Comparing droplet breakup for a high-pressure valve homogeniser and a Microfluidizer for the potential production of food-grade nanoemulsions

A comparison of the emulsification performance of a high-pressure valve homogeniser (HPH) and a Microfluidizer has been carried out for a range of different oil to aqueous phase viscosity ratios, emulsifier types, pressure drops and number of passes through the chambers. It has been shown that for the same pressure drop across the two chambers, similar droplet sizes are produced (after 5 passes). Differences in droplet size were observed after a single pass, with the HPH producing larger droplets with a wider distribution of sizes. This difference can be attributed to the design of the homogenisation chambers with the HPH producing a wide distribution of shearing forces, so all of the starting emulsion does not experience the maximum stresses at each pass. Droplet size has been shown to be independent of viscosity ratio (0.1–80) for both homogenisers indicating that breakup is occurring in turbulent flow. No effect of emulsifier was observed in the Microfluidizer with SDS, Tween 20 and sodium caseinate. However, with the HPH, the droplet size reached a limiting value after 2 passes with SDS while with Tween 20 and sodium caseinate 5 passes were required indicating that coalescence occurs in the HPH but this is more effectively eliminated by SDS.     

Preparation of microencapsulated xanthophyll for improving solubility and stability by nanoencapsulation

A microencapsulated xanthophyll preparation method, using an ultrasonic cell grinder synchronizing emulsification inclusion procedure, was developed for improving the stability and water solubility of xanthophyll. The microencapsulated xanthophyll was analyzed, tested and characterized by methods, including high performance liquid chromatography, Fourier transform infrared spectrum, high resolution scanning electron microscopy, thermo-gravimetric analysis, and X-ray powder diffraction. The half-life (t ½) of the microencapsulated xanthophyll against light, heat and oxygen was 7.1 weeks, 5.1 h and 9.2 weeks, respectively. Compared with non-encapsulated xanthophyll, the stability of the microencapsulated xanthophyll against light, heat and oxygen was improved by 5.6 times, 1.9 times and 7.7 times, respectively. The results also showed that the fat soluble xanthophyll was successfully converted into microencapsulated xanthophyll with good water solubility (over 0.125 g/g). The investigation can be of a great interest for food, drink, pharmaceutical, cosmetic and related scientists considering the health benefit effect of xanthophyll and the unsuccessful attempts hitherto to render it completely water-soluble for a full use.     

Physiological protection of probiotic microcapsules by coatings

Nowadays, food and nutrition have a greater impact in people's concerns, with the awareness that nutrition have a direct impact in health and wellbeing. Probiotics have an important role in this topic and consumers are starting to really understand their potential in health, leading to an increasing interest of the companies to their commercial use in foods. However, there are several limitations to the use of probiotics in foods and beverages, being one of them their efficiency (directly associated to their survival rate) upon ingestion.

This work is focused in microencapsulation techniques that have been used to increase probiotics efficiency. More specifically, this work reviews the most recent and relevant research about the production and coating techniques of probiotic-loaded microcapsules, providing an insight in the effect of these coatings in probiotics survival during the gastrointestinal phase.

This review shows that coatings with the better performances in probiotics protection, against the harsh conditions of digestion, are chitosan, alginate, poly-L-lysine, and whey protein. Chitosan presented an interesting performance in probiotics protection being able to maintain the initial concentration of viable probiotics during a digestive test. The analyses of different works also showed that the utilization of several coatings does not guarantee a better protection in comparison with monocoated microcapsules.     

