欧盟批准一种赖氨酸硫酸盐作为饲料添加剂

正据欧盟网站消息,2017年3月14日欧盟发布(EU)2017/439条例,批准一种L-赖氨酸硫酸盐作为饲料添加剂。这种L-赖氨酸硫酸盐由大肠杆菌发酵产生。用于饲料可作为动物赖氨酸的有效来源,不会对动物、人体以及环境构成影响。新条例同时规定了赖氨酸硫酸盐作为添加剂的组成、活性物质、检测方法以及最大残留量,同时规定食品标签中需要标明赖氨酸硫酸盐的添加量。     

L-赖氨酸硫酸盐对断奶仔猪生长和蛋白质利用的影响

断奶仔猪按饲养试验要求分为3组,试验1、2组分别在基础日粮中添加0.26%的L-赖氨酸盐酸盐和0.39%的L-赖氨酸硫酸盐,按产品中的赖氨酸含量计算,两组赖氨酸含量均为0.15%.结果表明,与对照组相比,添加赖氨酸盐酸盐和赖氨酸硫酸盐使断奶仔猪平均日增重分别提高了7.40%(P＜0.05)和13.93%(P＜0.05),料肉比分别降低了3.65%(P＞0.05)和8.33%(P＜0.05),氮表观消化率分别提高了4.48%(P＞0.05)和6.95%(P＜0.05),氮表观代谢率分别提高了8.47%(P＜0.05)和14.32%(P＜0.05),表观生物学价值分别提高了5.95%(P＜0.05)和9.76%(P＜0.05),收入分别增加了7.58和17.65元/头.     

制备硫酸盐木素基胶粘剂

木素的结构由本丙烷单元通过酸键和碳—碳键连接为多元酚，可供作为本酚树脂的原料。但是，由于硫酸盐术素的平均分子量较高，一般为1000～20000（酚醛树脂胶粘剂的分子量约为200），分子量大就不能充分地使其渗入木材表面，致使两面之间的粘合作用难以达到要求；同时，木素分子相互之间容易盼聚、结块，可塑性差以及木素具有交联能力的基团相当少，因此，未经改性的硫酸盐木素的胶粘性能是不能令人满意的。现将硫酸盐木素的化学元素、官能团分析结果和为了制备硫酸盐术素基胶粘刘，对木素的改性方法分析如下。试样为针叶木硫酸盐制浆原黑液…     

赖氨酸硫酸盐类产品应用连续喷雾流化床造粒技术的生产线配置

对赖氨酸硫酸盐类饲料添加剂产品应用连续喷雾流化床造粒的生产线配置进行统计分析,包括生产线产能配置、土建或钢架形式配置。结果表明:应用连续喷雾流化床造粒技术生产赖氨酸硫酸盐的生产线,采用1台造粒床与1台流化床的配置形式优于多台造粒床与1台流化床配置;在选择生产线数量时,以能满足生产规模所采用的生产线的最少数量为最佳方案。设计制造出更高产能的单套生产线,以降低投资、节能、提高稳定安全性、提高产品品质是目前喷雾流化床造粒技术的发展目标。     

食品粉末颗粒间的相互作用及结块行为的研究概述

粉体结块现象是食品工业中普遍存在的实际问题。本文针对食品粉体结块现象进行了综述,阐述了粉末颗粒间的相互作用,介绍了食品粉末结块的测试方法,分析了食品粉末结块动力学行为与结块控制方法,提出食品粉末结块研究中需要跟踪粉末颗粒间桥联的演变过程,并总结传热传质模型对食品粉末结块行为的重要作用,旨在为食品粉末结块的有效控制提供参考。     

五水硫酸铜、七水硫酸亚铁粉碎的试验研究

五水硫酸铜、七水硫酸亚铁的化学性质不稳定,在贮运过程中易吸湿结块。所以无论是饲料级还是工业级的硫酸铜和硫酸亚铁,前处理中都必须进行粉碎处理。这两种硫酸盐,除本身含有较高的结晶水外,由于它们的吸湿性,还含有一定数量的游离水。这样高的含水给粉碎带来了困难,这是硫酸盐前处理的难点之一。表１是笔者对硫酸铜、硫酸亚铁直接粉碎的试验情况。表１　硫酸盐直接粉碎试验记录原　　料总含水量／％结晶水数目ＨＬ５００型混碾机ＤＷＷＦ２００微粉碎机ＣｕＳＯ４·５Ｈ２Ｏ３８．０６５．４５约２０％过筛粘齿严重ＦｅＳＯ４·７Ｈ…     

