lower instability index compared to 0.30 % and 0.40 % levels. Fourier transform infrared spectroscopy (FTIR) showed HMP increased the random coil (%), accompanied by a reduction of alpha-helix structure (%) in MFGs/MFGM ingredients. SDS-PAGE analysis reveal lower band intensities of MFGM proteins, such as periodic acid Shciff III (PAS III), cluster of differentiation 36 (CD36), and butyrophilin (BTN) in the upper layers of 0.40 Pec compared to 0.30 Pec and 0.20 Pec materials. Rheograms demonstrated decreased viscosity in all materials with HMP, indicating shear-thinning behavior confirmed by flow behavior indexes (n) (0 < n < 1) using the Herschel-Bulkley model. Hierarchical cluster analysis (HCA) of the structural, compositional, physical stability, and rheological properties of MFGs/MFGM materials demonstrated that the 0.30 % and 0.40 % HMP levels gave the most pronounced effect.

The healthy benefits of milk fat globules and membrane (MFGs/MFGM) ingredients are increasingly recognized in the dairy industry. In this research, we examined the effects of ultrasonic treatment on the physicochemical and rheological properties, as well as the emulsions stability of MFGs/MFGM derived from bovine raw milk. Fresh milk was subjected to sonication at frequencies of 20 kHz and 40 kHz, either individually or simultaneously, for durations of 5 min or 15 min, using work/rest cycles of 5 s on and 3 s off. Bovine milk, without any treatment, served as the control. Regardless of the intensity difference, ultrasonic treatment for 5 min resulted in more pronounced changes in the regions of Amide II (1600-1500 cm- 1), Amide III (1500-1200 cm- 1), and fingerprint region (1200-1900 cm- 1) compared to both the 15 min treatments and control MFGs/MFGM. Principal component analysis (PCA) conducted on the entire spectra, as well as in the regions of Amide I, Amide II, and the fingerprint spectra, clustered the 5 min treatment distinctly from the control and MFGs/MFGM ultrasonically treated for 15 min. MFGs/MFGM samples following 20 kHz and 40 kHz synchronous treatment for 15 min exhibited lower absorbance bands at 1727-1726 cm- 1, whereas a higher content at 1740 cm-1 was observed compared to control MFGs/MFGM. Additionally, a more significant reduction in the intramolecular beta-sheet content in 20 + 40 kHz/ 15 min treatment was observed. According to the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) patterns, a diminished intensity of Periodic Acid Schiff 6/7 (PAS 6/7) bands was observed across all the MFGs/MFGM. Ultrasonic treatment retained more caseins while reducing the beta -LG levels compared to the controls, enhancing the stability of MFGs/MFGM, except in MFGs/ MFGM subjected to 20 and 40 kHz simultaneously treated for 15 min. The irregular sphericity of fat globules was noted particularly in MFGs/MFGM treated at 20 kHz independently or in combination with 40 kHz for 15 min. According to the confocal laser scanning microscopy (CLSM), ultrasonic treatment facilitated the binding of caseins or whey proteins to the MFGs surface and induced flocculation of membrane proteins. Hierarchical cluster analysis (HCA) heat map further underscored the impact of ultrasonic treatments on the structural and compositional changes, as well as rheology and emulsions stability, of MFGs/MFGM.

Background: Dairy powders enriched with milk fat globules (MFGs) and milk fat globule membrane (MFGM) materials are gaining interest in food industry due to their bioactive benefits, including the promotion of brain development and cognitive functions, as well as improvements in gut health and immunity. MFGs/MFGM ingredients have been incorporated into infant formula (IF) to bridge the nutritional gap between formula and breast milk. The structure and composition of MFGs/MFGM ingredients significantly influence their functionalities and physiological properties. Scope and approach: This review provides an update on recent research concerning the factors influencing the structure, composition, and functionalities of MFGs/MFGM ingredients, including the species, lactation stage and feeding methods. Additionally, conventional separation methods are discussed versus novel membrane filtration techniques. The main part of this review covers the recent progress and trends arising from the influence of the industrial dairy produce units, including thermal treatment and low temperature storage, homogenization, and non-thermal processes. Key findings and conclusions: Variability in reports on the structure and composition of MFGs/MFGM across studies poses challenges in discerning whether these differences arise from varied processing techniques or analytical methods. Establishing standard analytical methods remains an ongoing research topic. By-products such as cheese whey or buttermilk continue to serve as primary raw materials for the preparation of MFGs/ MFGM ingredients in the industry. Studies on the preparation of MFGs/MFGM materials while maintaining their natural state are relatively limited. Further research into the structural and compositional changes of MFGs/ MFGM during food processes is essential, as it has the potential to provide the key information on their physiological properties and tech-functionalities.

