Water soluble polymeric nanofibres for rapid flocculation and enhanced dewatering of mature fine tailings

Water-soluble polymer flocculants have been used to efficiently release entrapped water in oil sands tailings by bridging fine particles to create large heavier flocs which can then settle faster and release water more efficiently. Due to their initial interaction with the fine particles suspended in tailings, polymer nanofibres may perform better than their parent polymers because of the entire surface of the nanofibres being fully accessible to the fine particles. In this work, commercially available poly(acrylamide-co-diallyl dimethylammonium chloride) was chosen as a basis for this study. Initial settling rate, supernatant turbidity, water recovery, capillary suction time, and solids content were measured to determine the effect of polymer nanofibres on solid-liquid separation. The solid forms of the polymer (either as nanofibre or powder) perform better than the polymer solution in each test, with optimum dosages of 5 wt% mature fine tailings (MFT) loading. Nanofibres could achieve settling rates of 60 m/h, while the other forms were only able to achieve 42 m/h. Additionally, the turbidity of the supernatant obtained after flocculation with nanofibres was 15 nephelometric turbidity units (NTU), while the polymer solution and powder produced turbidites of 162 NTU and 70 NTU, respectively. In addition, polymer nanofibres and powders generated larger flocs compared to the polymer solution, which produced small, homogenized flocs.     

trans Fatty Acids in Colostrum,Mature Milk and Diet of Lactating Adolescents

The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15–19 years, 1–90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n‐3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t‐18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t‐18:1), whereas rumenic acid (9c,11t‐18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n‐3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants.     

Effects of skim milk concentrate dry matter and spray drying air temperature on formation of capsules with varying particle size and the survival microbial cultures in a microcapsule matrix

The impact of total solid (TS) content in combination with the feed rate and air inlet temperature on the survival of Lactobacillus paracasei ssp. paracasei F19 after spray drying in a skim milk matrix has been investigated and correlated with the capsule size. Depending on the experimental conditions, the survival rates ranged from 64 to 0.2%. The higher the air inlet temperature, the lower was the survival rate and an inversely correlation between the TS content and particle size has been determined. These results clearly indicate that process stress analyses and product-related characteristics must not be regarded separately.     

高效液相色谱法测定含乳饮料中苯甲酸、山梨酸钾、水杨酸

建立了含乳饮料中苯甲酸、山梨酸钾等添加剂的高效液相色谱仪同时检测的方法。含乳饮料经前处理后,由C18反相色谱柱进行分离,流动相A:磷酸盐缓冲溶液(1.25 g K2HPO4与1.25 gKH2PO4加水定容至500 mL),流动相B:乙腈,流动相A、B按9∶1比例洗脱,流速0.6 mL/min,进样量为10μL。苯甲酸检测波长为225 nm,山梨酸钾的检测波长为240 nm,水杨酸的检测波长为225 nm。该方法线性范围为0.6~30μg/mL,检测限为0.06μg/mL。     

运城盐湖矿物黑泥在化妆品洁面乳中的应用

简要介绍了运城盐湖矿物黑泥的形成历史及其富含成分,重点考察了其在洁面乳化妆品中的应用。结果表明,含有2.0%～4.0%黑泥的洁面乳配方性质稳定、性能温和,其各项指标均符合国家相关标准规定。含有黑泥的洁面乳经人群试用后的综合评价结果良好,黑泥在洁面乳体系中具有显著的去除多余油脂和去角质功能。     

高效液相色谱法检测强化牛奶中的维生素A

本文介绍了用高效液相色谱法检测强化牛奶中维生素A乙酸酯的方法。样品经乙醇沉淀蛋白质后用石油醚萃取,氮气吹干。液相色谱条件是以YWG—C_(18)(4.6mm×250mm)作色谱柱,甲醇为流动相,流速2ml/min,在UV325nm检测。样品整个分析周期为25～30min。该方法简便快速,重现性好,回收率95%～102%,变异系数小于3.5%。     

Preliminary study of saffron (Crocus sativus L. stigmas) color extraction in a dairy matrix

Saffron spice has been used for decades as an ingredient in many dairy products but changes in its coloring properties related to milk characteristics have not been paid appropriate attention. Saffron color was studied in ewes’ milk at different fat levels and saffron concentrations using tristimulus colorimetry. In order to evaluate saffron extraction, different temperatures and extraction times were tested. Color changes were demonstrated to be statistically significant when increasing the fat content in milk, as well as saffron concentration. The higher milk fat content, turned the extracts brighter and yellower, while less red and vivid, opposite to results obtained by increasing saffron concentration. Extraction time was not significant for color extraction. Milk extracts resulted slightly brighter and yellower when increasing temperature, probably due to crocetin esters degradation or isomerization from trans to cis configuration. Temperatures between 37 and 70 °C are recommended to avoid structural changes in milk or saffron. Color changes could be due to interactions mediated by phospholipids between milk fat globules and crocetin esters, as well as minor saffron carotenoids.     

Effect of processing conditions on physical properties of a milk fat model system: Rheology

The effect of processing conditions on rheological behavior of three blends of 30, 40, and 50% of high-melting fraction [melting point measured as Mettler dropping point (MDP)=47.5°C] in low-melting fraction (MDP=16.5°C) of milk fat was studied. The effects of cooling and agitation rates, crystallization temperature, chemical composition of the blends, and time of storage on complex, storage and loss moduli were investigated by dynamic mechanical analysis (DMA). Compression tests were performed on samples using frequency values within the linear viscoelastic range (1 to 10 Hz). Loss modulus was, on average, 10 times lower than elastic modulus and was generally not affected by processing conditions. Samples showed a more solid-like behavior that was better described by storage modulus. Storage modulus varied with all processing conditions used in this study, and even for the same solid fat content, different rheological properties were found. Storage and complex modulus increased with temperature of crystallization (25 to 30°C), even though solid fat contents of samples measured after 24 h at 10°C were the same. Moduli were higher for samples crystallized at slow cooling rate, decreased with agitation rate, and were lower for the 30–70% blend at all processing conditions used. Storage moduli also increased with storage time. Shear storage modulus was calculated from the DMA experimental data, and the results were in agreement with the values reported in literature for butter systems. Fractal dimensions calculated for these systems showed a significant decrease as agitation rate increased in agreement with the softening effect reported for working of butter.     

微多蛋白素饲喂产奶牛生物活性试验

微多蛋白素饲喂产奶牛试验,通过对试验组和对照组在各阶段产奶量变化的比较及乳品质量指标的测定表明,微多蛋白素饲喂产奶牛具有明显的增奶效果,其奶质量亦得到改善,产奶牛日粮添加微多蛋白素 １００ｇ／头,可增奶 １．７９ｋｇ／头,替代豆饼组饲喂微多蛋白素 １００ｇ／·日,可增奶 ０．２７ｋｇ／头·日。