Essential oils (EOs) are favored in green active food packaging research because of their excellent antibacterial and antioxidant performance. However, due to their unpleasant odor and high volatility, there is a need to control their concentration and duration after being released to avoid excessive odorant contamination of the targeted products and maintain their antimicrobial efficiency. In this paper, a facile and environmentally friendly strategy using cellulose nanofibers (CNFs), iron oxide (Fe3O4), and thyme EO (TEO) to fabricate TEO-Fe3O4-CNF aerogels with micronano porous structure for controlled release of volatile TEO to extend food shelf life and preserve their organoleptic properties is presented. The chemical deposition method is used to in situ mineralize < c magnetic nanoparticles (NPs) with high antimicrobial activity on CNF surface. An external magnetic field is employed to actuate the fiber movement and to control the aerogel pore structure during the freeze-drying process, which has a significant impact on the storage and release of TEO. Simultaneously, the synergistic interaction between TEO and Fe3O4 nanoparticles having a contact bacteriostatic effect endows the aerogel with excellent antibacterial performance. The results demonstrate the retention of TEO within the CNF network. These aerogels presents smaller and denser porous structure (11.49 nm), outstanding retention (15.48 mgg(-1)), and excellent antibacterial capacity (zone of inhibition greater than 25.5 mm, visible antibacterial activity after 48 days), making them antibacterial aerogels with self-controlled releasing property and a relatively stable release-adsorption-release system within an 10 day period. In practical applications, this sustained-release system can be utilized for packaging active foods such as pork and fruit to prolong their shelf life.

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The migration of photoinitiators (PIs): benzophenone (BP), ethyl 4-dimethylaminobenzoate (EDAB), and 4-chlorobenzophenone (CBP), from polyethylene (PE)-coated paper to 4% (v/v) acetic acid and 10% (v/v) salt-simulated food solution was quantitatively analyzed using gas chromatography–mass spectrometry. The migration behavior of the three PIs was studied under three specific working conditions: conventional heating, microwave power, and random vibration level. The migration rate of the three PIs in acidic food simulants was ranked from BP > EDAB > CBP under the specific working conditions. The mobility of the three PIs increased with increasing temperature, microwave power, and random vibration acceleration in 4% (v/v) acetic acid by 10, 10, and 15%, respectively. The experimental migration data of three PIs in PE-coated paper under different temperatures and microwave powers were used to establish the Crank monolayer migration model according to Fick’s second law. The diffusion coefficient D increased with an increase in experimental conditions. According to the migration data under the condition of random vibration level, a mathematical model conforming to the Fick model was established, fitting the migration process. These results showed that conventional heating, microwave heating, and vibration could affect the food safety of PE-coated paper.

目的 通过总结现有植物精油抗菌活性包装最新研究成果,为促进食品活性包装的进一步研究和应用提供指导.方法 介绍对食源性致病菌具有抑制作用的代表性植物精油及其主要化学成分;从破坏/影响细胞膜的结构及功能、遗传物质的复制、酶的活性和代谢功能等方面归纳总结植物精油对食源性致病菌的抑菌作用机制;分析总结植物精油活性包装材料的主要制备工艺;并介绍植物精油活性包装材料在食品保鲜中的最新应用成果;针对目前植物精油活性包装领域存在的问题提出解决方案.结论 部分具有抑菌作用的植物精油可作为化学合成防腐保鲜剂的有效替代品,随着精油在活性包装应用过程中存在的易挥发、有气味及食品安全风险等问题不断解决,植物精油活性包装将在食品保鲜领域具有良好的应用前景.

目的 将硅烷化木质素(SAL)与聚己二酸/对苯二甲酸丁二酯(PBAT)共混制备包装性能更为优良的SAL/PBAT复合包装膜,使其在包装领域应用更广.方法 通过对木质素进行硅烷化改性,以咪唑作为中间体,将叔丁基二甲基氯硅烷(TBDMSCl)接枝到木质素的羟基上制备SAL,并将SAL与PBAT进行熔融共混吹塑成膜,探讨其对包装膜的力学和阻隔等性能的影响.结果 与纯PBAT膜相比,SAL/PBAT复合包装膜拉伸强度提高了31.0％,断裂伸长率降低了37.4％,弹性模量提高了529.7％,氧气透过率降低了39.4％,水蒸气透过率降低了42.4％.结论 改性木质素与PBAT复合能够产生协同效应,可以有效改善SAL/PBAT复合包装膜的力学和阻隔性能.

