气调包装联合保鲜剂对‘塞外红’苹果中短期贮藏的影响

目的 探究不同贮藏温度、气调包装及保鲜剂对‘塞外红’苹果贮藏品质的影响。方法 采用冷藏、气调包装(O2与CO2的体积比为5∶1)以及复合保鲜剂(1-甲基环丙烯、CaCl2、甜菜碱)等处理方式，对新鲜采摘的‘塞外红’苹果进行60 d的贮藏实验，分析贮藏期间苹果的质构特性、呼吸强度、外观品质、褐变指数、可滴定酸含量、可溶性固形物含量、抗坏血酸含量、相对电导率、丙二醛含量的变化。结果 在贮藏温度0.5 ℃下，采用气调包装结合保鲜剂处理能够有效抑制‘塞外红’苹果的褐变指数、丙二醛含量和相对电导率的增加。与单独进行0.5 ℃冷藏处理相比，经过60 d贮藏，处理后苹果的褐变指数、丙二醛含量和相对电导率分别降低了42%、66%、14%。同时，该处理方式延缓了‘塞外红’苹果质构特性的下降，降低了果实的呼吸强度，并保持了较高的抗坏血酸、可溶性固形物和可滴定酸等含量。结论 在0.5 ℃下冷藏并配合气调包装和外源保鲜剂处理可以有效地抑制‘塞外红’苹果的细胞损伤和营养物质的损失，延缓苹果品质的恶化进程。     

鲜切香芋不同包装处理的贮藏效果及其生化变化

以粤北北乡香芋为试材,研究鲜切香芋在不同包装材料下的贮藏效果及生化变化.结果表明,在4℃贮藏温度下,与对照(普通塑料薄膜包装)、聚乙烯塑料薄膜(PE)包装相比,贮藏的前12天,真空包装(VP)能较好地保持鲜切香芋的可溶性固形物含量(TSS)和淀粉含量,褐变度、丙二醛(MDA)含量和多酚氧化酶的活性较低,而超氧化物歧化酶活性较高.随着贮藏时间延长,聚氯乙烯塑料薄膜(PVC)包装的鲜切芋头,酚类物质含量及丙二醛(MDA)含量低于其他包装,超氧化物歧化酶(SOD)活性最高,TSS和淀粉含量、多酚氧化酶(PPO)活性与VP处理的接近.总体看来,VP处理适合鲜切芋头的短期低温贮藏,PVC包装适合鲜切芋头的较长期贮藏.     

乙醇复合抗坏血酸处理对鲜切苹果贮藏品质的影响

目的 为了研究乙醇处理对鲜切苹果贮藏品质的保鲜效果。方法 以鲜切‘寒富’苹果为材料,比较乙醇、乙醇复合抗坏血酸（Vc）溶液处理对鲜切苹果在4 ℃下贮藏品质的影响。分析鲜切苹果包装内的气体成分变化、可溶性固形物含量、硬度、颜色、质量损失率等品质指标,还对组织衰老进程、酚类物质代谢和活性氧代谢及微生物数量进行评价。结果 研究表明,体积分数为30%的乙醇溶液浸泡鲜切苹果能有效保持冷藏货架期间果实的硬度、可溶性固形物含量、较低的质量损失率,延缓果实组织表面颜色变化和褐变的发生;进一步研究显示,乙醇可能是通过抑制酚类物质的氧化分解,从而减少了醌类物质在组织中的积累;乙醇处理还有利于抑制果实组织中电导率的升高,此外经乙醇处理后,大肠菌群和菌落总数均显著小于对照组和复合处理组中的数量。结论 采用乙醇处理鲜切‘寒富’苹果,有利于保持果实的品质,并延缓衰老和褐变进程,从而延长了货架期。     

