Modified Atmosphere Packaging of Guava Fruit

Fully matured fresh guava fruits (Lucknow‐49) were precooled at 10 °C for 1 h and pretreated with 500‐ppm benomyl for 5 min. The fruits were packed in 25‐µm and 50‐µm LDPE bags with active modified atmosphere packaging of 3% O₂ + 5% CO₂, 6% O₂ + 5% CO₂ and 9% O₂ + 5% CO₂ gas concentrations and stored at 5 ± 1 °C and 10 ± 1 °C temperatures as well as non‐packaged as control. The shelf life of guava could be increased up to 42 days by packaging in 50‐µm LDPE bags with a gas concentration of 9% O₂ + 5% CO₂ and stored at 10 °C without much change in physical, biochemical and sensory characteristics. Physico‐chemical changes viz., PLW, pulp to peel ratio, firmness, TSS, total sugar, ascorbic acid and titratable acidity were observed minimum for fruits packed in 50‐µm LDPE bags at 3% O₂ + 5% CO₂ gas concentration at 5 °C storage temperature, but sensory score decreased drastically after 21 days of storage. Chilling injury was observed for the fruits packed at 5 °C storage temperature after 21 days of storage, and it was severe in 25‐µm LDPE bag at later stage. Control fruits over‐ripened with the highest weight loss (12.47%) on 6 days of storage and discarded from the storage. Copyright © 2014 John Wiley & Sons, Ltd.     

Use of Sodium Lactate and Modified Atmosphere Packaging for Extending the Shelf Life of Ready‐to‐Cook Fresh Meal

In this work, the combined effects of sodium lactate and modified atmosphere packaging (MAP) in extending the shelf life of a ready‐to‐cook fresh skewer, made up of raw pork chops and semi‐dried vegetable mix (i.e. zucchini, peppers and tomatoes), were investigated. In the first experimental step, a sodium lactate solution was used to dip pork chops at three different concentrations: 20, 40 and 60% w/w. The second part of the work was focused on the use of MAP. In particular, the following MAPs were tested: MA1 (50%O₂/30%CO₂/20%N₂), MA2 (70%O₂/30%CO₂), MA3 (30%O₂/70%CO₂) and MA4 (30%O₂/30%CO₂/40%N₂). Finally, the optimal concentration of sodium lactate and the best gas composition were combined. The samples were stored at 4 °C; their microbial and sensory qualities were monitored along the entire observation period. The results indicate that the shelf life of the investigated ready‐to‐cook meal can be extended by approximately 83%, if compared with the control skewer packaged in air. The best preservation strategy is the combination of dipping of meat pieces in 40% sodium lactate solution and packaging under MA1. Copyright © 2014 John Wiley & Sons, Ltd.     

自然气调包装对采后苹果蒸腾作用的影响

基于自然气调包装技术设计了一种包装箱,通过对比实验,研究了自然气调包装对采后苹果蒸腾作用的影响规律,建立了自然气调包装苹果的蒸腾作用模型和参数。实验结果和数值分析表明,采用瓦楞纸箱和聚酯镀铝薄膜的自然气调包装技术,可使得采后苹果的蒸腾速率逐渐减小,最后趋于平衡,而且当自然气调包装内环境的相对湿度大于90%时,采后苹果的蒸腾作用可得到较大程度的抑制。     

气调包装对鲜切猕猴桃和木瓜贮藏品质的影响

采用以托盘盛装、上覆 PP 塑料薄膜的形式,对鲜切猕猴桃和木瓜组合拼盘进行了气调包装。 在 5 ℃ ,相对湿度 90% 的环境下,研究了 MAP1(3% O2 ,8% CO2 ,89% N2 )、MAP2(70% O2 ,30% N2 )、MAP3(80% O2 ,20%N2)3 组气调包装对鲜切猕猴桃和木瓜切面颜色、硬度、可溶性固形物含量、可滴定酸及 Vc 含量等指标的影响,并与空白组进行了对比。 结果表明,70% ~ 80% 的高氧条件对鲜切木瓜和猕猴獭娲盘保鲜效果最好,并且延长了它们的货架寿命。     

