【作者】 赵丹；

【导师】 陈光；

【作者基本信息】 吉林农业大学 ， 生物物理学， 2013， 硕士

【摘要】 玉米淀粉是制备可食性膜常用的天然物质,但是玉米淀粉膜的机械性能较差,本身具有亲水性,并且容易滋生细菌,影响食品的安全性和货架期,在实际应用中受到了一定的限制。本文将天然抑菌物质添加到玉米淀粉膜中,通过研究不同浓度的淀粉抑菌膜的机械性能,筛选出各项性能较好的淀粉抑菌膜,并将其应用在鲜猪肉的保鲜技术中,既不影响食用,又能有效抑制微生物在猪肉表面和膜表面的生长和繁殖,从而达到延长鲜猪肉贮藏期的目的。研究结果如下：(1)以大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和黑曲霉四个菌种为研究对象,采用双倍稀释法和抑菌圈法分别对肉桂精油、丁香油、小茴香精油、香兰素、壳聚糖和溶菌酶的最小抑菌浓度和抑菌效果进行研究。其结果是：肉桂精油、壳聚糖和溶菌酶在较低的浓度下就可以达到完全抑菌的效果,是6种抑菌剂中较优的3种；同一浓度的肉桂精油对4个菌种的抑菌圈直径大小为：金黄色葡萄球菌>黑曲霉>枯草芽孢杆菌>大肠杆菌。同一浓度的壳聚糖和溶菌酶对4个菌种的抑菌圈直径大小为：金黄色葡萄球菌>大肠杆菌>枯草芽孢杆菌>黑曲霉。(2)添加肉桂精油、壳聚糖和溶菌酶的玉米淀粉膜对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和黑曲霉的抑菌效果表明：对大肠杆菌的抑制效果是壳聚糖>肉桂精油>溶菌酶；对金黄色葡萄球菌的抑制效果是肉桂精油>壳聚糖>溶菌酶；对枯草芽孢杆菌的抑制效果是壳聚糖>肉桂精油>溶菌酶；对黑曲霉的抑制效果是肉桂精油>壳聚糖>溶菌酶。(3)以不同浓度的肉桂精油、壳聚糖和溶菌酶与4.5%的玉米淀粉、1.5%的甘油在90℃糊化20min的条件下制备玉米淀粉抑菌膜,测定膜性能等指标,通过三种抑菌剂对膜性能的影响研究表明：抑菌剂的浓度对玉米淀粉膜的厚度几乎没有影响；随着添加浓度的增加膜的抗拉强度逐渐增强；当壳聚糖、溶菌酶和肉桂精油的添加量分别在1.5%以上、2%以上和2.5%时,就可以有效提高膜的断裂伸长率；而添加抑菌剂的玉米淀粉膜的透光率却都小于对照膜；当壳聚糖的浓度为1%时,阻水性能最好,而当浓度大于2%时,阻水性能差,当肉桂精油的浓度在1%和1.5%时,阻水性能差,溶菌酶的浓度大于1.5%时,阻水性能则优于对照膜；当壳聚糖的浓度为0.5%、2%和2.5%时,阻油性能较好,而对于肉桂精油阻油性能差,对于不同浓度的溶菌酶阻油性能却较好。通过用差示扫描热量法(简称DSC)对玉米淀粉膜的热量特性进行分析表明,添加0.5%、1.5%和2.5%的壳聚糖在与淀粉成膜的过程中有良好的相容性；除了添加2.0%的溶菌酶外,其他浓度的溶菌酶在与淀粉成膜的过程中有良好的相容性；而只有添加2.0%的肉桂精油在与淀粉成膜的过程中才具有良好的相容性。(4)以添加不同浓度的肉桂精油、壳聚糖和溶菌酶的玉米淀粉抑菌膜对鲜猪肉进行保鲜研究,通过对感官指标、细菌总数、TVB-N值和pH值的分析表明：随着抑菌剂添加量的增加,对鲜猪肉有较好的保鲜效果,以添加1.5%以上浓度的壳聚糖、肉桂精油和2.5%浓度的溶菌酶的淀粉膜能使鲜猪肉在一级鲜度上延长6d。更多还原

