EVOH-植酸复合活性包装膜对鲈鱼肉的保鲜效果

选用基膜材料乙烯-乙烯醇共聚物（EVOH）,分别掺入0.05%、0.1%、0.2%（质量分数）的植酸,采用双螺杆挤出吹塑法制备得到安全保鲜薄膜,测定其透光率、水蒸气透过系数、雾度及抗拉强度来考察膜的基本性能。在冷藏（4±1）℃条件下使用聚乙烯（Polyethylene,PE）、EVOH及复合膜对鲈鱼肉进行保鲜,并以菌落总数（Total Viable Counts,TVC）、p H值、汁液流失率、挥发性盐基氮（Total Volatile Basic Nitrogen,TVB-N）、硫代巴比妥酸（Thiobarbituric Acid,TBA）以及感官评分作为鲜度指标评价其保鲜效果。与PE膜相比,添加0.2%植酸的复合膜雾度涨幅达到85.43%,透光率及抗拉强度显著下降（P<0.05）。贮藏期间,不同包装膜内样品的TVC、汁液流失率、TVB-N、TBA值均有不同程度的增加,其中PE膜与EVOH膜内样品的TVC值分别于第6、8 d达到不可接受的水平,而植酸的加入能有效的抑制各鲜度指标的增幅;与复合膜组相比,PE膜的鱼肉样品感官劣变更为显著（P<0.05）。综上所述,EVOH复合...     

植物精油-EVOH活性包装膜对草鱼鱼肉保鲜效果的研究

分别以2%葡萄籽精油、2%丁香精油、1%葡萄籽精油＋1%丁香精油为活性成分,乙烯-乙烯醇共聚物为基膜材料,用挤出吹塑法通过共混、吹塑等工艺制备活性保鲜薄膜,考察薄膜的基本性能。在冷藏（4±1） ℃条件下对草鱼鱼肉进行保鲜,并以挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、细菌总数、pH值、硫代巴比妥酸（thiobarbituric acid,TBA）值、持水率以及质构为鲜度指标对保鲜效果进行评价。结果表明：配比为1%葡萄籽精油＋1%丁香精油活性成分制成的活性薄膜对鱼肉具有最佳的保鲜效果,使草鱼鱼肉在（4±1） ℃条件下保鲜达8 d。     

牛至精油涂膜瓦楞纸箱对草莓保鲜效果的研究

将牛至精油与β-环糊精、壳聚糖复配制成复合涂膜液,涂布于瓦楞纸箱内表面制得具有抗菌功能的瓦楞纸箱,研究常温条件下(16～18℃,33%～35%RH)该瓦楞纸箱对草莓的保鲜效果。结果表明:当瓦楞纸箱中牛至精油、β-环糊精与壳聚糖的涂布量分别为1.52、6.4、8 g/m2时,可以较好地维持草莓的外观品质,与空白对照组相比,可以降低草莓腐烂率68.75%,延长草莓贮藏期3 d。     

牛至精油结合不同包装方式对冷鲜羊肉保鲜效果的影响

该文探讨植物精油和包装方式对冷鲜羊肉货架期及其品质的影响。研究采用2×2双因子试验设计,利用牛至精油和不同包装方式结合的保鲜方法研究羊肉在4℃下贮藏0、3、6、9、12 d的质构特性、肉色、pH、过氧化值(peroxide value,POV)、丙二醛(malondialdehyde,MDA)、挥发性盐基氮(total volatile base-nitrogen,TVB-N)及菌落总数(total bacteria count,TBC)的变化。结果表明,冷鲜羊肉贮存至第12天时,牛至精油与真空包装结合组中肉的红度(a^*值)、硬度、弹性、回复性均极显著高于牛至精油和普通包装结合组(P <0. 01),且其黏附性、POV、MDA、TVB-N和TBC在第12天时均极显著低于牛至精油和普通包装结合组中冷鲜羊肉该指标(P <0. 01)。牛至精油与真空包装结合的保鲜方法可使冷鲜羊肉贮藏时间延长至12 d。     

壳聚糖涂膜与牛至精油复配对鲜切菠萝的 保鲜作用

目的研究壳聚糖涂膜及与牛至精油复配对鲜切菠萝的保鲜的影响。方法在低温环境中,按照0.1%、0.3%和0.5%不同浓度的牛至精油与壳聚糖复配,并分别以水、壳聚糖涂膜处理为对照,分析不同处理方式对鲜切菠萝硬度、Vc含量、过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)和脂氧合酶(LOX)活性的影响。结果壳聚糖涂膜与0.5%的牛至精油复配后可减缓组织软化;与0.1%牛至精油复配可以维持Vc含量的缓慢降低。在不同处理组中,当含有0.3%和0.5%牛至精油时,鲜切菠萝的POD和CAT活性则呈下降趋势,而其他处理组则显著升高;当含有壳聚糖处理组时,其PPO和LOX活性则低于对照组。结论壳聚糖与牛至精油复配涂膜会在减缓鲜切菠萝营养损失的情况下延长其货架期。     

