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.     

Sweet cherry: Composition,postharvest preservation,processing and trends for its future use

BackgroundSweet cherries (Prunus avium L.) are a nutritious fruit which are rich in polyphenols and have high antioxidant potential. Most sweet cherries are consumed fresh and a small proportion of the total sweet cherries production is value added to make processed food products. Sweet cherries are highly perishable fruit with a short harvest season, therefore extensive preservation and processing methods have been developed for the extension of their shelf-life and distribution of their products.Scope and approachIn this review, the main physicochemical properties of sweet cherries, as well as bioactive components and their determination methods are described. The study emphasises the recent progress of postharvest technology, such as controlled/modified atmosphere storage, edible coatings, irradiation, and biological control agents, to maintain sweet cherries for the fresh market. Valorisations of second-grade sweet cherries, as well as trends for the diversification of cherry products for future studies are also discussed.Key findings and conclusionsSweet cherry fruit have a short harvest period and marketing window. The major loss in quality after harvest include moisture loss, softening, decay and stem browning. Without compromising their eating quality, the extension in fruit quality and shelf-life for sweet cherries is feasible by means of combination of good handling practice and applications of appropriate postharvest technology. With the drive of health-food sector, the potential of using second class cherries including cherry stems as a source of bioactive compound extraction is high, as cherry fruit is well-known for being rich in health-promoting components.     

Antimicrobial edible films and coatings for fresh and minimally processed fruits and vegetables: a review

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a very active research field worldwide. Antimicrobial agents have been successfully added to edible composite films and coatings based on polysaccharides or proteins such as starch, cellulose derivatives, chitosan, alginate, fruit puree, whey protein isolated, soy protein, egg albumen, wheat gluten, or sodium caseinate. This paper reviews the development of edible films and coatings with antimicrobial activity, typically through the incorporation of antimicrobial food additives as ingredients, the effect of these edible films on the control of target microorganisms, the influence of antimicrobial agents on mechanical and barrier properties of stand-alone edible films, and the effect of the application of antimicrobial edible coatings on the quality of fresh and fresh-cut fruits and vegetables.     

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.     

应用于鲜切果蔬中的保鲜技术研究进展

鲜切果蔬因其方便、健康、新鲜等特点日益受到人们的青睐,销售量逐年增加。鲜切果蔬又称为切割果蔬、半加工果蔬、调理果蔬等,通常是指改变了蔬菜、水果物理形状、但仍然保持其新鲜状态的果蔬制品或果蔬混合产品。其生产过程一般要经过清洗、分级、修整、切分、洗涤、干燥、包装、贮存、配送等工序,可供消费者直接食用或餐饮业使用。鲜切果蔬保鲜技术对果蔬的色泽、气味、质地、营养成分、组织状态等感官方面得以最大的保留,减少果蔬因经过清洗、去皮、等机械处理过程导致的品质改变。本论文主要对现阶段鲜切果蔬的保鲜技术研究进展进行综述,其主要技术包括物理、化学和综合保鲜技术,以期为今后更深入的研究与探索提供参考与借鉴,并对未来发展方向进行了展望。     

Nonthermal physical technologies to decontaminate and extend the shelf-life of fruits and vegetables: Trends aiming at quality and safety

Minimally processed fruits and vegetables are one of the major growing sectors in food industry. This growing demand for healthy and convenient foods with fresh-like properties is accompanied by concerns surrounding efficacy of the available sanitizing methods to appropriately deal with food-borne diseases. In fact, chemical sanitizers do not provide an efficient microbial reduction, besides being perceived negatively by the consumers, dangerous for human health, and harmful to the environment, and the conventional thermal treatments may negatively affect physical, nutritional, or bioactive properties of these perishable foods. For these reasons, the industry is investigating alternative nonthermal physical technologies, namely innovative packaging systems, ionizing and ultraviolet radiation, pulsed light, high-power ultrasound, cold plasma, high hydrostatic pressure, and dense phase carbon dioxide, as well as possible combinations between them or with other preservation factors (hurdles). This review discusses the potential of these novel or emerging technologies for decontamination and shelf-life extension of fresh and minimally processed fruits and vegetables. Advantages, limitations, and challenges related to its use in this sector are also highlighted.     

