Recent advances in modified atmosphere packaging and edible coatings to maintain quality of fresh-cut fruits and vegetables

Processing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O₂ and high CO₂ levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and nonconventional atmospheres such as the use of pressurized inert/noble gases and high levels of O₂ have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.     

非热技术在果蔬保鲜体系中的应用

随着人们生活质量的提高,果蔬的保鲜越来越受到人们的重视。近年来,果蔬保鲜技术的研究也日益增多,特别是辐照技术、高压电场技术、超高压技术等非热技术作为一类新型、简捷的技术也逐渐开始被应用在果蔬保鲜领域,且较其他保鲜技术有其独到之处。     

Preservation technologies for fresh meat – A review

Fresh meat is a highly perishable product due to its biological composition. Many interrelated factors influence the shelf life and freshness of meat such as holding temperature, atmospheric oxygen (O₂), endogenous enzymes, moisture, light and most importantly, micro-organisms. With the increased demand for high quality, convenience, safety, fresh appearance and an extended shelf life in fresh meat products, alternative non-thermal preservation technologies such as high hydrostatic pressure, superchilling, natural biopreservatives and active packaging have been proposed and investigated. Whilst some of these technologies are efficient at inactivating the micro-organisms most commonly related to food-borne diseases, they are not effective against spores. To increase their efficacy against vegetative cells, a combination of several preservation technologies under the so-called hurdle concept has also been investigated. The objective of this review is to describe current methods and developing technologies for preserving fresh meat. The benefits of some new technologies and their industrial limitations is presented and discussed.     

Spoilage and shelf‐life extension of fresh fish and shellfish

Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish‐processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low‐dose irradiation, ultra‐high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.     

High hydrostatic pressure (HHP) inactivation of foodborne pathogens in low‐acid juices

Consumption of unpasteurised fruit/vegetable juices has increased in recent years due to their freshness, low calorie contribution and good nutritional quality. However, unpasteurised fresh juices with low acidity (pH > 4.6) and high water activity (a_w > 0.85) can support the growth of pathogens. Hence, pasteurisation is a necessary process in the production of low‐acid juices. Consumer demand has required minimally processed high‐quality foods that are free from additives, that are fresh tasting and microbiologically safe, and with an extended shelf life. High hydrostatic pressure (HHP) treatment is considered to be an alternative to thermal pasteurisation for fruit and vegetable juices. HHP treatment could preserve nutritional value and the sensory properties of fruits and vegetables due to its limited effect on the covalent bonds of low‐molecular‐mass compounds such as colour, flavour compounds and vitamins. However, inactivation of important foodborne pathogens in low‐acid foods by HHP is most urgent and critical. More research should be performed in order to satisfy consumer demands for fresh‐tasting products while retaining safety.     

The Impact of Nonthermal Technologies on the Microbiological Quality of Juices: A Review

Fruit and vegetable juices are rich sources of nutrients that support microbiological growth and ultimately undergo rapid deterioration of safety and quality. The loss of nutritional quality of juices due to intensive thermal processing is a major problem encountered during the treatment of commercially preserved liquid foods. Conventional thermal processing technologies inactivate microorganisms and enzymes and extend the shelf life of foods but exert negative effects on nutritional and organoleptic properties of juices, for example, a loss of vitamins, of a desirable flavor, and of bioactive compounds and development of different sensory profiles as a result of heating. Nonthermal technologies including ultrasonication, a pulsed electric field, high‐pressure processing, irradiation, and their combinations are suitable alternatives for achieving the same preservation effect without the adverse effects of heat on the quality of juices and meet consumer demand for clean‐label, safe, and wholesome products without compromising their nutritional properties.     

果蔬和水产品新型干燥预处理技术研究进展及未来展望

果蔬和水产品营养价值丰富,但含水率较高,极易引起微生物生长繁殖,进而导致腐败变质.干燥是延长果蔬和水产品货架期的有效途径,但干燥时间长、干制品品质差是限制该领域发展的瓶颈问题.采用热力或非热力预处理可有效提高干燥效率,改善干制品品质.基于此,本文综述了果蔬和水产品新型烫漂(高湿气体射流冲击烫漂、红外辐射烫漂、微波烫漂、...     