包装材料对酱牛肉品质及保鲜期的影响

目的在常温下(15~20℃),为了延长酱牛肉的保鲜期,探讨6种不同的包装材料(PE塑料袋、PE/PP塑料袋、PET/AL/PE复合袋、PP塑料保鲜盒、玻璃保鲜盒和陶瓷保鲜盒)对酱牛肉保鲜期的影响。方法采用不同的包装材料对酱牛肉进行包装,以感官特性、理化性能、微生物为评价指标,比较不同包装材料的差异。结果各组的感官特性均呈下降趋势,采用PET/AL/PE复合袋和玻璃保鲜盒包装的牛肉感官特性值下降稍慢,可保持新鲜4 d;TVB-N值、TBARS值和菌落总数整体呈上升趋势,其中PET/AL/PE复合袋、玻璃保鲜盒以及陶瓷保鲜盒包装的这3个指标上升趋势较慢,可保持新鲜4~5 d。结论保鲜效果优劣顺序为PET/AL/PE复合袋玻璃保鲜盒陶瓷保鲜盒PP保鲜盒PE/PP塑料袋PE塑料袋组不包装组。     

高氧气调包装对金针菇保鲜品质的影响

研究了不同气体配比条件对金针菇保鲜效果的影响。 分别用 3% O2 +97% N2 ,80% O2 +20% N2 ,80% O2 +10% N2 +10% CO2 ,80% O2 +20% CO2 气体配比充气包装金针菇,空气包装为对照组。 评定其水分损失率、呼吸强度、色差、相对电导率、多酚氧化酶(PPO)、过氧化物酶(POD)和感官指标等。 结果表明,80% O2 +20% CO2 组水分损失、颜色变化最少,PPO 酶活力、呼吸强度最低,POD 酶活力较高,感官变化最小,贮藏保鲜效果好。     

Production and Application of Active Packaging Film with Ethylene Adsorber to Increase the Shelf Life of Broccoli (Brassica oleracea L. var. Italica)

Broccoli (Brassica oleracea L. var. Italica) florets were packaged in low‐density polyethylene (LDPE) bags with or without ethylene adsorber under passive modified atmosphere and then stored at 4°C for 20 days. LDPE films with (8% Tazetut® masterbatch, M2) or without ethylene adsorber (M1) were tested. The effects of modified atmosphere packaging treatments on gas concentrations (O₂, CO₂ and ethylene) in the headspace, the mass loss, colour, texture, pH, total soluble solids, chlorophyll content, total phenolic content and sensory quality of packaged broccoli were determined by comparing with unpackaged (control) florets. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by mass loss, chlorophyll degradation and stem hardening. Also, it was found unacceptable by sensory panel after 5 days. Conversely, in those florets packaged under modified atmosphere packaging, especially for LDPE with ethylene adsorber (M2), all changes related with loss of quality were significantly reduced and delayed with time. Additionally, total soluble solids and total phenolic content remained almost unchanged during the whole period. Ethylene concentration was determined as 61.8 ppm in M1 and 0.33 ppm in M2, respectively, at the end of the storage. Thus, broccoli packaged with M2 films had prolonged storability up to 20 days with high quality attributes, this period being only 5 days in unpackaged control broccoli. Oxygen concentration decreased below 1% after 5 days of storage in M1, and the shelf life of broccoli in these bags was limited to 5 days because of risk for anaerobic fermentation. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of Different Packaging Methods on Quality and Shelf Life of Fresh Reindeer Meat

