This study aimed to investigate the effect of active absorbent pad containing Carum copticum essential oil (C. copticum EO) on shelf life and quality of refrigerated chicken meat. C. copticum EO release, total viable count (TVC), pH, total volatile nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS) and sensory attributes were evaluated during 18 days of storage. The results showed that the release of thymol decreased gradually during storage and reduced to the lowest level on day 21. Active pad resulted in lower TVC, TVB-N, pH and TBARS level compared with the reference/without active pad. The sensory quality of chicken meat was maintained longer compared to the control sample, which was attributed to the significant antimicrobial and antioxidant activity of C. copticum EO against spoilage microorganisms. Active absorbent pad loaded with 100 mu l C. copticum EO demonstrated the best performance in extending the shelf life and maintaining the sensory attributes of the refrigerated chicken meat.

采用挤出吹塑法制备PLA/PHB复合膜,并利用液体增塑剂柠檬酸三乙酯(TEC)对PLA/PHB复合膜进行增塑改性.对不同TEC比例改性后的复合膜进行力学性能、透氧透湿、DSC性能测试,并结合红外光谱扫描、SEM断面观察,分析TEC添加前后复合材料的微观结构形态变化.结果表明:当TEC含量为7.5％时,复合薄膜具有较优的力学性能、透湿性能以及透气性能.DSC分析、IR分析以及SEM分析表明,TEC对复合材料的增塑作用比较明显,能够显著提高PLA/PHB复合膜玻璃化转变温度,提高复合膜的热稳定性能,改进断裂伸长率,提高材料的柔软性.

采用水蒸气蒸馏法从小茴香中提取精油,通过GC-MS技术对小茴香精油主要成分进行分析,其主要成分为反式茴香脑与4-烯丙基苯甲醚,绝对含量分别为96.7 mg/mL和32.23 mg/mL.通过傅里叶红外光谱对小茴香精油的主要成分在不同光照时长条件、不同pH值条件下的稳定性进行分析,结果表明:光照与pH值变化没有引发新官能团生成和能量偏移,对其稳定性影响较小.研究小茴香精油及其主要成分对青霉的抑菌效果,结果表明效果较好,其主要抑菌成分为反式茴香脑.

The purpose of this study was to evaluate the vapor-phase antibacterial efficacy of garlic essential oil (GEO) and citronella essential oil (CEO) against four foodborne bacteria and their vapor-phase antibacterial mechanism against Staphylococcus aureus (S.aureus). GC-MS analysis confirmed that diallyl disulfide (29.258 %) and citronellal (36.940 %) were the major constituents of GEO and CEO, respectively. GEO and CEO at concentrations of 80 mu L/L could completely inhibit the growth of all tested bacteria and the combinations of GEO with CEO displayed additive effects against the four tested bacteria with fractional inhibitory concentration index (FICI) values of 0.75 or 0.50. Furthermore, the scanning electron microscopy observations, the change of proteins concentration and catalase activity of S.aureus confirmed that the EOs impacting the membrane integrity and catalase activity of S.aureus. Thus, our study will provide a theoretical foundation for the applicability of EOs on the non-contact preservative packaging for food.

This work was aimed to explore the effect of antimicrobial packaging film coated with ajowan and cinnamon essential oil (EO) on shelf life of fresh chilled pork. Antimicrobial compound solution was prepared with ajowan EO, cinnamon EO, polyvinyl alcohol, glycerol, corn starch and distilled water according to a certain proportion, and it was coated on the corona-treated PP/EVA film to prepare antimicrobial films. The fresh pork was divided into 5 groups and packaged in bags which was made of films as follow, the blank PP/EVA film was used as the control group, and the antimicrobial films contain combination EO with concentration of 0.4, 0.8, 1.2 and 1.6% were recorded as BF1, BF2, BF3 and BF4 group respectively, and all groups were stored at 4 degrees C. The total viable count (TVC), total volatile basic nitrogen (TVB-N), pH, TBARS value and sensory quality of pork were tested for evaluating the effect of antimicrobial packaging film on quality of pork. The results showed that BF4 antimicrobial film could reduce the increase of TVC, TVB-N, pH and TBARS value of pork significantly (P < 0.05), and the BF4 film was superior to other kinds of antimicrobial film on maintaining the sensory quality of fresh pork. In conclusion, the fresh chilled pork packed in BF4 film presented the best quality and its shelf life was extended for 4 days.

