天然食品防腐剂对酱油防腐效果研究

研究采用纳他霉素、乳酸链球菌素、茶多酚这三种天然防腐剂复配用于酱油的防腐保鲜。试验以酱油菌落总数变化为指标,通过单因素分析和正交试验,研究了纳他霉素、乳酸链球菌素、茶多酚在传统酿造酱油中的防腐应用情况,确定了适宜的复合配方。通过对试验的相关数据分析,结果表明:在酱油中单添加其中任何一种防腐剂,只能起到部分抑制酱油中微生物的增殖作用,不能达到对酱油的保鲜效果。三者按合适的比例进行复配,利用它们的抑菌互补特性,在保质期1年内可以有效抑制酱油中微生物的增殖,样品达到我国现行酿造酱油的卫生标准。复合配方的最佳方案有两个,其一是乳酸链球菌素0.2g/kg,纳他霉素0.02g/kg,茶多酚0.1g/kg;其二是乳酸链球菌素0.1g/kg,纳他霉素0.02g/kg,茶多酚0.2g/kg。     

响应面法优化符离集烧鸡复合生物防腐剂的研究

为延长符离集烧鸡的货架期,将乳酸链球菌素(Nisin)、溶菌酶、茶多酚、壳聚糖、纳他霉素和ε-聚赖氨酸等6种生物防腐剂加入到符离集烧鸡中,以菌落总数、挥发性盐基氮、硫代巴比妥酸值和pH值为指标,研究生物防腐剂对符离集烧鸡的保鲜作用。单因素实验结果表明,和壳聚糖、纳他霉素、ε-聚赖氨酸相比,Nisin、溶菌酶、茶多酚3种生物防腐剂具有更好的抑菌效果,并能显著提高符离集烧鸡的品质;在此基础上,采用响应面优化法对3种生物防腐剂进行复配,经分析后建立多元回归模型,确定复合生物防腐剂最优添加浓度为Nisin 0.03 g/kg、茶多酚0.09 g/kg、溶菌酶0.10 g/kg。     

纳他霉素在蛋糕表面防腐保鲜中的应用研究

纳他霉素作为一种天然的新型食品防腐剂，对烘焙食品中的真菌具有高效而安全的抑菌作用。该研究采用不同浓度的纳他霉素对蛋糕表面进行防腐处理，探究了纳他霉素在蛋糕贮藏保鲜中的抑菌效果和作用。通过与糕点类食品中最常见的其他3种防腐剂进行比对，进一步研究了纳他霉素与山梨酸钾在蛋糕表面处理的复合防腐作用。结果表明，300～400 mg/kg的纳他霉素对蛋糕的抑菌防腐效果最佳，而喷洒质量分数为0.4 g/kg的纳他霉素与8 g/kg的山梨酸钾复配液可以将蛋糕保质期延长至10 d以上。通过对实际生产应用的成本分析，纳他霉素与山梨酸钾在蛋糕中的复配使用，既节约成本，又能有效的抑制蛋糕中细菌和霉菌的生长。     

不同防腐剂对盐鸡制品的抑菌性能及品质的影响

目的:研究防腐剂对盐焗鸡制品的抑菌性能及品质影响。方法:选取乳酸链球菌素(nisin)、双乙酸钠、脱氢乙酸钠、山梨酸钾、纳他霉素、ε-聚赖氨酸等作为防腐剂,菌落总数、p H、感官评定作为评价指标,考察防腐剂单独使用以及两两交互对盐焗鸡制品的抑菌性能及品质的影响。结果表明:单独添加4 g/kg的nisin或2 g/kg的ε-聚赖氨酸时,盐焗鸡制品的感官品质和p H达到最优,抑菌效果也较为显著;将5 g/kg的nisin和2.5 g/kg的ε-聚赖氨酸复配使用时效果最佳,菌落总数为5800 cfu/g,感官评分4.04,p H6.53,明显强于单独使用nisin的保鲜效果。     

