联合气调包装贮藏草莓实验研究

本实验采用冷藏条件下联合自发气调包装(CMP)方式对贮藏草莓进行了研究,贮藏15d的实验结果表明,与纯冷藏相比,联合气调包装保鲜方式可以有效降低采后草莓的呼吸强度和腐烂率,有效地保持了采后草莓的硬度,提高其耐贮性.     

叶菜类蔬菜气调保鲜包装研究

论述了叶菜类蔬菜采后的生理变化和气调包装保鲜的基本原理,并以小白菜、香菜和韭菜为例,对常温叶菜在不同气体成分下的气调保鲜进行了实验研究,提出了适合叶菜气调包装保鲜的最佳气氛配比.     

气调包装技术在食用菌中的研究进展

目的 概述气调包装技术(MAP)在食用菌中的应用和研究现状,开拓气调包装技术的研究思路,为其发展方向提供参考。方法 从气调包装结合不同保鲜技术及使用不同包装材料的气调包装技术在食用菌中的应用这2个方面介绍其研究进展,探讨食用菌在采后贮藏过程中的生理及其他品质的变化。结论 各种气调包装技术均对食用菌的保鲜具有一定的积极作用。对各种包装技术进行了概括和总结,并对食用菌保鲜技术的发展方向进行了展望。     

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。     

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。     

智能气调包装系统

针对我国气调保鲜包装技术及应用的落后状况,采用Mix9001气体混合器、CMV-2气体比例分析仪、DQB-700N气调包装机及PLC控制器,构建了基于气体在线检测与比例控制的智能气调包装系统。利用气体比例分析仪监控气体组分,PLC控制气体混合器和气调包装机,实现包装容器保鲜气体的比例混合和充气包装。实验表明,该系统可自动实现包装袋保鲜气体的比例混合和充气包装,减少了保鲜气体的耗气量,提高了工作效率,同时省却了传统气调包装的真空气室。     

运销两用鲜枣气调包装袋的设计

目的设计一种适合鲜枣运输和销售2种功能的气调包装袋。方法通过实验研究牛妈妈枣采后生理性能的变化特点,然后结合气调包装的理论数学模型,选用合适的包装材料,计算出包装一定质量的果品所需包装袋的用量;最后结合绿色消费、人性化设计绘制气调袋造型图。结果选择厚度为0.03 mm,透气系数比β为2.75的低密度聚乙烯(LDPE)保鲜薄膜0.25 m~2作为制作气调袋的材料,气调袋的结构满足多次使用、果核回收、直立展示、方便运输等功能。结论该设计延长了牛妈妈枣的食用价值和贮藏期。     

果蔬气调包装模型研究

文中对影响气调包装的因素进行了分析,建立了包装内环境动态模型.并以苹果为例进行实验,分析了呼吸速率与气体浓度及温度的关系,介绍了一种建立MAP系统设计模型的方法.     

使用食品气调包装技术四大要素

食品的气调包装技术首先出现在欧洲食品工业中,后传入美洲和日本并得到了广泛的应用。目前,我国的食品工业中应用气调包装技术来包装食品的并不多见,如何对食品进行气调包装是包装工作者急需研究解决的一个重要课题。     

气调微孔膜包装技术在鲜食葡萄贮运中的应用

目的 针对当前鲜食葡萄电商物流包装方式易引起果实无氧呼吸、酒化和异味等问题,开展气调微孔膜包装技术在鲜食葡萄贮运中的应用.方法 以新疆红地球、木纳格葡萄为材料,采用气调(体积分数为5％的O2+体积分数为8％的CO2)分别结合微孔膜M1(透氧量为6000 cm3/(m2?d))、微孔膜M2(透氧量为8000 cm3/(m2?d))和PE膜(透氧量为300 cm3/(m2?d))进行包装,其中一部分先在(0±0.5)℃下贮藏7 d后在(15±1.0)℃下货架9 d,另一部分采后直接在(15±1.0)℃下货架12 d,然后对其进行评价,确定无氧呼吸的发生时间,测定其生理生化指标,研究气调微孔膜包装对葡萄果实贮运品质的影响.结果 采用气调微孔膜包装可以减缓果实硬度、可溶性固形物(TSS)、可滴定酸(TA)、维生素C(Vc)和总酚含量的下降,抑制果实中pH的上升,维持采后品质.与M2包装对比,M1包装能够更大程度地抑制果实腐烂,延缓TSS、TA和Vc含量的下降.结论 气调微孔膜M1包装避免了鲜食葡萄在电商物流中无氧呼吸现象的发生,很好地保持了鲜食葡萄果实的外观和内在营养品质,减缓了果实衰老进程,延长了货架期.     

