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壳聚糖对金黄色葡萄球菌抑菌活性的研究 总被引:2,自引:0,他引:2
研究了壳聚糖对金黄色葡萄球菌抑菌活性,考察了不同壳聚糖浓度、pH值、金属离子、醋酸浓度对壳聚糖抑制金黄色葡萄球菌活性的影响,并以壳聚糖浓度、pH值、醋酸浓度为因素进行正交试验,确定了壳聚糖对金黄色葡萄球菌抑菌活性的最优条件。实验结果表明,壳聚糖对金黄色葡萄球菌的抑制能力随其浓度的升高而增强;壳聚糖溶于浓度为2%的醋酸溶液时,培养基pH控制在6.0时壳聚糖的抑菌活性最强;金属离子在一定程度上降低了壳聚糖的抑菌活性;这3个因素对壳聚糖的抑菌活性的影响程度为壳聚糖浓度pH值醋酸浓度。 相似文献
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对壳聚糖与阳离子淀粉的接枝共聚进行了研究,发现壳聚糖与阳离子淀粉共聚物的增强效果要优于未改性的壳聚糖,而且由于合成助剂对壳聚糖与淀粉的质量比是14所以这一改性方法还有效的降低了壳聚糖的使用量.少量的壳聚糖与阳离子淀粉共聚是一种对壳聚糖进行改性的有效方法. 相似文献
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壳聚糖对亚硝酸盐清除作用的研究 总被引:6,自引:0,他引:6
研究了体外模拟胃液条件下壳聚糖对亚硝酸盐的清除作用;用分光光度法测定了壳聚糖对亚硝酸盐的清除率,考察了反应时间、壳聚糖用最、壳聚糖的脱乙酰度和分了量对清除亚硝酸盐效果的影响;结果表明:随反应时间的延长、壳聚糖用晕的增加,壳聚糖脱乙酰度的增高和分了量的降低,壳聚糖对亚硝酸盐的清除能力升高;分了量0.98万的壳聚糖37.5mg能完全清除亚硝酸盐。 相似文献
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基于壳聚糖季铵盐良好的抑菌性和水溶性,将2,3-环氧丙基三甲基氯化铵与壳聚糖合成了壳聚糖季铵盐。采用最小抑菌浓度法测定和比较了壳聚糖及壳聚糖季铵盐的抗菌性,并将其用于桑蚕丝织物的抗菌整理,采用振荡烧瓶法对处理前后的丝织物进行抗菌性测试。结果表明:壳聚糖及其季铵盐对金黄色葡萄球菌和大肠杆菌均有显著的抑菌性,且壳聚糖季铵盐的抑菌效果优于壳聚糖;经壳聚糖及其季铵盐处理后,桑蚕丝织物对金黄色葡萄球菌和大肠杆菌的抑菌率均明显提高,且壳聚糖季铵盐的抑菌效果更好。 相似文献
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Vrzhesinskaia OA Filimonova IV Kodentsova OV Beketova NA Kodentsova VM 《Voprosy pitaniia》2005,74(3):28-31
Chitosan feeding (10 and 20 mg per 1 kg body mass) of 19 week-age laying hens during 1.5 months caused a decrease in whole egg content of vitamin A for 13% and 20% (p < or = 0.05), vitamin E--for 30%, lutein--17% and didn't effect on vitamin B2 level. Chitosan intake lead to cholesterol content 1.5-2 fold decrease and didn't influence on egg yolk lipids concentration. Low dose chitosan-receiving hens had eggs with 1.8-fold increased egg yolk phospholipids level. The most optimal dose of chitosan for the improvement of eggs nutritive value was 10 mg. Under minimal loss in vitamins its administration lead to the pronounced cholesterol decrease and marked phospholipids elevation. 相似文献
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Beketova NA Vrzhesinskaia OA Kodentsova VM Filimonova IV Kodentsova OV Kulakova SN 《Voprosy pitaniia》2007,76(5):39-42
Under insufficient vitamin content in a diet of laying hens in compliance with lowered vitamins A, E and carotenoids content in an egg yolk acid- and water-soluble chitosan feeding (10 and 20 mg per 1 kg body mass) within 6-9 months did not render appreciable influence on these vitamins egg content. Long-term inclusion of a sorbent in a forage was not reflected in vitamin B2 level in a whole egg, blood serum and tissues of hens. Chitosan intake didn't lead to total lipids and phospholipids concentration in a whole egg. Under 15 per cent decrease of the sum of polyunsaturated fat acids its administration lead to 24 per cent increase of omega-3 polyunsaturated fat acids in the whole egg. 相似文献
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Despite eggs having a natural packaging—shell—they are perishable and can lose their quality during storage. Chitosan‐based coatings were applied to shell eggs to examine potential effects on egg quality properties (weight loss, Haugh unit, yolk index) during 4 weeks of storage. Mineral amounts in yolks were also evaluated after 4 weeks of storage. Three chitosan‐based coatings produced with organic acids (acetic‐(C‐AA), lactic‐(C‐LA), and propionic (C‐PA)) were evaluated on shelf‐life enhancements of fresh egg quality. All chitosan‐coated eggs showed greater interior quality than the non‐coated eggs. The coatings significantly maintained weight loss compared to the control specimen (4.96%). Lower weight