【作者】 钱亮亮；

【导师】 金征宇；

【作者基本信息】 江南大学 ， 制糖工程， 2008， 硕士

【摘要】 本课题选用β-环糊精(β-CD)和挥发性食品抗菌剂肉桂醛,研究了环糊精在抗菌食品包装中的两种应用方式:一是先使环糊精与肉桂醛形成包合物,然后加入到食品包装材料中,通过肉桂醛从包合物中的缓慢释放以及在材料中的迁移,最后达到在食品表面发挥抗菌作用;二是先将环糊精固载在纤维包装材料上,然后通过固载环糊精对肉桂醛的包埋与缓释来实现纤维材料的抗菌性能。最后将这两种功能性包装材料应用于戚风蛋糕防霉包装上。肉桂醛(CIN)对食品常见腐败菌和霉菌都有很强的杀灭作用。首先以肉桂醛和β-环糊精为原料,采用密封控温法制备控释包合物,并确定了包合工艺参数和释放特性。结果表明:由单因素及响应面试验对包合工艺进行优化,最终包合条件为:加热温度100℃,加热时间2.5h,β-环糊精与肉桂醛包合比1:1.75。同时用红外光谱对包合物进行鉴定,发现已形成包合物,并通过分子模拟软件chemoffice2008确定包合形式。释放实验表明,包合物中肉桂醛释放速率与环境的相对湿度密切相关,与环境温度关系不大。选用聚乳酸膜作为包装材料基质,研究了肉桂醛环糊精包合物在聚乳酸膜中的迁移行为。结果表明,肉桂醛在膜中的迁移速度很大程度上受食品模拟液性质的影响,且迁移速度同时还受环糊精包合物控制释放机制的影响。在60%甘油体系和50%乙醇溶液中包合物膜中抗菌剂迁移速度较快,而在10%乙醇中则体现较明显的缓释效果,在正己烷中释放程度很低。该结果说明环糊精包合物聚乳酸膜在高水分活度的食品中可以发挥长效抗菌作用。肉桂醛包合物在膜中的释放过程可利用Fickian公式来进行预测,通过对不同时间迁移质量比的测定,利用matlab软件计算得出相应的迁移系数D,可建立起相应的数学模型。其次,采用柠檬酸酸作为交联剂,将β-环糊精接枝到纤维素对其工艺特点进行了探讨,然后利用该纤维素对挥发食品抗菌剂肉桂醛进行包埋,并研究了其释放特性。结果表明:柠檬酸法能够使β-环糊精固载于纤维素上,接枝工艺参数,加热时间在5～7min为宜;加热温度选择在160～180℃之间;柠檬酸和β-环糊精浓度摩尔比在5:1～7:1之间。当环糊精固载量控制在12～14%之间时,肉桂醛包埋量大约在8～9μL/g。肉桂醛在功能纤维素中的释放量随环境相对湿度增加而增大。最后,将制得的肉桂醛聚乳酸膜和肉桂醛功能纤维应用于戚风蛋糕,试验证明具有良好的防霉功效,可有效提高其安全性并延长货架期。更多还原

【Abstract】 In the present study, two application patterns ofβ-cyclodextrin (β-CD) in antimicrobial food packaging were investigated using the volatile antimicrobial cinnamaldehyde (CIN).One is to prepare the antimicrobial inclusion complex withβ-CD and then incorporate the inclusion complex directly into polymers material. The other way is to covalent immobilization ofβ-CD onto polymers to obtain the antimicrobial functional material by the complexation of the fixedβ-CD with antimicrobial agents. Finally these two functional packaging materials were used in chiffon cake to anti-mildew .Cinnamaldehyde (CIN) has strong activity in inhibiting molds and food spoilage bacterium. In the present study, packaging systems that release volatile antimicrobials was simulated by entrapping CIN withβ-CD or fixedβ-CD in fabrics. At first the controlled-releasing inclusion complex was prepared by cinnamaldehyde andβ-cyclodextrin as raw material through sealed-thermal control method .The parameters and controlled-release properties of inclusion complex were also obtained. The results showed that the optimum conditions for inclusion were established by one factor and response surface methodolody as follows: The inclusion time and temperature were for 2.5h and at 100℃, oil:β-cyclodextrin was 1:1.75.At the same, the inclusion complex was validated by IR. And through molecular modeling software packages chemoffice2008 identified the inclusion form. Release rate of cinnamaldehyde from theβ-CD-CIN complex is correlated with environmential relative humidity (RH),not with the temperature.Specific migration studies were performed for CIN using polylactic acid membrane matrix filled with food stimulant. The result showed that the migration behaviors were influenced by the type of food stimulant .In the low-alcohol food system, the CIN didn’t migrate in polylactic acid membrane, but did in high-alcohol solution .when inclusion complexes of antimicrobials were added into the membrane ,the migration had been much improved due to their impact on the membrane structure properties , and more the migration rate was also affected by the control release mechanism of cyclodextrin. In 50% ethanol solution or 60% glycerol system CIN moved faster from membrane , while in 10% ethanol solution the release become slow obviously and release level is very low in hexane .It could be concluded that the antimicrobial membrane withβ-CD complexes had longer-lasting effect in high-water-activity foods.β-cyclodextrin(β-CD) was grafted onto cellulose fibers used citric acid (CA) as crosslinking agent ,the process parameters were studied. The antimicrobial cinnamaldehyde was complexed with fiber-reactiveβ-CD ,the release properties of the obtained inclusion complex were investigated, it was observed thatβ-CD could be grafted onto fibers by CA method , graft technical parameters, heating time is 5～7 min; heating Temperature is 160～ 180℃; molar ratio (CIN :β-CD) is 5:1～7:1 when the grafting yield ofβ-CD was between 12% and 14%,the inclusion rate of cinnamaldehyde was about 8～9μL/g .Release rate of cinnamaldehyde from the functional fiber was increased as environmential relative humidity (RH) increased.Finally, the cinnamaldehyde polylactic acid membrane and cinnamaldehyde functional fibers were used in the chiffon cake packaging system, the test proved that they own a good anti-mildew effectiveness, which can effectively improve their security and to extend shelf life.更多还原