【Abstract】 Corn starch is commonly used in the preparation of natural edible films. However the poor mechanical properties of the corn starch film itself, having a hydrophilic and easy to breed bacteria, affect the safety and shelf life of the food, so restricting its practical application. When natural antibacterial substances are added to corn starch film, using the mechanical properties of different concentrations of starch antibacterial film, they enhance the performance of the starch antibacterial film screened for fresh pork preservation technology. Its application does not affect food and can effectively inhibit microbial growth and reproduction in the pork and membrane surfaces so as to achieve an extension of the storage period of fresh pork.(1) Four strains of Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger, double dilution method and the zone of inhibition of cinnamon oil, clove oil, fennel essential oils, vanillin, shell glycans and the minimum inhibitory concentration of lysozyme and antibacterial effect. The result is:cinnamon oils, chitosan and lysozyme in a lower concentration can achieve complete bacteriostatic effect. These are the best three out of the six kinds of antibacterial agents; same concentrations of cinnamon oil on the four strains inhibition zone diameter species:Staphylococcus aureus>Aspergillus niger> Bacillus subtilis> Escherichia coli. The same concentration of chitosan and lysozyme inhibition zone diameter of four strains:Staphylococcus aureus> Escherichia coli> Bacillus subtilis> Aspergillus niger.(2) Add cinnamon oil, corn starch film of chitosan and lysozyme on Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Aspergillus niger antibacterial effect:inhibitory effect on Escherichia coli chitosan>cinnamon oil>lysozyme;inhibitory effect of Staphylococcus aureus cinnamon oil>chitosan>lysozyme;inhibitory effect of Bacillus subtilis chitosan> cinnamon oils>lysozyme; inhibitory effect of Aspergillus niger cinnamon oils>chitosan> lysozyme.(3) Different concentrations of cinnamon oil,chitosan and lysozyme with4.5%of the corn starch,1.5%glycerol was prepared under the conditions of90℃and gelatinized20min corn starch Bacteriostasis film, film performance and other indicators were measured through three suppression agents on membrane performance. Research shows that:the concentration of the bacteriostatic agent. corn starch thickness of the film has almost no influence. It was gradually increased with the added concentration to increase the tensile strength of the film; when the additional amount of the chitosan, lysozyme and cinnamon oil in more than1.5%, respectively, more than2%and2.5%, it can effectively improve the elongation at the tearing of the film;while adding a bacteriostatic agent the light transmittance rate of the corn starch film is smaller than that of the control film;When the chitosan concentration is1%, the water-blocking performance is best when the concentration is greater than2%.Water-blocking performance is poor when the cinnamon essential oil concentration of1%and1.5%, the water-blocking performance, bacteriolytic the enzyme concentration is greater than1.5%, the water-blocking performance is superior to the control film; when the concentration of chitosan was0.5%, preferably2%and2.5%,the performance of the barrier oil, while the oil barrier performance for cinnamon oil is poor the different concentrations of lysozyme oil barrier performance was better.By using differential scanning calorimetry (DSC) thermal properties of corn starch film analysis demonstrate the addition of0.5%,1.5%and2.5%chitosan in the film deposition process with the starch has a good compatibility. In addition to adding2.0%of lysozyme and other concentrations of lysozyme in the film formation with the starch the process has good compatibility; and also while only2.0%of cinnamon oil has a good compatibility with starch deposition process.(4) Preservation of fresh pork with corn starch antimicrobial films with different concentrations of cinnamon oil, chitosan and lysozyme, show that through the analysis of the sensory index, the total number of bacteria, TVB-N value and pH value increased with the addition of antimicrobial agents:It keeps the pork more fresh Adding1.5%concentration of chitosan, cinnamon essential oil and2.5%concentration of lysozyme to the starch film can extend the viability of fresh pork by6d.更多还原