聚六亚甲基双胍盐酸盐抗菌剂在羊毛织物上抗菌性能的研究

聚六亚甲基双胍盐酸盐具有良好的广谱抗菌性和安全性,已被应用到织物的抗菌整理中。通过采用环保型化学物质聚六亚甲基双胍盐酸盐和柠檬酸,按轧——烘——焙工艺整理羊毛织物,使其获得良好的抗菌性能。分析了抗菌剂聚六亚甲基双胍盐酸盐用量、交联剂柠檬酸用量、焙烘温度和焙烘时间等因素对整理效果的影响,确定了抗菌整理的最佳工艺。借助Nikon型光学显微镜分析整理前后羊毛纤维表面形态和结构。运用傅里叶变换红外光谱图对抗菌剂聚六亚甲基双胍盐酸盐与羊毛的交联机理进行了探讨。结果表明,整理后的羊毛织物对金黄色葡萄球菌有良好的抑菌性和耐洗涤性能。     

传统中草药对鲜食核桃防腐保鲜的研究

通过对能够使鲜食核桃发霉的菌种进行分离、纯化,研究发现导致核桃腐败的真菌主要有4种,即木霉1和木霉2、毛霉和丝孢酵母。并且研究了丁香、八角、肉桂、黄连、厚朴、甘草、虎杖7种天然药用植物对所分离的真菌的抑制作用,发现除虎杖外其余药用植物均对这4种真菌都具有不同程度的抑菌作用,而丁香、肉桂、八角的抑制作用最显著。通过比较这3种中药的最小抑菌浓度,选择出丁香和肉桂为复合天然抑菌剂成分。通过响应面法优化复合抑菌剂配方,得出最优的复配条件为:丁香浓度1.5mg/mL;肉桂浓度2.5mg/mL。通过进一步的试验初步验证复合抑菌剂的防腐效果显著,因此认为该复合抑菌剂能够起到抑菌作用,有利于延长鲜食核桃的贮藏期。     

抗菌纺织品回顾(二)

PHMB聚双胍化合物是一种聚阳离子胺化合物,含有2个阳离子双胍,被相同或不同长度的烃链隔开。PHMB(聚六亚甲基双胍盐酸盐)是其中最重要的抗菌剂之一,含有平均11个双胍单位,平均分子质量约为2 500 Da。PHMB的抗菌性比单体和双胍二聚体强。具有高抗菌性和低毒性,最低抑菌浓度MIC为0.5~10 mg/kg。PHMB作为一种消毒剂,广泛用于医药领域,特别是用于治疗耐药性细菌感染的伤口,以及用作食品工业杀菌剂和泳池消毒剂,目前正在探索用于漱PHMB     

聚六亚甲基胍现场消毒效果的研究

目的:研究聚六亚甲基胍现场消毒效果。方法:使用1%聚六亚甲基胍消毒液喷洒于原材料仓、纸盒生厂区、成品仓,采集消毒前后的浮游霉菌和沉降霉菌;使用1%聚六亚甲基胍消毒液擦拭于纸板表面,通过擦拭法进行表面菌落计数,并参照ASTM G 21-2009合成聚合材料防霉性的测定进行防霉测试。结果:用1%聚六亚甲基胍消毒后,原材料仓、纸盒生厂区、成品仓空气中的沉降霉菌和浮游霉菌显著减少;纸板表面擦拭1%聚六亚甲基胍后,纸板表面的霉菌数由3.00(CFU/cm2)减少至0.85(CFU/cm2);接种霉菌后,未擦拭消毒剂的纸板表面长霉比表面擦拭1%聚六亚甲基胍的纸板的长霉情况明显严重。结论:1%聚六亚甲基胍现场消毒效果显著。     