纳他霉素在月饼中抑菌防腐的研究

纳他霉素作为一种天然的食品添加剂,对真菌具有广谱和高效的抑制和杀灭作用。本文采用不同浓度的纳他霉素处理液对月饼进行处理,研究了纳他霉素在月饼中的抑菌防腐作用,并与焙烤食品中常用的其他防腐剂进行了比较。论文也研究了纳他霉素和山梨酸钾对月饼的复合防腐效果。实验结果表明,纳他霉素应用于月饼表面防腐,其处理液的最佳浓度为300~400mg/kg。最佳防腐效果的复合配比为:纳他霉素处理液浓度0.4g/kg,山梨酸钾8g/kg。在生产实际应用中,纳他霉素和山梨酸钾的复配使用,能很好的抑制月饼中细菌真菌的生长,可使月饼保质期,在28℃恒温贮藏条件下,达到60d以上。     

乳酸链球菌素协同纳他霉素在豆腐保鲜中的应用

以豆腐为研究对象,通过添加乳酸链球菌素（nisin）和纳他霉素以提高豆腐的保鲜时间,以感官评分和菌落总数为评价指标,考察了乳酸链球菌素与纳他霉素添加量、杀菌温度和杀菌时间等对其的影响,通过正交试验得出最佳的优化条件为：nisin与纳他霉素添加量0.12 g/kg、杀菌温度90 ℃和杀菌时间20 min。此工艺条件处理后,冷却并在37 ℃恒温培养箱中保存7 d,测得试样的感官评分为93分,菌落总数为0.53×104 CFU/g。没有添加乳酸链球菌素和纳他霉素的对照组在同样条件下保存1 d,测得感官评分在50分以下,这为延长豆腐的保质期提供了实验基础和理论依据。     

复合防腐剂对低硝中式香肠贮藏期品质的影响

为减少亚硝酸盐在中式香肠中的用量,以山梨酸钾、Nisin、纳他霉素作为复合防腐剂,采用正交试验设计确定各因素水平的比例,对中式香肠贮藏期间挥发性盐基氮、菌落总数、亚硝酸盐残留量、质构指标进行测定。结果表明:复合防腐剂可以部分取代亚硝酸盐,三种添加剂的最优组合为山梨酸钾0.3g/kg、Nisin0.2g/kg、纳他霉素0.03g/kg、亚硝酸钠0.04g/kg,且按此量进行复配时,防腐效果明显优于对照组(亚硝酸钠0.15g/kg)。     

复合天然防腐剂对高沟捆蹄保鲜效果的研究

使用纳他霉素、茶多酚、植酸三种天然防腐剂处理高沟捆蹄,以37℃恒温贮存10d时菌落总数、感官评定结果为基础进行综合评分,通过双指标正交实验确定复合天然防腐剂应用于高沟捆蹄保鲜的最佳配方。结果表明,三种防腐剂单一使用时均有抑菌效果,其中纳他霉素效果最佳,正交实验得出纳他霉素0.06g/kg、茶多酚0.10g/kg、植酸0.04g/kg的复合天然防腐剂对高沟捆蹄的防腐有协同增效作用,明显强于单一使用效果。     

复配保鲜剂对“阳光玫瑰”葡萄保鲜效果

研究适用于“阳光玫瑰”葡萄保鲜的复配防腐剂。通过单因素试验和L9(34)正交试验测定水杨酸、纳他霉素、溶霉菌、乳酸链球菌素(nisin)对“阳光玫瑰”葡萄的保鲜效果。结果表明, 4种防腐保鲜剂对样品菌落总数影响的主次顺序为水杨酸>纳他霉素>溶菌酶>乳酸链球菌素。最优水平组合(最佳比例复配防腐保鲜剂)为水杨酸1.5 mol/L、纳他霉素0.04%、溶菌酶0.1%、乳酸链球菌素0.2%。低温贮藏试验中,最优水平组合组的葡萄的腐烂总数显著低于对照组, pH无明显变化,色泽优于对照组,总接受度更高,并且对比其他组,其对引起葡萄腐败的微生物生长有显著的抑制作用(P<0.05)。     