低压静电场结合包装对采后樱桃番茄品质的影响

目的 研究常温环境下低压静电场(Low Voltage Electrostatic Filed,LVEF)结合不同商业包装处理对樱桃番茄果实贮藏品质的影响,探索基于LVEF处理的樱桃番茄采后常温货架期间适宜的商业包装方式。方法 待测樱桃番茄随机分为LVEF处理组、LVEF+PP组、LVEF+PET组和无任何处理的对照组,在温度为(23±1)℃和相对湿度为75%的同一培养箱中储存16 d,LVEF处理在整个储存期内持续进行,定期测定樱桃番茄在贮藏期间的品质变化。结果 LVEF处理能抑制质量损失率和丙二醛含量的上升,同时减缓亮度、硬度、可溶性固形物、可滴定酸、抗坏血酸和番茄红素含量的下降。在LVEF贮藏环境下,PET包装在采后樱桃番茄的质量、硬度、色度、可溶性固形物和抗坏血酸等质量指标方面优于PP包装和未包装的樱桃番茄。结论 LVEF处理对采后樱桃番茄有一定保鲜效果,且在LVEF贮藏环境下,PET包装樱桃番茄比PP包装的保鲜效果更好。     

高阻隔HDPE包装对NFC橙汁品质和货架期的影响

目的 研究高阻隔HDPE包装对NFC橙汁品质和货架期的影响,为果汁生产加工企业提供信息和参考.方法 采用巴氏杀菌法对NFC橙汁进行灭菌处理,研究在4,25,37℃时PET包装、普通HDPE包装、高阻隔HDPE包装的NFC橙汁各项指标的变化情况,通过对抗坏血酸和整体接受度的结果分析,建立NFC橙汁的动力学模型,利用阿伦尼乌斯方程对其货架期进行预测.结果 高阻隔HDPE包装相较于其他2种包装的NFC橙汁褐变小、抗坏血酸和胡萝卜素损失少、喜好度高.以抗坏血酸含量损失50％为标准,温度为4,25,37℃时的货架期分别为152,55,31 d;以整体接受度5分为标准,温度为4,25,37℃时的货架期分别为183,44,21 d.结论 高阻隔HDPE包装可以有效地延长NFC橙汁的保质期,并保证其在保质期内的品质,在NFC果汁中有很好的应用前景.     

魔芋葡甘露聚糖/纳米ZnO复合涂膜对香蕉常温保鲜效果的影响

目的探讨魔芋葡甘露聚糖/纳米ZnO复合涂膜对常温贮藏香蕉保鲜效果的影响,为香蕉的采后常温保鲜贮藏提供新途径。方法以巴西蕉为实验材料,采用KGM涂膜液(A组)和KGM/纳米ZnO复合涂膜液(B组)等2种可食性涂膜液对香蕉进行涂膜处理,以不做任何处理为对照(CK组),置于夏季常温(32±2)℃下贮藏,每天取样测定果实的好果率、褐变指数、质量损失率、可溶性固形物含量、Vc含量等指标。结果在整个贮藏期间,与KGM涂膜和对照组相比,KGM/纳米ZnO复合膜能显著维持香蕉的好果率,抑制香蕉的褐变,降低香蕉在贮藏期的质量损失率,减少可溶性固形物和维生素C等营养物质的损失。结论 KGM/纳米ZnO复合涂膜液对采后香蕉的常温贮藏效果最好,能够维持香蕉较好的贮藏品质。     