Innovative processes and technologies for modified atmosphere packaging of fresh and fresh-cut fruits and vegetables

Modified atmosphere packaging (MAP) technology has been commercially viable since the 1970s. Currently, MAP is extensively used worldwide to preserve the quality and extend the shelf-life of whole fresh fruits and vegetables, but is also increasingly used to extend the shelf-life of minimally processed fresh fruit and vegetables. This review discusses new processes and technologies that can be used to improve quality preservation and consumer acceptability of minimally processed produce where high respiration rates and challenging degradation processes operate. New packaging innovations are enabling producers and retailers to further maintain quality for longer. Innovative approaches to extend shelf-life include active MAP with differentially permeable films, films that incorporate antimicrobial properties, edible coatings that confer barriers properties, and the use of non-traditional gases to modify respiration. Intelligent packaging using integrated sensor technologies that can indicate maturity, ripeness, respiration rate and spoilage are also appearing. This review demonstrates that preservation technologies and associated packaging developments that can be combined with modified atmosphere are constantly evolving technology platforms. Adoption of combinations of technology improvements will be critical in responding to commercial trends towards more minimally processed fresh-cut and ready-to-eat fruit and vegetable products, which require specialized packaging solutions.     

热处理对鲜切果蔬品质影响的研究进展

鲜切果蔬方便、营养的特性越来越受到加工者和消费者的重视和青睐,然而短暂的货架期已成为限制鲜切果蔬发展的瓶颈难题。为了在保证其食用安全性的前提下,延长鲜切果蔬的货架期,有必要寻找或开发更为环保和安全的鲜切果蔬加工方法,来取代氯水清洗或其他化学试剂在果蔬去皮、切块、清洗等工序中的使用。热处理是一种传统的物理保鲜方法,而将热处理技术应用在鲜切果蔬贮藏保鲜是近年来的研究热点。为此,本文概括了热处理和热处理与其他技术相结合对鲜切果蔬感官品质、营养品质和安全品质的影响,同时归纳了热处理对鲜切果蔬保鲜的机理。以期为热处理应用于鲜切果蔬的贮藏保鲜和提高鲜切果蔬的食用安全提供参考。     

The effect of high pressure processing on nutritional value and quality attributes of Cucumis melo L.

To determine the effect of cultivar on high pressure processing (HPP) performance three commercial melon varieties were assessed before and after HPP for vitamin C and β-carotene by HPLC and for ferric ion reducing capacity (FIRC) using the Ferric Reducing Ability of Plasma (FRAP) assay. Total titrable acids (TTA), °Brix and colour were also recorded for fresh,−HPP (material cut and packaged) and +HPP samples (material cut, packaged and subject to HPP). The HP process was non-thermal so as to determine the effect of pressure alone on these phytochemicals. There were significant differences between cultivars in vitamin C, β-carotene, TTA, °Brix and colour parameters in fresh samples prior to HPP. HPP did not have an effect on TTA or °Brix, but colour was adversely affected. FIRC and vitamin C concentrations were decreased by HPP and these losses were cultivar dependent for vitamin C. Levels of β-carotene were significantly increased. Cultivar was identified as an important parameter in raw material selection for HPP and retention of vitamin C as a good measure of both quality and cultivar suitability.Industrial relevanceThere is an increasing consumer demand for fresh, natural and healthy fruit and vegetable products with an extended shelf life. This demand is driving industry to look at alternative preservation technologies. HPP has the potential to deliver safe, preserved fruit and vegetables through enzyme inactivation of microbe destruction. HPP removes the need for additives or preservatives and the process is therefore viewed as closer to “natural” by consumers. We show that HPP results in minimal loss of sensorial properties and health-promoting phytochemicals; thus providing consumers a high quality, healthy product with extended shelf life. The introduction of non-thermal processing techniques has the potential to move the focus of the Australian food processing industry from safety to the dual aims of safety and health, resulting in an increase of health-promoting phytochemicals in highly consumed processed foods.     

