新型脂肪胺荧光标记试剂的合成及小分子 脂肪胺的衍生检测

目的合成一种新的以荧光素为荧光团,N-羟基琥珀酰亚胺活性酯为反应基团的脂肪胺荧光标记试剂,并建立以新试剂标记短链脂肪胺并用高效液相色谱-荧光检测法进行分离的方法。方法在p H 8.5的Na2B4O7-H3BO3缓冲溶液中,25℃下,衍生试剂浓度为50μmol/L,衍生反应进行10 min,衍生物峰面积即可达到最大且稳定。结果在优化的条件下,建立的检测方法的线性范围为0.01~2μmol/L,线性回归系数0.999,检测限达到0.1~1μg/L。结论衍生后的产物利用高效液相色谱-荧光检测法,可以使得6种小分子脂肪胺得到有效分离,方法具有衍生速度快,灵敏度高等优点。     

微生物胺氧化酶研究进展

胺氧化酶是一类有特殊生物功能的蛋白质,它能将生物胺降解为乙醛、氨、过氧化氢,从而可以减缓生物胺在食品中的危害。该文主要针对微生物所产的胺氧化酶的分类进行综述,根据辅助因子的不同将其分为含铜胺氧化酶和含黄素胺氧化酶,并从食品质量安全角度出发介绍了胺氧化酶在食品领域中的应用,最后展望了微生物胺氧化酶研究的前景。对微生物胺氧化酶种类的了解提供了依据,并对胺氧化酶在食品工业中应用提供了借鉴。     

反应型受阻胺类紫外线吸收剂的应用性能研究

以三聚氯氰、受阻胺哌啶醇和多元胺磺化物为原料合成了一种反应型受阻胺类紫外线吸收剂,并利用红外光谱(IR)和紫外光谱(UV)对其结构和紫外吸收特征进行了初步表征.通过正交实验得到了紫外线吸收剂的优化整理工艺,即浴比1:15,55 ℃反应20 min,元明粉用量40 g/L,纯碱用量20 g/L,90℃固着处理30 min.整理后织物应用性能测试表明:制备的紫外线吸收剂具有优良的防紫外线性能和耐洗涤性能,经50次洗涤后,织物的抗紫外指数保留率仍高于80%;当整理剂用量为10%(owf)时,整理后织物的日晒牢度可提高1级左右;此外,整理前后织物的物理机械性能变化较小.     

发酵肉制品中生物胺研究进展

食品中生物胺主要来源于游离氨基酸被微生物产生的脱羧酶脱羧形成,往往在食品腐烂或发酵过程中产生.本文综述了发酵肉制品中产生物胺微生物种类及影响因素.目的是为了控制发酵肉中生物胺含量,确保发酵肉制品安全.     

Heterocyclic amine formation during frying of frozen beefburgers

The formation of heterocyclic amines (HCAs) was studied during frying of beefburgers with different fat contents (6.7%, 16.1% and 39%). Beefburgers were fried from the frozen state for 60, 90, 120 s, and until the centre temperature had reached 72 °C (approximately 150 s) in a double‐sided pan fryer. The beefburgers were analysed for HCAs with solid‐phase extraction and LC/MS detection, and 2‐amino‐3,8‐dimethylimidazo[4,5‐f]quinoxaline (MeIQx), 2‐amino‐3,4,8‐trimethylimidazo[4,5‐f]quinoxaline (4,8‐DiMeIQx), 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), 1‐methyl‐9H‐pyrido[3,4‐b]indole (Harman) and 9H‐pyrido[3,4‐b]indole (Norharman) were detected in all samples. The concentrations of HCAs ranged between 0 and 2.3 ng g^?1. The HCAs concentrations were fitted to a first‐order reaction model. The amounts of HCAs in beefburgers fried from the frozen state were in the same range as in beefburgers that have reached room temperature before frying. Furthermore, it was found that the formation of HCAs is not only concentration‐controlled but also mass transport‐controlled and that kinetic models stated in earlier studies fit relatively well our analysed values on HCAs in fried beefburgers.     

