Apple,Carrot, and Hibiscus Edible Films Containing the Plant Antimicrobials Carvacrol and Cinnamaldehyde Inactivate Salmonella Newport on Organic Leafy Greens in Sealed Plastic Bags

The objective of this study was to investigate the antimicrobial effects of carvacrol and cinnamaldehyde incorporated into apple, carrot, and hibiscus‐based edible films against Salmonella Newport in bagged organic leafy greens. The leafy greens tested included organic Romaine and Iceberg lettuce, and mature and baby spinach. Each leafy green sample was washed, dip inoculated with S. Newport (10⁷ CFU/mL), and dried. Each sample was put into a Ziploc® bag. Edible films pieces were put into the Ziploc bag and mixed well. The bags were sealed and stored at 4 °C. Samples were taken at days 0, 3, and 7 for enumeration of survivors. On all leafy greens, 3% carvacrol films showed the best bactericidal effects against Salmonella. All 3 types of 3% carvacrol films reduced the Salmonella population by 5 log₁₀ CFU/g at day 0 and 1.5% carvacrol films reduced Salmonella by 1 to 4 log₁₀ CFU/g at day 7. The films with 3% cinnamaldehyde showed 0.5 to 3 log reductions on different leafy greens at day 7. The films with 0.5% and 1.5% cinnamaldehyde and 0.5% carvacrol also showed varied reductions on different types of leafy greens. Edible films were the most effective against Salmonella on Iceberg lettuce. This study demonstrates the potential of edible films incorporated with carvacrol and cinnamaldehyde to inactivate S. Newport on organic leafy greens.     

百里香酚和肉桂醛联用对沙门氏菌的协同抑菌效应及其应用

研究了百里香酚和肉桂醛联用对沙门氏菌的抑菌效果,并将两者作为复配抗菌剂应用于盐焗鸡中以探究其保鲜效果。采用微量稀释法确定了百里香酚和肉桂醛对沙门氏菌的最小抑菌浓度及联合抑菌效果,结果显示百里香酚和肉桂醛的最小抑菌浓度均为0.25 mg/mL、最小杀菌浓度均为0.5 mg/mL;此外,两者联用时的分级抑菌浓度指数为0.75,表明百里香酚和肉桂醛具有较好的协同抑菌效应;该结论同样被时间-杀菌曲线、扫描电子显微镜、PI染色实验的结果所证实,百里香酚和肉桂醛联用可以显著地破坏沙门氏菌细胞膜的完整性,改变细菌形态,从而导致胞内物质泄漏、最终菌体裂解死亡,表明其具有一定的防腐保鲜应用潜力。因此,该研究以盐焗鸡作为食品模型从微生物和脂质氧化两方面探究了百里香酚和肉桂醛的防腐保鲜效果,结果显示百里香酚和肉桂醛联用可以显著地抑制盐焗鸡中细菌的增殖和脂质的氧化,表明百里香酚和肉桂醛联用可以作为一种天然复配抗菌剂应用于盐焗鸡等熟肉制品的保鲜中。     

脲溶液修饰γ-Al_2O_3及其对La_2O_3/γ-Al_2O_3催化肉桂醛MPV反应的影响

采用探针-TPD、探针-IR和电势测量等方法研究不同浓度脲溶液浸泡γ-Al2O3颗粒对γ-Al2O3表面酸碱性质的影响和脲修饰对γ-Al2O3及La2O3/γ-Al2O3催化肉桂醛MPV反应的影响。结果表明,经不同浓度的脲溶液浸泡后,γ-Al2O3表面酸、碱位点强度分布均发生变化,催化肉桂醛MPV反应,生成肉桂醇的选择性随着修饰用脲溶液浓度增加而下降。以脲溶液修饰的γ-Al2O3为载体制备的La2O3/γ-Al2O3催化肉桂醛MPV反应,具有与γ-Al2O3催化该反应类似的变化现象。     

乙醇注入法制备肉桂醛脂质体的工艺优化

目的:确定肉桂醛脂质体的最佳制备工艺条件,得到具有较高包封率和稳定性的肉桂醛脂质体.方法:采用乙醇注入法制备肉桂醛脂质体,考察蛋黄卵磷脂质量浓度、蛋黄卵磷脂与胆固醇质量比、蛋黄卵磷脂与肉桂醛质量比及注射速度对肉桂醛脂质体包封率、粒径、多分散指数的影响,并利用响应面法进行工艺优化.结果:肉桂醛脂质体制备的最佳工艺为蛋黄卵...     

阿斯巴甜衍生物甜味剂的合成研究

在成功合成纽甜的基础上,以肉桂醛与阿斯巴甜为原料制备了3-苯基丙烷衍生物为取代基的阿斯巴甜衍生物甜味剂的模拟化合物,并且依据此合成工艺,以4-甲氧基肉桂醛和阿斯巴甜为原料,制得甜度与纽甜相当的3-(4-甲氧基苯基)-丙基阿斯巴甜,产率为66.0%。此合成工艺简单、产率高,对研究3-苯基丙烷衍生物为取代基的阿斯巴甜衍生物甜味剂的合成具有积极的意义。     

聚乙烯醇/二氧化硅/肉桂醛复合膜的制备及应用

为开发新型食品包装材料,以聚乙烯醇(polyvinyl alcohol,PVA)为基质,添加肉桂醛(cinamaldehyde,CIN)和纳米二氧化硅(n-SiO2)制备复合包装膜(PVA-CIN-Si),研究了该复合膜对樱桃番茄的保鲜效果.采用扫描电镜(scanning electron microscope,SEM...     

