微流化对豆乳粉蛋白结构及溶解性的影响

以传统湿法工艺技术制备豆乳粉为基础,对浆渣分离后的豆乳进行微流化处理,研究微流化处理压力（0、42.5、89.0、123.5、152.0?MPa）对豆乳粉蛋白结构及溶解性的影响。结果显示：微流化处理样品的游离巯基含量、体积平均粒径及蛋白质表面疏水性均显著高于未经微流化处理的样品（P＜0.05）。当微流化处理压力为123.5?MPa时,蛋白质表面疏水性达到最大值,提高至未处理样品的1.6?倍;蛋白质游离巯基含量达到最大值7.62?μmol/g,与未处理样品相比增加了24.96%;豆乳粉具有最小的体积平均粒径和粒径分布宽度;豆乳粉溶解度达到最大值79.47%。但当微射流压力增加到152.0?MPa时,豆乳粉溶解性下降。     

豆乳粉的制法

本发明是关于水分散性优良的豆乳粉的制法。 豆乳粉因蛋白质和脂肪酸的含量高,水分散性差,常可以看到原粉未溶的现象。要提高豆乳粉的水分散性,增大粉末的粒径,使粒度分布范围缩小,具有一定效果,这可以利用速溶设备使粉末颗粒化。经过速溶设备处理后的豆乳粉的粒径虽然变大,但由于此工序的加热,可能增加了豆乳粉蛋白质的不溶性,所以尽管水分散性得到改善,却降低了蛋白质的溶解性及其功能。     

高压射流磨处理对燕麦浆稳定性的影响

目的：研究高压射流磨对燕麦浆稳定性的影响及机制,为全谷物饮料加工提供依据。方法：采用不同压力高压射流磨对燕麦浆进行处理,比较贮藏期（30 d）的形态、不稳定指数、粒径、流变特性变化,并对微观形貌（光学显微镜、激光共聚焦扫描显微镜、扫描电子显微镜）、可溶性成分含量（可溶性固形物、可溶性蛋白、可溶性膳食纤维）进行分析。结果：高压射流磨处理使燕麦浆的粒径、不稳定指数、表观黏度逐渐减小,并能减缓淀粉的老化和颗粒的聚集。高压射流磨能均化蛋白和油脂,破坏细胞壁组织纤维,使更多可溶性物质溶出,并在颗粒内部产生孔腔,增加水合能力,提高体系总体稳定性。结论：高压射流磨技术可提高全谷物产品贮藏稳定性,延长货架期。     

超高压微射流处理对火龙果汁微生物指标及理化特性的影响

目的 研究不同超高压微射流处理条件对火龙果汁品质和安全性的影响。方法 火龙果汁分别采用100、150和200MPa的超高压微射流处理1次和2次,测定不同处理条件下火龙果汁理化指标(平均粒径、总酸、可溶性固形物含量、总酚和花青素含量)和微生物指标(菌落总数、大肠菌群和酵母菌)。 结果 果汁的平均粒径、总酸含量、可溶性固形物含量随压力的增加而减小,总酚含量随压力的增加变化差异不显著,花青素含量随压力的增加先减少后增加;相同压力下,处理次数对平均粒径、总酸含量、可溶性固形物含量和总酚含量的影响不显著,100MPa下花青素的含量随处理次数增加而降低,但150、200MPa下花青素的含量随处理次数增加而增加;菌落总数、大肠菌群和酵母菌的数量均随着压力和处理次数的增加而减少。结论 超高压微射流处理能够对火龙果汁的理化特性产生影响,并且能够有效杀灭火龙果汁中的微生物,最终实现火龙果汁品质和安全的控制。     