Milk fat globules or milk fat globule membranes (MFGs/MFGM) have been added to the infant formula to fortify the phospholipids and narrow the nutritional gap from breast milk. The main aim of this study was to profile the interfacial and thermal properties of MFGs/MFGM prepared from ultrasonicated bovine milk. Bovine milk was sonicated at ultrasonic intensities of 20 kHz and 40 kHz independently or synchronously with the duration time of 0 min (control), 5 min, 10 min, and 15 min (work/rest cycles = 5 s: 3 s). Ultrasonic treatments at 20 kHz/ 5 min and 20 + 40 kHz/ 5 min improved the volume density (%) of smaller particles (1-10 mu m) while significantly decreasing the surface hydrophobicity (H-0) (p < 0.05). 40 kHz/5 min samples showed significantly higher zeta- potential than the other samples (p < 0.05), which might be because more negative charges were detected. In comparison with control samples, ultrasonic treatments decreased the interfacial tension (pi) between the air and MFGs/MFGM liquid phase. 20 kHz ultra-sonicated treatments decreased the diffusion rate (k (diff)) of MFGs/MFGM interfacial compositions significantly as the duration prolonged from 5 min to 15 min (p < 0.05) but did not affect the adsorption or penetration rate (k (a)) (p > 0.05). X-ray diffraction (XRD) results showed that alpha-crystal peaks only existed in control and ultrasonicated 5 min samples but disappeared in all 15 min samples. According to the different scanning calorimetry (DSC), one or two new exothermic events (in the range of 17.29 - 18.81 degree celsius and 22.14 - 25.21 degree celsius) appeared after ultrasonic treatments, which, however, were not found in control samples. Ultrasonic treatments resulted in the low-melting fractions (LMF) (T-M1) peaks undetectable in MFGs/MFGM samples in which only peaks of medium-melting fractions (MMF) (T-M2) and high-melting fractions (HMF) (T-M3) were detected. Compared with the control, both enthalpies of crystallisation (Delta H-C) and melting (Delta H-M) decreased in ultrasonicated samples. In conclusion, ultrasonic treatment affects the interfacial and thermal properties of MFGs/MFGM.

Ethanol solvent exchange combined with supercritical-CO2-drying (SE + SCD), was applied to upcycle substandard peas generated by industrial processing into food powders with target technological and sensory properties. Control powders were produced by traditional air- (AD) and freeze- (FD) drying. SE + SCD promoted carbohydrate and lipid leaching, resulting in a pea powder with protein (32 g/100 g) and fiber content (30 g/ 100 g) higher than that of AD and FD powders. SE + SCD also caused conformational changes in hemicellulose and partial protein denaturation, as detected by FTIR. Compared to AD and FD powders, SE + SCD one was colourless and more porous, as indicated by the low density (0.16 g cm -3) and SEM microstructure. The openpore structure of SE + SCD powder also accounted for higher water (5.2 g water/g powder) and oil (4.7 g oil/g powder) holding capability. Sensory analysis revealed that SE + SCD produced a flavourless powder, with no vegetable sensory notes.

