基于气相色谱-离子迁移谱法的不同地区驴乳粉挥发性风味物质指纹图谱分析

目的 探究不同地区驴乳粉挥发性风味物质组成及差异。方法 采用顶空气相色谱-离子迁移谱法(gas chromatography-ion mobility spectroscopy, GC-IMS)对5种驴乳粉的挥发性风味物质进行分析。结果 5种驴乳粉共鉴定出53种挥发性风味物质, 主要包括醇类、醛类、酮类、酸类、酯类、萜烯类、呋喃类和含硫化合物等。喀什产驴乳粉中共鉴定出48种挥发性风味物质, 哈密产两种驴乳粉均鉴定出47种挥发性风味物质, 山东和昌吉产驴乳粉均鉴定出40种挥发性风味物质。 2-甲基丙酸只在山东产驴乳粉中检出; 丁酸乙酯只在昌吉和喀什产驴乳粉中检出; 3-甲基-1-丁醇、1-戊醇二聚体和辛酸乙酯只在喀什产驴乳粉中检出, 1-辛醛二聚体、丙酸丁酯、丁酸丁酯和γ-萜品烯只在哈密产驴乳粉中检出。通过构建的GC-IMS指纹图谱，可筛选出每个产地驴乳粉的特征风味区域，主成分分析也可将5种驴乳粉很好地区分开。结论 不同地区驴乳粉其挥发性风味物质种类和含量均存在一定差异。通过GC-IMS构建的指纹图谱可以直观地将不同驴乳粉特征风味区域表征出来, 这一研究结果为不同地区驴乳粉风味品质评价和产地鉴别提供理论依据。     

新疆疆岳驴乳粉增强小鼠免疫功能的研究

探讨驴乳冻干粉对环磷酰胺所致小鼠免疫功能低下的影响。环磷酰胺诱导小鼠免疫功能低下,给小鼠饲喂不同剂量的驴乳冻干粉,并于30 d后测定免疫指标。结果表明:饲喂驴乳粉后,小鼠的T淋巴细胞阳性率由免疫低下组的23.89%上升至驴乳高剂量组的55.70%;白细胞数量由免疫低下组的4.36上升至高剂量组的9.21;吞噬率由免疫低下组的20.9%提高到高剂量组37.2%,吞噬指数由免疫低下组的0.31提高到驴乳高剂量组的0.62;小鼠胸腺指数由免疫低下组的0.012上升到高剂量组的0.02;CD4+/CD8+比例由免疫低下组的0.82提高到高剂量组的1.81,血清IgG质量浓度由免疫低下组的0.453 g/L提高到高剂量组的0.727 g/L。驴乳不仅能提高机体的免疫能力,而且对环磷酰胺所造成的免疫低下具有缓解作用。     

疆岳驴乳成分测定

连续3d采集12头疆岳驴共72头份驴乳和4份混合乳进行乳成分测定。结果表明。驴乳蛋白质、脂肪、乳糖和灰分的含量分习1为1．35，1．16，6.52和0．35g／100g；8种人体必需氨基酸（未含色氨酸Trp）的含量占氨基酸总量的44％；人体必需脂肪酸亚油酸、亚麻酸的含量分别占脂肪酸总量的26．83％和3．6％；含多种矿物元素和维生素，其中Se含量迭80μg／kg，Vc含量达5．16mg／100g。驴乳的营养成分和人乳相近．可作为婴幼儿代乳品或代乳品基料，也适合于心脑血管病、“三高症”及肥胖症等患者饮用。     

马乳和驴乳中营养成分及加工技术研究进展

马乳及驴乳作为特色乳之一，具有较高的营养价值及功能特性，受到消费者的关注。然而，马乳及驴乳中溶菌酶、乳铁蛋白等特征性活性成分对热处理、酸碱等敏感，在产品加工方面有待进一步研究。因此，本文对比分析了马乳、驴乳与母乳、牛乳中营养成分的差异及生物活性功能，对目前马乳及驴乳的加工处理技术研究进行系统的评价，为马乳及驴乳产品加工和品质调控提供参考。     

响应面法优化风味驴乳酸奶发酵工艺的研究

在驴乳中添加牛乳粉制作酸奶，通过单因素试验和响应面优化法研究了风味驴乳酸奶最佳发酵工艺。结果表明，以牛乳粉添加量、发酵温度和发酵时间为自变量，以感官评价为因变量，响应面法优化出风味驴乳酸奶的最佳发酵工艺为：牛乳粉添加量10%、发酵温度42 ℃、发酵时间5.5 h。在此优化条件下，风味驴乳酸奶口感细腻爽滑，酸甜适口，有浓郁的驴乳香味与滋味，感官评分达到92分，与预测值（90.85分）相差较小。产品的理化及微生物指标均符合相关国标要求。     

新疆疆岳驴乳研究进展

介绍了新疆疆岳驴乳研究进展情况.包括:驴乳的化学成分和理化指标、蛋白质和脂肪酸组成、矿物元素和维生素质量分数、功能性物质及其质量分数、驴乳中的微生物以及驴乳的抗茵作用、抗疲劳作用、抗肿瘤作用和免疫功效.文章还对今后驴乳研究工作的重点提出了建议.     

