Effects of α s1-casein (CSN1S1) and κ-casein (CSN3) genotypes on milk coagulation properties in Murciano-Granadina goats

The effects of the caprine α s1-casein (CSN1S1) polymorphisms on milk quality and cheese yield have been widely studied in French and Italian goat breeds. Much less is known about the consequences of κ-casein (CSN3) genotype on the technological and coagulation properties of goat milk. In the current study, we have performed an association analysis between polymorphisms at the goat CSN1S1 and CSN3 genes and milk coagulation (rennet coagulation time, curdling rate and curd firmness) and technological (time to cutting of curd and cheese yield) properties. In this analysis, we have included 193 records from 74 Murciano-Granadina goats (with genotypes constituted by different combinations of alleles B, E and F of the gene CSN1S1 and alleles A and B of the gene CSN3) distributed in three herds, which were collected bimonthly during a whole lactation. Data analysis, using a linear mixed model for repeated observations, revealed significant associations between CSN1S1 genotypes and the rate of the curdling process. In this way, milk from EE goats had a significantly higher curdling rate than milk from BB individuals (P<0?·05). Contrary to previous experiments performed in French breeds, cheese yield was not significantly different in BB, EE and EF goats. Moreover, we have shown that CSN3 genotype has a significant effect on the rennet coagulation time (BB>AB, P<0?·05) but not on cheese yield. No interaction between the CSN1S1 and CSN3 genotypes was observed.     

Short communication: Effect of αS1-casein (CSN1S1) and κ-casein (CSN3) genotypes on milk composition in Murciano-Granadina goats

The effects of the caprine α_S1-casein (CSN1S1) polymorphisms on milk quality have been widely demonstrated. However, much less is known about the consequences of the κ-casein (CSN3) genotype on milk composition in goats. Moreover, the occurrence of interactions between CSN3 and CSN1S1 genotypes has not been investigated. In this study, an association analysis between CSN1S1 and CSN3 genotypes and milk quality traits was performed in 89 Murciano-Granadina goats. Total milk yield as well as total protein, fat, solids-not-fat, lactose, α_S1-casein (CSN1S1), and α_S2-casein (CSN1S2) contents were recorded every other month during a whole lactation (316 observations). Data analysis using a linear mixed model for repeated observations revealed no interaction between the CSN1S1 and CSN3 genotypes. With regard to the effect of the CSN3 locus, AB and BB genotypes were significantly associated with higher levels of total casein and protein content compared with the AA CSN3 genotype. In strong contrast with French breeds, the CSN1S1 genotype did not affect protein, casein, and fat concentrations in Murciano-Granadina goats. These results highlight the importance of taking into consideration the CSN3 genotype when performing selection for milk composition in dairy goats.     

Novel milk–juice beverage with fermented sheep milk and strawberry (Fragaria × ananassa): Nutritional and functional characterization

This study was aimed at developing a new functional fermented beverage manufactured with semi-skimmed sheep milk and strawberry pulp (Fragaria × ananassa Duch.) and commercial prebiotic ingredients. We also compared the performance of the yogurt starter cultures and a Lactobacillus plantarum strain (CECT_8328) with potential probiotic properties. We assessed the nutritional profile, bioactivity compounds, viability of lactic acid bacteria during storage, and survival of L. plantarum after in vitro simulated digestion during the storage period. The lactic acid bacteria were viable throughout the storage period, but only L. plantarum maintained good viability after simulated digestion. Nevertheless, neither inulin nor potato starch increased bacterial viability. The fermented semi-skimmed sheep milk strawberry beverages we developed are good sources of minerals and proteins.     

Allergic responses induced by goat milk αS1-casein in a murine model of gastrointestinal atopy

Up to 3% of young children develop milk allergy and this may influence the development of immune-mediated diseases in later life. One protein that has been associated with allergic reactions to ruminant milk is α(S1)-casein (CN). Studies suggest that goat milk with low levels of α(S1)-CN may reduce allergenicity of milk, but the dose response to α(S1)-CN has not been confirmed. In this study, we examined the immune response to varying levels of goat α(S1)-CN in a mouse model of gastrointestinal allergy. BALB/c mice (aged 5 wk) were given intraperitoneal injections with α(S1)-CN and aluminum as adjuvant at 1 and 3 wk to sensitize mice to the antigen. In wk 5, groups of fasting mice (n=8/group) were challenged 4 times on alternate days by intragastric gavage with saline or 2, 10, or 20mg of α(S1)-CN. Serum levels of specific IgE, IgG(1), and IgG(2a) antibodies and mouse mast cell protease-I were determined. Interleukin-4, IL-10, and IFN-γ responses to 48-h activation with antigen were measured in cultured splenocytes. We determined that mice sensitized with α(S1)-CN had higher titers of specific IgG(1) and IgE antibodies compared with controls; however, groups challenged with differing doses of α(S1)-CN did not differ. The group challenged with the highest dose of α(S1)-CN had a 10-fold increase in mouse mast cell protease-I compared with the group challenged with saline. Both IL-4 and IL-10 were produced in a dose-dependent manner by cultured splenocytes incubated with α(S1)-CN. Overall, α(S1)-CN stimulated the production of cytokines associated with allergic disease in a dose-dependent manner. Thus, milk with lower levels of α(S1)-CN should contribute to a lesser antigenic burden.     