Milk fat globule and membrane (MFGs/MFGM) ingredients are the main source of the phospholipid supplementation in the dairy industry. Their physicochemical properties and functionalities play important roles for their application. This study investigated the effect of the acidification (pH 6.30 and pH 5.30) on the microstructure, interfacial and thermal properties of MFGs/MFGM sourced from bovine milk (control pH 6.70). Meanwhile, sweet whey was prepared to mimic the raw material used in industrial production of MFGs/MFGM (MFGM-C). The study revealed a broad particle size distribution of MFGs/MFGM at pH 5.30, while smaller particles were found in MFGM-C. This was confirmed by confocal scanning microscopy (CLSM) images, which showed that rare intact MFGs existed in the MFGM-C. Fourier Transform Infrared Spectroscopy (FTIR) indicated more peaks belonging to the protein-lipids associations presented at pH 6.30. Additionally, the interfacial tension of MFGs/MFGM at pH 6.30 was significantly lower than at pH 6.70 and 5.30. X-ray Diffraction Spectra (XRD) showed that the fat inMFGM-C exhibited no detectable crystalline structures, and fewer α and β' crystals appeared at pH 6.30. All MFGs/MFGM from bovine milk or whey exhibited both exothermic and endothermal events. The smallest heat enthalpy of crystallization (ΔHC) and melting (ΔHM) was observed in MFGM-C, followed by those at pH 6.30. Compared to MFGs/MFGM at pH 6.70, pH 6.30 induced more profound effects on the interfacial and thermal properties of MFGs/MFGM than pH 5.30. Acidification and the use of different raw materials lead to differentiation in the physicochemical and techno-functionalities of MFGs/MFGM.

Milk fat globules (MFGs) have tri-layer biological membrane structures, and their compositions are gaining more interest for their physiological benefits. In this study, the changes in MFGs and milk fat globule membrane (MFGM) proteins after cream separation from different pH bovine raw milk were investigated. Raw milk samples were adjusted to pH 5.30 and 6.30 using citric acid at 25 °C. The effect of pH and centrifugation on the structure of MFGs was evaluated by means of particle size, zeta potential and confocal laser scanning microscopy (CLSM). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze the proteins in the obtained fractions. It was found that both pH and centrifugation could affect the particle size of all samples. As the volume distribution (Dv; Dv (10), Dv(50)and Dv (90)) decreased, the corresponding specific surface area (SSA) increased, and span and uniformity values showed the same trend. The decrease in the zeta potential of MFG correlated with the Dv(50), which was further confirmed by CLSM observation. More butyrophilin (BTN) and periodic acid Schiff 6/7 (PAS 6/7) were lost in cream samples at pH 5.30. The findings could provide valuable knowledge for the application of MFGs ingredient in the food industry since their structures and compositions could affect their potential functional and physiological properties.

In this study, we prepared a cold‐set whey protein emulsion gel that was mediated by citric acid and a pre‐emulsification method. A pre‐emulsified solution was prepared with thermally denatured whey protein and butter. The stability and rheological properties of the emulsion gel were examined. The results demonstrated that the system changed from liquid behaviour at low protein contents to emulsion gel behaviour at high protein contents. Moreover, this method could produce a stable emulsion gel and its properties could be modulated by altering the protein and fat contents.

Waxy rice starch, sodium carboxymethyl cellulose (CMC) and glutamine transaminase (TG) were used in mozzarella cheese as texturizers and crosslinking agents. The effects of waxy rice starch (1%), CMC (0.5%) and TG (0.5%) on the texture and rheological properties of mozzarella cheese were evaluated. Protein dissociation tests and the fluorescence probe method were used to evaluate the interactive forces in cheese. The results showed that cheeses with 0.5% CMC added had a smoother surface and lower degree of protein crosslinking. Waxy rice starch had a lower crosslinking effect on cheese. The detection of surface hydrophobicity revealed that CMC and TG promoted the hydrophobic interaction between molecules, whereas starch reduced the hydrophobic interaction. TG can significantly enhance the protein structure; however, it inhibits the meltability and stretchability of cheese.

探索不同超声波处理时间(超声波频率20 kHz、振幅50％、处理时间5 min、15 min)对于稀奶油中脂肪球粒径、黏度影响,并评价其制成Mascarpone干酪的得率、成分、乳清析出率和质构特性.结果 表明,与对照样品比较,超声波处理15 min,稀奶油的黏度显著增加;随着超声波时间的延长,稀奶油粒径值中D50和D90均呈现先降低后增加趋势,超声波5min处理D10,与对照样品没有显著差异(p＞0.05),但显著大于超声波15min处理样品(p＜0.05);超声波处理对于干酪中蛋白质、矿物质含量没有显著影响(p＞0.05),脂肪含量和水分显著增加(p＜0.05);超声波处理稀奶油制成干酪,硬度、均一性和凝聚性均显著增加,且随着超声波时间的延长,增加程度进一步提高(p＜0.05),而黏度指数呈现相反的变化趋势.