驴乳营养成分和生物活性研究进展

中医古籍记载,驴乳具有清热解毒、润燥止渴等功效。欧洲和南美,驴乳流行作为人乳的替代品。研究表明,驴乳含有蛋白质、必需脂肪酸、矿物质、维生素等丰富的营养成分,而且其含量与人乳接近,有利于人体吸收和利用。生物活性研究表明,驴乳的蛋白质构成特点使驴乳致敏性低,可用于对牛乳过敏的婴儿。驴乳富含溶菌酶,具有抗菌功能。随着我国驴产业链的发展,驴乳资源将越来越丰富,市场和应用前景广阔。     

驴乳营养成分和生物活性研究进展

中医古籍记载,驴乳具有清热解毒、润燥止渴等功效.欧洲和南美,驴乳流行作为人乳的替代品.研究表明,驴乳含有蛋白质、必需脂肪酸、矿物质、维生素等丰富的营养成分,而且其含量与人乳接近,有利于人体吸收和利用.生物活性研究表明,驴乳的蛋白质构成特点使驴乳致敏性低,可用于对牛乳过敏的婴儿.驴乳富含溶菌酶,具有抗菌功能.随着我国驴产业链的发展,驴乳资源将越来越丰富,市场和应用前景广阔.     

高通量测序技术探究驴乳粉对皮肤细胞的影响

基于RNA-seq技术探究驴乳与角质形成细胞和成纤维细胞的相互作用。驴乳分别与角质形成细胞、成纤维细胞共孵育后,采用RNA-seq筛选差异表达基因（DEGs）,进行GO和KEGG富集分析。驴乳作用角质形成细胞后共筛选出819个DEGs,其中420个上调基因,399个下调基因。GO富集分析显示,差异表达基因参与与表皮发育、角质细胞分化、角化等生物学过程。KEGG富集分析显示,驴乳作用角质形成细胞涉及的分子机制包括IL-17信号通路、细胞因子-细胞因子受体相互作用、金黄色葡萄球菌感染等。驴乳作用成纤维细胞后共筛选出507个DEGs,其中298个基因上调,209个基因下调。GO富集分析显示,驴乳参与成纤维细胞的细胞黏附的正调控、脂质定位的调节、脂质转运的调节等生物学过程;KEGG结果显示,驴乳作用成纤维细胞涉及的分子机制包括细胞因子-细胞因子受体相互作用和c GMP-PKG信号通路等。为阐明驴乳对皮肤细胞功能的分子作用机制提供了科学依据。     

冻干驴乳粉全成分分析

为从分子水平阐明驴乳粉的功效物质基础和表征我国特有德州驴乳粉的成分,本实验采用UPLC-Orbitrap MS技术定性分析驴乳粉的有效成分。共鉴定出87种代谢物,主要有氨基酸及其衍生物类、糖类、有机酸类、脂质类和其他5大类。驴乳粉不仅含有6种必需氨基酸,而且含有γ-氨基丁酸、牛磺酸、焦谷氨酸等活性氨基酸。首次在驴乳粉中鉴定出海藻糖、尿酸、马尿酸、杜鹃花酸、尿囊素和肌肽等成分。这些活性成分从分子基础上揭示了驴乳防治糖尿病和美容养颜的潜在功效。为驴乳的深层次开发提供理论依据。     

贮藏条件对驴初乳理化性质的影响

对新疆岳普湖驴乳37℃贮藏的理化性质进行研究。研究表明,随放置时间的延长,pH、相对密度呈下降趋势,而酸度则呈上升趋势;蛋白质、非脂乳固体含量均呈下降趋势;而乳糖含量及微生物数量则随放置时间的延长逐渐上升。     

Invited review: Human,cow, and donkey milk comparison: Focus on metabolic effects

Milk is an important food of the daily diet. Many countries include it in their dietary recommendations due to its content in several important nutrients that exert beneficial effects on human health. Human milk is a newborn's first food and plays an important role in the growth, development, and future health of every individual. Cow milk is the type of milk most consumed in the world. However, its relatively high content of saturated fats raises concerns about potential adverse effects on human health, although epidemiological studies have disproved this association. Indeed, dairy consumption appear to be linked to a lower risk of mortality and major cardiovascular disease events. In the last few years many researchers have begun to focus their attention on both the production and quality of cow milk as well as the analysis of milk from other animal species to evaluate their effect on human health. The need to investigate the composition and metabolic effects of milk from other animal species arises from the adverse reactions of individuals in several groups to certain components of cow milk. It has emerged that donkey milk compared with that of other animal species, is the nearest to human milk and an excellent substitute for it. Milk from various animal species shows substantial differences in nutritional composition and distinct metabolic effects. In this review, we discussed the main compositional features and metabolic effects of 3 types of milk: human, cow, and donkey milk.     

