【作者】 张力；

【导师】 丁武；

【作者基本信息】 西北农林科技大学 ， 工程硕士（专业学位）， 2017， 硕士

【摘要】 利用纳米技术缓释食品配料或食品添加剂制备缓释型纳米微粒在食品领域中应用广泛,具有延长食品加工、运输、贮藏过程的有效时长,保持食品的独特风味,延长食品的货架期等优点。丁香酚作为植物源天然食品防腐抗菌剂,其抑菌谱广,兼备抗氧化性,但因其易挥发,稳定性差,具特有的香气和辛香味,在食品中的实际应用受到限制。为扩大丁香酚的使用范围,提高其生物利用度,开发天然来源的食品防腐剂在冷鲜肉制品保鲜保质的潜在应用。基于此,本文首先采用复合凝聚法制备明胶-壳聚糖可溶性复合物,以此为载体包封丁香酚,采用自组装法制备丁香酚纳米微粒。通过正交试验优化纳米微粒制备的最优工艺条件,并进行验证,将其应用到冷鲜猪肉的贮藏保鲜中,探究丁香酚纳米微粒对冷鲜猪肉贮藏中品质变化的影响,主要内容与结果如下:(1)采用自组装法制备丁香酚纳米微粒,以粒径大小和包封率为指标,通过单因素和正交试验分析了壳聚糖浓度、明胶浓度、丁香酚浓度、转速和交联时间五个因素对制备条件的影响。得制备丁香酚纳米微粒的最优工艺:壳聚糖浓度2 mg/mL,明胶浓度2 mg/mL,丁香酚浓度5 mg/mL,调节胶体溶液pH至6.0,转速800 r/min,交联时间30min,搅拌结束后在60℃水浴加热20 min。制得的丁香酚纳米微粒粒径229.09 nm,包封率为50.69%。(2)对最优条件下制备的丁香酚纳米微粒进行表征分析,TEM观察丁香酚纳米微粒呈较规则圆形,分布较为均匀,粒径大小220 nm,FTIR、DSC分析证明丁香酚被包封在壳聚糖与明胶形成的复合物体系中,并与明胶以氢键和疏水作用力相互作用。丁香酚纳米微粒具有缓释性能,1 h丁香酚的释放量为10.66%,10 h后处于缓慢释放阶段,24 h释放量为65.09%,趋于稳定,36 h释放量达到75.47%,证明制备的丁香酚纳米微粒是新型的有实用价值的缓释体系。(3)丁香酚纳米微粒对冷鲜猪肉保鲜试验表明,丁香酚纳米微粒有效抑制肉品细菌总数增长,贮藏期可延长至15 d,与CK组有显著差异(P<0.05)。丁香酚纳米微粒在贮藏期间能延缓冷鲜肉TBARS值、TVB-N值的增长(P<0.05),显示出较好抗氧化性能,对肉品色泽有保护作用,菌落总数和理化指标表明,与CK组8 d的保鲜期相比,延长了7 d的货架期。证明丁香酚纳米微粒对冷鲜肉贮藏保鲜有改善作用。更多还原

【Abstract】 The use of nano-technology slow-release food ingredients or food additives preparation of sustained-release nano-particles in the field of food widely used to extend the food processing,transportation,storage process of effective length,to maintain the unique flavor of food and extend the shelf life of food and other advantages.Eugenol as a natural source of plant preservative antibacterial agent,its antibacterial spectrum is broad,both antioxidant,but volatile,poor stability,with unique aroma and aroma,in the practical application of food is limited.To expand the scope of application of eugenol,to improve its bioavailability,and to develop natural sources of food preservatives in the cold meat products,the potential preservation of the potential application.Based on this,the Gel-CS NPs was prepared by compound coacervation method,and Euo-Gel-CS NPs were prepared by self-assembly method.The optimum technological conditions for the preparation of nanoparticles were investigated by orthogonal test.The effects of eugenol nanoparticles on the quality of chilled pork were studied.The main contents and results are as follows:(1)The Euo-Gel-CS NPs were prepared by self-assembly method,and the particle size and EE were used as indexes.The effects of CS concentration,Gel concentration,Euo concentration,rotational speed and crosslinking time were analyzed by single factor and orthogonal test on the Preparation Conditions.The optimum conditions of preparation of EuoGel-CS NPs were as follows:CS concentration 2 mg/mL,Gel concentration 2 mg/mL,Euo concentration 5 mg/mL,adjusting colloidal solution pH 6.0,speed 800 r/min,crosslinking time 30 min,After the end of heating in 60 ℃ water bath for 20 min.The obtained eugenol nanoparticles had a diameter of 229.09 nm and EE of 50.69 %.(2)The Euo-Gel-CS NPs prepared under the optimal conditions were characterized by characterization.TEM observation of eugenol nanoparticles were more regular round,the distribution is more uniform,the size of 220 nm.FTIR and DSC analysis showed that eugenol was encapsulated in the complex system of chitosan and gelatin,and interacted with gelatin with hydrogen bonds and hydrophobic interaction.In addition,eugenol nanoparticles with sustained-release properties,1 h eugenol release of 10.66 %,there is a slow release stage,after 10 h,24 h release of 65.09 %,stabilized,36 h release of 75.47 %.It is proved that the preparation of eugenol nanoparticles is a new type of sustained-release system with practical value.(3)The results showed that Euo-Gel-CS NPs could effectively inhibit the growth of meat bacteria.Storage period can be extended to 15 d,and CK group was significantly different(P <0.05).Eugenol nanoparticles can delay the increase of TBARS and TVB-N(P <0.05)during cold storage,showing better antioxidant properties,It has a protective effect on the color of meat.The total number of colonies and physical and chemical indicators showed that compared with the control group 8 days of shelf life,extended 7 days shelf life.It was proved that Euo-Gel-CS NPs could improve the preservation of cold meat.更多还原