Aflatoxin M1 in raw milk from different regions of São Paulo state – Brazil

A total of 635 raw milk samples from 45 dairy farms, from three regions of São Paulo state – Brazil, were evaluated during 15 months for aflatoxin M₁ (AFM₁). AFM₁ was determined by high performance liquid chromatograph with fluorescence detection. AFM₁ was detected (>0.003 µg kg^?1) in 72.9%, 56.3% and 27.5% of the samples from Bauru, Araçatuba and Vale do Paraíba regions, respectively. The mean AFM₁ contamination considering all the samples was 0.021 µg kg^?1. Furthermore, the concentration of AFM₁ was quite different among Bauru (0.038 µg kg^?1), Araçatuba (0.017 µg kg^?1) and Vale do Paraíba (<0.01 µg kg^?1) regions. Only three samples (0.5%) had higher contamination than the tolerated limit in Brazil (0.50 µg kg^?1) and 64 samples (10.1%) had a higher contamination than the maximum limit as set by the European Union (0.050 µg kg^?1). The estimated AFM₁ daily intake was 0.358 and 0.120 ng kg^?1 body weight per day for children and adults, respectively.     

关于函数(S)k(n)的均值

研究了函数S^-k（n）的均值性质,并用初等方法得到了关于它的一个渐近公式.     

High postnatal exposures to polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) via breast milk in California: does BDE-209 transfer to breast milk?

Breast milk samples collected during 2003-2005 from 82 first-time mothers in 24 communities located throughout California contained levels of polybrominated diphenyl ethers (∑(tri-hexa (8))PBDEs; median = 53.3 ng/g lw, range = 9.60-1291) and polychlorinated biphenyls (∑(12)PCBs; median = 73.4 ng/g lw, range = 22.2-433) that are among the highest in the world. PBDE levels varied 100-fold. BDE-47 was the dominant PBDE congener, with levels exceeding the U.S.EPA Reference Dose (RfD) for neurodevelopmental toxicity (100 ng/kg/day) in most (60%) breast milk samples. In some samples, BDE-209 (2/82) and/or BDE-153 (5/82) were the dominant congeners, suggesting that BDE-209 can transfer to breast milk and/or break down in the mother and transfer to the nursing infant as the lower-brominated PBDEs associated with adverse effects. PBDE levels in California breast milk are approaching those of PCBs, and the trend PBDEs > PCBs may continue as PBDEs migrate from products to the indoor and outdoor environments.     

书讯(1)

由中钢集团金属制品研究院牵头组织 ,又为行业推出了两本内容丰富 ,可适合众多读者口味的两本新书———《重要用途线材制品生产技术》和《钢丝》译文。《重要用途线材制品生产技术》一书是由金属制品研究院组织行业内 18位著名专家编写的。全书集中、系统地介绍了金属制品行业 2 0年来在引进国外先进技术装备时消化、吸收、创新方面的成果和宝贵的生产经验。代表性产品的用途及特性 ,工艺制造新方法、新技术、新装备 ,国内外产品质量存在的差距 ,影响产品质量的因素分析 ,提高产品质量的措施。读者对象为从事金属制品生产、设计、教学等方…     

基于三菱FX_(1S)PLC的脉冲编码器数字给定系统

在复杂的电磁环境下,设备控制系统的给定信号如果采用电位器式的模拟信号,常会因干扰问题影响设备正常运行,在信号传输距离较长时该问题更加突出。采用由脉冲编码器和三菱PLC构成的给定单元,通过通讯和系统连接,可彻底解决信号波动和干扰问题。介绍铝包钢丝生产线的基本组成,原控制系统存在的问题和基本结构,改进后系统组成。重点说明改进后系统的硬件型号、接口组成及接线,给出控制框图及部分控制程序。使用表明,改进后生产线运行速度由原来的100m/min提高到180m/min,生产效率提高了80%,系统稳定性大大提高,减少维护时间。     

发烧友培训班(1)

很想添置一套音响,来满足自己欣赏音乐的愿望,可是,如何挑选才能够买到音质完美的音响呢?我们在这里为您开办了发烧友培训班,为您讲解本关知识。     

发烧友培训班(1)

很想添置一套音响,来满足自己欣赏音乐的愿望,可是,如何挑选才能够买到音质完美的音响呢?我们在这里为您开办了发烧友培训班,为您讲解本关知识。     

涂饰技术讲座(1)