loss (3.45% for C‐PA, 3.53% for C‐LA) was observed in the coated eggs. Eggshell chitosan coat containing lactic and propionic acids maintained higher Haugh unit and yolk index than eggs coated with acetic acid. Uncoated (UC) eggs changed from grade ‘A’ to ‘B’ after 1 week of storage. Chitosan‐based coating containing lactic and propionic acids maintained eggs in grade ‘A’ for 4 weeks. Haugh unit showed that C‐LA and C‐PA effectively maintained eggs at grade ‘A’ quality for at least 3 weeks more than control and 1 week more than C‐AA. Results also indicated that the chitosan coating maintained mineral amounts at nutritional values (especially calcium, iron and magnesium concentration) in yolks after 4 weeks storage. Copyright © 2006 Society of Chemical Industry 相似文献
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The interior quality of eggs, shell impact strength, and consumer perception of eggs coated with chitosan containing an organic acid (acetic, lactic and propionic) were evaluated. Uncoated eggs had the highest albumen pH and lowest albumen viscosity. The viscosity of eggs coated with chitosan and lactic or propionic acids were the highest. Chitosan coating also improved shell strength with chitosan + lactic acid being the best coating in this regard. The colour of shell and yolk as measured by lightness (L*), a*, b*, chroma and hue of coated and uncoated eggs were not significantly different but the difference was detected in the colour of albumen, which is an effective indication of freshness and egg quality. Based on sensory evaluation, consumers could not differentiate coated eggs from uncoated eggs; thus the general acceptability of the coated eggs was the same as uncoated eggs. This study shows a great potential of using chitosan and lactic acid mixture as a coating material for egg coating to extend the shelf life. It has no effect on consumer acceptability of the product. Copyright © 2007 Society of Chemical Industry 相似文献
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尝试在糟辣椒加工保藏中添加壳聚糖,研究其对糟辣椒品质及保藏性影响.通过对糟辣椒总酸、VC、亚硝酸盐含量和菌落总数的检测,以及感官品质评定,结果发现:壳聚糖对糟辣椒前期乳酸发酵有一定抑制作用,而发酵结束后其总酸含量与对照差异不大;保藏期间壳聚糖组VC损失率、亚硝酸盐积累均较苯甲酸钠组和对照组低;壳聚糖能明显提高产品耐藏性,并对糟辣椒褐变有一定抑制作用,对其感官品质无不良影响.综合指标评价得出:在糟辣椒发酵中添加壳聚糖能提高产品品质及保藏特性,试验中0.3%壳聚糖添加量效果最佳. 相似文献
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Gaëlle Legendre Karine Vallée‐Réhel Isabelle Linossier Fabienne Faÿ 《International Journal of Food Science & Technology》2015,50(3):736-743
Chitosan films were prepared in combination with sodium tripolyphosphate (TPP) cross‐linking and were investigated on the prevention for trans‐contamination and preservation of egg quality. The study demonstrated that chitosan films significantly decrease Salmonella enteritidis settlement (from 7% to 0.5%) and penetration of eggshells (from 93 to 58% of penetrated eggs). Due to neither bactericidal action nor bacteriostatic effect of films was observed by the enumeration method, films seem to act as a physical barrier. Moreover, results showed potential applications of coating with properties to preserve the internal quality of eggs: the weight loss is not significantly affected (weight loss remains 4% average after 23 days) and the Haugh unit is significantly higher (26 and 37 were evaluated for eggs uncoated and coated, respectively) in the presence of chitosan film. 相似文献
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《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(7):1168-1174
