油酸合成酸性磷酸酯胺盐及其摩擦性能研究

油酸经氨化、加氢合成油胺,进而与P2O5、异癸醇合成的酸性磷酸酯进行反应以合成酸性磷酸酯胺盐。对酸性磷酸酯胺盐的合成条件进行了优化,并对其结构和性能进行了表征和测试。结果表明,酸性磷酸酯胺盐的最佳合成条件为:n(P_2O_5)∶n(异癸醇)∶n(油胺)=1∶3∶0. 9,总反应时间12. 5 h。在最佳合成条件下,产物的pH在5. 5左右,收率可达92. 76%。通过红外、核磁和VPO相对分子质量表征,确定产物为目标产物。通过四球实验、抗腐蚀性测试及油溶性的考察表明,合成的酸性磷酸酯胺盐不仅有良好的油溶性、抗腐蚀性,且在极压抗磨性上有很大的提高,在加剂量2. 0%时效果最佳。     

Short communication: Toxicokinetics of ochratoxin A in dairy ewes and carryover to milk following a single or long-term ingestion of contaminated feed

Ruminal microbes have the capacity to inactivate ochratoxins, rendering ruminants less sensitive to this fungal contaminant found in cereal feeds. However, ochratoxin A has been reported in milk surveys. The objective of this study was to assess the toxicokinetics, excretion, and transmission into milk of ochratoxin A using doses similar to those of naturally occurring field contaminations. Six Lacaune dairy ewes in late lactation were separated into 2 groups that received a single dose of contaminated wheat containing 5 or 30 μg of ochratoxin A/kg of body weight. After administration, toxicokinetics and excretion were monitored for 48 h. Subsequently, ewes were administered the corresponding toxin dose daily for 24 d followed by a second toxicokinetics and excretion monitoring period for this long-term exposure. The doses used did not affect production or health of ewes. After a single dose, ochratoxin A and its main metabolite, ochratoxin α, were found in blood 1 h postexposure. The maximum blood concentrations of ochratoxin A and α, respectively, were dose dependent and were observed, on average, 6 and 8 h after exposure. Long-term exposure increased the maximum concentration of ochratoxin A detected in blood, whereas ochratoxin α was not affected. In contrast, the time to reach the maximum concentration was reduced to 3 h for both molecules. Ochratoxins, essentially ochratoxin α, were mainly excreted in feces. Ochratoxin A and α were detected in milk at concentrations that were dose dependent but with a low carryover rate (<0.02%). Chronic administration did not increase the concentration of toxin in milk. Even though ochratoxin A can escape ruminal degradation and traces were found in milk of experimentally exposed ewes, the low carryover of ochratoxin A in milk minimizes the risk to consumers.     

Depletion of florfenicol and florfenicol amine in eggs of laying hens and growing pullets after oral administration

ABSTRACT

In this study, we carried out two experiments to evaluate depletion of florfenicol (FF) and its metabolite florfenicol amine (FFA) in eggs from growing pullets and laying hens. Eggs were collected, and the egg white and yolk were separated. FF and FFA were analysed by liquid chromatography-tandem mass spectrometry. In the first experiment, 30 laying hens were given FF capsules at 50 mg/kg·bw^?1 daily for 5 d. FF + FFA was detectable in egg white (1,190 µg/kg) on day 1 of treatment and increased slowly thereafter. After treatment, the residues decreased rapidly and were not detected by day 11. In yolk, residues were detected at a lower concentration on day 1 and increased dramatically to 3308 µg/kg at the end of treatment. The residues remained steady over the next 4 days post-treatment, followed by a rapid drop. Residues were not detectable on day 15 post-treatment. In the second experiment, four groups (B1 through B4) of growing pullets were treated in the same manner for 25, 20, 15, and 10 days before egg primiparity. FF and FFA were not detectable in the eggs of group B1; however, they were detectable in egg whites and yolks of groups B2, B3, and B4. The highest total concentrations of FF and FFA detected in egg white and yolk of group B4 were 3,190 µg/kg and 3,214 µg/kg, respectively. Thereafter, concentrations decreased until no more residues were detected in egg whites or yolks on days 17 and 21 post-treatment, respectively. Therefore, drug treatment should be stopped at least 21 d before primiparity of growing pullets to guarantee food safety.     