鲜切果蔬贮藏保鲜技术的研究进展

鲜切果蔬因具有营养丰富和新鲜度高的优点,日益受到国内外消费者的喜爱。鲜切果蔬经清理、去皮、切分等处理后,组织结构受到损害,容易出现组织褐变、质地下降和微生物侵染等问题,货架期随之缩短。简述了影响鲜切果蔬品质的原因,并重点介绍了近年来国内外鲜切果蔬保鲜技术的新进展,其中包括物理、化学、生物及综合保鲜技术。     

Effect of Cold Atmospheric Plasma processing on quality and shelf-life of ready-to-eat rocket leafy salad

The effect of Cold Atmospheric Plasma (CAP) on ready-to-eat (RTE), fresh cut, leafy rocket salad (ready-to-eat arugula leaves packed in pouches of 125 g) was investigated, aiming at quality retention and shelf-life extension. CAP was generated via a surface dielectric barrier discharge source and its efficiency on rocket leaves was evaluated at different processing times through microbial, texture, pH value and colour analyses. A reduction of 0.57 to 1.02 log CFU/g was observed for the total microbial load after processing times ranging from 5 to 20 min, respectively. A CAP processing time of 10 min was considered as optimum, for a sufficient reduction of the microbial load while maintaining colour and texture. The shelf-life of the optimum CAP-processed rocket stored at 2-9 °C was estimated through analysis of specific quality parameters. Pseudomonas spp. growth (higher count of approximately 7.0 log CFU/g) was considered to be the dominant deterioration factor. The shelf-life of the CAP-treated leafy rocket salad was estimated as 116, 84 and 55 h compared to 63, 57 and 37 h for the control samples after storage at 2, 5 and 9 °C, respectively.Industrial relevanceSpoilage of fresh-cut vegetables due to microbial growth has a significant economic impact causing food waste by reducing the shelf-life of the products and posing a risk for the public health through possible foodborne illnesses. As a result, there is a real need to seek for alternative methods for preservation of fresh produce. Cold Atmospheric Plasma technology could potentially be applied for microbial load reduction of leafy salads. The proposed protocol along with the device used for Surface Dielectric Barrier Discharge treatment, could be a potential solution for extending the shelf-life of significantly perishable fresh produce.     

水果纸干燥技术研究进展

水果纸是新鲜水果经过打浆、熬煮和干燥后制成的脱水干果纸状薄片小吃。干燥是最古老的食品保存方法之一,可去除水果中的水分,延迟其贮藏期限供全年食用。最常见的干燥方式包括热风干燥、真空干燥、冷冻干燥及联合干燥技术。干燥过程的能源效率和水果纸的品质是水果干燥中需考虑的重要因素。本文归纳了可用于水果纸干燥的热风干燥、冷冻干燥、真空干燥、微波干燥、红外辐射干燥和折射窗干燥的研究现状以及水果纸的预处理方法和干燥工艺对其形态、质构、营养成分的影响,旨在提高水果纸的干燥效率,最大限度地保留水果的活性成分,为今后食品行业中进一步研究水果纸的干燥加工提供参考。     

龙眼果实品质劣变和贮藏保鲜技术研究进展

龙眼是中国南方重要的亚热带特色水果,其果实成熟于高温季节,采后极易发生果皮褐变、果肉自溶及病原菌侵染所致果实腐烂等品质劣变,是限制龙眼果实采后保鲜期的主要因素。本文就龙眼果实采后品质劣变(果皮褐变、果肉自溶、病原菌侵染导致果实变质腐烂),热处理、紫外线-强效应波长(UV-B)辐照处理、二氧化氯处理、壳聚糖处理、低温贮藏、气调冷藏、微生物生物保鲜等龙眼果实采后处理及保鲜技术的国内外研究进展进行综述,旨在为延缓采后龙眼果实品质劣变、延长龙眼果实保鲜期提供技术参考。     

采后荔枝果实安全保鲜技术研究进展

荔枝果实在采后贮藏和运输中极易发生病原菌侵染、褐变及腐败而导致品质劣变。目前常用的物理保鲜方法成本高,而人工合成化学杀菌剂处理可能会有一定残留且病原菌容易产生抗药性,故使用无毒害、可生物降解、对环境无污染的新型安全保鲜技术是目前的研究热点。对国内外壳寡糖涂膜保鲜技术、植物提取物保鲜技术和生物拮抗菌保鲜技术等安全保鲜技术在采后荔枝果实保鲜应用的研究进展进行了综述,旨在为维持采后荔枝果实品质,延长荔枝果实贮藏期提供技术参考。     