以新鲜稀奶油为原料,考察了不同冷冻时长及解冻方式对稀奶油的微观结构、脂肪球粒径、脂肪附聚率、冻融稳定率及油水分布情况的影响,并以植脂奶油为对比.结果 表明:冷冻24 h的稀奶油冷藏解冻后粒径值D×(50)最大,较原样增大了128％;而水浴解冻时冷冻2h的稀奶油D×(50)最大,随着冷冻时长增加,D×(50)逐渐减小.冷冻解冻后导致了新鲜稀奶油油水分离,检测到的游离脂肪信号幅度增强;脂肪球液滴被迫聚集,脂肪附聚率逐渐增加;稀奶油体系结构被破坏,冻融稳定率持续降低,冷冻24 h的样品冷藏解冻后降低了60.54％,水浴解冻后降低了53.17％,水浴解冻后稀奶油的冻融稳定率均高于冷藏解冻处理后的样品.最终稀奶油无法打发,而植脂奶油则仍保持均一稳定状态.

试验探索了超声波工艺在无添加剂常温发酵乳生产工艺中的应用,并比较未进行超声波处理和超声波处理(超声波频率20 kHz,振幅50％,处理时间400s)对于酸奶发酵过程及其产品性质的影响.结果表明,添加发酵剂后进行超声波处理能够缩短发酵时间1h,而加入发酵剂前超声波处理与对照样品没有显著差异(p＞0.05);破乳前酸奶TPA测试结果中,BC比对照和AC具有较高的硬度、凝聚性和弹性,但是胶黏性和黏着性较低,破乳后测定结果中黏度显示,BC样品比对照和AC样品呈现较好的性质,且在产品30℃加速保质期试验中,BC样品上下黏度差较小,产品较稳定;同时持水性和脱水收缩测试也表现出类似的结果,BC样品30℃放置30 d后持水性仍然较好,脱水收缩现象较弱.

Milk protein concentrate 80 (MPC80) was prepared with different emulsifying salts (ES). The effects on particle size (D50), solubility, and surface hydrophobicity (H-0) of MPC80 were then observed after production. The molecular weight and secondary structure of MPC80 protein were also investigated through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier Transform Infrared (FTIR) spectrometry. Particle size (D50) was reduced from 31.37 to 20.67 m following the addition of sodium phosphate (SPS). The solubility of MPC80 fortified with sodium citrate salt (SCS), SPS, and sodium pyrophosphate (SPP) was improved by 80.32, 78.23, and 55.80%, respectively. The SDS-PAGE pattern showed no significant difference between the control and single-ES-fortified samples, but major protein bands ((s)-CN, -CN, -CN, BSA, and -LG) had a stronger intensity than binary-ES-fortified MPC80. The FTIR results showed that the -sheet content of ES-fortified MPC80 was relatively higher than that in the control. Compared with analogue cheeses made by MPC80 with and without ES, SCS-SPP (92:8)-modified MPC80 presented a better fluid mass and homogeneous colour.

马斯卡彭尼(Mascarpone)是一种起源于意大利的酸凝新鲜干酪.试验研究了不同凝乳温度(70℃,75℃,80℃,85℃和90℃)对干酪得率、水分含量、质构、流变性和感官性质的影响.结果表明,当凝乳温度从70℃上升到90℃时,Mascarpone干酪得率显著提高(p＜0.05),水分含量由41.87％下降到38.05％.90℃下凝乳形成干酪的硬度黏性、涂抹性和凝聚性较70℃分别增加了132.63％,177.09％,158.75％和123.10％.90℃凝乳形成的Mascarpone干酪风味、质地和色泽较佳,且乳清析出较少.随着凝乳温度的升高,Mascarpone干酪的储能模量G'值和损耗模量G”都显著增加(p＜0.05),tanδ值显著下降(p＜0.05),说明随着温度的上升,干酪的弹性成分逐渐占优势,整个体系显现出固体的特征.