四种低温储藏条件对橙汁品质的影响研究

研究了巴杀橙汁在较高温冷藏环境(8℃)、较低温冷藏环境(4℃)、冰温(-2℃)以及冻藏(-20℃)四种不同温度下储藏五周的品质变化规律。结果表明:与其他储藏温度相比,冰温条件下储藏的橙汁在可溶性物、挥发性风味物质等与风味相关的指标上更具优势,也就是该条件下储藏的橙汁的风味品质更优。在维生素C的保存方面,冻藏则更具优势。8℃储藏条件下的橙汁在品质上劣于其他三种储藏温度。1)冰温条件下,储藏期间橙汁的可溶性固形物变化最小;检测出的挥发性风味物质种类最多,其中萜烯类、醇类种类最多,醇类和酯类的相对含量最高。2)冻藏条件下,第五周时VC含量最高;检测出的挥发性风味物质中,醛类的相对含量也最高。3)冷藏条件下,较高储藏温度的果汁的可溶性固形物含量变幅较大;检测出的挥发性风味物质中,化合物总数最少,但烯萜类组分的相对含量最高,重要风味贡献物月桂烯、里那醇和柠檬醛的相对含量最低。4)各储藏条件下,橙汁的总酸、pH值和色度的变化差异不显著。     

充氮包装下榛子品质变化的动力学建模

探索了不同包装方式对榛子品质变化的影响,结果表明充氮包装保鲜效果最好。建立了充氮包装下酸价、过氧化值随贮藏温度和时间变化的动力学模型,以控制榛子在贮藏过程中的品质和货架期。结果表明,随着贮藏时间的延长和贮藏温度的升高,榛子的酸价和过氧化值不断增加,普通包装增加最快,充氮包装由于良好的保鲜性能而增长较慢。酸价、过氧化值对一级化学反应模型和Arrhenius方程具有很高的拟合精度。     

胺基载体选择性渗透膜对西兰花品质的影响

目的研究自制胺基载体选择性渗透膜对西兰花品质的影响。方法以自制选择性渗透膜为包装材料,纯LDPE薄膜处理、硅藻土改性基膜处理、自然放置为对照,于室温密封储存,定期测定各种包装材料内西兰花的品质变化。根据贮存期间各包装材料内西兰花的质量损失率、色差、可溶性固形物含量、硬度、褐变度、维生素C含量等各项指标的变化来评价所制备选择性渗透膜的保鲜性能。结果贮存9 d后,自制选择性渗透膜包装内西兰花的质量损失率、色差、可溶性固形物含量、硬度、褐变度、维生素C含量等指标均高于纯LDPE薄膜、基膜和自然放置对照组,但褐变度低于对照组。结论自制选择性渗透膜能够通过调节包装中CO_2和O_2的选择性渗透,有效控制果蔬呼吸速率,以达到延长储存期的目的。     

自然气调包装对采后猕猴桃保鲜效果和品质的影响

基于自然气调包装技术,提出了一种复合保鲜纸箱包装采后"海沃德"猕猴桃。通过3种保鲜贮藏条件下果品的外观质量、硬度、失重量、可溶性固形物、维生素C、薄片细胞结构的变化情况,验证其包装的有效性。实验结果表明:这种纸箱包装保鲜贮藏技术对"海沃德"猕猴桃的保鲜贮藏是有效的;在温度为5℃,相对湿度60%环境下的保鲜包装猕猴桃,保鲜贮藏期可达60 d,有利于采后猕猴桃在非冷库、非气调库中的保鲜贮运。     

不同采收成熟度盖县李果实贮藏品质的综合评价

目的探讨不同成熟度盖县李果实的低温(温度±0.5℃,相对湿度80%~90%)贮藏品质,以及各指标与李果实贮藏品质关系的综合评价方法。方法以盖县李果实为材料,采用多变量分析方法研究贮藏过程中李果实硬度、可溶性固形物(SSC)、p H值、可滴定酸、失重率、出汁率、褐变度、总酚等指标的变化规律。利用主成分分析法等多变量分析方法,综合评价各指标间的相互关系,以及对李果实贮藏品质的影响。结果褐变是影响李果实低温贮藏品质较大的劣变因子,它与果实p H值存在显著正相关关系;其次是SSC和可滴定酸,它们作为内在品质因子对果实食用品质和风味特征起着重要作用。通过主成分分析构建的综合评价模型可知,高熟李果实综合得分在采收时最大;低熟、中熟盖县李果实采后品质均呈现先上升后下降的趋势,在贮藏2~4周时综合品质达到最佳,在贮藏10周时果实失水及褐变严重,失去食用价值。结论通过多变量分析方法综合分析了不同成熟度盖县李果实低温贮藏品质的变化情况及影响因素,明确了其合理的贮藏期限。     

