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1.
以大头菜为原料腌制泡菜,研究其发酵过程中亚硝酸盐含量的变化,通过调整腌渍液的起始pH、食盐添加量、Vc添加量及发酵温度,并采用人工接种乳酸菌的方法研究控制泡菜发酵过程中亚硝酸盐的含量。  相似文献   

2.
亚硝酸盐作为肉制品生产中被普遍使用的发色剂,赋予了肉制品诱人的色泽,使它们更能吸引人的眼球。然而,亚硝酸盐具有一定毒性,会与胺类物质发生反应产生致癌因子。为了对肉制品中亚硝酸盐含量实施有效的监督,本文综述了近年来检测肉制品中亚硝酸盐含量的方法,并对它们进行比较和方法改进。  相似文献   

3.
目的:亚硝酸盐作为一种常见的食品添加剂,被广泛应用于腊肉等肉类食品,由于生产者不能清楚地认识到亚硝酸盐对人体的危害性,仅仅为追求其发色效果而过多使用亚硝酸盐,导致亚硝酸盐含量超标,严重危害消费者的人身健康。针对这一问题,以腊肉为对象,探讨了高光谱技术在亚硝酸含量快速检测的可行性。方法:首先采集腊肉的高光谱数据,然后利用偏最小二乘法(PLS)将获取的高光谱数据与国标法获取的亚硝酸盐实际含量值关联起来,建立腊肉亚硝酸盐含量预测模型。结果:采用不同光谱预处理方法,比较其所建模型,其中一阶导数+矢量归一化所建模型效果最佳,模型交互验证均方差RMSECV为0.251,决定系数R2为0.972。结论:研究结果表明,高光谱技术可以用于腊肉亚硝酸盐含量快速检测。  相似文献   

4.
目的:亚硝酸盐作为一种常见的食品添加剂,被广泛应用于腊肉等肉类食品,由于生产者不能清楚地认识到亚硝酸盐对人体的危害性,仅仅为追求其发色效果而过多使用亚硝酸盐,导致亚硝酸盐含量超标,严重危害消费者的人身健康。针对这一问题,以腊肉为对象,探讨了高光谱技术在亚硝酸含量快速检测的可行性。方法:首先采集腊肉的高光谱数据,然后利用偏最小二乘法(PLS)将获取的高光谱数据与国标法获取的亚硝酸盐实际含量值关联起来,建立腊肉亚硝酸盐含量预测模型。结果:采用不同光谱预处理方法,比较其所建模型,其中一阶导数+矢量归一化所建模型效果最佳,模型交互验证均方差RMSECV为0.251,决定系数R2为0.972。结论:研究结果表明,高光谱技术可以用于腊肉亚硝酸盐含量快速检测。  相似文献   

5.
通过实验比较了新鲜清补凉在常温和冰箱冷藏条件下亚硝酸盐含量随时间的变化关系,以及清补凉配料中各类食材对亚硝酸盐的富集贡献情况。结果发现常温和冰箱冷藏条件下清补凉的亚硝酸盐含量都随时间的变化先增加后减少,其中室温下放置的清补凉在放置4h后测得的亚硝酸盐含量最高,冰箱冷藏放置的清补凉在放置2d后测得的亚硝酸盐含量最高,而测得的各个分类中的亚硝酸盐含量依次为豆类谷物类水果类椰奶。建议清补凉最好在半小时内食用,放置在冰箱冷藏的时间不宜超过8h。清补凉配料中椰奶和水果要选用较新鲜的或者适当减量。豆类和谷物类可以相对多加一点,尤其是红豆、玉米和紫薯。  相似文献   

6.
文章介绍了熟肉食品中亚硝酸盐含量的测定过程:在弱酸性溶液中亚硝酸盐与对氨基苯磺酸发生重氮反应,生成的重氮化合物盐酸萘乙二胺偶联成紫红色的偶氮染料,通过分光光度计在545nm处测定其吸光度,再在标准曲线上找到该吸光度所对应的亚硝酸盐的量,最后求算出样品中亚硝酸盐的含量(mg/kg)。  相似文献   