黄酒中生物胺对小鼠胺类氧化酶和免疫功能的影响

为了观察黄酒及生物胺（BA）对胺类氧化酶活性和机体免疫功能的影响,将4周龄雄性昆明小鼠随机分为三个对照组（空白、 酒精和BA）、黄酒组和黄酒+BA（9倍、99倍）组（N=10）。 持续灌胃30 d后,各组间二胺氧化酶（DAO）活性差异不明显（P＞0.05）、肝脏 病理形态正常;酒精、BA对照组小鼠的大脑单胺氧化酶（MAO）活性高于空白对照组（P＜0.05）,黄酒组低于酒精对照组（P＜0.05）, 黄酒+BA（9倍、99倍）组高于黄酒组（P＜0.05）;BA对照组肝脏MAO活性比空白对照组低（P＜0.05）;BA对照组白细胞介素（IL-1β）低 于空白对照组（P＜0.05）,黄酒+99倍BA组IL-1β低于空白、酒精对照组和黄酒+9倍BA组（P＜0.05）。 限量饮用该黄酒不会引起胺类氧 化酶和免疫功能的异常;黄酒与外源性BA共同作用时,会改善一定剂量BA引起的大脑MAO活性升高、IL-1β水平失调。     

Lactobacillus rhamnosus GG modulates gastrointestinal absorption,excretion patterns,and toxicity in Holstein calves fed a single dose of aflatoxin B1

The aim of the present study was to evaluate the effects of Lactobacillus rhamnosus GG (LGG; ATCC 53013) on growth performance and hepatotoxicity in calves fed a single dose of aflatoxin B₁ (AFB₁) and to investigate the absorption, distribution, and elimination of AFB₁ and the hydroxylated metabolite aflatoxin M₁ (AFM₁) in rumen fluid, blood, and excretions. Twenty-four male Holstein calves were blocked for body weight and age and were randomly assigned to 1 of 3 treatment groups: (1) untreated control, (2) treated with 4.80 mg of AFB₁ (AFB₁ only), or (3) treated with 1 × 10¹⁰ cfu of LGG suspension and 4.80 mg of AFB₁ (AFB₁ plus LGG). The calves received LGG suspension in 50 mL of phosphate-buffered saline daily via oral administration for 14 d before and on the day they received a single oral dose of AFB₁. Body weight was recorded at the beginning of the study (before LGG administration), at the day of AFB₁ administration, and at the end of the trial. Rumen fluid, blood, urine, and feces samples were collected continuously for 96 h after AFB₁ administration. Average daily gain (ADG) and plasma biochemical parameters were analyzed, and concentrations of AFB₁ and AFM₁ in the samples were determined for monitoring excretion pattern and toxicokinetics. The results showed that ADG was lower in AFB₁-treated animals; LGG administration partially mitigated the decrease in ADG (0.85 ± 0.08 vs. 0.76 ± 0.18 kg of gain/d). The AFB₁ treatment increased plasma aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase levels. Administration of LGG alleviated the AFB₁-induced increase in plasma enzymes activity. The excretion patterns of AFB₁ and AFM₁ were surprisingly regular; toxins were rapidly detected in all samples after a single oral dose of AFB₁, and the peak of toxins concentrations was sequentially reached in rumen fluid, plasma, urine, and feces (except AFM₁ in rumen fluid), followed by an exponential decrease. The excretion curves showed that AFB₁ and AFM₁ concentrations were the highest in feces and urine, respectively. Administration of LGG decreased the concentrations of free AFB₁ and AFM₁ in rumen fluid and reduced the release of toxins into plasma and urine. Toxicokinetic parameters (except for the time of maximum concentration and the terminal half-life) were reduced by LGG administration. In conclusion, the absorption, distribution, and excretion of AFB₁ and AFM₁ were rapid in calves fed a single dose of AFB₁. Urine was the main route for the excretion of AFM₁, and the clearance pattern from the peak of concentration was well fitted by exponential decreasing function. Administration of LGG reduced the absorption of AFB₁ in the gastrointestinal tract by increasing the excretion via the feces, thus alleviating the hepatotoxic effect of AFB₁.     