乳酸链球菌素与纳他霉素在低盐酱菜中应用的研究

以萝卜为原料,进行酱菜制作,重点研究了天然防腐剂乳酸链球菌素(Nisin)与纳他霉素(natamycin)在酱菜加.工中的应用,结果表明,采用天然防腐剂乳酸链球菌素与纳他霉素复配,可有效提高酱菜保藏品质,其最优复合配方为300mg/kg乳酸链球菌素+150mg/kg纳他霉素;乳酸链球菌素与纳他霉素复合防腐剂对酱菜总酸度影响较小:酱菜在保藏3个月内,乳酸链球菌素与纳他霉素复合防腐剂可以改善酱菜的感官品质.     

熟食肉鱼制品氧化安全性评价

对市售火腿肠、肉片、肉松、腊肠和鱼片5类19种熟食肉鱼制品的氧化产物丙二醛(MDA)和亚硝酸盐(NO2)这2种致癌物的含量进行了测定和分析。结果表明,只有1种鸡肉卷火腿肠的NO2残留量(36mg/kg)超标,其余熟食制品的NO2含量均在允许安全范围。猪肉和牛肉火腿肠的MDA值均低于05mg/kg,未出现任何异味,表现出很高的安全性,但是脂肪和蛋白质含量普遍偏低,影响了口感和应有的品质。鸡肉火腿肠的MDA值在05～10mg/kg范围内,出现氧化异味。肉片、鱼片、肉松及腊肠制品的MDA值在抽样时多数都超过10mg/kg,氧化安全期与标签保质期相差42～177d,对这类熟食肉鱼制品在标签保质期内所存在的氧化安全隐患,应引起足够的重视。     

Effective use of nisin to control lactic acid bacterial spoilage in vacuum-packed bologna-type sausage.

Lactic acid bacteria (LAB) commonly cause spoilage in minimal heat-treated vacuum-packed cured delicatessen meats. Predominant species are Lactobacillus sake and L. curvatus. LAB strains isolated from spoiled products of this type (liver sausage, ham and bologna sausage) were found to be sensitive to low nisin concentrations (maximum of 1.25 microg g(-1)). Addition of 25 microg g(-1) nisin (as Nisaplin) inhibited the growth of LAB spoilage organisms inoculated into vacuum-packed pasteurized bologna-type sausages stored at 8 degrees C. Control sausages became spoiled (>10(8) LAB CFU g(-1)) by day 7, whereas sausages containing nisin remained unspoiled for >50 days. The effect of three types of phosphates (used as emulsifiers) on nisin activity in the sausages was compared. LAB growth rate was fastest in samples containing orthophosphate, and slowest in sausages containing diphosphate. The shelf life was also greatly extended in the latter. Fat content also affected nisin activity. Nisin activity (as indicated by LAB inhibition) was greatest in samples containing 15% > 25% > 37% (wt/wt) fat. In a sausage formulation containing 37% fat and incorporating diphosphate as emulsifier, levels of nisin as low as 2.5 microg g(-1) showed antibacterial effects. A nisin level of 6.25 microg g(-1) totally inhibited LAB growth for over 4 weeks and 25 microg g(-1) for 5 weeks. Spoilage control was achieved in the same sausage formulation but with 25% (wt/wt) fat; 12.5 microg g(-1) nisin prevented LAB growth for 5 weeks.     

UPLC-MS-MS法测定八宝粥罐头中乙二胺四乙酸二钠残留量

建立超高效液相色谱-串联质谱法测定八宝粥罐头中乙二胺四乙酸二钠（ethylenediaminetetraacetic aciddisodium,EDTA-2Na）残留量的检测和确证方法。试样中残留的EDTA-2Na用水高速匀浆提取,提取液经三氯化铁衍生化、三氯甲烷和MAX阴离子交换柱净化后,用超高效液相色谱-串联质谱仪检测和确证,外标法定量。EDTA-2Na质量浓度在1.0～50.0 μg/mL范围内时,线性关系良好,EDTA-2Na的相关系数（R2）为0.992 2。在20～400 mg/kg添加范围内,样品平均加标回收率在79.4%～105.3%之间,相对标准偏差为7.93%～9.94%。EDTA-2Na的最低检出限为20 mg/kg。该方法具有灵敏、准确、稳定等优点,可用于八宝粥罐头中EDTA-2Na残留量测定。     