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.

为解决甜樱桃容易腐烂的问题,以肉桂精油、壳聚糖和埃洛石等为原料,制备一种涂布抗菌纸.采用扫描电镜观察埃洛石纳米管负载肉桂精油的微观结构,并研究抗菌纸对6种食源性致腐微生物的抑菌效果.将抗菌纸结合带孔隔离纸在室温条件[(27±2)℃,相对湿度(50±10)％)]下对甜樱桃进行保鲜应用,研究其对甜樱桃感官品质、腐烂率、菌落总数、硬度、质量损失率和可溶性固形物的影响.结果表明,埃洛石纳米管在负载肉桂精油后直径明显变大,呈现光滑棒状结构;当肉桂精油体积分数≥2％时,抗菌纸对4种霉菌均具有较强抑制作用,对2种细菌的抑制作用低于霉菌.与对照组相比,精油体积分数为4％的抗菌纸可显著降低甜樱桃腐烂率,减缓菌落总数和质量损失率的上升,同时保持甜樱桃感官品质和硬度,可延长甜樱桃货架寿命约3d.肉桂精油抗菌纸在甜樱桃防腐保鲜方面具有良好的应用价值.

A green modification method for effectively enhancing toughness of PLA was established. Herein, alkaline lignin (LG) was firstly alkylated with dodecane, and then grafted with lactide (LA). The alkylated lignin-lactide graft copolymer (GLG-g-LA) was obtained via ring-opening polymerization (ROP). GLG-g-LA copolymer can be utilized as a functional filler to toughen polylactic acid (PLA) packaging film. The 31P-NMR of alkylated lignin (GLG) demonstrated that the peak of phenolic hydroxyl groups disappeared completely, while the relative peak intensity of carboxyl hydroxyl groups decreased significantly. The grafting rate of GLG-g-LA copolymer was improved more than twice times compared with lignin-lactide graft copolymer (LG-g-LA). Then LG-g-LA and GLG-g-LA copolymer were mixed with PLA to prepare different PLA composite films via casting method, respectively. Particularly, the elongation at break of PLA/GLG-g-LA2 composite film increased to 41.98%, which was more than 20 times higher than PLA. In general, PLA/GLG-g-LA composite film with toughness, excellent UV barrier, water resistance and controllable gas permeation could be used as high-performance and biodegradable materials in packaging field.

研究了3种不同厂家的百里香精油对灰霉、青霉、交链孢霉、根霉的抑菌效果,采用气相色谱-质谱联用仪分析其组成成分,并探讨百里香精油中不同成分对其抑菌效果的影响;将优选的百里香精油、大豆分离蛋白、吐温-80制成纳米乳液涂布于A楞纸板制备抗菌纸箱,在室温条件下[(26±2)℃,相对湿度(45±5)％]对草莓进行贮藏处理,通过考察不同精油浓度对草莓的感官质量、腐烂率、菌落总数、失重率、可溶性固形物等的影响来评价不同抗菌包装纸箱对草莓的保鲜效果.结果表明:1号、2号、3号百里香精油中百里香酚和香芹酚的峰面积之和的百分数分别为16.03％、27.09％、75.62％;3号百里香精油对4种供试霉菌的抑菌活性强于1号、2号精油;在室温条件下体积分数为4％的3号百里香精油抗菌纸箱可有效降低草莓的腐烂率和菌落总数,也有利于草莓保持较好的感官品质,与对照组相比可延长草莓货架寿命约1～2d.

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.

目的制备一种以肉桂精油柠檬草精油为防腐保鲜剂,聚乙烯醇为基材的抗菌膜,并探索其在常温条件下（温度为（27±2）℃,相对湿度为（40±5）%）对甜樱桃的保鲜效果。方法采用GS-MS分析肉桂精油和柠檬草精油的化学成分,将肉桂精油与柠檬草精油与吐温-80、大豆卵磷脂、玉米淀粉、聚乙烯醇采用刮膜的方式制备成抗菌膜,并测试其针对根霉等4种霉菌的抑菌圈直径;通过测试甜樱桃的感官品质、腐烂率、菌落总数、质量损失率、可溶性固形物含量等指标来评价抗菌膜对甜樱桃的保鲜效果。结果肉桂精油最主要的成分是反式肉桂醛,峰面积比例为83.09%,柠檬草精油的主要成分包括橙花醛（28.45%）、柠檬醛（22.94%）、D-柠檬烯（22.31%）。精油体积分数为3%的抗菌膜对根霉、灰霉、青霉、交链孢霉的抑菌圈直径分别为35,40,80,50 mm,该抗菌膜对甜樱桃表面易造成损伤,反而加速了甜樱桃的腐烂,不利于其保鲜。体积分数为2%的复配精油抗菌膜可有效降低甜樱桃在贮藏期的腐烂率和菌落总数,显著优于其他各处理组（P＜0.05）,并可较好地保持其外观品质,对可溶性固形物含量无明显影响。结论体积分数为2%的肉桂柠檬草复配精油抗菌膜可有效维持甜樱桃的品质,延长其贮藏期3~4 d。