Cationic dyeing properties of trilobal high dimethyl 5-sulfoisophthalate sodium salt (SIP) content cationic dyeable polyester (THCDP) fabrics

To make the polyester ionically dyeable, trilobal high dimethyl 5-sulfoisophthalate sodium salt (SIP) content cationic dyeable polyester (THCDP) was developed in this study which aimed to investigate its structural and dyeing properties. Its lower glass transition temperature and crystallinity degree contributed to lower dyeing temperature. A low-cost and environmentally friendly dyeing solution was applied in this study and the dyeing temperature of newly THCDP fabric could be reduced to 90°C, distinctly different from the previous cationic dyeable polyester which needed more than 100°C to reach dyeing standard. Meanwhile, THCDP showed its higher dyeing saturation value than normal acrylic fabric and cationic dyeable polyester with the Cationic Red X-GRL dyestuff. In present, both pure THCDP and blend textiles were developed. A series of THCDP/Cotton blends’ (20/80, 35/65, 65/35, 80/20) dyeing behaviors were tested, and found they could be dyed at 90°C with good color fastness and levelness.     

Short communication: Effects of milk removal on teat tissue and recovery in Murciano-Granadina goats

The aim of this work was to study how machine milking (MM) carried out in appropriate conditions affects teat wall thickness and canal length and their return after milking to premilking conditions compared with other milk removal methods considered biological referents: kid suckling (KS), catheter removal (CATH), and hand milking (HM). Three Latin square experiments were designed, each divided into 2 periods. In the first period, the left glands of each animal were machine milked and the KS, CATH, and HM treatments were applied to the right glands in experiments 1, 2, and 3, respectively. Subsequently, in the second period, the removal methods were interchanged. Teat wall thickness, teat wall area, teat end wall area, and teat canal length were measured from the ultrasound images. Milk removal using the reference methods (KS, CATH, and HM) and by MM caused increases in teat wall thickness and teat canal length, which were greater with MM. The time needed for the teat walls and canal to return to their physiological conditions before milk removal was greater than 10 h in the reference methods and following machine milking.     

酿造酱油生产过程中铵盐含量超标的处理方法

在酱油酿造过程中，提高氨基酸生成率的同时也会增加铵盐的生成量，容易造成铵盐含量的超标而使酱油风味不佳。为酱油酿造企业研究了酱油中铵盐合理超标的处理方法，结果表明：将酱油pH值调至9．0置于65～75℃水浴中加热20min，或于80℃水浴中加热10min，再用乳酸将酱油的pH值调至4．7左右，可以去除过量铵盐，恢复酱油风味，且氨基酸受损率小。此方法可为铵协含量超标酱油的处理再利用提供了有效的依据，避免了可利用原料的大量浪费。     

降胆固醇优良菌株的筛选及其胆盐水解酶特性研究

对已证实具有降胆固醇能力并能产生胆盐水解酶（BSH）的3株乳酸菌进一步筛选,综合模拟人工胃肠液的耐受性、疏水性能力和去结合胆盐能力三个指标,筛选出一株具有优良的降胆固醇综合性能的潜力菌株,并对其产生的BSH的部分特性进行研究。结果表明,屎肠球菌90-1作为降胆固醇潜力菌株其综合性能较好,其所产的BSH最适反应pH为6.0,最适反应温度为37℃,最适底物浓度为7mmol/L,最适三磷酸腺苷二钠（ATP）浓度为2.5mg/mL。      