有机抗菌剂应用于纺织品的研究进展

介绍了有机抗菌剂的抗菌机理,着重论述了季铵盐类、卤胺化合物、聚六亚甲基双胍盐酸盐类、甜菜碱类和有机天然抗菌剂应用于纺织品的研究进展,讨论了有机抗菌剂应用于纺织品的难点和未来的发展方向。     

双胍基苯甲酰壳聚糖盐酸盐抗菌活性的研究

以邻、间、对双胍基苯甲酸为起始原料,在甲磺酸体系中,以不同的CPBGH与氯化亚砜反应得到的双胍基苯甲酰氯直接改性壳聚糖,得到了系列水溶性双胍基苯甲酰壳聚糖盐酸盐(BGBCH)。分别研究了双胍基苯甲酰壳聚糖盐酸盐对革兰氏菌的抗菌活性。实验表明,双胍基苯甲酰壳聚糖盐酸盐对大肠杆菌、金黄色葡萄球菌都具有抑制作用,抗菌活性随浓度的增加而增强;邻双胍基苯甲酰壳聚糖盐酸盐对大肠杆菌、金黄色葡萄球菌最低抑菌浓度分别为0.008mg/mL和0.004 mg/mL,优于间、对双胍基苯甲酰壳聚糖盐酸盐。     

聚六亚甲基胍消毒效果及安全性能研究

目的:研究聚六亚甲基胍消毒效果及相关安全性能。方法:通过定量杀灭实验及空气消毒试验研究了聚六亚甲基胍的消毒效果,依据《消毒技术规范》(2002版)急性经口毒性实验性验证其安全性能。结果:悬液定量杀灭试验中,1%聚六亚甲基胍作用10min对大肠杆菌、金黄色葡萄球菌、白色念珠菌、黑曲霉的杀灭率菌大于99.99%,杀灭对数值均大于5;空气消毒试验中,1%聚六亚甲基胍作用1h对白色葡萄球菌的杀灭率,3次试验菌大于99.99%;急性口服毒性试验中,1%聚六亚甲基胍LD50>5000mg/Kg体重,属实际无毒。结论:1%聚六亚甲基胍消毒效果良好,并且安全无毒性。     

壳聚糖／壳寡糖衍生物的制备及其抗氧化性能研究

壳聚糖和壳寡糖经化学改性得到季铵盐衍生物-O-2′-羟丙基三甲基氯化铵壳聚糖/壳寡糖,通过红外光谱对其结构进行表征.考察了两种季铵盐衍生物对DPPH自由基的清除活性以及还原能力.当质量浓度为0.6 mg/mL时,壳聚糖季铵盐和壳寡糖季铵盐对DPPH自由基的清除率分别为9.5 %和29.3 %.在还原体系中,当质量浓度为2.5 mg/mL时,其吸光度分别为0.11和0.43.结果表明:通过化学改性,得到的壳聚糖季铵盐衍生物水溶性优良、具有抗氧化活性;壳寡糖季铵盐清除自由基的活性和还原能力强于壳聚糖季铵盐衍生物.这可能由于壳寡糖分子链短,更多活性氨基和羟基暴露出来参与抗氧化反应所致.     