7.
亚硝酸盐是潜在的致癌物质,人体摄入的硝酸盐含量过高可能使血液中的变性蛋白增加。在环境监测中,硝酸盐和亚硝酸盐是重要的分析项目。本文主要分析了几种典型的、有代表性的硝酸盐、亚硝酸盐的光谱测定法。  相似文献   

8.
亚硝酸盐是一种致癌物质,如果水中含有大量的亚硝酸盐,将危害人的健康,因此对水中亚硝酸盐含量的测定尤为重要。水中亚硝酸盐的测定,通常采用重氮化偶合比色法,但该法偶合后受时间因素的影响较大,随着时间的增长和光密度的增高。其准确性降低,特别是含量高者尤为明显,在pH值为2.0~2.5时进行偶合,配显色剂时采用盐酸,但放置时间受到限制,使用甚感不便。本文阐述了采用加入HCL—KCL溶液控制pH值的方法,其操作简单、快速,测定的精密度更好、准确度更高。  相似文献   

9.
亚硝酸盐是一种有毒物质,进入血液后与人体中血红蛋白结合,会导致人体组织缺氧,通过对测定不同煮沸时间饮用水的亚硝酸盐含量和细菌数,为人们健康饮水提出一个明确的建议.  相似文献   

10.
亚硝酸盐的添加既能使肉品保持色泽鲜红又能增加产品独特风味,但是亚硝酸盐是强致癌物N-亚硝胺的前体物,对人体健康有一定危害。本文对近年来在降低肉制品中亚硝酸盐含量及其替代物方面的研究进行了总结综述。  相似文献   

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13.
以纯菌种发酵制备黄瓜泡菜.以植物乳杆菌B4、弯曲乳杆菌A8为发酵菌种制备黄瓜泡菜.研究了了黄瓜发酵过程中的pH、活菌数、亚硝酸盐等的变化.结果表明人工接种发酵的黄瓜泡菜与自然发酵的黄瓜泡菜相比,在第5天时有较低的pH、较高的活菌数,较低的亚硝酸盐含量.  相似文献   

14.
为了研究软枣猕猴桃蛋白酶提取液的抗氧化性能和它对亚硝酸盐的清除作用。本实验测定不同浓度的软枣猕猴桃蛋白酶提取液对亚硝酸钠和DPPH的清除能力。并向蛋白酶提取液中添加了一定浓度的抗坏血酸和丁羟基茴香醚,测定它们之间协同作用的抗氧化性能和清除亚硝酸盐能力。试验结果表明,软枣猕猴桃蛋白酶提取液的抗氧化性能和对亚硝酸盐的清除能力都与浓度呈正相关。软枣猕猴桃蛋白酶提取液可有效清除亚硝酸盐,并具有一定的抗氧化能力。  相似文献   

15.
Defective sperm function is the most common cause of infertility. A prospective study was carried out to correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with leukocytospermia, and sperm membrane integrity. Total Fifty-seven normozoospermic subjects with and without leukocytospermia visiting the Infertility clinic at KH and MRC, Karad, were included in the present study. Semen samples were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration and sperm membrane integrity as Hypoosmotic Swelling Test. Similarly the concentration of nitrite in seminal plasma was measured by Griess reaction and total antioxidant power measured as ferric reducing ability of plasma. The concentration of nitrite in seminal plasma was found to be raised with significantly increased leukocyte concentration in semen. Also significantly lowered levels of total antioxidant power along with defective sperm function was observed. Our results suggest that supplementary treatment of antioxidants with antibiotic for leukocytospermic infertile male patients may improve the sperm membrane integrity.  相似文献   