晶体类食品添加剂结块的成因与防止

晶体类物质往往存在结块问题,而结块问题又往往是影响产品质量的重要因素。本文简介了晶体类食品添加剂的结块现象对产品的危害和有关其结块机理的主要理论学说;并从结构理论、多晶现象、玻璃态转化和国内外对晶体类食品添加剂结块的研究成果等几个方面,较详细地分析了晶体类食品添加剂结块的成因及影响因素的影响概况;对国内外有关晶体类食品添加剂结块和防结块测定的评价进行了科学地概述;也针对有效预防晶体类食品添加剂结块提出了优化生产工艺参数、改善包装方式、合理使用防结块剂和科学设置贮藏条件等一系列具体的防止办法和措施;还就我国食品类防结块的形势作了简要展望。     

食品粉末颗粒间的相互作用及结块行为的研究进展

粉体结块现象是食品工业中普遍存在的实际问题。针对食品粉体结块现象进行了综述,阐述了粉末颗粒间的相互作用,介绍了食品粉末结块的测试方法,分析了食品粉末结块动力学行为与结块控制方法,提出食品粉末结块研究中需要跟踪粉末颗粒间桥联的演变过程,并总结传热传质模型对食品粉末结块行为的重要作用,旨在为食品粉末结块的有效控制提供参考。     

防止盐固结的方法浅议

盐的结块问题困扰着盐业生产和运销单位,本文通过大量资料文献,分析了盐的结块机理,提出了解决结块的方向,对防结块方法的研究有一定的指导意义。     

食用盐结块原理及不同材质外包装抗结块能力差异性分析

外包装一定程度上会影响食用盐的抗结块能力。文章对食用盐的基本结块原理进行分析,认为吸湿、放湿等是造成食用盐结块的最根本原理,对影响食用盐结块的因素包括粒度、对己量、杂质成分等因素进行总结,分析了在不添加抗结剂时,氧化膜、镀铝膜、铝箔膜等不同食用盐外包装抗结块能力的差异性,旨在为抗结块食用盐外包装开发提供借鉴。     

Caking of lactose: A critical review

BackgroundCaking is a recurrent problem in various industries, whether it occurs during the production, storage or transport of powders. Caked powder results in longer processing times and decreased product quality, leading to significant economic loss. Several caking mechanisms have been described in the literature. However, they are often difficult to take into account in an industrial context, given the many parameters which influence the overall caking phenomenon.Scope and approachThis review describes the three relevant caking mechanisms for food powders in general. Focussing on predominantly crystalline lactose powder, we discuss how each of these mechanisms can explain caking and be prevented in the industrial context. The second part of this paper presents a critical review of the methods used to characterise caking to date.Key findings and conclusionsThe presence of amorphous material and other impurities must be assessed in crystalline lactose powders, as they can trigger amorphous and humidity caking. Particle size distribution is another key parameter requiring control as it can encourage caking through enhancement of particle interactions. In general, preventing caking in food powders can only be achieved by a thorough understanding of the production process and storage conditions. Moreover, the characterisation of caking remains a challenge as most methods published in the literature do not fit the needs of the food industry. The real demand is for a reliable method to predict caking which would be rapid and easy enough to be applied to each batch for quality control.     

Optimization of Maltodextrin and Tricalcium Phosphate for Producing Vacuum Dried Mango Powder

Drying of mango pulp into powder is a challenging operation, mainly due to the sticky issue of mango powder in the dryer and caking during handling and storage. To overcome the above problem, maltodextrin, MD (drying aid) and Tricalcium Phosphate, TCP (anti caking agent) were added to the mango pulp at three levels and vacuum dried. The dried powder was analysed for properties such as hygroscopicity, degree of caking, flowability and sticky point temperature. Factorial design of experiment was used to investigate the effect of MD and TCP on the mango powder properties. The amount of MD and TCP required to reduce powder stickiness and caking were optimized based on the powder properties. At the optimum amount of MD (0.527 kg per kg dry mango solid) and TCP (0.0167 kg per kg dry mango solid), the values of mango powder properties were: hygroscopicity = 6.4 %; degree of caking = 7.8%; flowability = 18.6 s; sticky point temperature = 47.4°C.     