Release properties of cinnamaldehyde loaded by montmorillonite in chitosan-based antibacterial food packaging

This work aimed to prepare a controlled-release antibacterial food packaging film by solvent volatilisation using chitosan (CS) and acidified modified montmorillonite (MMt) loaded with CIN (acid-MMt-CIN). MMt was successfully acidified and CIN was successfully loaded into acid-MMt, which had been confirmed by X-ray diffraction. The coordination of acid-MMt-CIN significantly increased the barrier properties of CS film to water vapour, as well as the rigidity and ductility of the film. Furthermore, the CS/acid-MMt-CIN film could significantly improve their UV resistance. It was found that the CIN release time of CS/acid-MMt-CIN film in isooctane (simulated fatty food) could reach 168 h, which was 72 h longer than that of CS/CIN film. The addition of acid-MMt-CIN had a significant inhibitory effect on Staphylococcus aureus and Escherichia coli. In short, CS/acid-MMt-CIN film could potentially be used as an antibacterial active food packaging film.     

Preservation of acidified cucumbers with a combination of fumaric acid and cinnamaldehyde that target lactic acid bacteria and yeasts

The naturally occurring compound, fumaric acid, was evaluated as a potential preservative for the long-term storage of cucumbers. Fumaric acid inhibited growth of lactic acid bacteria (LAB) in an acidified cucumber juice medium model system resembling conditions that could allow preservation of cucumbers in the presence of sodium benzoate. Forty millimolars of fumaric acid were required to inhibit growth of an extremely aciduric Lactobacillus plantarum LA0445 strain at pH 3.8. Half of this concentration was required to achieve inhibition of L. plantarum LA0445 at pH 3.5. As expected growth of the spoilage yeasts Zygosaccharomyces globiformis and Z. bailii was not inhibited by fumaric acid at near saturation concentrations in the same cucumber juice medium. To usefully apply fumaric acid as a preservative in acidified foods it will be necessary to combine it with a food grade yeast inhibitor. The antimicrobial agent, cinnamaldehyde (3.8 mM) prevented growth of Z. globiformis as well as the yeasts that were present on fresh cucumbers. Acidified cucumbers were successfully preserved, as indicated by lack of yeasts or LAB growth and microbial lactic acid or ethanol production by a combination of fumaric acid and cinnamaldehyde during storage at 30 °C for 2 mo. This combination of 2 naturally occurring preservative compounds may serve as an alternative approach to the use of sodium benzoate, potassium sorbate, or sodium metabisulfite for preservation of acidified vegetables without a thermal process. PRACTICAL APPLICATION: This study evaluates the potential application of alternative preservatives for the long-term storage of cucumbers in a reduced NaCl cover brine solution and without a thermal process.     

Antimicrobial edible apple films inactivate antibiotic resistant and susceptible Campylobacter jejuni strains on chicken breast

Abstract: Campylobacter jejuni is the leading cause of bacterial diarrheal illness worldwide. Many strains are now becoming multidrug resistant. Apple‐based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible C. jejuni strains on chicken. Retail chicken breast samples inoculated with D28a and H2a (resistant strains) and A24a (a sensitive strain) were wrapped in apple films containing cinnamaldehyde or carvacrol at 0.5%, 1.5%, and 3% concentrations, and then incubated at 4 or 23 °C for 72 h. Immediately after wrapping and at 72 h, samples were plated for enumeration of viable C. jejuni. The antimicrobial films exhibited dose‐ and temperature‐dependent bactericidal activity against all strains. Films with ≥1.5% cinnamaldehyde reduced populations of all strains to below detection at 23 °C at 72 h. At 4 °C with cinnamaldehyde, reductions were variable for all strains, ranging from 0.2 to 2.5 logs and 1.8 to 6.0 logs at 1.5% and 3.0%, respectively. Films with 3% carvacrol reduced populations of A24a and H2a to below detection, and D28a by 2.4 logs at 23 °C and 72 h. A 0.5‐log reduction was observed for both A24a and D28a, and 0.9 logs for H2a at 4 °C at 3% carvacrol. Reductions ranged from 1.1 to 1.9 logs and 0.4 to 1.2 logs with 1.5% and 0.5% carvacrol at 23 °C, respectively. The films with cinnamaldehyde were more effective than carvacrol films. Reductions at 23 °C were greater than those at 4 °C. Our results showed that antimicrobial apple films have the potential to reduce C. jejuni on chicken and therefore, the risk of campylobacteriosis. Possible mechanisms of antimicrobial effects are discussed. Practical Application: Apple antimicrobial films could potentially be used in retail food packaging to reduce C. jejuni commonly present on food.