涂饰的重要性不言而喻 ,它决定着成品革的外观及物性要求。本刊推出制革技术讲座和毛皮技术讲座以后 ,受到了广大读者的推崇和喜爱 ,应读者的要求 ,从本期开始 ,我们将开设涂饰技术讲座 ,并请到了曾在罗门 -哈斯公司工作多年 ,在涂饰方面有丰富实践经验的李林主持这一讲座。内容将涉及涂饰的基本原理 ,苯胺涂饰 ,效应涂饰 ,辊印涂饰及防水革涂饰等     

专利集锦(1)

专利名称:蚕茧筛选装置专利申请号:CN201210101169.7公开号:CN102634854A申请日:2012.04.09公开日:2012.08.15申请人:陕西科技大学蚕茧筛选装置,包括传送带,传送带中间部分安装有推板和链板,链板和推板构成均匀的隔栅,传送带的一侧均匀布置有多个铁片,所述传送带下方依次设置有放料板、透视     

Effects of the circadian rhythm on milk composition in dairy cows: Does day milk differ from night milk?

Metabolism in most organisms can show variations between the day and night. These variations may also affect the composition of products derived from livestock. The aim of the present study was to investigate the difference in composition between the day milk and night milk of dairy cows. Ten multiparous Holstein cows (milk yield = 25.2 ± 5.00 kg/d) were randomly selected during mid lactation. Milk samples were collected at 0500 h (“night milk”) and 1500 h (“day milk”) and analyzed to determine their composition. Mid-infrared spectroscopy was used to analyze macronutrient content of milk. Metabolomics and lipidomics were used to detect and analyze small molecules and fatty acids, respectively. An automatic biochemical analyzer and ELISA kits were used to determine biochemical indicators, as well as antioxidant and immune parameters in the milk. Though milk fat, protein, lactose, and total milk solids were not different between day milk and night milk, small molecules, metabolites and lipids, and hormones and cytokines differed between day milk and night milk. Regarding biochemical and immune-related indicators, the concentrations of malondialdehyde, HSP70, and HSP90 in night milk were lower than that in day milk. However, interferon-γ levels were higher in night milk. Additionally, night milk was naturally rich in melatonin. Lipidomics analyses showed that the levels of some lipids in night milk were higher than those in day milk. Metabolomics analyses identified 36 different metabolites between day milk and night milk. Higher concentrations of N-acetyl-d-glucosamine, cis-aconitate, and d-sorbitol were observed in day milk. However, the other 33 metabolites analyzed, including carbohydrates, lipids, AA, and aromatic compounds, showed lower concentrations in day milk than in night milk. The present findings show that the composition of night milk differs considerably from that of day milk. Notable changes in the circadian rhythm also altered milk composition. These results provide evidence to support the strategic use and classification of day milk and night milk.     

染色基础讲座(1)

美国《纺织化学家与染色家》杂志1980年1～12月号刊载了供初学者参阅的《染色基础讲座》共12讲。本刊拟从1981年第一期开始连载,以供从事印染行业的技术人员、工人和干部参考。     

Validation of a lateral flow test (MRLAFMQ) for the detection of aflatoxin M1 at 50 ng l−1 in raw commingled milk

Aflatoxin M₁ contamination in dairy products is a risk when feedstuff contaminated with aflatoxin B₁ produced by moulds is consumed by milk-producing animals. Milk can be screened for aflatoxin M₁ at the European Union maximum limit of 50 ng l^?1 by a lateral flow test, the MRLAFMQ (Aflatoxin M1) Test. The method takes 15 min with no milk dilution or a sample preparation step. The lateral flow assay was validated at the Technology and Food Science Unit of the Institute for Agricultural and Fisheries Research (ILVO-T&V) according to European Union guidelines using fortified raw milk samples. A detection capability of 50 ng l^?1 was demonstrated with a false negative rate lower than 2% at 50 ng l^?1 and a false positive rate of less than 0.3%. Quantitative readings had a mean bias of +2 to 6 ng l^?1 at 50 ng l^?1 with a standard deviation of 5–8 ng l^?1. Based on the validation results, the test could be considered appropriate for milk screening prior to milk unload at dairies.     

QBASIC编程一点通(1)

我们少年朋友都喜欢玩电脑,利用电脑可以玩电脑游戏、画画、听歌曲、看电影、做动画、上网、聊天、画表格、一下子算出很复杂的计算等等,简直是无所不能。可你想过这是为什么吗?简单地说,这是因为我们为电脑编写了功能丰富的电脑程序,我们为电脑编写了什么样的程序,电脑就具有什么样的功能!看到这里,你是否想马上着手编程,体验真正驾驭电脑的感觉?别急,先让我们一起来了解些关于编程的基础知识。