【作者】 吕飞；

【导师】 叶兴乾；

【作者基本信息】 浙江大学 ， 食品安全， 2009， 博士

【摘要】 食品抗菌包装可以有效地抑制食品表面微生物的生长,延长食品的货架期,保证食品品质。我国是世界最大的水产品生产国和消费国,由于鱼类自身的一些特点决定了其易腐性,本论文主要研究了生物抗菌包装体系及其在水产品保鲜中的应用。主要研究结论如下：(1)试验从13种植物精油中筛选出抗菌能力最强的精油——肉桂油,它对枯草芽孢杆菌、蜡样芽孢杆菌、金黄色葡萄球菌、大肠杆菌和鼠伤寒沙门氏菌的MIC值分别是0.2,0.1,0.1,0.4和0.4μL/mL。通过添加不同浓度的EDTA来改善Nisin(乳酸链球菌素)的抑菌效果,结果表明2000 IU/mL的Nisin溶液中添加150μg/mL的EDTA是最为经济有效的。(2)采用琼脂稀释棋盘法研究了肉桂油和百里香油、丁香油以及Nisin联合抗菌效果。结果表明：肉桂油联合用药具有协同或相加作用。通过不同的食品模型,以大肠杆菌为指示菌测定了pH和食品组分对肉桂油抗菌效果的影响,结果表明：肉桂油在酸性环境下抗菌作用增强；淀粉含量对肉桂油的抗菌效果影响不显著；蛋白质含量≤2.5%时,肉桂油的抗菌作用不受影响,随着蛋白质含量的增加,抗菌作用受到抑制；脂肪显著抑制肉桂油抗菌效果。(3)不同因素对肉桂油／海藻酸钠膜抗菌性能、薄膜厚度、薄膜透光率、薄膜色泽以及薄膜水蒸气透过系数的试验结果表明：海藻酸钠浓度、膜液pH值和成膜膜液的体积对肉桂油／海藻酸钠薄膜厚度影响显著；肉桂油浓度、海藻酸钠浓度和膜液体积等对膜的透光率影响显著;肉桂油浓度、海藻酸钠浓度和膜液体积对肉桂油／海藻酸钠薄膜的色差值a和b有一定影响；肉桂油含量和成膜温度对肉桂油／海藻酸钠薄膜抗菌性能和薄膜水蒸气透过系数影响显著。(4)不同肉桂油浓度下肉桂油／海藻酸钠薄膜中主要抗菌成分桂皮醛的释放符合一级动力学模型,试验推导出不同肉桂油浓度下桂皮醛的表观扩散系数和释放瞬间水溶液中的桂皮醛含量。(5)以黑鱼为保鲜材料,研究含Nisin的抗菌涂膜对其保鲜效果。结果表明：在4℃下,含1000 IU/mL Nisin和150μg/mL EDTA海藻酸钠涂膜对黑鱼片具有较好的保鲜效果,明显地抑制细菌总数的增长,维持较低TVB-N值,有效地延长黑鱼货架期。(6)以黑鱼为保鲜材料,比较了肉桂油／海藻酸钠涂膜或薄膜,Nisin海藻酸钠涂膜或薄膜以及肉桂油+Nisin海藻酸钠涂膜或薄膜对黑鱼的保鲜效果。结果表明膜液处理和薄膜处理均能不同程度地维持黑鱼品质,膜液处理尤其是含有肉桂油的膜液处理能显著抑制微生物生长,维持较低TVB-N值,抑制脂肪氧化,但其处理使黑鱼变黄。含肉桂的薄膜处理对抑制微生物生长,维持较低TVB-N值和抑制脂肪氧化有一定作用,效果不如膜液处理显著,薄膜处理对黑鱼色泽影响小更多还原

【Abstract】 Food antimicrobial packaging can inhibit the microbial populations of the food surface, extend shelf-life and maintain the quality of the food. China is the largest aquatic products producer and the largest aquatic products consumer in the world, however, the aquatic products are easy perishable, the bio-antimicrobial packaging systems and their application on the aquatic products to maintain their quality were researched in this dissertation. The key results are followed:(1) By comparing the antimicrobial activity of 13 essential oils on eight food spoilage and pathogentic bacterial species, cinnamon oil was the strongest antimicrobial agents in them, the MICs of it against Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium were 0.2,0.1,0.1,0.4 and 0.4μL/mL. EDTA was added into nisin to increase its antimicrobial activity, and when its content was 150 ug/mL, nisin could most encomically inhibit the bacteria.(2) The synergy effects of cinnamon were evaluated by the agar dilution checkerboard method when it was combined with thyme, clove or nisin against the food related bacteria. This study indicated that the combination of cinnamon oil with other essential oils and nisin had synergistic effects or additive effects. The effects of food ingredients and pH on the antimicrobial efficacy of cinnamon were performed using a range of model media and E. coli as the indicator strain. The results indicated that:The antimicrobial activity of cinnamon oil increased when it was at pH 4-5 food models; The anitimicrobial activity of cinnamon oil was not affected by food starch; When the content of food protein was lower than 2.5%, the antimicrobial activity of cinnamon oil was not affected by food protein, but when the content was higher than 2.5%, the activity of cinnamon oil decreased; With the increase of food fat, the antimicrobial activity of cinnamon oil decreased significantly.(3) The different factors on the antimicrobial activity of film, film thickness, film transparency, film color and film water vapor permeability (WVP) of cinnamon/alginate film were tested. The results showed that:The film thickness was affected significantly by alginate concentration, pH of film formation solution and volume of film formation solution; Cinnamon content, alginate concentration and volume of film formation solution affected significantly the film transparency, furthermore, they also affected the color of the films to some extent; And the WVP and the antimicrobial activity of the films were significantly affected by the cinnamon content and the temperature of film formation.(4) The release of cinnamaldehyde (the main composition of cinnamon) from cinnamon/alginate film to water was accorded with the first order model. The apparent diffusion coefficients of cinnamaldehyde and the concentrations of cinnamaldehyde in water when the films were put into water were calculated.(5) The antimicrobial coatings of calcium-alginate containing nisin and EDTA were applied to maintain the quality of northern snakehead. The results showed that calcium-alginate coating containing 1000 IU/mL nisin and 150μg/mL EDTA could inhibit the microbial growth, maintain lower TVB-N content, and extend the shelf-life of northern snakehead.(6) The antimicrobial coatings and films containing cinnamon, nisin, or cinnamon and nisin were used to keep the quality of northern snakehead. The results showed that: The coatings and films containing antimicrobial agents could maintain the quality of northern snakehead, but the coatings, especially the coatings containing cinnamon had a better effect than the films containing cinnamon on inhibiting the microbial growth, decreasing the TVB-N and restraining the lipid oxidation of northern snakehead. However, the coating treatments containing cinnamon could change the fish fillets color into more yellow than the film treatments containing cinnamon.更多还原