生鲜果蔬物流及包装技术研究与展望

生鲜果蔬是人们膳食结构的基本组成,在国民经济发展中占有重要的战略地位。然而,生鲜果蔬在物流过程中存在保质期短、营养流失严重等难题,难以满足产业快速发展及人们对高品质生活的需求。作者从生鲜果蔬动态物流保鲜的视角,从采后预冷技术、物流包装材料与技术、蓄冷与保温技术、物流过程品质监测技术等方面,全面综述了国内外生鲜果蔬物流及包装技术的研究现状和科技前沿,并对未来的研究趋势进行了展望,旨为生鲜果蔬物流与包装技术的科技创新和产业发展提供参考。     

低盐腌菜保藏技术研究进展

传统腌菜含盐量太高,不利于人体健康。因此近年来国内外市场对低盐腌菜的需求急剧增加。由于腌菜主要是依据食盐的高渗透压得以长期保存。故低盐腌菜难以满足保存要求的矛盾便显得尤为突出。本文对低盐腌菜保藏技术的研究概况进行了综述。包括物理方法如巴氏杀菌法、超高压杀菌法、微波杀菌法、真空耐热包装法;化学防腐剂法;天然防腐剂法、栅栏技术、加强乳酸发酵法等。建议腌菜生产企业拓展低盐腌菜的物理保藏技术,科学使用防腐剂,利用栅栏技术等综合提高低盐腌菜的保质期和食用安全性。     

蔬干燥前处理技术的应用及研究进展

目前,针对果蔬干制加工中存在的能耗高、时间长、营养成分损失严重等问题,主要通过干燥技术的创新以及干燥设备的研发予以不断改善,而干燥前处理技术在国内发展相对缓慢。干燥前处理技术是指通过物理、化学、生物等技术手段对物料进行处理,从而起到加快物料干燥速率、提高产品外观及营养品质、延长货架期的作用。目前常用的果蔬干燥前处理技术有:热烫、冻融、渗透、化学试剂、超声、超高压、高压脉冲电场、二氧化碳浸渍处理等。本研究针对上述几种前处理技术的原理、特点进行综述,对比不同前处理技术的作用机制及适用果蔬的种类,并展望了不同前处理技术的发展前景与趋势,以期为果蔬干燥新技术的研究与开发提供指导意见。     

国内新鲜食品气调包装技术研究现状

气调包装是一种重要的食品保鲜方法,可以有效延长产品的货架期。使用气调包装技术保鲜食品时,影响保鲜效果的因素主要有三个,一是包装气体的初始组分,二是保鲜过程中包装气体的变化,三是保鲜的温湿度条件。总结目前常用的两种果蔬呼吸模型,并分析其适用范围。总结出保鲜新鲜果蔬、鲜切蔬菜和肉类产品的初始气体组分。介绍不同包装膜对包装内外气体交换的影响。概述气调包装温湿度的相关研究。最后,对气调包装技术研究提出建议。     

Recent developments in non-thermal processing for seafood and seafood products: cold plasma,pulsed electric field and high hydrostatic pressure

Seafood and seafood products (SSPs) are highly perishable foods due to their chemical composition (high moisture content and nutrients). They are regarded as highly sensitive to different processing technologies. SSPs are subjected to various processing conditions with intent to extend their shelf life, quality and minimal nutritional degradation. Recently developed non-thermal technologies (NTTs) have proved their efficacy in inactivation of microorganisms and enzymatic activities, enhancing the shelf life while maintaining the nutritional quality. Considering the significant impacts of NTTs on shelf life extension and maintaining quality parameters, it has attracted considerable interest by scientific communities and commercial applications in some cases. Thus, this article focuses on recent developments in the application of NTTs namely, cold plasma, pulsed electric field and high hydrostatic pressure as well as advantages and limitations of NTTs. In addition, their impacts on microbiological, physicochemical, quality and safety of SSPs are elucidated.     