目的 以厚朴提取物为抑菌成分研制抗菌包装纸,并研究其对奶酪保鲜效果的影响.方法 采用超声辅助提取法提取厚朴中的抑菌成分,利用高效液相色谱仪对其进行定性分析,并通过福林酚比色法测试总酚含量.采用涂布和浸渍这2种方法分别制备涂布抗菌纸和浸渍抗菌纸,并对其物理性能进行测试,将2种抗菌包装纸应用于奶酪保鲜,测试其感官品质、菌落总数和过氧化值.结果 厚朴提取物中含有厚朴酚、和厚朴酚,总酚含量为47.4 mg/g.涂布抗菌纸的平滑度、定量、抗张强度、撕裂度均优于原纸,仅吸水性出现降低现象.与原纸相比,浸渍抗菌纸和涂布抗菌纸对于保持奶酪的感官品质以及抑制其菌落总数和过氧化值的上升具有明显作用(P＜0.05),其中质量分数为10％的厚朴提取物涂布抗菌纸对奶酪保鲜效果最优,与原纸相比可延长其货架寿命约14 d.结论 厚朴提取物涂布抗菌纸对奶酪具有较好的保鲜效果,可以明显延长其货架寿命.

在包装教育中,科研与科研相互促进,科研成果可以有效促进教学质量的提高.在国内包装教育快速发展的过程中,以湖南工业大学为代表的一些高校,重视包装复合型人才的培养,依托科研条件与成果,积极探索教学内容与实验手段的改革,大力加强包装教育的内涵建设,取得了卓有成效的成绩.

目的 研究三乙酸甘油脂(GTA)对PLA/PHB包装膜性能的影响.通过添加GTA提高PLA与PHB的相容性,改善包装膜的力学和透湿透氧性能.方法 以GTA为增塑剂,聚乳酸(PLA)和聚β-羟基丁酸酯(PHB)为原料,利用熔融共混吹膜的方法制备PLA/PHB复合膜,通过对复合材料的DSC测试,以及透湿透氧性能、力学性能和红外光谱分析,研究GTA质量分数不同时对复合材料的拉伸性能、断裂伸长率、透湿透氧性能和相容性的影响.结果 随着GTA含量的增加,薄膜拉伸强度整体呈下降趋势,同时断裂伸长率不断增大.当GTA质量分数大于4％时,拉伸强度急剧下降,断裂伸长率由原先的快速增长变为缓慢增长.透湿性能随GTA质量分数的增加先不断增大后减小,透氧性能增长不明显.通过DSC图结合包装膜断面结构微观图发现,GTA的加入减弱了聚合物分子链段之间的作用力,促进了链段的运动,使得薄膜断面上的微孔消失,形成层状结构.结论 GTA的加入改善了PLA和PHB的相容性,并且在GTA质量分数为4％时,复合包装膜既具有较好的拉伸性能和断裂伸长率,还具有较好的透湿透氧性能.

目的 设计一款集个性化、便携性和功能性于一体的新型卷烟包装盒型.方法 通过烟支规格和烟支排列形式设计软盒硬化小盒外形尺寸;自粘封签设计异型裁切边和“开启”字样提示,内衬纸增加圆角梯形撕片设计,小盒商标增加半圆形取烟口设计;对GDX1软盒硬化包装机上相应的设备配件进行改进优化.结果 7-6-7排列的20支中支烟形成的软盒硬化小盒外形尺寸为44.5 mm×18.5 mm×86 mm;自粘封签、内衬纸和小盒商标的设计便于烟支的取出和保润功能的实现.结论 通过包装结构设计和设备配件改进,此款烟盒满足上机适用性要求,此款新型的中支软盒硬化烟盒能够成功应用于GDX1包装机组.

To explore the effect of different concentrations of PBAT on the performance of PLA / PHB composite films, PBAT was blended with PLA / PHB in a certain proportion. The films were prepared by extrusion blow molding and their DSC, SEM, mechanical properties, water vapor permeability, oxygen permeability and biodegradation were measured. The results show that when the content of PBAT is 10%, water vapor permeability and oxygen permeability of the film are the best. When the PBAT content is 20%, the tensile strength decreases from 35.86MPa to 20.75MPa and the decrease is 42% .The elongation at break and biodegradation increase with the increase of PBAT content. Properties of the material can be improved after adding PBAT by a certain proportion.