The ability of several oenological fining agents to remove ochratoxin A (OTA) from red wine was studied. The adsorbents tested were activated sodium bentonite, egg albumin, allergen-free adsorbents (complex PVPP, plant protein and amorphous silica (complex) and high molecular weight gelatine), and the non-toxic biodegradable polymers (chitin and chitosan). Several dosages within the oenological use range were tested and the wine pH, colour parameters and polyphenol concentration impact associated with each fining agent were studied. Generally, OTA removal achieved in all treatments was higher when the adsorbent dosage increased, but the impact on wine quality also was higher. Chitin at 50?g?hl?1 removed 18% the OTA without affecting significantly the wine-quality parameters. At the highest dosage tested the gelatine and complex treatments achieved greater OTA removal (up to 39–40%) compared with bentonite, egg albumin and chitin. Moreover, the gelatine and the complex had a lower impact on colour parameters and polyphenol concentration compared with chitosan, whilst OTA was reduced to around 40%. Chitosan achieved the greatest OTA removal (67%), but it strongly affected the wine-quality parameters. Otherwise, bentonite showed a relative efficiency to remove OTA, but the CI value decreased considerably. The egg albumin treatment only removed OTA up to 16% and moreover affected strongly the CI value and CIELab parameters. The results of this survey showed that the non-toxic chitin adsorbent and the allergen-free adsorbents tested could be considered as alternative fining agents to reduce OTA in red wine. 相似文献
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壳聚糖改性及其在造纸中的应用 总被引:7,自引:0,他引:7
论述了壳聚精的制取、改性、分子结构特点,比较了各种改性方法的优点,以及作为造纸助剂使用的特性,在造纸工业中的应用现状和前景。可看出通过各种改性方法可赋予壳聚糖以各种优良的性能,使其成为优良的造纸助剂。 相似文献
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Quintela S Villarán MC López De Armentia I Elejalde E 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2012,29(7):1168-1174
The ability of several oenological fining agents to remove ochratoxin A (OTA) from red wine was studied. The adsorbents tested were activated sodium bentonite, egg albumin, allergen-free adsorbents (complex PVPP, plant protein and amorphous silica (complex) and high molecular weight gelatine), and the non-toxic biodegradable polymers (chitin and chitosan). Several dosages within the oenological use range were tested and the wine pH, colour parameters and polyphenol concentration impact associated with each fining agent were studied. Generally, OTA removal achieved in all treatments was higher when the adsorbent dosage increased, but the impact on wine quality also was higher. Chitin at 50 g hl(-1) removed 18% the OTA without affecting significantly the wine-quality parameters. At the highest dosage tested the gelatine and complex treatments achieved greater OTA removal (up to 39-40%) compared with bentonite, egg albumin and chitin. Moreover, the gelatine and the complex had a lower impact on colour parameters and polyphenol concentration compared with chitosan, whilst OTA was reduced to around 40%. Chitosan achieved the greatest OTA removal (67%), but it strongly affected the wine-quality parameters. Otherwise, bentonite showed a relative efficiency to remove OTA, but the CI value decreased considerably. The egg albumin treatment only removed OTA up to 16% and moreover affected strongly the CI value and CIELab parameters. The results of this survey showed that the non-toxic chitin adsorbent and the allergen-free adsorbents tested could be considered as alternative fining agents to reduce OTA in red wine. 相似文献