几种阳离子表面活性剂单一组分及复合体系对致病菌杀菌性能的研究

考察了新型反离子季铵盐双癸基二甲基甲酸铵(DDAF)、双烷基(C8~10)二甲基氯化铵(D8-10)、聚六亚甲基双胍盐酸(IB)、双癸基甲基羟乙基氯化铵(DEQ)和十二烷基苄基氯化铵(1227)等5种阳离子表面活性剂对白色念珠菌、金黄色葡萄球菌和大肠杆菌的杀菌性能。结果表明,在质量浓度为100 mg/L、作用时间为20 min时,DDAF和DEQ表现出较好的杀菌性能,但未能达到QB/T 2738-2012日化产品抗菌/杀菌标准要求。结合密度泛函理论,在B3LYP/631G水平上对各种杀菌剂分子进行结构优化。计算结果表明:DDAF和DEQ极性头基上的正电荷密度高于其他几种表面活性剂分子,这与其良好的杀菌效果密不可分。另外,阳离子季铵盐表面活性剂分子不仅在其尾链上带有较弱的正电荷,而且与头基相连的α-亚甲基上带有明显的正电荷,分子表面正电荷的分布越广以及正电荷密度越大,有助于提高阳离子表面活性剂的杀菌效率和杀菌效果。通过5因素、3水平[选择L18(35)正交表]的正交试验研究5种阳离子表面活性剂复合后的杀菌性能,确定最佳组合为DDAF 30 mg/L、D8-10 20 mg/L、IB 10 mg/L、DEQ 30 mg/L、1227 10mg/L,与100 mg/L下的单一组分阳离子表面活性剂相比,杀菌性能明显提高。以白色念珠菌的杀菌效果为依据,进一步优化配方,得到组合为:DDAF 30 mg/L、D8-10 20 mg/L、IB 30 mg/L、DEQ 30 mg/L、1227 30 mg/L。     

精盐果蔬洗涤剂产品的研究与应用

利用盐的天然消毒杀菌作用,并选用"绿色"功能性表面活性剂烷基糖苷以及杀菌剂聚六亚甲基双胍盐酸盐为原料,研究开发精盐果蔬洗涤剂产品。通过测试结果证明,精盐果蔬洗涤剂产品的抑菌、农药残留去除效果良好,各项指标符合国家标准规定。     

Antimicrobial activities of polyhexamethylene biguanide against biofilm-producing Prototheca bovis causing bovine mastitis

Prototheca spp. is a frequent cause of bovine mastitis and is highly resistant to commonly used disinfectants. This study aimed to: (1) evaluate the antimicrobial activity of polyhexamethylene biguanide (PHMB) against mastitis-causing Prototheca spp., and (2) evaluate the biofilm production ability of Prototheca spp. A total of 85 Prototheca bovis and 2 Prototheca blaschkeae isolates from bovine mastitis cases were submitted to biofilm production assays and antimicrobial susceptibility tests against PHMB and disinfectants commonly used in dairy herds (chlorhexidine digluconate, povidone-iodine, sodium dichloroisocyanurate, and sodium hypochlorite). The minimal inhibitory concentration (MIC) and minimal algicidal concentration (MAC) were determined by microdilution assays. We observed that PHMB (MIC₉₀: ≥2 µg/mL and MAC₉₀: ≥4 µg/mL) and chlorhexidine gluconate (MIC₉₀ and MAC₉₀: ≥2 µg/mL) presented the highest antimicrobial activity against P. bovis isolates, followed by sodium dichloroisocyanurate (MIC₉₀ and MAC₉₀: ≥1,400 µg/mL), sodium hypochlorite (MIC₉₀ and MAC₉₀: ≥2,800 µg/mL), and povidone-iodine (MIC₉₀ and MAC₉₀: ≥3,200 µg/mL). Concerning P. blaschkeae isolates, PHMB (MIC and MAC ≥1 µg/mL) and chlorhexidine gluconate (MIC and MAC ≥1 µg/mL) were the disinfectants that presented the lowest concentration values required to inhibit the isolates. Regarding biofilms formation, 63.5% (n = 54/85) of the P. bovis isolates were classified as strong, 28.3% (n = 24/85) moderate, and 8.2% (n = 7/85) weak biofilm producers. In contrast, the P. blaschkeae isolates were classified as weak and moderate biofilm producers. These findings suggest that PHMB has the potential to be used for teat and milking-equipment disinfection for the prevention of mastitis-causing Prototheca spp. in dairy herds.     

