菠菜采后保鲜包装技术研究进展

目的通过介绍国内外针对菠菜的贮藏保鲜包装技术,以及其对菠菜采后生理生化、营养成分、硝酸盐和亚硝酸盐含量的影响,为菠菜贮藏保鲜及有害物质的控制提供理论参考。方法分析目前主要用于菠菜贮藏保鲜包装的方法,包括低温、气调、1-MCP处理、辐照、二氧化氯和臭氧等,同时针对菠菜在贮藏过程中容易积累硝酸盐和亚硝酸盐的问题,综述不同贮藏方式对菠菜贮藏过程中硝酸盐和亚硝酸盐的影响及调控。结论各种传统贮藏保鲜技术仍存在一定缺陷,尤其是质量安全问题;同时要结合基础研究,明确贮藏方式与菠菜衰老、有害物质的形成机制等的关系,以期为菠菜贮藏保鲜和质量安全研究提供新的研究方向和思路。     

不同保鲜方式对葡萄保鲜效果影响的对比研究

目的研究气调包装和微孔膜包装对葡萄贮藏期间品质的影响,为延长葡萄货架期提供依据。方法以新鲜葡萄为实验材料,分别采用O2(5%)+CO2(5%)+N2(90%)(气调1)和O2(10%)+CO2(10%)+N2(80%)(气调2)等2种气体比例(均用体积分数表示)的气调包装,以及PE参尼龙多层共挤材质的微孔保鲜膜(微孔膜)对新鲜葡萄进行包装,在温度为4℃的条件下进行贮藏,每隔48h对葡萄的硬度、pH值、可溶性固形物、可滴定酸、抗坏血酸、色度和质量损失率等变化进行测定,并进行感官评价。结果在贮藏0～12 d,从整体保鲜效果来看,微孔膜气调2气调2裸放组。结论葡萄在采后贮运期间,当葡萄的货架期≤12d时,使用3种包装均有利于延缓其衰老进程,PE参尼龙共挤微孔膜保鲜膜的保鲜效果最好。     

微孔膜果蔬气调包装设计方法研究

分析了微孔膜果蔬气调包装设计的因素,基于努森扩散理论与微孔膜气调包装模型,建立了在硬质盒包装方式下的微孔膜果蔬气调包装设计方法.微孔膜果蔬气调包装设计方法的主要内容为确定果蔬的初始包装条件、选择合适的微孔膜特征参数,依据实际情况选择合适值的微孔薄膜,最终确定微孔膜特征参数方案.     

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。     

微孔和硅窗自发气调包装的内部气体成分变化分析

自发气调包装是果蔬保鲜的重要手段,其中微孔气调包装和硅窗气调包装在调节包装气氛效果显著。通过试验证明微孔孔径、微孔数量、硅窗面积对两种气调包装的气氛调节有所影响,在合理控制上述参数的前提下,微孔气调包装和硅窗气调包装在果蔬保鲜领域具有较大的推广价值。     

微孔薄膜在果蔬气调包装中的应用及发展前景

本文对微孔薄膜用于果蔬气调包装(MAP)保鲜技术的现状进行了比较全面的分析,介绍了微孔薄膜的特点、加工方法及其在果蔬气调包装领域的应用,指明了微孔薄膜的发展前景.     

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.     

贮藏温度对微孔膜包装茶树菇的保鲜效果影响

目的研究贮藏温度对微孔膜包装的茶树菇品质的影响。方法采用微孔保鲜膜包装茶树菇,并在4,6,9,14,20℃等5个温度条件下贮藏,评价其感观质量,并测试茶树菇的质量损失率、硬度、粗蛋白和顶空气体等指标。结果在4,6,9,14,20℃条件下,随着时间推移,茶树的新鲜度下降,质量损失率逐渐增大,硬度逐渐降低,粗蛋白含量也有一定程度减少。在20,14,9,6,4℃贮藏条件下,贮藏期分别为2,6,9,12,15 d。结论在4℃贮藏条件下,微孔膜包装茶树菇能实现更长时间的保鲜。     

果蔬气调贮藏保鲜技术探讨

近年来，世界工业发达国家的果蔬贮藏保鲜技术发展很快，其中采用降温、降氧、控制二氧化碳及乙烯含量的气调保鲜是世界上果蔬贮藏的最先进方法。本文介绍了气调贮藏保鲜的原理及方法、果蔬气调贮藏保鲜的工艺条件及气调库的气密性要求和施工技术。     

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。     

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。     

气调包装的效果以及影响因素分析

随着气调包装的使用日渐广泛,针对不同的内容物填充合适的气体,使其发挥最佳的效果,是如今气调包装生产和应用的重中之重。在气调包装的应用中,填充气体尤其是CO2,其抑菌选择性和浓度,以及包装材料的选择都会对气调包装的效果产生影响,需要包装生产企业和使用方多加重视。     