羊毛二乙胺预处理及其染色工艺探讨

用二乙胺预处理羊毛,可以改善羊毛的染色性能,达到低温染色的目的,文章主要讨论了二乙胺预处理羊毛的工艺,对预处理后羊毛的染色性能等也进行了研究。     

生物胺降解菌株的筛选与鉴定

从实验室保藏的不同来源乳酸菌菌株中筛选出具有生物胺降解能力的菌株,测定其在不同盐浓度、pH下的生长能力。结果表明,筛选出3株具有生物胺降解能力的菌株,经16SrDNA序列分析,菌株HM22鉴定为发酵乳杆菌(Lactobacillus fermentum),菌株HM24为植物乳杆菌(Lactobacillus plantarum),菌株YF10042为粪肠球菌(Enterococcus faecalis);其中植物乳杆菌HM24的降解能力最优,对色胺、苯乙胺、腐胺、尸胺、组胺、酪胺、亚精胺、精胺的降解率分别为(25.90±2.30)%,(35.75±2.71)%,(27.61±3.94)%,(25.91±3.76)%,(22.54±2.64)%,(34.55±1.90)%,(39.25±1.86)%,(55.66±7.08)%;当盐浓度为4%～10%时,3株菌株耐受力随盐浓度的增加而降低,;当pH为3.5～9.5时,3株菌株均可生长。     

氨基树脂-醛-铬结合鞣特性的研究

用氨基树脂、醛和铬对酸皮进行结合鞣制 ,坯革的收缩温度高 ,增厚明显 ,丰满性好 ,粒面平细 ,色泽浅淡 ,鞣制废液中铬的含量低。该结合鞣制工艺属一种清洁型的少铬鞣制方法。     

Carotenoids from tomatoes inhibit heterocyclic amine formation

Tomatoes are a rich source of antioxidants and they are commonly used for meat cooking in Mediterranean countries. The effects of tomato antioxidants on the formation of carcinogenic/mutagenic heterocyclic amines were investigated. A liquid model system containing as precursors creatinine, glucose and glycine in molar concentrations comparable to those present in bovine meat (chemical model system) was employed. A freeze-dried bovine meat juice (meat juice model system) was also used for some experiments. In both model systems, an inhibiting effect of tomato carotenoid fraction on the formation of imidazoquinolines (IQx, MeIQx and DiMeIQx) was observed. Using carotenoid extract at a concentration of 1000 ppm, inhibitions of 36% and 11% of IQx and MeIQx formation respectively in the chemical system and of 13% of MeIQx and of 5% of 4,8-DiMeIQx in the meat juice system was observed. The effect of the main tomato flavonoid, quercetin, was investigated using the meat juice system. Quercetin gave an inhibition of MeIQx formation between 9% and 57% with a maximum effect of 67% at 10 ppm.     

发酵肉制品中生物胺研究进展

生物胺是一类含氮碱性有机化合物,食品中生物胺主要来源于游离氨基酸被微生物产生的脱羧酶脱羧形成。往往在食品腐烂或发酵过程中产生。由于其潜在的毒性和作为食品腐败变质的标志而被广泛研究。本文综述了发酵肉制品中产生物胺微生物种类及影响因素。目的是为了控制发酵肉中生物胺含量,确保发酵肉制品安全。     

不同啤酒生物胺含量的比较

使用反相高效液相色谱法,测定啤酒中8种常见生物胺含量。以苯甲酰氯为衍生试剂,Agilent EclipseXDB-C18为固定相,乙腈和乙酸铵溶液为流动相,紫外检测波长设置为254 nm,梯度洗脱。本文首先对国内市售啤酒生物胺种类及含量范围进行研究,检测结果表明国内啤酒中8种生物胺均有存在,但不同样品所含种类不同,且有个别胺含量偏低无法定量。不同厂家的产品在种类和含量上存在差别,但整体含量接近,生物胺总量为4.21～10.59 mg/L,不足以对人类健康产生危害。原麦汁浓度、酒精度与生物胺含量的关系显示,二者与生物胺有一定联系,但非主要因素,相对于生产厂家和发酵情况,原麦汁浓度、酒精度对生物胺含量的影响较小。     