臭氧结合1-MCP对桃子货架期品质的影响

为研究臭氧结合1-MCP对桃子货架期品质的效果,以"红桃"桃子为试验材料,采用3种不同地处理(臭氧、1-MCP、臭氧+1-MCP)及对照(CK)对桃子进行货架期贮藏(20±0.5℃)保鲜,研究不同处理对桃子货架期间品质的变化。结果表明,与对照组比较,3种处理均能够推迟桃子的生理代谢水平,保持桃子的货架期品质。其中,臭氧结合1-MCP对桃子的保鲜效果更好,能够显著抑制桃子腐烂指数、呼吸强度及乙烯生成速率的上升,推迟桃子硬度和可溶性固形物含量的降低,保持桃子过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)和脂氧合酶(LOX)的活性。因此,臭氧结合1-MCP处理对桃子的保鲜效果最好,能够更好地保持桃子的货架期品质。     

物理方法在鲜切苹果保鲜中的应用研究进展

鲜切苹果具有新鲜、方便等优点,深受消费者的青睐。但鲜切时造成的机械损伤会破坏苹果天然的组织结 构,极易出现褐变、果实软化、腐烂等问题。传统的化学保鲜方法已不能满足消费者对食品安全高质量的要求,而 物理保鲜技术因其处理条件易于控制、保鲜效果好、安全性高的优势,在果蔬贮藏保鲜中应用广泛。本文综述了光 电方法、高压技术、气调贮藏技术、温度调控和其他物理技术在提高鲜切苹果贮藏品质方面的研究进展,分析了这 些技术通过钝化酶活性、抑制酶促褐变、杀灭微生物的方式以保持和提高鲜切苹果感官品质方面的可能机理。随着 这些技术的应用和发展,鲜切苹果的贮藏保鲜品质将得到保障。     

乳酸菌作为生物保护菌的抑菌机理及其在食品中应用的研究进展

食品在加工和贮藏过程中易受到有害微生物污染,导致食品腐败变质,造成食用安全隐患。而现在常用的物理或化学保鲜方法虽然可以有效延长食品货架期,但应用范围有限、存在安全隐患且容易造成资源浪费。乳酸菌因其天然、安全、高效的抑菌活性被作为生物保护菌应用于食品中。本文主要从乳酸菌产生的抑菌活性物质、微生物群体感应以及竞争作用等角度综述了乳酸菌的抑菌机制;同时介绍了近年来乳酸菌作为生物保护菌在乳制品、肉制品、水产品和果蔬产品中的最新应用进展,为今后食品高效保鲜提供新思路。     

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。     

Biocontrol of Postharvest Anthracnose of Mango Fruit with Debaryomyces Nepalensis and Effects on Storage Quality and Postharvest Physiology

Anthracnose is presently recognized as one of the most important postharvest disease of mango worldwide. To control the disease, chemical fungicides for a long time was widely used among fruit farmers, but recently found that pathogen had developed increasingly resistance to it. With people's growing desire of healthy and green food, finding new and environmentally friendly biological control approach was very necessary. In this paper, we provided a kind of new antagonistic yeast which enriched the strain resources and the efficacy of Debaryomyces nepalensis against postharvest anthracnose of mango fruit and the influence on quality parameters were investigated. The results showed that the decay incidence and lesion diameter of postharvest anthracnose of mango treated by D. nepalensis were significantly reduced compared with the control fruit stored at 25 °C for 30 d or at 15 °C for 40 d, and the higher concentration of D. nepalensis was, the better the efficacy of the biocontrol was. Study also found that 1 h was the best treatment duration and antagonistic yeast inoculated earlier had good biocontrol effect on anthracnose. Meanwhile, treatment by D. nepalensis could significantly reduce postharvest anthracnose of mango, delay the decrease in firmness, TSS, TA, and ascorbic acid value, and do not impair surface color during postharvest storage. Moreover, the increase in MDA (malondialdehyde) content and increase in cell membrane permeability of fruit treated by D. nepalensis was highly inhibited. The results suggested D. nepalensis treatment could not only maintain storage quality of mango fruit, but also decrease the decay incidence to anthracnose disease. All these results indicated that D. nepalensis has great potential for development of commercial formulations to control postharvest pathogens of mango fruit.     

