Desalted duck egg white nanogels combined with κ-carrageenan as stabilisers for food-grade Pickering emulsion

There was an extensive interest in food-grade Pickering emulsions formulated by natural stabilisers owing to the gradual growing demand for pursuing green-label products. Based on this, the desalted duck egg white nanogels (DEWN) combined with κ-carrageenan (CAR) (CAR/DEWN) were used as stabilisers to prepare environment-friendly Pickering emulsions. The DEWN and CAR/DEWN as well as the particles-stabilised emulsions were all characterised. Compared with the DEWN- and CAR-stabilised emulsions, Pickering emulsions based on CAR/DEWN were investigated to illustrate the long-term stability according to the results of visual appearance, static multiple light scattering and centrifugation experiments. In addition, CAR/DEWN could prepare stable high internal phase emulsions, which may give a new perspective for nutraceutical or drug encapsulation and delivery. Adding CAR to the DEWN not only increased the apparent viscosity of the emulsions to 122.2% but also enhanced the thixotropic recovery rate to 87.7%. In general, CAR/DEWN as stabilisers significantly promoted the Pickering emulsions' properties, and provided a possibility for the application of Pickering emulsion in foods.     

微量成分形成的反胶束对亚麻籽油氧化稳定性的影响

以富含α-亚麻酸的亚麻籽油为研究对象,测定多种微量成分（磷脂、油酸、β-谷甾醇、二酰基甘油）在stripped亚麻籽油中的临界胶束浓度,并研究反胶束的形成对亚麻籽油氧化稳定性以及生育酚抗氧化活性的影响。结果表明,磷脂是形成反胶束的重要组分,其临界胶束浓度为125 μmol/kg;与对照组相比,低浓度（低于临界胶束浓度）微量成分对亚麻籽油的热稳定性无显著影响,但形成反胶束后则能显著降低油脂的起始氧化温度（约12%）以及氧化诱导时间（约33%）,增加贮藏过程中氢过氧化物（约36%）、丙醛（约13%）和己醛（约200%）的含量,显示出促氧化活性;与对照组相比,生育酚的添加能抑制油脂氧化进程,但反胶束的形成使油脂中氧化产物浓度高于对照组,降低了生育酚的抗氧化活性。因此控制亚麻籽油中反胶束的形成将有助于油脂氧化稳定性,为富含n-3多不饱和脂肪酸油脂的稳态化控制提供新的策略与途径。     

钙离子对亚麻籽胶-紫苏分离蛋白负载DHA藻油乳液储藏特性与递送虾青素效果的影响北大核心CSCD

DHA藻油是补充ω-3多不饱和脂肪酸的重要非动物来源,但因其自身水溶性差、易氧化产生不良风味等特点,极大约束了其摄入途径。据此,采用高压微射流技术与逐层沉积技术(LBL)制备负载DHA的亚麻籽胶(FG,质量分数为0.4%)-紫苏分离蛋白(PPI,质量分数为0.225%)双层乳液,研究Ca^(2+)添加量(0%~0.5%)对上述双层乳液体系稳定性的影响;同时,采用INFOGEST体外模拟消化模型,探究PPI-DHA藻油单层乳液、FG-PPI-DHA藻油双层乳液、Ca^(2+)-FG-PPI-DHA藻油双层乳液中DHA的消化特性,以及上述3种体系递送虾青素的效率,并通过监测其在消化过程中粒径分布、电荷特性及微观状态变化等解释其内在机理。结果表明:DHA藻油双层乳液储藏20 d后,未添加Ca^(2+)的双层乳液的粒径从10.4μm降低至4.3μm,Zeta-电位从-23 mV降低至-33 mV,Ca^(2+)添加量为0.4%的双层乳液的粒径和电位未发生显著变化,乳液液滴分布均匀,无分层、絮凝、沉淀现象;DHA藻油双层乳液储藏20 d后,添加Ca^(2+)的双层乳液的Turbiscan抗重力稳定性指数(TSI)较未添加Ca^(2+)的双层乳液有明显改善;3种乳液体系模拟消化过程中,游离脂肪酸释放量分别为68.88%、50.84%、52.32%,虾青素生物可及性分别为47.42%、12.54%、9.66%。说明添加Ca^(2+)有利于DHA藻油双层乳液的稳定储藏,但对消化过程中脂肪酸与虾青素的释放具有一定迟缓效果,研究结果可为设计靶向递送体系提供重要理论依据。     