Quality Changes of Extra Virgin Olive Oil Packaged in Coloured Polyethylene Terephthalate Bottles Stored Under Different Lighting Conditions

In this paper, the influence of light storage and the exposure on quality parameters of a monovarietal extra virgin olive oil packaged in polyethylene terephthalate (PET) bottles were investigated. Coloured PET bottles (clear, green, orange, white and blue) were stored under different artificial lighting conditions in order to simulate the market environment (one fluorescent cool white lamp) and to perform an accelerated test (four fluorescent cool white lamps); storage in the dark was considered as a control. Total peroxide value, polyphenols, chlorophyll and carotenoids contents were, among the ones tested, the quality indexes most affected by lighting and were useful to investigate the bottle colour influence. Concerning the global quality of olive oil, under one fluorescent lamp, the best performances were obtained using blue and white PET bottles; whereas under accelerated conditions, the differences in the protection efficacy offered by the differently coloured bottles were reduced. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of packaging materials and storage conditions on bacterial growth,off‐odour,pH and colour in chicken breast fillets

A comparison was made of the effect of different packaging materials on bacterial growth, off‐odour, pH and colour of chicken breast fillets stored at 4°C. For one of the packaging materials, the effects of temperature (4°C and 8°C) and initial oxygen present (0%, 2% and 4%) on bacterial growth, off‐odour, pH and colour in chicken breast fillets were also evaluated. Chicken breast fillets stored in the packaging material with the highest oxygen transmission rate (OTR) measured at actual storage conditions had the highest bacterial growth and the highest degree of off‐odour. Chicken breast fillets stored in packaging material mainly consisting of expanded PET had similar bacterial growth and off‐odour as in the barrier display film (BDF) packages, despite a smaller headspace volume and lower initial concentration of CO₂. No differences in discoloration and pH of the chicken breast fillets, due to storage temperature and amount of initial oxygen present, were found when one of the packaging materials was studied. In the early phase of the storage period, Pseudomonas spp. constituted the majority of the total viable counts, while after about 12 days, lactic acid bacteria dominated. At the end of the storage period, both Pseudomonas spp. and Enterobacteriaceae were present in high numbers. Significant differences in counts of Brochothrix thermosphacta were only obtained with initial presence of oxygen. The storage temperature had greater impact on microbial growth and off‐odour than the initial presence of oxygen in the packages. Copyright © 2004 John Wiley & Sons, Ltd.     

气调包装对黄藤笋贮藏品质的影响

为了延长黄藤笋的货架期,采用3种不同体积分数配比的气体对黄藤笋进行包装处理,于8℃下贮藏,定期测定黄藤笋的硬度、细胞膜的透性以及可溶性固形物(TSS)、VC、纤维素、总酚和丙二醛(MDA)的含量等指标。结果表明,气调包装能较好保持黄藤笋的硬度和细胞膜的透性,减少TSS和VC的损失,延缓纤维素和总酚含量的上升,抑制MDA的生成,延长保质期。其中,以体积分数为3%O2+5%CO2+92%N2的气体配比,贮藏效果最好。     

永定红柿最适贮藏温度研究

柿果在常温贮藏过程中容易软化、褐变和腐烂,食用品质受到很大影响。因此本文主要研究了柿子的最适贮藏温度,旨在探明低温贮藏对柿子食用品质的影响。研究结果如下,以柿果感观品质、呼吸强度、可溶性糖含量、Vc含量、失重率、可滴定酸含量为考核指标,探讨了贮藏温度与柿果贮藏品质的关系。结果表明：在0℃-2℃下贮藏的柿子能够保持良好的色泽和较高硬度,呼吸强度、失重率较低,可溶性糖含量、Vc含量、可滴定酸等营养成分保持得较好。     