ASE/HPLC测定纸塑包装中荧光增白剂VBL

建立加速溶剂萃取/高效液相色谱检测食品纸塑包装材料中荧光增白剂VBL的方法。以食品纸塑包装材料为研究对象,采用单因素试验和正交试验优化加速溶剂萃取法提取荧光增白剂VBL的条件:提取溶剂N,N-二甲基乙酰胺(DMF),静态萃取时间7 min,冲洗体积75%,循环次数3次,静态萃取温度110℃;选择了合适的色谱条件:采用月旭AQ-C18色谱柱,以甲醇∶水=90∶10为流动相,流速为1.0mL/min,荧光检测器激发波长362 nm、发射波长430nm,柱温为35℃,进样量10μL。采用该方法检测纸塑包装材料中VBL,当浓度0.1～10.0μg/mL时,浓度与峰面积之间存在良好的线性关系,线性方程为Y=313.13x-6.537 5(R2=0.999 9)。该方法的回收率为89.86%～91.40%,相对标准偏差RSD为2.07%～2.18%,检测限为0.20mg/kg,定量限0.40mg/kg。结果表明,该方法准确可靠,可用于纸塑包装材料中荧光增白剂VBL的检测。     

聚氯乙烯类食品包装材料中三甲基锡向食品模拟物的迁移规律

目的：建立聚氯乙烯类包装材料和食品模拟物中三甲基锡的超高效液相色谱-串联质谱（ultra performanceliquid chromatography-tandem mass spectrometry,UPLC-MS/MS）联用测定方法。用该方法研究聚氯乙烯中的三甲基锡向食品模拟物的迁移规律。方法：聚氯乙烯包装材料样品用乙酸乙酯提取。食品模拟物经阳离子固相萃取柱净化富集,洗脱液水浴条件下氮气吹干,残渣用流动相溶解,旋涡混匀,过0.22 μm微孔滤膜,经C18色谱柱完成分离,MS/MS仪上采用多反应监测正离子模式测定三甲基锡,外标法定量。在设定的不同温度条件下,将聚氯乙烯包装材料浸泡于食品模拟物中,于不同的时间点移取浸泡液,经前处理后测定三甲基锡迁移量。结果：三甲基锡在0.1～100.0 μg/L范围内线性关系良好（相关系数r=0.999 8）,检出限为0.02 μg/L。在1.0、10.0、50.0 μg/L 3 个添加水平范围内的平均回收率为90.6%～97.3%,相对标准偏差不高于6.9%。测定结果显示,三甲基锡迁移量在水模拟物中为0.19～1.65 μg/L、在体积分数10%乙醇模拟物中为0.19～9.89 μg/L、在3 g/100 mL乙酸模拟物中为0.11～9.96 μg/L、在正己烷模拟物中为0.15～3.54 μg/L。结论：建立的阳离子固相萃取-UPLC-MS/MS联用法测定食品模拟物中三甲基锡的方法快速简单、准确有效,三甲基锡在体积分数10%乙醇溶液和3 g/100 mL乙酸溶液迁移量较高,且随温度升高、时间延长,迁移量增加,一定时间后达到迁移平衡。     

Uptake and release of polyhexamethylene biguanide (PHMB) from hydrogel and silicone hydrogel contact lenses using a radiolabel methodology