Enzymatic chemoselective synthesis of secondary-amide surfactant from N-methylethanol amine

Efficient selective synthesis of the secondary amide surfactant N-methyl lauroylethanolamide from methyl laurate and N-methylethanol amine by carrier-fixed Chirazyme L-2 (Candida antarctica) using a kinetic strategy has been demonstrated. When different solvents were screened for product yields using Chirazyme L-2, acetonitrile was found to be optimal. The rate of the reaction increased sharply by increasing the molar ratio of the reactants and the reaction temperature. When the reaction was performed at 50 degrees C for 36 h with 50 mmol ester and 100 mmol amine, the product was obtained in a 97.1% yield. With 50 mmol ester and 150 mmol amine, the highest yield (97.3%) was obtained after 16 h of incubation at 50 degrees C. It took only 5 h to get a yield of 95.8% at 60 degrees C using 50 mmol ester and 200 mmol amine. The enzyme activity in the amidation reaction mixture did not decrease notably even after six uses.     

Biogenic amine production of makgeollis with controlled alcohol concentrations

Food Science and Biotechnology - In this study, we examined the effects of controlling the alcohol concentration of non-sterilized makgeolli on the levels of biogenic amines (BAs) as an indicator...     

论葡萄酒中生物胺生成的影响因素及其检测方法

该文论述了生物胺的种类,葡萄酒中生物胺的生成的影响因素及生物胺的危害和限量,及其对生物胺的主要检测技术和方法。为研究和生产优质葡萄酒提供参考。     

Volatile amine production in uncured pork during storage

The concentration of volatile amines and the bacterial counts were determined in pork meat stored at ?20, +5 and +20 °C. Amine formation appeared to be independent of bacterial growth until the count reached 10⁹/cm². The meat spoiled before the dimethylamine/trimethylamine content reached a concentration likely to yield a detectable amount of N-nitrosodimethylamine in a cured product.     

生物胺降解菌在酱油中的应用

将生物胺降解菌Wickerhamomyces anomalus和Millerozyma farinosa作为发酵剂接种至酱油发酵醪中,考察其对酱油发酵过程中生物胺含量及酱油其他指标的影响。结果表明,实验组(J2,J3)中的8种胺的含量显著低于自然发酵组(K)(P0.01),说明生物胺降解菌J2和J3能显著抑制酱油发酵成熟过程中生物胺的形成。此外,对发酵过程中微生物菌落数的统计分析可得:2株菌在发酵酱醪中均保持着一定存活力和生长能力。发酵成熟时J2、J3的p H范围基本符合酱油产品的p H值(4.6～4.8);发酵过程中Na Cl浓度发酵前后没有显著差异(P0.05); TVB-N的含量在酱油发酵过程中呈现上升的趋势;通过游离氨基酸的分析可以知道酱油品质满足基本要求;因此接种生物胺降解菌可以很好地控制酱油的生物胺,提高其食用安全性。     

纺织品禁用芳香胺测定的不确定度评定

以3,3'-二甲氧基联苯胺为例,按GB/T 17592-2006<纺织品禁用偶氮染料的测定>测定纺织品中的禁用芳香胺含量,分析了测试过程中不确定度的来源,对各不确定度分量进行评定及合成,并计算得出合成不确定度和扩展不确定度.结果表明,对本测试方法影响较大的不确定度分量是标准物质配制、溶液体积引入和测试过程中的随机因素.在重复测定的条件下,测定结果的不确定度仅与溶液中的芳香胺质量浓度有关.