微射流对野生黑豆蛋白结构及功能性的影响

探究微射流(0、42.5、89.0、123.5、152.0、175.5 MPa)作用下野生黑豆蛋白结构变化规律,研究表明:微射流处理促进了野生黑豆蛋白质分子间的疏水交互作用,蛋白中的不稳定聚集体逐渐分解成小分子可溶性聚合物,而在超过123.5 MPa时,高强度的剪切作用使可溶性蛋白重新聚合,其乳化性随均质压力增加先增大后减小,乳化稳定性变化不显著(P0.05)。拉曼光谱分析结果表明:与未处理野生黑豆蛋白相比,微射流均质处理下所有蛋白均发生了α-螺旋结构相对含量增加和β-折叠结构相对含量减少的现象。拉曼光谱在760 cm-1色氨酸归属峰处强度降低,表明均质处理使野生黑豆蛋白发生了部分的解折叠,蛋白表现为"暴露"态。均质处理下酪氨酸归属峰强度显著增加,表明微射流均质处理改变野生黑豆蛋白酪氨酸的微环境。拉曼归属谱带强度随着均质压力的增加而增大,使二硫键的t-g-t型构象转化为g-g-t型构象。     

喷雾干燥温度对牦牛乳粉溶解特性的影响

为探讨喷雾干燥温度对牦牛乳粉溶解特性的影响,分析了在进风温度（出口温度）分别为130（56）、150 （64）、170（73）、190（81）、210（90）℃条件下喷雾干燥牦牛乳粉样品的溶解特性参数,并通过相关性分析对其进行聚类分析。结果表明：喷雾干燥温度对牦牛乳粉的溶解特具有显著影响（P＜0.05）,170（73）℃下喷雾干燥牦牛乳粉样品具有较高的水合能力、堆积密度、溶解度,较小的休止角和分散时间,具有较好的溶解特性,优于在其他温度下干燥牦牛乳粉的溶解特性;牦牛乳粉溶解特性参数间具有较好的相关性,聚类分析可实现对不同喷雾干燥温度条件下牦牛乳粉溶解特性的区分,为对喷雾干燥温度的评价提供参考。     

低抗营养因子豆乳粉的喷雾干燥工艺研究

本文以木瓜蛋白酶水解后的传统生浆工艺制备豆乳为原料,研究其制备低抗营养因子豆乳粉的喷雾干燥工艺条件,并与6种市售豆粉进行分析比较。以豆乳粉的物性为评价指标进行单因素对比试验,得出喷雾干燥优选工艺条件为:进风温度185℃,进料速度350 m L/min,亲水性单甘脂和吐温80(3:2)用量2.0%,麦芽糊精添加量5.4%。在此条件下制得的豆乳粉润湿性和分散性比冰泉速溶豆乳粉高74.05%和11.94%,溶解度除维维和黑牛豆乳粉外,均优于其它市售豆乳粉;经检测其脲酶活性呈阴性,大豆球蛋白、β-伴大豆球蛋白和植酸含量均低于市售豆乳粉,胰蛋白酶抑制剂比冰泉速溶豆乳粉低15.32%,大豆凝集素比永和豆浆粉低14.00%。数据表明经本工艺制得的豆乳粉豆香味浓郁,溶解状态良好,其中大豆球蛋白、β-伴大豆球蛋白和植酸含量均显著低于市售豆乳粉。     

超高压微射流对石榴汁品质的影响

以石榴汁为原料,研究超高压微射流对石榴汁中总酚、粒径、色泽、花色苷含量、可滴定酸及可溶性固形物的影响。结果显示,在不同压力下处理的石榴汁的总酚含量、平均粒径、色差值、花色苷含量有显著差异(P0.05)。然而,在40 MPa下处理果汁的可溶性固形物含量变化不显著,在120 MPa和200 MPa下有显著差异(P0.05)。而经超高压微射流处理的石榴汁的可滴定酸含量变化不显著(P0.05)。结果表明,超高压微射流可以改善石榴汁的品质,如增加总酚含量和对色泽的改善,为消费者提供更好质量的果汁。     

限制性酶解—钙融合制备高钙豆粉的工艺研究

以传统湿法工艺技术制备豆粉为基础,利用木瓜蛋白酶和风味蛋白酶复合酶对豆乳进行酶解处理并混入Ca CO3以提高豆乳粉的钙融合性。在单因素试验基础上,采用响应面优化分析法对限制性酶解—钙融合制备高钙豆乳粉工艺进行优化,确定最优限制性酶解—钙融合工艺参数为酶解时间1.56 h、酶添加量1.59%、均质压力29.18MPa、均质时间9.55 min,此条件下蛋白质分散指数为80.02%、可溶性钙结合量为1.85 mg/g。     