16.
The present work was aimed to study the association of one carbon genetic variants, hyperhomocysteinemia and oxidative stress markers, i.e., serum nitrite, plasma malondialdehyde (MDA) and glutathione (GSH) on intimal medial thickening (IMT) in patients with type 2 diabetes mellitus (T2D). A total number of 76 subjects from ACS Medical College and Hospital, Chennai, India were included in the study, i.e., Group I (n = 42) of T2D and Group II (n = 34) of age- and sex matched healthy controls. The glycated haemoglobin was measured by ion-exchange resin method; plasma homocysteine by Enzyme Linked Immunosorbant Assay method; serum nitrite (nitric oxide, NO), plasma MDA and GSH by spectrophotometric methods; the IMT by high frequency ultrasound. The polymorphisms of one carbon genetic variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism methods. Results indicate that methyltetrahydrofolate homocysteine methyl transferase (MTR) A2756G allele was found to be protective in T2D and the other variants were not significantly associated with T2D. Glutamate carboxypeptidase II (GCP II) C1561T (r = 0.34; p = 0.05) and methylene tetrahydrofolate reductase (MTHFR) C677T (r = 0.35; 0.04) showed positive correlation with plasma homocysteine in T2D cases. In this study, MTR A2756G allele was found to be protective in T2D; GCP II C1561T and MTHFR C677T showed positive association with plasma homocysteine in T2D cases. Among all the genetic variants, MTR A2756G was found influence IMT. RFC 1 G80A and TYMS 5′-UTR 2R3R showed synergistically interact with MTR A2756G in influencing increase in IMT.  相似文献   

17.
The objective of the study was to estimate the serum concentrations of oxidative stress markers-lipid hydroperoxide (MDA-Malondialdehyde), lactate dehydrogenase (LDH), nitrite; and ferric reducing antioxidant power (FRAP) — a measure of total antioxidant capacity in serum. Serum nitrite levels were high in fertile women than in infertile women (p<0.001), whereas MDA was high in infertile women than in fertile group (p<0.018). On classifying the entire group of women with infertility based on the etiology, serum MDA and LDH levels were higher in women with infertility due to unexplained factor than in women with other causes contributing to infertility compared to controls (p<0.001, p<0.02). A positive correlation among serum prolactin and nitrite suggested that hyperprolactinemia could contribute to infertility by inducing oxidative damage. Serum FRAP levels showed no significant difference in the groups studied. Lipid peroxidation was high in women with unexplained infertility which may be due to hyperprolactinemia.  相似文献   

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19.
纳滤组合工艺对自来水中主要有害物质去除效果研究   总被引:4,自引:0,他引:4  
珠江三角洲地区自来水中主要有毒有害物质是:有机物、消毒副产物、氨氮及亚硝酸盐。应用纳滤组合工艺技术对这类自来水进行了饮水深度处理试验研究。结果表明,活性炭 纳滤组合工艺可有效去除这类污染物,对有机微污染物去除率高达 80 %以上,可使净化水达到较高饮水标准  相似文献   

20.
Folic acid is used for preventing and treating multiple diseases and disorders, administered in the form of oral supplements. The present research work was aimed to study the influence of two non-ionic surfactants Poloxamer and Tween 80 (Polysorbate 80) on pectin submicrospheres formulations. Typical natural polymer pectin was used to encapsulate folic acid by cross linking method. The resultant submicrospheres contributed to improve the aqueous solubility to enhance the bioavailability of folic acid. During investigation, it was observed that pectin polymers influenced kinetics of the rate of reaction more intensively than the surfactants. The physical phenomenon caused the change in their size, shape and chemistry of pectin polymers transforming into submicrospheres in aqueous condition. The characteristic differences of submicrospheres were assessed by scanning electron microscopy, differential scanning calorimetry and Fourier-transform infrared spectroscopy. The average diameters of the submicrospheres ranged between 250 and 500 nm. The encapsulation efficiency of submicrospheres ranged between 80 and 96 %. The characteristic swelling behavior of lyophilized submicrospheres was influenced by the ratio of pectin polymers and folic acid used in the formulations. The submicrospheres systems exhibited controlled release of folic acid due to the pH-dependent solubility of pectin polymers in aqueous medium. The submicrospheres showed good haemocompatibility suggesting them to be promising candidates for oral delivery.  相似文献   

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