Prediction of plastic film thickness based on gas permeability and validation with ‘Kyoho’ table grapes for optimal modified atmosphere packaging

Modified atmosphere packaging (MAP) storage has become a useful technique for extending the shelf life of fruit and vegetables. However, the success of MAP depends on many factors, including types of fresh products, storage conditions, and the characteristics of the packaging films. To achieve the optimal gas composition in the package headspace and improve the postharvest quality of fresh produce, the packaging film with appropriate barrier properties needs to be selected. This study aimed to predict the film thickness by applying produce respiration rate and package film permeability data measured in given product weight and storage conditions. An available film (eg, 25‐μm‐thick low‐density polyethylene) was used to pack fresh produce, and the respiration rate of fresh produce and in‐package O₂ and CO₂ concentrations at steady state were measured. Permeability of the film was calculated based on mass balance, and the thickness of the film could be predicted if the recommended target O₂ and CO₂ concentration was obtained from the literature. To validate the predicted thickness value, an experiment was conducted by packaging fresh table grapes in bags of the predicted thickness. The effect of packaging with different film thicknesses on the quality of the fruit was determined. The results showed good agreement between the predicted and the experimental in‐bag O₂ and CO₂ concentrations, and the MAP with predicted thickness (90 μm) film was more effective in maintaining postharvest quality of grapes during low‐temperature storage than the thinner films (30 and 60 μm) and the control.     

基于BP网络的苹果硬度高光谱无损检测

目的为了实现基于高光谱成像以及误差反向传播(BP)网络模型的苹果硬度快速无损检测。方法利用高光谱成像采集系统采集采后"富士"苹果的高光谱图像,然后提取整个苹果样本区域的平均反射光谱;利用连续投影算法(SPA)和竞争性自适应重加权算法(CARS)实现对标准正态变换预处理后光谱数据的降维;研究基于全光谱以及特征光谱的预测苹果硬度BP网络模型。结果采用SPA和CARS分别从256个全光谱中提取了18个和16个特征波长,明显提升了预测模型的运行效率,且SPA+BP网络模型具有相对较好的苹果硬度预测能力(rp=0.728,RPm=0.282 kg/cm2)。结论研究表明基于高光谱成像技术和BP网络建立的预测模型可快速无损预测苹果的硬度。     

薄膜包装对娃娃菜采后贮藏品质的影响

目的探究适用于娃娃菜采后贮藏保鲜的包装材料。方法采用4种不同厚度的聚乙烯薄膜(10,20,30,40μm)包装娃娃菜,以市场销售的原包装薄膜为对照,测定在常温(23±2)℃下贮藏28 d的品质变化,之后以筛选出的薄膜材料为研究对象,进一步分析其对娃娃菜采后贮藏品质的影响。结果与其他薄膜包装相比,厚度为30μm的聚乙烯薄膜包装材料对娃娃菜的保鲜效果最好,其可溶性糖、蛋白含量分别为13.49 mg/g,3.79 mg/g,MDA的质量摩尔浓度为1.51μmol/g。与对照组相比,厚度为30μm的薄膜包装能够有效抑制娃娃菜表面菌落总数的生长,延迟腐烂现象的发生,维持其组织较高的抗坏血酸、总酚、可溶性糖、总硫苷和萝卜硫素含量。主成分法综合评价的结果也显示,厚度为30μm的薄膜包装对减缓娃娃菜品质劣变的效果更理想。结论厚度为30μm的聚乙烯薄膜包装能更好地维持采后娃娃菜的贮藏品质,适宜用作采后娃娃菜的包装贮运材料。     

Integral approach for optimizing modified atmosphere packages for elstar apples: A combination of product and packaging constraints

Modified atmosphere packages with Elstar apples in various packaging systems have been investigated. Loss of firmness during shelf-life is used as the quality aspect to judge the performance of the modified atmosphere packages. A system-oriented model is derived that describes the experimentally found concentrations well. In the overall approach the time dependency of the oxygen and carbon-dioxide concentrations are discussed. It is shown that the quality attribute, the softening of apples, can be affected by the choice of packaging material. Hence this approach can be used to optimize modified atmosphere packaging of Elstar apples.     

多层苹果刚性跌落冲击模型与冲击响应研究

基于损伤条件下果实刚性跌落冲击变形特征,提出一表征其非线性黏弹性的动态流变模型,建立多层果实跌落冲击模型.以"富士"苹果为研究对象,实施多个高度下的跌落冲击试验,进行动态流变模型的参数识别、4层苹果跌落冲击响应的理论分析与试验结果比较.结果表明,试验结果与理论模型结果吻合性好,所提出苹果流变模型、多层果实跌落冲击模型能合理地表征苹果的非线性黏弹性流变特征、跌落中击动力学特征.研究结果为果实的合理运输包装设计提供了理论基础.     

Modified atmosphere packaging of fresh mushrooms

The storage life of harvested fruits and vegetables is influenced by their continued respiration and biochemical activity. Lowering the temperature, and modifying the atmosphere surrounding the product, can extend the shelf-life of the produce. Mushrooms (Agaricus bisporus) were placed into different structural containers covered with PVC films and stored at three temperatures. The effect of key variables, such as temperature, respiration rate, critical and optimal concentrations of O₂ and CO₂, package-weight/area ratio and film permeability, were studied. It was concluded that a highly perishable product, such as mushrooms, must be wrapped and refrigerated in order to prevent transpiration and shrivelling. Modified atmosphere packaging (MAP) may be beneficial but was not found to be essential. If a certain batch of mushrooms respires faster than predicted, or is exposed to large temperature fluctuations, MAP could have a damaging effect.