超微化雷竹笋膳食纤维对火腿肠品质的影响

为了研究超微化雷竹笋膳食纤维(dietary fiber,DF)对火腿肠品质特性的影响,将2%和4%(以100 g猪肉计)三种粒径(DF1:(177.82±6.25) μm、DF2:(19.87±1.76) μm、DF3:(8.89±0.45) μm)的膳食纤维应用于火腿肠的制作工艺中。采用感官评价、质构分析、低场核磁共振等方法对新型火腿肠进行综合评价。结果表明:添加4% DF3的火腿肠的持水力最大为(90.28±0.54) g/g,与对照相比提高8.50%,膳食纤维能显著提高火腿肠的持水性(p<0.05);添加2% DF3的火腿肠的硬度及咀嚼性下降,但弹性、黏聚性及凝胶强度增强;低场核磁共振中显示新型火腿肠中的水分向快迟豫(即水分结合紧密的方向,T₂时间短的方向)方向移动,结合水比例增加、自由水比例减少更有利于火腿肠储藏;添加2% DF3的新型火腿肠的色差及感官评分与对照组不存在显著性差异,不影响产品销售。综上可知,2% DF3是制备新型火腿肠的最佳选择。     

Efficacy of nisin and/or natamycin to improve the shelf-life of Galotyri cheese

The present study evaluated the use of nisin, natamycin and/or their combination as antimicrobial treatments to improve the shelf-life of Galotyri cheese. Samples were treated with nisin [N1 (100 IU/g), N2 (200 IU/g)], natamycin [NA1 (0.01% w/w), NA2 (0.02% w/w)] and their combinations N1–NA1, N1–NA2, N2–NA1 and N2–NA2. A Galotyri control (N0) cheese sample was also tested (absence of nisin or natamycin). Single N1, N2 treatments reduced lactobacilli and lactococci populations, but their effect was less pronounced, as compared to the combined nisin–natamycin treatments between days 14 and 28 of storage. Yeast populations in natamycin-treated Galotyri cheese samples or those additionally treated with nisin were significantly suppressed throughout the entire period of storage. Control N0 or N1, N2 treated samples received significantly lower acceptability scores, as compared to either natamycin or natamycin–nisin treated samples. Natamycin, added either singly or in combination with nisin, efficiently suppressed fungal growth in the Galotyri cheese. The observed shelf life of Galotyri, based on overall acceptability data, was the longest for N1–NA1, N1–NA2, N2–NA1 and N2–NA2 cheese samples (>28 days) followed by the N1, N2 treated samples (18–19 days) whereas for the control N0 a shelf-life of 14–15 days was attained.     

核桃仁种皮的护色研究

研究核桃仁种皮在加工过程中的护色工艺。通过定性试验初选出护色效果相对较好的护色剂,再经单因素试验和L9(33)正交试验选出护色效果最佳的护色剂组合,以保持种皮的颜色。结果表明：最佳护色剂组合为1.0g/L柠檬酸+6.5g/L乙二胺四乙酸二钠+25.0g/L CaCl2;其中对颜色改善效果影响最大的因素为柠檬酸,其次为乙二胺四乙酸二钠,影响最小的为CaCl2。SPSS分析结果表明,柠檬酸和乙二胺四乙酸二钠对结果的影响显著,而CaCl2对结果的影响不显著。     