The impact of different packaging methods [vacuum, modified atmosphere packaging (MAP) (60% CO₂ and 40% N₂) and MAP + CO₂ emitter] on the quality of fresh reindeer meat (M. semimembranosus) stored at 4°C for 21 days was investigated. Colour and odour of the meat, drip loss, pH, microbial content, antioxidant capacity and cooking loss were measured. The MAP + CO₂ emitter resulted in prolonged microbial shelf life compared with vacuum and MAP without CO₂ emitter as lower level of total viable counts was detected after 13 and 17 days. Samples stored with CO₂ emitter also had lower drip loss. Samples stored in vacuum had significant lower L*‐value, higher a*‐value and lower intensity of freshness (odour and colour) compared with those stored in MAP and MAP with CO₂ emitter. However, MAP with a gas‐to‐product volume ratio of 1 : 1 seems to be too low in quality preserving. Increased partial pressure by adding a CO₂ emitter improved bacterial inhibition compared with vacuum and traditional MAP. Copyright © 2014 John Wiley & Sons, Ltd.     

Quality Evaluation of Grated Graviera Cheese Stored at 4 and 12°C using Active and Modified Atmosphere Packaging

The effect of active [oxygen absorber (OA) combined with an ethanol emitter (EE)] and modified atmosphere (100% Nitrogen) packaging in combination with a high barrier experimental polyethylene terephthalate‐silicon oxides//low density polyethelene film on shelf‐life extension of grated Graviera cheese stored at 4 and 12°C was investigated. Microbiological (total viable counts, Pseudomonads, lactic acid bacteria, Enterobacteriaceae and Yeasts/Moulds), physico‐chemical (pH, thiobarbituric acid and colour) and sensory (odour and taste) changes occurring in the product were monitored as a function of treatment and storage time (10 weeks). Sensory shelf‐life was approximately 1, 1.5, 4.5, 6, 9 and at least 10 weeks for control samples (12 and 4°C), for N2 packaged samples (12 and 4°C) and samples packaged with the OA + EE (12 and 4°C), respectively. At the point of sensory rejection, yeasts and moulds increased from 2.00 to 3.60 and 5.55 log CFU/g for control samples stored at 4 and 12°C, respectively. Similarly, for samples stored under nitrogen, yeasts and moulds reached 2.00 and 2.32 log CFU/g at 4 and 12°C, respectively. Yeasts and moulds in samples with the OA + EE remained below 2 log CFU/g throughout the entire storage period, irrespective of storage temperature. pH varied between 5.72 and 6.49 depending on specific treatment. Malondialdehyde absorbance ranged between 0.05 for fresh samples and 0.79 mg/kg at the time of sensory rejection of samples. Light parameters L and b decreased while parameter a increased during storage, reflecting a gradual discolouration of all samples and especially those stored at 12°C.     

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.     

气调包装对软枣猕猴桃品质的影响

目的 研究自发气调处理对采后软枣猕猴桃果实品质的影响。方法 将软枣猕猴桃置于塑料气调箱内,气调处理组果实放入气调箱封盖处理,对照组进行不封盖处理,于4 ℃下贮藏64 d,每16 d对软枣猕猴桃呼吸代谢及抗性相关指标进行测定,即气调箱内CO2和O2含量,可溶性固形物（TSS）、丙二醛（MDA）、总酚含量,及抗氧化相关酶活性等指标。结果 自发气调处理能够使CO2和O2含量维持在适宜的贮藏范围内,从而保持较高的TSS和总酚含量,抑制MDA含量及多酚氧化酶（PPO）活性,增强过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）和过氧化氢酶（CAT）活性。结论 贮藏48~64 d,自发气调处理软枣猕猴桃的最适宜气体环境为体积分数3%左右的CO2和体积分数16%左右的O2,保持了软枣猕猴桃较好品质的机制,通过诱导果实的苯丙烷及抗氧化代谢实现。     

气调保鲜包装技术的应用

气调保鲜包装是针对真空包装和高温灭菌等传统包装方法带来的不足而研发的新型包装技术.介绍了气调保鲜包装技术的基本原理以及在食品和果蔬等产品包装中的应用,探讨了其保鲜包装方法和特点.     