目的 研发一种以丁香精油为抑菌剂的涂布纸箱,并研究不同浓度丁香精油对水蜜桃保鲜效果的影响.方法 将不同浓度的丁香精油与聚乙烯醇涂布到瓦楞纸板上制备成涂布纸箱,测试抗菌纸板对灰霉、交链孢、黑曲霉的熏蒸抑菌效果;并以水蜜桃为研究对象,研究不同浓度丁香精油对水蜜桃保鲜效果的影响.结果 抗菌纸板的抑菌率随着丁香精油浓度的增加而逐渐增强,丁香精油涂布纸箱可明显降低水蜜桃的腐烂率,并维持其感官品质,贮藏13d后,体积分数为0.6％的丁香精油涂布纸箱对水蜜桃的保鲜效果最佳,其感官品质分数为6.2,腐烂率仅为26％.结论 丁香精油涂布纸箱对灰霉、交链孢霉、黑曲霉等霉菌具有抑制作用,可减缓水蜜桃的腐烂,延长其货架寿命4～5 d.

以吸水纸为芯纸,两侧覆上面纸,以热熔胶黏合,在芯纸上均匀打孔载入定量的1-MCP药剂,制得1-MCP保鲜纸,并采用GC-MS,对保鲜纸中1-MCP的释放规律进行研究.研究表明,实验条件下1-MCP处于气态,在第2 d保鲜纸中的1-MCP释放达到最大值,说明此时的湿度达到适合1-MCP释放的条件.以油桃为实验对象,研究保鲜纸中1-MCP用量对果实感官评价、失重率、呼吸强度及可溶性固形物含量等指标的影响.结果表明,质量浓度为4 mg/L的1-MCP保鲜纸对油桃感官评价的影响最小,对果实失重率、呼吸强度、可溶性固形物含量的抑制作用最明显,整体而言,对油桃的保鲜效果最好.

Analysis of main components and quantitative analysis of antibacterial composition of basil essential oil are conducted by using gas chromatography-mass spectrometry (GC-MS).Stability analysis of supermarket fresh light beam and pH value on antibacterial components is studied by ultraviolet spectrophotometry.Antibacterial effect of basil essential oil is determined by filter paper diffusion method.Through the observation of change of cell by using scanning electron microscope (SEM),the bacteriostatic mechanism of basil essential oil is explored.The results show that the main antibacterial composition of basil essential oil is eugenol whose absolute content is 0.9734 g/mL.Light has little influence to the stability of eugenol.It has good stability if the solution pH value is in the range of 5～8.Basil essential oil has significant inhibition on Escherichia coli and Staphylococcus aureus by breaking the integrity of cell.

以油桃为试材,在常温下利用实验室自制的一种含有60 μL牛至精油和4mg1-甲基环丙烯(1-MCP)保鲜剂的复合保鲜纸置于油桃果实PE包装中,同时分别以不放置保鲜纸、放置含等量牛至精油的精油保鲜纸以及放置含等量1-MCP保鲜剂的1-MCP保鲜纸为对照,定期测试油桃的感官评价、失重率、腐烂率、呼吸强度、可滴定酸含量、可溶性固形物含量等指标,以考察实验室自制的新型复合保鲜纸对呼吸跃变型果蔬的保鲜效果,为复合保鲜纸在这类果蔬保鲜的应用提供参考依据.结果表明:复合保鲜纸同时起到了抑菌和抑制乙烯的作用,明显改善了油桃的感官品质,减缓了呼吸作用,降低了失重率,同时抑制了可滴定酸和总糖含量的下降,可将油桃保鲜期由7d延长至13 d.说明这种新型复合保鲜纸对呼吸跃变型果蔬具有良好的保鲜效果,为这类果蔬的保鲜提供了一种有效方法.

With the method of steam distillation,on the basis of the analysis of sodium chloride solution concentration,the ratio of liquid to solid,the time of distillation,the ultrasonic power and the ultrasonic time,the method of central composite response surface design (CCD) is used to optimize the extraction process,and the chemical components of citronella oil are analyzed and identified by GC-MS method.The results show that the concentration of NaC1 solution is 9％,the ratio of liquid to solid is 15:1,the distillation time is 170 rin,the ultrasonic power is 420 W when ultrasonic time is 65 min,and citronella extraction rate reaches the maximum value of 2.69％.A total of 44 kinds of chemical components are identified,and the highest content is citronellal,which accounts for 36.94 ％.