全脂乳粉和脱脂乳粉在1kHz～10MHz下的介电特征研究

分别研究了各4种不同品种的全脂乳粉和脱脂乳粉在1kHz～10MHz波段的介电特性。结果发现:随着频率的增加,全脂乳粉和脱脂乳粉的ξ’和ξ″值呈单调递减趋势;全脂乳粉的ξ’和ξ″值都高于脱脂乳粉,相同类型乳粉各品种间的ξ’和ξ″差异不大;全脂乳粉的ξ″值在103～105Hz频率段减小趋势明显,且ξ″值的对数与频率的对数成线性反比关系,而脱脂乳粉无此规律;全脂乳粉和脱脂乳粉的穿透深度Dp随频率的提高而减小,两类乳粉的介电特性差异可能与它们各自的脂肪和乳糖含量有关。     

模拟母乳及婴儿配方奶粉的研究

介绍了人乳中的主要功能因子及其对婴儿的生长发育所具有的生理意义。比较、分析了现阶段婴儿配方奶粉与人乳成分中存在的差别及不足，并针对婴儿的生长特点及现阶段生产技术，对婴儿配方奶粉的生产及发展进行了叙述。     

Distribution of selected trace elements in the major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Zn, Cu, Mn, Se, Mo, Co, Li, B, Ti, Cr, Rb, Sr, Cd, and Pb in donkey milk and their distribution in major milk fractions (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were provided by 16 clinically healthy lactating donkeys. Subsequent centrifugation, ultracentrifugation, and ultrafiltration were carried out to remove fat, casein, and whey proteins to obtain skim milk, a supernatant whey fraction, and the aqueous phase of milk, respectively. Concentrations of the elements were measured in whole milk and fractions by inductively coupled plasma-mass spectrometry, and the concentrations associated with fat, casein, and whey proteins were then calculated. The effect of removal of fat, casein, and whey proteins was determined by repeated-measures ANOVA. The fat fraction of donkey milk carried a small (～4.5% to 13.5%) but significant proportion of Mo, Co, Ti, Cr, and Sr. The casein fraction in donkey milk carried almost all milk Zn, a majority of Cu and Mn, and most of Mo, Ti, and Sr. Relevant proportions, between 20% and 36%, of Se, Co, and Cr were also associated with caseins. The majority of Se, Co, Li, B, Cr, and Rb, and relevant proportions of Mn, Mo, Ti, and Sr were found in soluble form (ultracentrifuged samples) and distributed between whey proteins and the aqueous phase of milk (ultrafiltered samples). Whey proteins in donkey milk carried the majority of milk Se and Co. All Li and B was present in the aqueous phase of milk, which also contained most Rb and Cr, and 17% to 42% of Mn, Se, Mo, Co, Ti, and Sr.     

Effects of milk powders in milk chocolate

The physical characteristics of milk powders used in chocolate can have significant impact on the processing conditions needed to make that chocolate and the physical and organoleptic properties of the finished product. Four milk powders with different particle characteristics (size, shape, density) and "free" milk fat levels (easily extracted with organic solvent) were evaluated for their effect on the processing conditions and characteristics of chocolates in which they were used. Many aspects of chocolate manufacture and storage (tempering conditions, melt rheology, hardness, bloom stability) were dependent on the level of free milk fat in the milk powder. However, particle characteristics of the milk powder also influenced the physical and sensory properties of the final products.     

近红外快速检测奶粉乳清粉成分研究

采用Perten8620近红外奶粉分析仪检测奶粉的近红外光谱特性，建立了奶粉近红外检测的校准模型。结果表明，近红外检测技术无需称重和化学试剂，可在1min以内快速检测奶粉和乳清粉的蛋白、脂肪、水分等指标，其准确性和精度可以达到在国际允许的误差范围内。根据近红外技术可能在短时间内收集大量样品的光谱图，开发了新检测项目的校准曲线。     

The behaviour of Arabian donkey milk during acidification compared to bovine milk

To better understand the fermentation kinetic of Arabian donkey milk, its physicochemical properties, conductivity and viscosity were assessed during acidification, and compared to that of the bovine milk. Donkey milk showed a shorter latency phase and slightly lower acidification rate than bovine milk. Measurement of electric conductivity during acidification showed that maximum demineralisation of casein micelles occurred at around pH_I 5.44 for donkey milk and pH_I 5.16 for bovine milk. Donkey milk was also found to be less viscous. The technological characteristics of donkey milk were different from those of bovine milk due to intrinsic physicochemical properties of both milks.     

高效液相色谱法分析原料乳和奶粉中三聚氰胺

建立了二极管阵列检测器-高效液相色谱测定原料乳及奶粉中三聚氰胺的方法。奶粉样品经三氯乙酸超声提取,乙酸铅沉淀蛋白,三氯甲烷除去脂肪和非极性杂质,PROELUTPXCSPE阳离子交换固相萃取小柱进一步除去样品基质干扰,氨化甲醇洗脱。实验对色谱分离条件进行了优化,三聚氰胺的质量浓度在1.0～100.0μg/mL范围内与色谱峰面积呈良好的线性关系,回归方程为y=89.763x-113.72,相关系数为R2=0.9988。加标回收率为90.5%～105.0%,相对标准偏差(RSD)小于4.0%。该方法简单、快速,结果准确可靠。