天然复合保鲜涂膜液对卤鸭脖的保鲜效果研究

为研究天然复合保鲜涂膜液对卤鸭脖品质的影响,首先以菌落总数、挥发性盐基氮(TVB-N)、pH和硫代巴比妥酸值(TBARS)为检测指标,通过单因素实验分别考察海藻酸钠、乳酸链球菌素(Nisin)和纳他霉素对卤鸭脖品质的影响,再通过L₉(34)正交试验法比较3种不同比例天然保鲜剂对卤鸭脖品质的影响,筛选最优组合的保鲜涂膜液。结果表明:3种天然保鲜剂的保鲜效果均优于空白组,其中Nisin显示出较强的抑菌效果,海藻酸钠形成的薄膜具备较好的抗氧化效果。当3种天然保鲜剂浓度配比为海藻酸钠1.0 g/100 mL、Nisin 0.9 g/100 mL、纳他霉素0.18 g/100 mL时,涂膜液对卤鸭脖品质的保鲜作用最佳,涂膜后4 ℃冷藏第15 d菌落总数、TVB-N、pH、TBARS和色差值分别为(5.37±0.08)lg CFU/g、(20.86±0.79) mg/100 g、(5.85±0.06)、(2.68±0.08) mg/kg、(1.51±0.07),均显著优于对照组(p<0.05),能够有效延长卤鸭脖冷藏的货架期。     

ε-聚赖氨酸复配防腐剂在酱腌菜中的应用

为延长酱腌菜保质期,研究ε-聚赖氨酸（ε-ploy-L-lysine,ε-PL）与其他防腐剂和抗氧化剂复配对酱腌菜的防腐效果。结果表明,生物防腐剂乳酸链球菌素（Nisin）、纳他霉素和抗氧化剂茶多酚对酱腌菜中的腐败微生物有很好的抑制作用,并且同时使用具有协同增效的作用。通过响应面法复配防腐剂各成分配比为：ε-PL?0.06?μg/mL、Nisin?0.06?μg/mL、纳他霉素0.035?μg/mL和茶多酚0.40?μg/mL。经验证在酱腌菜拌料时添加复配防腐剂比在干制萝卜复水时添加防腐剂效果更好,可以延长其保质期至21?d,品质较好,总菌落数、大肠菌群数、总酸及氨基酸态氮含量符合国家标准,为ε-PL在酱腌菜中的应用提供了理论支持。     

Bioassay for nisin in sausage; a shelf life study of nisin in cooked sausage

A bioassay for nisin, an antimicrobial peptide used as a food additive, was developed for sausages based on nisin induced GFP-fluorescence (green fluorescent protein), and that could be performed on a microplate. The amount of GFP-fluorescence was easily measurable and dependent on nisin concentration. This GFP-bioassay for nisin had a detection limit in sausage as low as 0.9 ppm (0.9 μg/g), and it was used to assay shelf life of nisin in cooked sausage. Of the added nisin 68% could be detected from the sausages after storage of 28 days at 6?°C.     

Inhibition of Listeria monocytogenes in cooked ham through active packaging with natural antimicrobials and high-pressure processing

Enterocins A and B and sakacin K at 200 and 2,000 activity units (AU)/cm2, nisin at 200 AU/cm2, 1.8% potassium lactate, and a combination of 200 AU/cm2 of nisin and 1.8% lactate were incorporated into interleavers, and their effectiveness against Listeria monocytogenes spiked in sliced, cooked ham was evaluated. Antimicrobial-packaged cooked ham was then subjected to high-pressure processing (HPP) at 400 MPa. In nonpressurized samples, nisin plus lactate-containing interleavers were the most effective, inhibiting L. monocytogenes growth for 30 days at 6 degrees C, with counts that were 1.9 log CFU/g lower than in the control after 3 months. In the other antimicrobial-containing interleavers, L. monocytogenes did not exhibit a lag phase and progressively grew to levels of about 8 log CFU/g. HPP of actively packaged ham slices reduced Listeria populations about 4 log CFU/g in all batches containing bacteriocins (i.e., nisin, sakacin, and enterocins). At the end of storage, L. monocytogenes levels in the bacteriocin-containing batches were the lowest, with counts below 1.51 log CFU/g. In contrast, HPP moderately reduced L. monocytogenes counts in the control and lactate batches, with populations gradually increasing to about 6.5 log CFU/g at the end of storage.