盐胁迫下微生物在发酵食品中耐盐及促发酵机制研究进展

随着生理学结合多组学技术的应用,将实现盐胁迫下发酵微生物耐盐及促发酵机制的精准解析,为有效调控盐卤发酵、实现传统发酵食品风味提升奠定基础。文章综述了发酵食品中常见的耐盐微生物、主要耐盐机制、高盐环境中的促发酵特性以及研究耐盐及促发酵机制的方法,并对其未来发展方向进行了展望。     

氟苯尼考及其代谢物氟苯尼考胺在肉鸡中残留消除规律

目的 评估氟苯尼考及其代谢物氟苯尼考胺在不同品种肉鸡中的残留消除规律。方法 选用AA肉鸡、WOD168肉鸡、雪山鸡和狼山鸡为试验对象, 于出栏前3周开始按氟苯尼考25 mg/kg体重饮水给药, 连用5 d, 于停药后1、3、5、7、10、14 d采集肌肉、肝脏、肾脏、皮脂, 检测其中的氟苯尼考和氟苯尼考胺残留量, 并利用WT1.4软件计算休药期。结果 氟苯尼考及其代谢物氟苯尼考胺可迅速残留于肉鸡肌肉、肝脏、肾脏和皮脂中, 残留物以氟苯尼考为主。停药后第1 d残留量达到峰值, 肾脏组织中的残留量最大; 停药后第3 d, 各组织中氟苯尼考和氟苯尼考胺的残留量进入快速消除期, 均低于最大残留限量值; 停药后第14 d已基本消除完全。利用WT1.4软件计算出AA肉鸡、WOD168肉鸡、雪山鸡和狼山鸡休药期分别至少为3.22、3.85、4.49和4.32 d。结论 氟苯尼考在慢速型肉鸡体内的休药期要长于快速型肉鸡, 但都小于5 d。     

发酵香肠中产生物胺的微生物及其检测方法研究

发酵香肠中过量的生物胺不仅会降低产品的品质,而且会对机体健康造成不良影响,具有氨基酸脱羧酶活性的微生物会导致生物胺的大量积累,准确全面地检测产生物胺的微生物对保障香肠的安全具有重要意义。本文综述了发酵香肠中生物胺的形成途径并重点介绍了产生物胺的微生物及其检测方法,以期为研发安全的发酵剂和保障发酵香肠的品质提供参考。     

Tissue deposition and residue depletion of melamine in fattening pigs following oral administration

The adulteration of animal feed as well as milk products with melamine has led to concerns about the ability to establish appropriate withdrawal intervals to ensure food safety. Two experiments were conducted in this study. The first was to investigate the deposition and depletion of melamine in blood and tissues of pigs exposed to adulterated feed with high doses of melamine. A total of 500 or 1000 mg kg^–1 melamine was added to the diet for fattening pigs (initial BW = ±60.24 kg). Melamine residues were detected in tissues (brain, duodenum, liver, heart, muscle and kidney) by LC-MS/MS. Dose-dependent effects were found between melamine residual concentration and its dose in feed. Five days after the withdrawal of melamine from the diets, the residue concentration in tissues fell below 2.5 mg kg^–1. In the second experiment, blood samples were taken at different time points from fattening pigs (BW = 100 kg) fed with adulterated feed with 1000 mg kg^–1 of melamine for 42 days. Results from the pharmacokinetics analysis showed that it would take 83 h for the melamine level in plasma depleting to the safe level of 50 ng ml^–1 after an expose of 1000 mg kg^–1 melamine contaminated feed for 42 days.     