胶束化和碱溶酸沉提取羽扇豆蛋白的物化特性

利用胶束化和碱溶酸沉2 种提取方法从羽扇豆中提取羽扇豆蛋白,并对2 种方法提取羽扇豆蛋白的物化特性进行研究。结果表明：羽扇豆蛋白分子质量主要集中在18～90 kDa之间,是由多种分子质量的蛋白组成。碱溶酸沉提取羽扇豆蛋白的氨基酸总含量（66.2%）显著（P＜0.05）高于胶束化提取羽扇豆蛋白的氨基酸总含量（27.8%）。2 种提取方法提取羽扇豆蛋白的等电点pI接近5.0。胶束化提取羽扇豆蛋白的持水性显著（P＜0.05）高于碱溶液酸沉法提取的羽扇豆蛋白,而持油性无显著差异（P＞0.05）。碱溶酸沉法提取羽扇豆蛋白的起泡性在pH 2.0～6.0之间显著减小,在pH 6.0时起泡性最低,其泡沫稳定性的变化趋势与其起泡性类似。而胶束化提取羽扇豆蛋白的起泡性受pH值的影响不显著（P＞0.05）。胶束化提取的羽扇豆蛋白在pH 4.0时乳化性最小,然后随pH值的升高蛋白乳化活性也随之增加,2 种提取方法所提羽扇豆蛋白在pH 10.0时乳化活性最高。碱溶酸沉法提取的羽扇豆蛋白在pH 4.0时溶解度最小,而随着pH 4.0～10.0的增加,蛋白溶解度迅速增加。而胶束化提取羽扇豆蛋白的溶解度随pH 2.0～10.0的升高也逐渐增大。该研究为羽扇豆蛋白在食品工业中的开发与应用提供一定理论支持。     

利用图像分析和深度学习预测油菜籽中总酚含量

目的 建立了一种结合图像分析和深度学习的油菜籽中总酚含量的快速预测方法。方法 利用VGG19网络进行油菜籽图像籽粒特征的提取,通过多个卷积层来学习油菜籽图像的特征,并建立了回归模型用于预测油菜籽的总酚含量。共收集了100种油菜籽样本,将油菜籽样本按照3:1的比例划分为训练集和测试集,利用均方损失函数(MSELoss)和决定系数(r2)评估模型预测准确性。结果 测试集MSELoss=0.0085、r2=0.9914,表明该预测模型具有一定的准确性和实用性。结论 本研究提出了一种快速、准确的评估油菜籽总酚含量的方法,为油菜籽的总酚测定提供一种快速、准确的智能化检测方法。     

Composition,processing, and quality control of whole flaxseed products used to fortify foods

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid–amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.     

基于脂质组学揭示饲喂裂殖藻粉对山羊乳脂质的影响

基于气相色谱法和超高效液相色谱-四极杆-飞行时间串联质谱法探究饲喂裂殖藻粉（Schizochytrium spp.）对山羊乳脂肪酸组成及全脂质组成的影响，并与市售纯牛乳和二十二碳六烯酸（docosahexaenoic acid,DHA）牛乳进行差异性分析。结果表明，山羊乳脂肪含量显著高于牛乳，肉豆蔻酸、棕榈酸和油酸是乳中主要的脂肪酸组成。饲喂裂殖藻粉能显著增加山羊乳中DHA含量。甘油三酯是2种乳中主要的脂质成分，山羊乳中磷脂含量显著高于牛乳。DHA在乳品脂质中主要以甘油酯型DHA形式存在，山羊乳较牛乳含更丰富的磷脂型DHA。裂殖藻粉添加量50 g/d为山羊乳中DHA富集的最佳添加量。通过在日粮中添加DHA原料，能够进一步提高山羊乳的营养价值，解决目前膳食DHA来源单一的问题。本研究为婴幼儿配方奶粉及富DHA功能性乳脂产品的开发和营养调控提供有力的理论依据和参考，并为乳制品类型的鉴定提供方法与数据基础。