可食性活性涂膜在鲜切果蔬保鲜中的应用

可食性涂膜是一种由天然可食性材料制成的选择透过性薄膜,具有调节果蔬内部气体交换、减少水分损失、降低腐烂率及延长货架期的特性,在果蔬包装及保鲜领域中已引起广泛关注。鲜切果蔬具有新鲜、方便、快捷等特点,已在全球范围内广泛供应餐饮业及零售业。可食性涂膜作为多种食品添加剂的载体常应用于生鲜产品中,且将活性添加剂与可食性涂膜结合可以延长鲜切果蔬的货架期,提高果蔬品质,减少果蔬表面致腐及致病菌增长的风险。可食性活性涂膜将作为一种绿色、安全、营养的保鲜技术,并将应用于鲜切果蔬保鲜领域的研究。本文综述了可食性涂膜的分类及其添加的抗菌剂、抗氧化剂、塑形剂、营养素等活性成分在鲜切果蔬保鲜中的应用,旨在开发用于鲜切果蔬保鲜的功能性可食性涂膜。     

Cold Plasma‐Mediated Treatments for Shelf Life Extension of Fresh Produce: A Review of Recent Research Developments

Fresh produce, like fruits and vegetables, are important sources of nutrients and health‐promoting compounds. However, incidences of foodborne outbreaks associated with fresh produce often occur; it is thus important to develop and expand decay‐control technologies that can not only maintain the quality but can also control the biological hazards in postharvest, processing, and storage to extend their shelf life. It is under such a situation that plasma‐mediated treatments have been developed as a novel nonthermal processing tool, offering many advantages and attracting much interest from researchers and the food industry. This review summarizes recent developments of cold plasma technology and associated activated water for shelf life extension of fresh produce. An overview of plasma generation and its physical–chemical properties as well as methods for improving plasma efficiency are first presented. Details of using the technology as a nonthermal agent in inhibiting spoilage and pathogenic microorganisms, inactivating enzymes, and modifying the barrier properties or imparting specific functionalities of packaging materials to extend shelf life of food produce are then reviewed, and the effects of cold plasma‐mediated treatment on microstructure and quality attributes of fresh produce are discussed. Future prospects and research gaps of cold plasma are finally elucidated. The review shows that atmospheric plasma‐mediated treatments in various gas mixtures can significantly inhibit microorganisms, inactive enzyme, and modify packaging materials, leading to shelf life extension of fresh produce. The quality attributes of treated produce are not compromised but improved. Therefore, plasma‐mediated treatment has great potential and values for its application in the food industry.     

Recent Application of Modified Atmosphere Packaging (MAP) in Fresh and Fresh-Cut Foods

Modified atmosphere packaging (MAP) has been applied in the food industry for about 90 years to extend shelf life and maintain quality of fresh and fresh-cut foods. Recently, MAP has experienced a rapid development in both scientific and industrial communities, which was one of the most appropriate and practical technologies for packaging fresh and fresh-cut produce. This paper reviews some recent developments of newly emerged MAP systems such as high-oxygen MAP, controlled MAP, and intelligent MAP and provides an overview of MAP applications for fresh and fresh-cut fruits, vegetables, mushrooms, meat, and aquatic products.     

Recent developments in cold plasma-based enzyme activity (browning,cell wall degradation,and antioxidant) in fruits and vegetables

According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented.     

荷兰豆真空预冷及其对贮藏品质的影响

真空预冷可在果蔬采后迅速移除果蔬田间热,有效延长产品保质期,是近年来发展迅速的果蔬保鲜技术之一。为考察真空预冷对荷兰豆贮藏品质的影响,本实验采用1、3、5、7℃四个终温和3%、5%的补水率,8组交叉实验分别对样品进行真空预冷处理。结果表明：补过水的荷兰豆经真空预冷处理后,不仅货架期得到延长,而且贮藏品质较好,差异突出体现在失水率及感官品质方面。其中,经5%补水预冷终温为5℃的荷兰豆在16d的贮藏过程中各项指标均较好。