GC-MS/MS测定面包和饼干中富马酸二甲酯的研究

建立了利用气相色谱-三重串联四级杆质谱联用仪（GC-MS/MS）测定面包和饼干中富马酸二甲酯的方法。采用超声波辅助提取的方法,以乙酸乙酯为提取溶剂,通过GC-MS/MS,以选择反应监测（SRM）模式进行检测,用于定量分析的离子反应为m/z113→85。该方法在0.001～1.00μg/mL质量浓度范围内呈线性关系,相关系数为0.9999,定量检出限为0.0075mg/kg,加标回收率为84.7%～99.8%,相对标准偏差为1.46%～3.61%。结果表明,该方法具有准确、回收率高、检出限低等优势。      

Impact of tarragon usage on lipid oxidation and heterocyclic aromatic amine formation in meatball

Herein, the effects of tarragon on lipid oxidation and heterocyclic aromatic amines (HAAs) formation in meatballs were determined. A significant (P < 0.05) reduction in pH and TBARS values of the meatballs with tarragon was determined, while no significant effect (P > 0.05) was observed regarding water content of the samples. Only 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) compound (up to 0.06 ng g⁻¹) was detected in the control group meatballs. On the other hand, in the meatballs with tarragon, no HAAs could be detected. Tarragon use completely inhibited the formation of MeIQ. The total HAA content of the samples in the control group increased with increasing the cooking temperature. The total HAA contents of the control group meatballs changed between not detected and 0.06 ng g⁻¹. In conclusion, it can be recommended to use tarragon in meatball production as it completely inhibits the HAA formation and reduces TBARS value compared to the control group meatballs.     

植酸及植酸胺在气相防锈纸中的应用及适用性

对植酸及植酸胺在气相防锈纸中的适用性进行了探讨，其中包括防锈原纸浸渍植酸或植酸胺后纸张强度，外观质量的变化等，并进行了植酸及植酸胺对黑色金属及各种有色金属的气相防锈能力的检测和评价。结果表明：未调节pH（pH为5．0～4．0）的植酸并不适用于气相防锈纸；植酸腰对黑色金属、铜、铝有非常好的缓蚀效果，但其对锌的缓蚀能力并不理想。     

Influence of starter and nonstarter on the formation of biogenic amine in goat cheese during ripening

Two commercial starters were investigated for their potential ability to decarboxylate amino acids during goat cheese ripening. Two batches of goat cheese were produced with identical pasteurized milk but different starter cultures. One of them contained Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris and the other Lactococcus lactis subsp. lactis. The amine contents, microbial counts, proteolysis-related parameters, pH, total solids and salt content were studied in raw materials and cheeses. In raw materials, polyamines were the prevailing amines, whereas the main amines in cheeses were putrescine, tryptamine and, in particular, tyramine (94.59 mg/kg). Aerobic mesophilic microorganisms and Lactococcus counts increased throughout ripening, while Enterobacteriaceae were no longer detectable in cheese after 30 days of ripening. Amine concentration rose during cheese ripening in both batches. Moreover, the decarboxylase activity of microorganisms isolated from samples during cheese ripening was assayed and discussed.     

烘烤对肉制品中多环芳烃和杂环胺含量的影响

烘烤是肉制品加工中重要的工艺之一,但经烘烤的肉制品中含有多环芳烃、杂环胺等有害物质,对消费者的健康造成很大的威胁.介绍了多环芳烃、杂环胺及其对人体的危害,重点阐述了烘烤对肉制品中多环芳烃和杂环胺含量的影响及其控制方法.     

我国市售不同类型及品牌腐乳中生物胺含量的分析与比较

为了揭示我国商业腐乳中生物胺存在形式和水平,采用丹磺酰氯柱前衍生结合高效液相色谱法（HPLC）对我国市售的20个品牌白方腐乳和20个品牌红方腐乳中的生物胺含量进行了分析。结果表明,我国市售的腐乳中存在的主要生物胺为酪胺、组胺、腐胺、色胺、β-苯乙胺和尸胺,其平均含量分别为73.7 mg/kg、43.7 mg/kg、38.5 mg/kg、27.7 mg/kg、5.4 mg/kg和5.4 mg/kg;每种生物胺在白方腐乳中的含量均显著高于红方腐乳（P＜0.05）,前者的酪胺、组胺、腐胺、色胺、β-苯乙胺和尸胺的平均含量分别为后者的1.6、1.9、3.4、3.3、2.3和3.0倍;且每种生物胺的水平在同一类型不同品牌腐乳之间均呈现高度差异化。