A blend of poly(lactic acid) (PLA) (70% by weight) and poly(3-hydroxybutyrate) (PHB) (30% by weight) with a solubilizing agent (PBAT) at four different concentrations (5%, 10%, 15% and 20% by weight per 100 parts of the blends) were investigated by FTIR, SEM, mechanical testing, water vapor permeability test and biodegradation studies. SEM showed that PBAT can improve the compatibility between PLA and PHB. The film show a great Oxygen transmission rate and Water vapor permeability property when the content of PBAT is 10%.

Combining with ultrasonic assisted technology, citronella oil is extracted by steam distillation.The effects of material liquid ratio, NaCl concentration and extraction time on the yield of essential oil are investigated.On the basis of single factor experiment, the extraction process is optimized by orthogonal experiment.Finally, the chemical constituents of citronella essential oil are analyzed and identified by using gas chromatography-mass spectrometry (GC-MS).The results show that when the solid-liquid radio is 1∶20, the amount of NaCl is 10%, the extraction time is 180 min, the yield of citronella essential oil is 2.8%, under the premise of ultrasonic power is 420 W, the ultrasonic time is 30 min.Citronella oil contains 45 kinds of chemical composition by GC-MS detection technology, in which the highest relative content is citronellal, followed by geraniol, citronellol.

Whey protein coating with antibacterial activity was prepared by adding different natural antibacterial agent,such as e-polylysine,Nisin,lysozyme and essential oil.The process conditions for preparing whey protein coating were optimized through single factor experiments.The factors including concentration of whey protein,amount of glycerol,sodium sulfite and glutamine transaminage were selected and their effects on the properties of whey protein coating were evaluated.Then the effects of whey protein coating in the preservation of eggs were evaluated and the indexes of TVBN value and total bacterial colonies were investigated.The results showed that when the concentration of whey protein was 11％,the amount of glycerol was 4％,the amount of sodium sulfite was 0.1％,the amount of glutamine transaminage was 0.1％,the barrier properties for oxygen and water vapor and mechanical properties of whey protein coating film were superior.Eggs coated by whey protein coating had better performance in TVBN value,egg contenting total bacterial colonies than control experiments,especially,whey protein coating containing antibacterial agent of 1 mg/mL ε-polylysine and 1 mg/mL Nisin had better fresh-keeping effect,which could prolong the shelf life of eggs more than double.Whey protein coating had a good effect on the preservation of eggs.

In order to improve the preservation effect of nectarine fruit,a new composite preservative paper coated with PVA as the barrier layer,Oregano essential oil and 1-methylcyclopropene(1-MCP)as preservative was prepared,it both can antibacterial and inhibit the activity of ethylene,delay the breathing process of nectarine. And the release regularity of the essential oil's antimicrobial components and of the 1-MCP were studied by using the GC-MS;Actual preservation effect of self-made composite preservative paper to nectarine fruit was tested by measuring the respiratory intensity and decay index.The results show that this new composite preservative paper has good resistance to reservoir properties,could significantly inhibit the nectarine respiration intensity,reduce the decay index. The preservation effect is obviously superior to the single use oregano essential oil or 1-MCP.This new type of composite preservative paper on respiratory jump variant of nectarine with good preservation effect,provides an effective method for this type of fruits and vegetables preservation.

Objective: To find a natural plant essential oil (EO) with excellent antimicrobial effect on food-borne bacteria and to explore the mechanism of its antimicrobial function against Escherichia colt (E. cal). Methods: The antimicrobial activity of seven EOs against Gramnegative E. coli ATCC 8739 and Gram-positive Staphylococcus aureus ATCC 6538 was investigated using agar disk diffusion method, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each EO was determined using the broth dilution method. The chemical composition of the Trachyspermum copticum (T. copticum) EO was analyzed using gas chromatography mass spectrometry (GC/MS). In order to explore the mechanism of the antimicrobial action, 1 MIC and 2 MIC of T. copticum. EO was added to a suspension of E. coli, the growth curve and the scanning electron microscopy (SEM) analysis of E. coli, and the release of cell constituents and protein and potassium ions from the bacterial cell were measured. Results: The T. optician EO had the best antimicrobial activity against the test bacteria, and 10 compounds accounting for 94.57% of the total oil were identified, with the major components being thymol (46.22%), p-cymene (19.03%), and y-terpinene (22.41%). The addition of I MIC T. copticum. EO significantly inhibited the growth of E. coli and increased the release of cell constituents and protein and potassium ions from the bacterial cells. Scanning electron micrographs showed that T. copticum EO caused most of the E. co/i cell membranes to collapse and rupture, leading to cell death. Conclusions: These results indicate that T. copticum EO is a good natural antimicrobial agent for food-borne pathogens.