目的 研究一种精油抗菌纸及其对草莓的防腐保鲜效果.方法 从百里香等5种植物精油中筛选出对灰霉等4种微生物具有强抑制作用的精油,并对其成分进行气相色谱-质谱(GC-MS)分析.将筛选出的精油结合聚乙烯醇涂布于纸张表面制得抗菌纸,采用熏蒸法测试其对供试微生物的抑制作用,并研究其对草莓的保鲜效果.结果 百里香精油和丁香罗勒精油对4种供试微生物的抑菌效果较强.百里香精油的主要成分为百里香酚和香芹酚,其峰面积百分比分别为77.04％和16.46％;丁香罗勒精油的主要成分为丁香酚和β-石竹烯,其峰面积百分比分别为77.95％和18.80％.涂布液中精油体积分数为4％的抗菌纸(双层涂布,下同)抑菌效果最强.精油体积分数为3％的抗菌纸抑菌效果次之,但其对维持草莓感官品质、抑制草莓的腐烂、延缓其菌落总数上升具有最佳的效果,显著优于精油体积分数为4％,2％和1％的抗菌纸及原纸(P＜0.05).抗菌纸对草莓可溶性固形物含量无明显影响.结论 体积分数为3％的百里香-丁香罗勒精油抗菌纸对草莓具有较好的保鲜效果.

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.

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 ％.

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.

Citronella essential oil was extracted by ultrasonic pretreatment combined with steam distillation method and the optimization of extraction process was carried out by using central composite response surface methodology (CCD).The growth curve and the gas phase minimum inhibitory concentration of Escherichia coli,as well as the cell structure of E.coli by scanning electron microscopy were studied to quantify the gas phase antibacterial properties of citronella essential oil on food spoilage microorganisms.The results showed that when the concentration of NaC1 solution was 9％,the ratio of liquid to material was 15∶1 (mL/g),distillation time was 170 min,ultrasound power was 420 W and ultrasound time was 65 min,citronella essential oil extraction rate reached the maximum value 2.69％.Citronella essential oil vapor fumigation could inhibit the growth of E.coli and destroy the integrity of cell.Citronella essential oil had good gas phase antibacterial effect on E.coli and other bacterias,and it had a good application prospect in the field of non contact packaging preservation of food.

实验教学示范中心建设是教育部本科质量工程的重要内容.探索了包装工程实验教学示范中心的定位、实验师资队伍建设、实验教学体系建设、专业综合实验教学平台构建、实验教学方法改革,以及取得的教学效果,可为兄弟院校相关专业实验教学教学中心的建设提供借鉴和参考.

The effect of modified atmosphere packaging for strawberry was discussed in this study. The best gas condition was explored to extend the shelf life of strawberry in refrigerated temperature. The 20μm PE film was used to build modified atmosphere packaging. The optimum gas condition for strawberrys modified atmosphere packaging was selected while concerned with the respiration rate, firmness, rot grade, vitamin C content, total soluble solids, titratable acidity, sensory evaluation and other quality indicators respectively. The results suggest that: In 60% O2 + 1.5% CO2 gas condition, it could be kept low rot grade, maintained the firmness, vitamin C content, total soluble solids, titratable acidity content, and sensory evaluation was not falling heavily. As the season in which strawberries were abundant was of high temperature, the effect of preservation was more apparent in 5±1°C. Modified atmosphere packaging discussed above could extend the strawberrys shelf life to 22 days.

The problems of large instrument management in university experimental centers of China were analyzed. Several measures to improve the utilization efficiency of large instruments were proposed based on the situation of packaging engineering experimental center in Tianjin University of Science and Technology, including the purchase planning and assessment system of large instruments, the construction of management platform, management system and experimental technical team, and so on. Benefits from these measures were also discussed.