PurposeThe purpose of this study was to evaluate the uptake and release of radiolabelled polyhexamethylene biguanide (PHMB) on reusable daily wear contact lenses (CLs) over 7 days.MethodsThree silicone hydrogel (SH) contact lens materials (lotrafilcon B, balafilcon A, senofilcon A) and two conventional hydrogel (CH) materials (etafilcon A, omafilcon A) were examined. In experiment 1 (1-day study), CLs were soaked in 2 mL of phosphate buffered solution (PBS) containing radiolabelled ¹⁴C PHMB (1 µg/mL) for 8 h. The release kinetics of ¹⁴C PHMB from the CLs was measured at t = 0.25, 0.5, 1, 2, 4, 8, and 24 h in fresh 2 mL PBS. In experiment 2 (7-day study), the CLs were soaked in the ¹⁴C PHMB (1 µg/mL) solution for 8 h followed by a 16-hour release in 2 mL PBS. The lens cycle was repeated daily for 7 days. After both experiments, the residual amount of PHMB remaining within the lenses was extracted to determine the total uptake of PHMB.ResultsIn experiment 1, the total uptake of PHMB for etafilcon A was significantly greater than senofilcon A (p = 0.01). There were no significant differences in total uptake of PHMB between other lens materials (p > 0.05). Etafilcon A released more PHMB compared to all other lens types over a 24-hr period (p < 0.001). In experiment 2, all CL materials continued to sorb more PHMB over time (p < 0.001). By day 7, the amount of PHMB sorbed by etafilcon A was significantly greater than senofilcon A (p = 0.02). After day 2, the CH materials released significantly more PHMB than the SH materials (p < 0.01).ConclusionThe CL materials continued to sorb PHMB with no signs of saturation after 7 days. All lens materials released a consistent amount of PHMB each day. Radioactive labelling provides a sensitive method of assessing the uptake and release of PHMB from CL materials.     

New Improved Method for Evaluation of Growth by Food Related Fungi on Biologically Derived Materials

ABSTRACT: Biologically derived materials, obtained as commercial and raw materials (Polylactate (PLA), Polyhydroxybutyrate (PHB), potato, wheat and corn starch) were tested for their ability to support fungal growth using a modified ASTM G21-96 (American Society for Testing and Materials) standard as well as a new method where 10 μl of a spore suspension is placed in a spot on the test sample. The new method gave additional information about fungal growth on biologically derived materials, revealing a clear difference between survival and growth. PHB and PLA turned out to be most suitable for food packaging application as no significant growth was seen within 28 d of incubation at 30°C.     

鱿鱼丝加工中真菌菌相变化规律及优势真菌的分离鉴定

为减少鱿鱼丝加工过程中真菌污染,提高鱿鱼丝产品的质量,将传统的微生物鉴定技术与5.8S r DNA-ITS序列分析法相结合,并通过系统发育树分析,探索鱿鱼丝加工过程中真菌菌相变化规律及优势菌株。结果表明,在鱿鱼丝加工过程中,不同阶段样品中真菌数量差异显著(p0.05),在加工终点(即烘干包装后)时真菌数量高达2.61 log cfu/g,其中调味和烘干包装阶段是真菌污染的主要环节。加工终点的鱿鱼丝中分离出6种酵母菌和4种霉菌,经测序并通过National Center for Biotechnology Information(NCBI)数据库比对,确定它们分别属于假丝酵母属(Candida sp.)、隐球酵母属(Cryptococcus sp.)、座囊菌属(Dothideomycetes sp.)、胶红酵母属(Rhodotorula sp.)、丝孢酵母属(Trichosporon sp.)、茎点霉属(Phoma sp.)、青霉属(Penicillium sp.)、曲霉属(Aspergillus sp.)、枝孢霉属(Cladosporium sp.)。其中,青霉菌(M-03)和假丝酵母菌(Y-04)为鱿鱼丝加工过程中的优势菌,在加工终点时的数量分别为1.85 log cfu/g和2.15 log cfu/g。     

快速协同浊点萃取-荧光分光光度法测定5种食品塑料包装材料中的浸出苯酚

建立快速协同浊点萃取-荧光分光光度法测定食品塑料包装材料中浸出苯酚的方法。以直链型的非离子表面活性剂聚乙二醇6000为萃取剂,正辛醇作浊点的诱导协同剂,与无水硫酸钠共同作用将聚乙二醇6000浊点温度降至室温(约20 ℃),整个实验过程仅需3 min,并对影响苯酚萃取率的因素(聚乙二醇6000、无水硫酸钠和正辛醇的用量、溶液pH)进行考察。结果表明,溶液pH6.0、0.2 g/mL聚乙二醇6000 8.0 mL、无水硫酸钠3.0 g及正辛醇5.0 mL的萃取效果最佳。苯酚在0.02~1.60 μg/mL范围内线性良好,R2为0.9998,检出限为0.0064 μg/mL,相对标准偏差为4.49%(n=8)。对于50 mL的样品溶液,苯酚萃取率可达89.8%,加标回收率为90.5%~109.5%。5种食品塑料包装材料中,只有样品2检出苯酚0.0310 μg/mL,但未超标,其它4种塑料包装材料均未检出。该方法简便、快速、省时、灵敏度高,适用于食品塑料包装材料中浸出苯酚的测定。     