乳蛋白浓缩物(Milk protein concentrate,MPC)是近年来新兴的牛乳蛋白制品,在食品加工中有着广泛的应用.本试验采用薄膜蒸发浓缩牛乳超滤截留液至固形物含量为15.55％,18.17％和26.12％,研究了不同浓缩程度对MPC粉末的粒径,溶解性,流动性和喷流性指数等性质的影响.结果表明,浓缩至超滤截留液固形物含量为26.12％时,MPC具有较好的加工特性.

研究了不同脂肪质量分数的稀奶油对马斯卡彭尼(Mascarpone)干酪得率、水分质量分数、质构性质、感官评定和流变的影响.结果表明,随着原料中脂肪质量分数的提高,干酪的水分质量分数显著降低.当脂肪质量分数为40％时,干酪的硬度,涂抹性,黏着性和凝聚性都达到最大值.感官评定结果分析,脂肪质量分数35％和40％生产的干酪风味和质地较好,40％的乳清排出比35％的更少,说明脂肪质量分数40％时形成的干酪体系更均一稳定.随着脂肪质量分数增加,G'储能模量和G"损耗模量增加,损耗角正切tanδ显著下降.

研究乳化盐强化对乳蛋白浓缩物85(MPC85)基本成分、粒径、溶解性和表面疏水性(H0)以及蛋白分子量的影响.结果表明,柠檬酸钠(scs)单独使用或者与焦磷酸钠(SPP)复配均能够显著改变MPC85的粒径和溶解性,且缩短了达到稳定粒径和溶解性所需要的时间(p＜0.05).其中,单独使用SCS可使得MPC85粒径由31.37 μm降低至20.67 μm,达到稳定粒径值的时间缩短至360 min.SCS与SPS按照不同比例使用时,随着SCS占比的增加,粒径值显著降低(p＜0.05),且溶解性由77.42％增加至81.43％,同时达到稳定溶解度的时间缩短;乳化盐可以改变蛋白构象,使得更多疏水基团暴露,从而提高Ho;复配乳化盐会降低分子量＞60 ku的蛋白含量,且SPP和磷酸三钠(SPS)使得MPC85形成小分子量蛋白,分子量介于K-CN与β-LG之间.

通过质谱技术联用分析了自制Quark干酪中水溶性多肽的组成,测定了干酪的理化指标及其多肽和蛋白的一级结构,结果显示:干酪涂抹性良好,质谱联用检测到62种蛋白和223条多肽,蛋白主要有K-酪蛋白、β-酪蛋白、α-sl-酪蛋白、β-乳球蛋白等,优势肽段主要来自于这些蛋白,此外,大多数多肽序列与功能性活性多肽相近或相关.

从红曲类食品中分离出一株高产色素,不产桔霉素的红曲霉菌种R-15,以红曲霉R-15替代白霉用于类Camembert干酪生产.以传统Camembert干酪为对照,研究红曲霉R-15对类Camembert干酪成熟过程中(28 d)水分含量、pH、蛋白水解程度和挥发性风味物质的影响.结果表明,成熟过程中,对照和红曲霉干酪表皮和中心的水分含量不断降低,并在接近28 d时趋于稳定;两种干酪pH在干酪成熟过程中先降低后升高,且干酪表皮pH以及变化范围都显著大于中心部位(p＜0.05);成熟后期,对照样品的表皮和中心处pH4.6酸可溶性氮含量分别显著高于红曲霉干酪(p＜0.05),且成熟14～21 d期间,两种干酪的12％三氯乙酸可溶性氮含量增加速率最快.红曲霉干酪成熟过程中产生主要挥发性物质共35种,包括酮类、醛类、酸类、醇类和酯类等,各类物质的种类和含量都有别于对照样品.

综述了超高压技术在各类乳制品应用的研究进展,包括液奶、发酵乳、干酪和奶油类制品等.关于超高压在乳制品中的应用还仅是在研究阶段,市场上尚未有超高压处理乳制品销售,这些研究为促进超高压技术在乳制品加工中的产业化提供依据.