正交实验法确定乙丙装置水洗单元的最佳工艺条件

在乙丙橡胶后处理步骤的水洗过程中胶液难于分相,乙丙橡胶己烷溶液相与水相分界边缘较浑浊,胶液提取困难。作者通过水凝聚正交实验法进行了包括温度、水相pH值、m（胶）：m（水）、搅拌速度等因素条件的正交筛选实验,确定了最佳的水洗条件。     

乳化技术-原子吸收法测定涂料催干剂中钴、铅

将涂料催干剂样品溶解在体积比为1∶1的丙酮-甲基异丁基酮混合溶剂中,再用乳化剂OP将样品溶液乳化而配制成均匀、透明或半透明的样品乳浊液,建立了乳化技术-火焰原子吸收光谱法快速测定涂料催干剂中钴、铅的新方法。介质对试液的粘度、表面张力和火焰的燃烧性质无影响,试液的粘度与水的粘度一致,可以以水为参比。用工作曲线法测定,对样品处理条件、介质的影响、线性范围、背景吸收干扰及检出限进行了考察。测定结果的相对标准偏差小于0.9%,加标回收率为95.4%～104.3%。质量浓度线性范围:钴为0～10mg/L、铅为0～12mg/L。检出限:钴为0.067mg/L、铅为0.17mg/L。     

新型天然亲水胶体-亚麻籽胶

亚麻籽胶是一种新型天然亲水胶体,本文对亚麻籽胶的粘度、乳化性等性质以及上述性质与酸度变化、盐的影响、温度改变、加热或冷冻等因素的关系进行了研究。讨论了亚麻籽胶与蛋白质、脂肪、糖类、其他天然亲水胶体的相互作用结果,推荐了亚麻籽胶在一些食品生产中的应用方法。     

Efficiency of a range of homogenisation technologies in the emulsification and stabilization of cream liqueurs

High-pressure homogenisers, including a Microfluidizer, an orifice nozzle homogeniser and a radial diffuser homogeniser, and an ultrasonic system were evaluated and compared in terms of their efficiency in model cream liqueur emulsification. As the size distribution of the fat globules after homogenisation is very important for product quality, influence of homogeniser type and processing parameters on the droplet size distribution were studied. The Microfluidizer homogeniser produced cream liqueurs with fat droplets of the smallest diameters, while homogenisation by an orifice nozzle or a radial diffuser homogeniser produced cream liqueurs with very wide volume frequency distributions of fat droplet diameters. For all high-pressure homogenisation processes, cream liqueurs with fat droplets of smaller mean droplet diameters were produced at higher pressures, and it was found that lower fat droplet diameters resulted in cream liqueurs with improved storage stability. Using the ultrasonic homogeniser, it was also possible to produce a cream liqueur with finely-dispersed fat droplets; however, problems during shelf-life appeared for highly processed samples.

Industrial relevance

Other than typical dairy homogenisation processes, relatively few emulsification processes have been reported for the production of cream liqueurs. This work has important consequences in improving the efficiency of cream liqueur homogenisation processes and extending the shelf-life of cream liqueurs.     

石蜡细小乳状液的制备

以吐温60、司本60以及两种助表面活性剂作乳化剂,应用HLB理论制得0/W型稳定石蜡细小乳状液。其中石蜡20.0分、吐温60为1.6分、司本60为1.4分、两种助表面活性剂共2.0分、余量为水（质量水）。经激光粒度分析仪检测该乳状液平均粒径为0.682um。而仅用吐温60、司本60作乳化剂,只制得石蜡普通乳状液。     

常压直馏柴油碱洗乳化原因分析

直馏柴油碱洗乳化问题一直困扰着炼油厂,炼油厂在不断地寻找破乳途径。本文从乳化物的形成过程、形成机理及影响乳化物稳定性因素等方面对直馏柴油碱洗乳化原因进行了分析,旨在为直馏柴油碱洗破乳提供帮助。     

三相乳化油的制备与物理性质研究

用两步法配制油包水包油（O／W／O）三相乳化油，首先用亲水性表面活性剂Tween60制成水包油（O／W）乳化液，然后用亲油性表面活性剂Span60将O／W乳化液制成O／W／O三相乳化油。进一步研究乳化剂的亲水亲油平衡值（HLB）、掺水量对O／W／O三相乳化油的乳化稳定性（ES），乳化活性（EA）及运动黏度等物理性质的影响。试验发现，采用表面活性剂span60和Tween60作为乳化剂，当HLB值为6到9，掺水量为10％，表面活性剂总的添加量为2％时，O／W／O三相乳化油具有合适的运动黏度和稳定性，适合作为柴油机的代用燃料。