大气压冷等离子体在鲜切果蔬保鲜中的应用研究进展

鲜切果蔬因具有新鲜方便、无添加剂和营养价值高等优点而广受消费者喜爱,但是鲜切果蔬在加工和贮藏过程中极易受微生物污染,导致食品品质劣变并缩短货架期。大气压冷等离子体（Atmospheric cold plasma,ACP）是一种新型非热加工技术,广泛应用于食品及生物医药领域。本文综述了ACP对鲜切果蔬表面微生物的灭活效果以及对鲜切果蔬中酶活的作用,同时探讨了ACP处理对鲜切果蔬品质的影响,旨在为ACP在鲜切果蔬保鲜中的应用提供参考。     

Quality of fresh‐cut products as affected by harvest and postharvest operations

There is a rising demand for fresh‐cut convenience products with high quality and nutritional standards that needs to be met by the fresh‐cut industry. It is well known that harvest and postharvest handling of fresh produce has a paramount impact on its quality and storage, although most of the existing literature has focused on these impacts related only to fresh produce that is destined for the final consumers. Indeed, current harvest methods and postharvest technologies have improved fruit and vegetable handling and distribution processes by slowing down physiological processes and senescence. Nonetheless, these technologies and methods may influence the quality of fresh produce as raw material for fresh‐cut processing as a result of the dynamic responses of fresh produce to handling procedures and treatments. Here, we review the existing literature on the challenges facing the fresh‐cut industry, focusing on the impact of harvest, maturity, and handling of fruit and vegetables on the quality of raw materials, as well as the implications for fresh‐cut products. The review also highlights areas for further research with the aim of enhancing the sensorial, nutritional and biochemical quality of such products. © 2018 Society of Chemical Industry     

Recent trends in detecting,controlling, and detoxifying of patulin mycotoxin using biotechnology methods

Patulin (PAT) is a mycotoxin that can contaminate many foods and especially fruits and fruit‐based products. Therefore, accurate and effective testing is necessary to enable producers to comply with regulations and promote food safety. Traditional approaches involving the use of chemical compounds or physical treatments in food have provided practical methods that have been used to date. However, growing concerns about environmental and health problems associated with these approaches call for new alternatives. In contrast, recent advances in biotechnology have revolutionized the understanding of living organisms and brought more effective biological tools. This review, therefore, focuses on the study of biotechnology approaches for the detection, control, and mitigation of PAT in food. Future aspects of biotechnology development to overcome the food safety problem posed by PAT were also examined. We find that biotechnology advances offer novel, more effective, and environmental friendly approaches for the control and elimination of PAT in food compared to traditional methods. Biosensors represent the future of PAT detection and use biological tools such as aptamer, enzyme, and antibody. PAT prevention strategies include microbial biocontrol, the use of antifungal biomolecules, and the use of microorganisms in combination with antifungal molecules. PAT detoxification aims at the breakdown and removal of PAT in food by using enzymes, microorganisms, and various adsorbent biopolymers. Finally, biotechnology advances will be dependent on the understanding of fundamental biology of living organisms regarding PAT synthesis and resistance mechanisms.     

Review: Comparison of the effectiveness of decontaminating strategies for fresh fruits and vegetables and related limitations

ABSTRACT

Given that it should be aware of the nutritional benefits, resulting from the consumption of fresh fruits and vegetables consumed raw and/or minimally processed, comparing the efficacy of different individual sanitizing methods against the major food-borne pathogens localized in fresh commodities is of much importance; these products are easily vulnerable to the microbial contamination. In this review, the current propensity of alternative sanitizing methods was introduced, as well as principal elements for deteriorating the cleaning effects were also discussed. Chlorine-based-sanitizers exhibited the microbial reduction of <1.12 log₁₀ CFU/g on fruits and vegetables. Most of aqueous disinfectants showed ≤3.01 log₁₀-redcutions against a variety of microorganisms inoculated on fresh commodities. Similarly, several physical technologies such as hydrostatic pressure and ultraviolet light were effective for reducing surviving bacterial cells could recover and grow rapidly during the whole processing, posing a potential risk of causing food-borne outbreaks associated with the fresh products. The invasion and subsequent localization of the organisms into the inner parts of products, interactions between the microbial cell and food-contacting surfaces, as well as development of biofilms could restrict the antimicrobial activity of the currently used approaches.