食品包装和接触竹材的壳聚糖防腐研究

竹材常被用于食品包装或食品接触材料,然而其总会出现发霉情况。为研究壳聚糖对竹材的防腐效果,从发霉的竹材中分离真菌。采用不同质量浓度壳聚糖对竹材进行常温、沸水、超声浸泡处理,接种真菌,测定其菌落总数。测定不同温度下,壳聚糖的黏度变化和对真菌的抑制作用。结果表明:壳聚糖浸泡处理可增加竹材的防腐性,结合热浸泡处理可极大地提高壳聚糖对竹材的防腐性,当采用5 mg/mL壳聚糖,60℃浸泡24 h处理竹材时,可以获得很好的抑菌效果。     

Overall migration from commercial coextruded food packaging multilayer films and plastics containers into official EU food simulants

The overall migration from a wide range of commercial five-layer coextruded packaging films into aqueous food simulants (distilled water, 3% aqueous acetic acid) and alternative fatty food simulant (iso-octane) was studied. The overall migration from commercial plastics cups (PS, HIPS, and PP) used for ice-cream or yogurt packaging into distilled water and 3% aqueous acetic acid was also studied. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to the EU directives and CEN-standards. The results showed that for all tested five-layer films and plastics (PS, HIPS, and PP) cups values of overall migration into aqueous simulants (0.11-0.79 mg/dm², 2.3-15.9 mg/l) and (<0.10-0.41 mg/dm², <0.80-3.1 mg/l) were significantly lower than the upper limit (10 mg/dm²) for overall migration from plastic packaging materials and articles into food and food simulants set by the EU Directive 90/128/EEC and their revisions. The overall migration values from five-layer materials into iso-octane were significantly higher (0.94-8.23 mg/dm², 18.8-164.7 mg/l) than the above values but are still lower than the upper limit for overall migration. Global migration values of five-layer films into aqueous food simulants seems to be independent of material thickness. In contrast, overall migration into iso-octane increases with film thickness.     

Physical,Barrier, and Antioxidant Properties of Pea Starch-Guar Gum Biocomposite Edible Films by Incorporation of Natural Plant Extracts

Active food packaging based on pea starch and guar gum (PSGG) films containing natural antioxidants (NAs) was developed. Four kinds of NAs (epigallocatechin gallate (EGCG), blueberry ash (BBA) fruit extract, macadamia (MAC) peel extract, and banana (BAN) peel extract) were added into the PSGG-based films as antioxidant additive. The effects of these compounds at different amounts on the physical and antioxidant characteristics of the PSGG film were investigated. The antioxidant activity was calculated with three analytical assays: DPPH radical scavenging ability assay, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing activity power (FRAP). EGCG-PSGG films showed higher antioxidant activity, followed by BBA-PSGG, MAC-PSGG, and BAN-PSGG films, at all concentrations (0.75–3 mg/mL) and with all procedures tested. Additionally, the antioxidant activity of films showed a concentration dependency. The results revealed that addition of NAs made the PSGG film darker and less transparent. However, the moisture barrier was significantly improved when NAs were incorporated into the film. The FTIR spectra were examined to determine the interactions between polymers and NAs. The results suggested that incorporation of EGCG, BBA, MAC, and BAN into PSGG films have great potential for use as active food packaging for food preservation.