超高压-限制性酶解法降低豆乳粉致敏性工艺优化

以传统湿法工艺技术制备豆乳粉为基础,对浆渣分离后的豆乳进行超高压-限制性酶解处理,降低豆乳粉致敏性。在单因素试验基础上,采用响应面分析法对超高压-限制性酶解制备低致敏性豆乳粉工艺进行优化,确定最优超高压-限制性酶解的工艺参数为超高压处理压强320.00?MPa、超高压处理时间15?min、酶解时间60?min、酶添加量0.3?U/g,此条件下致敏性降低率为88.09%,但制备的豆乳粉具有微苦味,需要进一步调配以改善口感。超高压处理与酶解具有协同效应,可显著提高豆乳粉蛋白质体外消化率、显著降低豆乳粉致敏性,对不同加工工艺豆乳粉进行蛋白质体外消化率、蛋白质分散指数、过敏原含量及蛋白电泳分析,进一步证明超高压与酶解的协同效应。     

Characterization of stipe and cap powders of mushroom (Lentinus edodes) prepared by different grinding methods

The effects of micronization methods, mechanical and jet millings, on the physico-chemical properties of mushroom (Lentinus edodes) powder were investigated in contrast to shear pulverization. The powders of dried mushroom cap and stipe were prepared to obtain six powders. Compared to shear pulverization, mechanical and jet millings effectively reduced particle size and brought about a narrow and uniform particle size distribution. With the same material, powders from mechanical and jet millings had higher values in soluble dietary fiber content, surface area, bulk density, water soluble index and nutrient substance solubility, but lower values in the angles of repose and slide, water holding and swelling capacities than shear pulverized powder. These indexes were tightly dependent on particle size with absolute coefficients beyond 0.8330. With the same grinding method, cap powders possessed higher values in water soluble index, swelling capacity, bulk density, protein and soluble dietary fiber than stipe powders.     

超微豆粕粉体特性研究

以六种不同粒径的脱脂豆粕粉为研究对象,以粉体的体积密度、固体密度、粉体流动性、电导率、色差、持水力与水溶性等理化特性为指标,考察随着颗粒的细微化,粉体理化性质的变化。结果表明:随着颗粒的细化,体积密度、持水力、水溶性与电导率呈现明显的增大趋势;固体密度和粉体流动性则有下降的趋势。     

普通粉碎与超微粉碎对茶树菇粉体加工物理特性的影响

为研究茶树菇粉体的加工适应性,探究更适宜生产的粉碎方法,以3个不同品种的茶树菇为原料,通过普通粉碎得到茶树菇粗粉,然后利用超微粉碎将粗粉制成茶树菇超微粉,比较茶树菇粗粉和超微粉的加工物理特性。结果表明,粗粉的中值粒径平均值为84.03μm,超微粉中值粒径平均值为24.57μm,与粗粉相比,超微粉粒径明显减小;扫描电镜下观察发现,随着粉体粒径的减小,粉体表面由片层状结构向絮绒状转变;堆密度减小,填充性降低;滑角和休止角减小,流动性提高;持水力和膨胀力减小,水合能力降低;粗粉和超微粉的水溶性指数均随温度升高呈先上升后下降最终趋于平缓的趋势,在60℃时水溶性指数最高,且超微粉的水溶性指数均大于粗粉;红外光谱分析结果显示,超微粉碎后茶树菇粉官能团结构没有明显变化。研究表明,茶树菇超微粉具有广阔的应用前景,研究结果为茶树菇的深加工提供了一定的理论依据。     