牛至精油-白藜芦醇乳液的制备及抑菌活性研究

基于牛至精油具有较强的刺激性气味、白藜芦醇溶解性低,以及二者稳定性差的应用缺陷,构建以酪蛋白酸钠为乳化剂,菊粉和阿拉伯胶为稳定剂,牛至精油为油相并包埋白藜芦醇的乳液;以鼠伤寒沙门氏菌为目标微生物,探讨牛至精油、白藜芦醇、牛至精油-白藜芦醇及其乳液的抑菌效果,以及4,25℃储藏期间抑菌效果的变化,并在鲜切卷心菜中初步应用。结果表明:牛至精油和白藜芦醇对鼠伤寒沙门氏菌有很好的协同抑菌作用;2.0%菊粉/阿拉伯胶可以提高牛至精油-白藜芦醇的抑菌效果;乳液可降低二者的氧化降解速率并保护其生物活性,乳液4℃贮藏20d,25℃贮藏12d后仍有较好的抑制作用。接种鼠伤寒沙门氏菌的鲜切卷心菜在牛至精油-白藜芦醇及其酪蛋白酸钠、酪蛋白酸钠-菊粉/阿拉伯胶乳液中处理1min,8℃储藏4d后菌落数分别降低了1.52,2.04,2.67,2.98lg CFU/g。     

牛至精油微胶囊的制备、表征及在杏贮藏期的抑菌效果

为进一步开发植物精油在果蔬采后抑菌保鲜中的应用,本实验以牛至精油为芯材,以明胶、阿拉伯胶为壁材,采用复凝聚法,通过工艺优化制备了牛至精油微胶囊,并通过扫描电子显微镜、傅里叶变换红外光谱、热重分析和差示扫描量热分析进一步表征了其理化特性和缓释性能,最后评估了不同施用剂量的牛至精油微胶囊在杏果实采后贮藏中的抑菌效果及其对腐...     

大蒜/肉桂精油复配PE膜对双孢菇的保鲜研究

将大蒜精油与肉桂精油以1∶2的比例复配,分别吸取5、10、15、20μL复配精油添加到双孢菇PE膜包装袋中,根据双孢菇保鲜评价指标评价组合包装对双孢菇的保鲜效果。试验结果表明:与单独PE膜包装相比,10μL大蒜/肉桂精油复配PE膜可有效保持双孢菇的感官、Vc含量和总酚含量,降低褐变度,对还原糖含量和失重率影响不大;可将双孢菇的保鲜期延长2d。     

PBAT/EVOH气调薄膜对香菇的保鲜效果评价

以未包装的香菇为对照,探讨添加不同质量分数(0%和10%)的乙烯乙烯醇共聚物(EV(OH)的聚己二酸对苯二甲酸丁二酯(PBAT)/EVOH薄膜对香菇保鲜效果的影响。贮藏条件为温度4℃,相对湿度90%,贮藏期间测定包装内气体组分和香菇相关理化指标。结果表明,PBAT/10%EVOH薄膜能使包装环境形成低氧高二氧化碳的气体环境,较好地维持香菇感官品质,保持较高的色泽、硬度和V_C含量。贮藏14 d仍保持较高的感官品质和营养品质。     

负载山梨酸的壳聚糖微囊-EVOH抗菌薄膜对黑鱼鱼肉保鲜的影响

分别以质量分数3%山梨酸(sorbic acid,S)、3%壳聚糖(chitosan,CS)、3%山梨酸-壳聚糖微囊粉末(sorbic acid-chitosan microcapsules,S-MP)为抗菌物质,以乙烯-聚乙烯醇共聚物(ethylene-vinyl alcohol,EVOH)为基材树脂,通过共混造粒、挤出吹塑等工艺,制备山梨酸-EVOH(S-EVOH)、壳聚糖-EVOH(CSEVOH)、山梨酸-壳聚糖微囊-EVOH(S-MP-EVOH)3种抗菌薄膜,并以对苯二甲酸乙二醇酯(polyethylene terephthalate,PET)薄膜为外层薄膜进行复合,制备出S-EVOH/PET、CS-EVOH/PET、S-MP-EVOH/PET复合薄膜以及纯EVOH/PET,在(4±1)℃对黑鱼鱼块进行冷藏保鲜,通过菌落总数、挥发性盐基氮含量、硫代巴比妥酸值、pH值、汁液流失率、K值和感官评定对抗菌薄膜的保鲜效果进行评价。结果表明,若以菌落总数小于6?(lg(CFU/g))为可食用的标准,在(4±1)℃贮藏环境下,相对于EVOH/PET薄膜,CS-EVOH/PET薄膜能有效延长黑鱼货架期2 d,S-EVOH/PET、S-MP-EVOH/PET两种复合薄膜均能有效延长黑鱼货架期4 d。     