本征型聚酰亚胺膜气体分离性能的研究进展

包装内环境气氛对产品 的性能具有重要的影响。选择合适的包装材料,控制包装内环境气氛的成分与含量,可有效延长产品的储存时间与使用寿命。为了实现良好的包装内环境气氛控制效果,包装材料需具备合适的气体分离性能。聚酰亚胺因其优异的气体分离性能、热稳定性和结构可设计性等特点受到关注,但气体渗透-选择性的平衡问题限制了其广泛应用。梳理了聚酰亚胺气体分离膜性能的研究进展,重点阐述了如何通过分子结构设计实现聚酰亚胺致密膜与微孔膜的性能调控,并对聚酰亚胺基气体分离膜材料的发展进行了展望。     

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.     

Combined effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on quality of tomatoes

Effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on quality of tomatoes were studied. Prior to packaging with low‐density polyethylene (LDPE) film (0.02 mm in thickness), tomatoes were immersed in hot water (42.5°C) for 30 min. Control tomatoes were not treated and were stored for 2 weeks at 10°C and then for 3 days at 20°C without packaging. Steady states of O₂ and CO₂ concentrations inside the package were about 5 and 8%, respectively, and were reached after 6 and 4 days of storage, respectively. MAP reduced weight loss of tomatoes to about 41% of that of unpackaged fruit during a 2‐week storage period. The use of a combination of HWT and MAP reduced weight loss and decay, inhibited color development and maintained firmness of tomatoes but had no effect on soluble solids content or titratable acidity. HWT slightly reduced mold growth of tomatoes stored in MAP. Packaging of control fruit in MAP resulted in stimulation of mold growth around the stem end of the fruit after about 1 week of storage and also resulted in cracking and decay. HWT could be used as disinfectant for tomatoes prior to storage in MAP in order to reduce microbial growth, cracking and decay that may be caused by excessive water vapor inside the package. Copyright © 2003 John Wiley & Sons, Ltd.     

Effect of hinokitiol impregnated sheets on shelf life and quality of “KEK‐1” tomatoes during storage

Hinokitiol (β‐thujaplicin, volatile oil extracted from the wood of Hiba arborvitae [Thujopsis dolabrata var. hondae], cypress family) is a natural preservative, antimicrobial, and chelating agent, used to prevent decay and extend the shelf life of fruits and vegetables. In the present study, we used nonwoven rayon sheets impregnated with hinokitiol to conduct packaging studies. Mature green tomatoes var. “KEK‐1” were packaged under three packaging conditions, ie, modified atmosphere packaging (MAP), MAP + hinokitiol (MH), and perforated film package (as control), and their quality attributes were compared during storage. The packaging materials used were low‐density polyethylene (LDPE) film (40 μm) and fresh sheets of nonwoven rayon impregnated with hinokitiol. O₂ in the MAP packaged tomatoes were retained throughout the storage period (3% to 5% O₂). Results showed that MH had slightly improved quality attributes throughout the storage period when compared with MAP alone. Expression levels of LeACS, LeADH, and LeTBG4 genes were higher in 5 and 9 days of control when compared with MAP and MH. “KEK‐1” tomatoes had longer shelf life under MAP and MH packaging and maintained the quality at 15°C. Hence, the effect of the MAP with bioactive packaging treatments could be effective in the future application for the extension of shelf life and quality of fruits and vegetables.     

Use of a pinhole to develop an active packaging system for kimchi,a Korean fermented vegetable

A pinhole in a packaging system for kimchi, a Korean lactic acid fermented vegetable, was found to actively modify the headspace gas and improve the quality of the product. The effect of the presence of a pinhole on the headspace atmosphere and microbial flora was investigated in the packaging system and a prototype of this active packaging system was fabricated and tested for its effectiveness in improving quality. The incorporated pinhole eliminated pressure build-up in the package by allowing restricted flow of gas to the atmosphere. O₂ and N₂ gases in the headspace were flushed out by CO₂ gas produced continuously from lactic acid fermentation and this modified atmosphere enhanced the growth of lactic acid bacteria. In particular, the growth of Leuconostoc species, heterofermentative lactic acid bacteria, was promoted by the pinhole. The increased amount of heterofermentative lactic acid bacteria led to a higher accumulation of CO₂ in the package and this provided the kimchi with a stronger cool carbonic taste and a desirable flavour. An elaborate design of the pinhole incorporating microporous film and a gas adsorvent could be adopted to improve the kimchi packaging system by preventing leakage of fermentative aroma and possible contamination from outside atmosphere. © 1997 John Wiley & Sons, Ltd.