Effect of pressure and fat content on particle sizes in microfluidized milk

Average diameters and particle size distributions in fluid milks with different fat contents and subjected to various homogenization pressures with a "microfluidizer" were evaluated. Skim, 2%, and whole milks were microfluidized at 50, 100, 150, and 200 MPa. Cream containing 41% milk fat was microfluidized at 50, 100, and 150 MPa. Particle sizes were determined by laser light scattering. As microfluidization pressure was increased from 50 to 100 MPa, particle sizes in skim, 2%, and whole milks decreased. Microfluidization at pressures greater than 100 MPa had little additional effect on reducing the particle sizes in skim and 2% milks compared with microfluidization at 100 MPa, but the particle sizes in whole milk increased as the microfluidization pressure was increased from 100 to 200 MPa due to formation of homogenization clusters. The particle sizes in cream increased as the microfluidization pressure was increased from 50 to 150 MPa. When the microfluidization pressure was held constant, the particle sizes increased as the milk fat concentration was increased. The coefficients of variations of the volume-weighted particle size distributions for cream were higher than for skim, 2%, and whole milks. Larger "big" particles and smaller "small" particles were formed in whole milk after microfluidization at 200 MPa than at 100 MPa. Although microfluidization can be used to produce small particles in skim, 2%, and whole milks, a higher than optimum pressure (above 100 MPa) applied to whole milk will not lead to the minimum d(43) (volume-weighted average diameter) due to formation of clusters.     

不同11S/7S比值原料豆乳的乳液特性研究

为探明大豆蛋白11S/7S比值对豆乳乳液特性的影响,选取7个不同11S/7S比值(0.55~5.09)的大豆品种制备豆乳,并检测豆乳中蛋白溶解度、粒径、Zeta电位、豆乳粘度、游离巯基、表面疏水性和沉淀率等与豆乳乳液特性紧密相关的指标。结果表明:大豆中11S/7S比值较小时,豆乳中蛋白溶解度高,粒径小,豆乳粘度小,蛋白Zeta电位绝对值高,游离巯基含量多,表面疏水性高,豆乳沉淀率低,豆乳稳定性高。反之,大豆中11S/7S比值较大时,蛋白溶解度低,粒径偏大,豆乳粘度大,蛋白Zeta电位绝对值低,游离巯基含量少,表面疏水性低,造成豆乳沉淀率高,豆乳稳定性低。但当原料中11S/7S比值处于3.0~3.49时,各豆乳上述指标之间差异不显著(P>0.05)。     

Effects of particle characteristics on bulk properties of norwegiata fish meals

Three categories of Norwegian fish meats with different particle size, shape and particle surface stickiness characteristics were exposed to angle of repose and bulk density tests. The results presented indicate that the angle of repose increases with decreasing particle size, increasing amounts of fibrous particles in the powder and increasing particle surface stickiness. The bulk density, on the other hand, did not correlate with the particle size in the range considered, but increased with decreasing amounts of fibrous materials and decreasing surface stickiness.     

Effect of carrier types and compositions on the production yield,microstructure and physical characteristics of spray dried sour cherry juice concentrate

In this study, the effect of different carriers including maltodextrin (MD), gum arabic (GA) and whey protein concentrate (WPC) and their combination on the production yield, moisture content, bulk and tapped density, solubility, wettability, flowability indexes (Hausner ratio, compressibility, angle of repose), hygroscopicity and deliquescence process, color index and microstructure of spray dried sour cherry juice concentrate was investigated. The results showed increased powder production yield with a mixture of MD and GA (40:10 weight ratio). Use of 5% WPC in combination with the GA and MD increased powder production yield from 45.66 to 55.66% and 42.23 to 52.86%, respectively. Bulk density, tapped density, solubility and wettability significantly decreased with increasing concentration of WPC. Also, the use of 30% WPC in combination with the MD or GA increased particle size substantially. The surface morphology of the particles (with a smooth, shrunk and dented surfaces) was affected by feed composition.     

Food Powder Characteristics Important to Nonelectrostatic and Electrostatic Coating and Dustiness

ABSTRACT: Corn starch, maltodextrin, powdered sugar, cellulose, soy flour, corn flour, wheat flour, cocoa, nonfat dry milk, and salt were coated at 0, 19, and 25 kV using corona particle charging. Particle size, powder charge, density, and flow characteristics (flow index, cohesiveness, angle of repose, Hausner ratio) were correlated to coating efficiency and dustiness. Nonelectrostatic coating efficiency improved with large particle size, small powder charge, and low cohesiveness. Electrostatic coating at 25 kV improved with small particle size, low flow index, and high particle density. Dustiness decreased with large particle size-particle density interaction, high flow index, and low cohesiveness. Electrostatics improved coating efficiency 68% and decreased dustiness 65% (excluding largest salt).