Characterisation and antimicrobial activity of active polypropylene films containing oregano essential oil and Allium extract to be used in packaging for meat products

Cooked ham is more prone to spoilage than other meat products, making preservation a key step in its commercialisation. One of the most promising preservation strategies is the use of active packaging. Oregano essential oil (OEO) and Proallium® (an Allium extract) have previously been shown to be useful in polylactic acid (PLA)-active films for ready-to-eat salads. The present work aims to study the suitability of polypropylene (PP) films containing OEO and Proallium® in the preservation of cooked ham. Concerning the technological features of the studied material, no significant changes in the mechanical or optical properties of PP films containing the active substances were recorded in comparison to the PP film without extracts. However, films containing both active substances were more flexible than the control film and less strong, highlighting the plasticisation effect of the natural extracts. Moreover, physical properties changed when active substances were added to the film. Incorporation of 4% Proallium® affected the transparency of the film to a higher extent compared to 8% OEO, undergoing decreases in transparency of 40% and 45%, respectively. Moreover, only the film containing the highest amount of OEO (8%) significantly decreased the thickness. Both active substances showed antibacterial properties; however, Proallium®-active films seemed to be more effective against Brochothrix thermosphacta than PP films containing OEO, with all percentages of Proallium® killing the bacterial population present in the ham after 60 days. In addition, materials containing the lowest Proallium® content exhibited higher acceptability by consumers in the sensory analyses with 63–100% willing to purchase, better even than the control package (56–89%). In fact, 2% of Proallium® obtained the best results in the odour study performed by the panellists.     

Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging

Consumers’ concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.     

复配精油对粮油中霉菌防治的增效作用及机理研究

开发新型天然防霉剂控制粮食霉变是保障粮食质量安全的重要途径之一。为研究复配植物精油对粮油储藏过程中常见霉菌赭曲霉(Aspergillus ochrator)、黄曲霉(Aspergillus flavus)和黑曲霉(Aspergillus niger)的防霉效果,挑选活性较强的植物精油进行复配并对联合防霉效果进行评价。通过复配植物精油对霉菌孢子萌发、菌丝干重和细胞完整性的影响,对其防霉机理进行初步探究。结果显示,牛至精油对赭曲霉和黑曲霉的防霉效果最好,抑菌圈直径分别为（27.83±0.58 ）、（15.33±0.29）mm,肉桂醛对黄曲霉的防霉效果最好,抑菌圈直径为（18.50±0.87 ）mm;山苍子精油与牛至精油、肉桂醛与牛至精油复配体积比为2：8时对3种霉菌的防霉效果较优;通过对部分抑菌浓度指数判读,两组植物精油复配对黑曲霉和赭曲霉的防治效果为协同作用,对黄曲霉的防治效果为相加作用;山苍子精油与牛至精油按体积比2：8复配可抑制霉菌孢子萌发和菌丝生长、破坏细胞的完整性、改变孢子和菌丝结构;山苍子精油和牛至精油按体积比2：8复配施用于含黄曲霉的玉米上,可有效降低玉米中黄曲霉毒素B1和赭曲霉毒素的含量。本研究为山苍子精油与牛至精油复配作为防霉剂提供理论支持。     

Antioxidant activity of essential oil of oregano species from Argentina in relation to their chemical composition

The purpose of this work was to determine chemical composition and antioxidant activity of essential oil of different oregano species from Argentina: ‘Cordobes’, ‘Criollo’, ‘Mendocino’ and ‘Compacto’. The essential oil composition was determined by gas–liquid chromatography and mass spectrometry. Scavenging activity was analysed by DPPH test. The antioxidant activity of the essential oils was determined by an accelerated oxidation test in canola oil. Thirty‐nine compounds were identified in the oregano essential oils. The oregano species showed differences in their chemical composition, radical scavenging activity and antioxidant activity. The main compounds in the studied oregano species were thymol and trans‐sabinene hydrate followed by γ‐terpinene, terpinen‐4‐ol and α‐terpinene. The oregano, ‘Criollo’, was rich in γ‐terpinene and had lower thymol and trans‐sabinene hydrate and higher α‐terpinene and carvacrol contents than the other oregano species. ‘Mendocino’ had higher trans‐sabinene hydrate and limonene than the other oregano species. ‘Cordobes’ and ‘Compacto’ had higher thymol content, radical scavenging activity and antioxidant activity in canola oil.