Migration of Aluminum and Silicon from PET/Clay Nanocomposite Bottles into Acidic Food Simulant

Poly(ethylene terephthalate) (PET)/clay nanocomposite samples were prepared by melt blending PET and Cloisite 20A nanoparticles. A stretch blow‐moulding machine was used to produce bottles from neat PET and PET nanocomposite. Tests were performed on the migration of aluminum and silicon from PET nanocomposite bottles into acidic food simulant. The samples were stored at room temperature (about 25°C) and 45°C for time durations ranging from 7 to 90 days. A specific surface of sheets (prepared from PET/clay nanocomposite) immersed in acidic food simulant, and two‐sided migration of Al and Si was investigated. According to X‐ray diffraction analysis, the nanoclays show intercalated structure in the PET matrix. Transmission electron microscopy and atomic force microscopy micrographs displayed both intercalation and exfoliation morphology for PET/clay nanocomposites. Inductively coupled plasma was used to quantify amounts of Al and Si that had migrated into the acidic food simulant. It was observed that the migration process is dependent on storage time and temperature, and the molar ratio of aluminum and silicon in the acidic aqueous solution (Al/Si)_aq to the ratio in the solid phase of prepared nanocomposites (Al/Si)_solid was about 23% higher in the samples stored at 45°C. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of package light transmittance on the vitamin content of milk,part 3: Fortified UHT low‐fat milk

This work is the third and last part of a milk study evaluating the effect of package light transmittance on the vitamin content of milk, in this case on fortified UHT low‐fat milk. The milk was stored under light with an intensity of 700 lux in polyethylene terephthalate (PET) bottles with varying light transmittance to monitor the changes in the vitamin A, B₂ and D₃ contents over a storage period of 12 weeks at 23°C. Milk packed in pigmented PET bottles with the lowest light transmittance, which was stored in the dark under the same experimental conditions, served as the ‘control’ sample. In clear PET bottles, a reduction of 93% of the initial content was observed for vitamin A and 66% for vitamin D₃, while the vitamin B₂ content was completely degraded. In all pigmented PET bottles, the vitamin retention was only slightly higher; the losses ranged between 70 and 90% for vitamin A, between 63 and 95% for vitamin B₂, and between 35 and 65% for vitamin D₃ depending on the pigmentation level. In the dark‐stored ‘control’ sample, a 16% loss could be observed for vitamin A, while the level of vitamins B₂ and D₃ remained almost stable. Copyright © 2008 John Wiley & Sons, Ltd.     

不同包装容器对劲酒品质的影响

目的 研究包装容器对酒体品质的影响因素,为劲酒包装容器的选择提供科学的数据支撑。方法 采用光学透过率测试仪对不同包装容器的透光率进行了测定,并对贮存2年的劲酒的总黄酮含量、总皂苷含量、色率、淫羊藿苷含量、口感进行分析,数据分析的方法为随机区组设计资料的方差分析。结果 无色玻璃瓶、PET瓶透光率高达90%以上,深色瓶、涂漆瓶、陶瓷瓶、不锈钢瓶透光率均极小。总体来说高硼硅玻璃瓶和PET瓶储存的劲酒均有不同程度的颜色变浅,总黄酮、总皂苷含量降低,口感变差,其他容器储存的酒体之间没有明显差异,且它的总体品质要高于高硼硅玻璃瓶和PET瓶储存酒体的总体品质。结论 包装容器的透光性会对劲酒的品质产生影响,避光包装容器可能更适合劲酒的储存,避光容器的材质和形状对劲酒品质基本没有影响;对于透光性容器,容器形状可能影响劲酒品质,相较于圆柱型的包装容器,扁平型的可能更能保护劲酒品质。