L-赖氨酸高产菌选育的研究

以黄色短杆菌ATCC140 6 7为出发菌株 ,经亚硝基胍 (NTG)、硫酸二乙酯 (DES)逐级诱变处理 ,S 2 氨基乙基 L 半胱氨酸 (AEC)、磺胺胍 (SG)等氨基酸结构类似物及琥珀酸为唯一碳源平板定向育种 ,获得 1株L 赖氨酸高产菌XQ 8(AECrSucgThr- SGr)。在含有 16 0 g/L葡萄糖的培养基中 ,摇瓶发酵 72h ,L 赖氨酸积累可达 77～ 82 g/L。     

锌强化营养盐结块因素分析及防范措施

通过对锌营养盐结块因素分析,强化锌强化营养盐生产控制,从而达到改善防范锌盐结块的效果。     

Formulation of Caking-Resistant Powdered Soups Based on NMR Analysis

ABSTRACT: This study demonstrates that the caking tendencies of powdered soups could be altered by adjusting the proportions of existing ingredients in the recipes without using anticaking chemicals. The composition adjustment was guided by the knowledge of the caking tendencies of individual ingredients, which was acquired with a low field nuclear magnetic resonance (NMR) instrument. This study showed that increasing the proportions of caking-resistant ingredients in soup recipes lowered the caking tendency. Multiple regression models based on the data from NMR experiments and storage tests were used for prediction of days-until-caking (DUC) values of soup products stored at different temperatures (37 to 65°C).     

精制盐的抗结块研究

通过对盐结块机理以及影响盐结块因素研究分析,在逆向反循环真空蒸发制盐工艺的基础上,通过一定的生产工艺改进,生产大颗粒盐并使其大小均匀,从而不添加任何抗结剂防止盐的结块,满足各种盐产品需求。     

Moisture-induced caking of beverage powders

BACKGROUND: Beverage powders can exhibit caking during storage due to high temperature and moisture conditions, leading to consumer dissatisfaction. Caking problems can be aggravated by the presence of sensitive ingredients. The caking behaviour of cocoa beverage powders, with varying amounts of a carbohydrate sensitive ingredient, as affected by climate conditions was studied in this work. Sorption isotherms of beverage powders were determined at water activities (a_w) ranging from 0.1 to 0.6 in a moisture sorption analyser by gravimetry and fitted to the Brunauer–Emmett–Teller (BET) or the Guggenheim–Anderson–de Boer (GAB) equation. Glass transition temperatures (T_g) at several a_w were analysed by differential scanning calorimetry and fitted to the Gordon–Taylor equation. Deduced T_g = f(a_w) functions helped to identify stability or caking zones. Specific experimental methods, based on the analysis of mechanical properties of powder cakes formed under compression, were used to quantify the degree of caking. Pantry tests complemented this study to put in evidence the visual perception of powder caking with increasing a_w. RESULTS: The glass transition approach was useful to predict the risks of caking but was limited to products where T_g can be measured. On the other hand, quantification of the caking degree by analysis of mechanical properties allowed estimation of the extent of degradation for each product. CONCLUSION: This work demonstrated that increasing amounts of a carbohydrate sensitive ingredient in cocoa beverages negatively affected their storage stability. Copyright © 2011 Society of Chemical Industry     

Study of Caking in Powdered Foods Using Nuclear Magnetic Resonance Spectroscopy

Twenty-three powdered foods and ingredients were subjected to 2 treatments: temperature scan from -20 to 110 °C within 2 hours, and storage at 37 °C and 55 °C for 60 d. During temperature scans, the spin-spin relaxation time T₂ values of individual samples were determined using a nuclear magnetic resonance (NMR) technique, resulting in a temperature-T₂ curve for each sample. Four typical temperature-T₂ curve patterns were identified and were found to be closely related to the physical changes in the samples, including agglomeration, water vaporization, and caking observed during temperature scans. Based on the temperature-T₂ curve patterns, the samples were classified into 4 groups each having distinguished caking behavior. In the storage tests, the samples were removed from the incubators every half an hour during first 2 d of storage period and every day afterwards. The storage test also suggests a strong relationship between molecular mobility and caking. Monitoring changes in T₂ as a function of temperature provides information useful for predicting whether and when caking would occur.