气调保鲜包装对双孢菇贮藏效果的影响

为保持双孢菇贮藏品质、延长货架期,采用不同配比的气体吸收剂和不同厚度聚乙烯薄膜对双孢菇进行包装,置于4℃下贮藏,定期测定双孢菇的表面颜色、呼吸强度、失重率、硬度、PPO和POD活性的变化。结果表明:采用组成为1.44 g脱氧剂、0.5 g乙烯脱除剂、1.2 g CO2脱除剂的气体吸收剂及厚度为0.05 mm的聚乙烯薄膜包装方案,对双孢菇贮藏中的褐变具有明显的抑制作用,能够有效降低双孢蘑菇呼吸强度,延长双孢菇的贮藏保鲜期。     

烟草包装中的裂缝面积与保存期

根据烟草包装的保存期与裂缝面积的关系曲线,定义了临界裂缝面积.并讨论了影响临界裂缝面积的因素.     

盒式气调包装下温度对薄膜透气性能的影响

以高阻隔膜、双层膜、聚丙烯(PP)膜及双向拉伸聚丙烯(BOPP)膜为材料,采用小袋法,分析了盒式气调包装下,各薄膜在4,10,25,30℃温度下的薄膜透气系数和透气系数比的变化规律。结果表明:随着温度的升高,4种薄膜的透气系数都呈上升趋势;同时,高阻隔膜和双层膜的透气系数比显著降低,而BOPP膜和PP膜的透气系数比则逐渐升高。同一温度条件下,PP膜的透气性能最好,BOPP膜次之,双层膜和高阻隔膜的透气性能较低。试验中,透气系数的自然对数与绝对温度的倒数满足阿累尼乌斯方程,以此可求得不同薄膜材料在其他温度下的透气系数。     

烟草包装裂缝大小对保存期影响的处理

烟草包装中存在裂缝,会影响防潮功能.讨论了不同大小的裂缝面积时,烟草保存期的不同计算方法.     

菠菜常温气调包装研究

为在常温下保持菠菜的品质,延长其货架期,研究了气调包装对菠菜的保鲜效果。采用4种不同的配比的O2,CO2,N2混合气体对菠菜进行包装,置于常温下贮藏,定期间隔2d检测菠菜的失重率、呼吸速率、VC含量、叶绿素含量及感官指标的变化情况。实验结果表明:在常温下,当混合气体体积分数配比为10%O2+10%CO2+80%N2时,菠菜的保鲜效果较好,在此条件下菠菜的货架寿命可达8d。     

动力学理论预测食品包装货架寿命模型的研究

探讨了不同反应级数的食品品质函数的形式及其确定方法,总结了5种以食品品质损失动力学模型为基础的食品货架寿命预测的研究方法,即Arrhenius方程、WLF方程、Q10模型、Z值模型法和WHA方法。     

包装材料对樱桃番茄气调保鲜效果的影响

目的探究包装材料的阻隔性对樱桃番茄的气调保鲜效果。方法选择EHA/PE(乙烯乙烯醇共聚物、聚酰胺/聚乙烯复合膜)、PA/PE(聚酰胺/聚乙烯复合膜)、PE(聚乙烯膜)等3种薄膜气调包装樱桃番茄后于(23±2)℃温度下贮藏,无包装的樱桃番茄在同样条件下作为空白对照。定期检测包装袋内气体组分变化及感官、硬度、可溶性固形物含量、维生素C的变化情况。结果 PE组在整个贮藏过程中CO_2体积分数在5%左右,O_2的体积分数在6%~16%范围内波动,樱桃番茄处于低O_2高CO_2环境中,呼吸受到抑制,具有24 d的保鲜期。PA/PE膜、EHA/PE膜包装的樱桃番茄呼吸产生的CO_2及空气中的O_2无法透过包装膜,包装中O_2含量在第3天时便已为0,CO_2在第6天时达到30%以上,樱桃番茄处于高浓度CO_2中加速了组织腐烂,同时空白组的樱桃番茄呼吸强度和水分流失不受抑制,因此,贮藏期只有18 d。结论适宜阻隔性的材料气调包装保鲜樱桃番茄,可明显延长其保鲜期。