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。     

EXTENDING SHELF LIFE OF FRESH-CUT PERSIMMON BY HONEY SOLUTION DIPS

Ripe persimmon fruit ( Diospyros kaki L) cv. "Hachiya" were diced, then treated with 10–20% w/v diluted honey solution or water as the control, followed by cold storage at 4C until loss of acceptable quality. The persimmon cubes were subject to assessments during the storage of organoleptic and visual quality, softness and exuding juice, soluble solids content (SSC), and absorbance at 436, 440, 675 and 760 nm, respectively. Honey treatments prevented off-aroma development and delayed jelling. Softness and exuding juice of the fresh-cut persimmon cubes increased with time, with the increase in both parameters being significantly suppressed by honey solution dips. Changes in SSC, pH and the absorbance at 436, 440, 675 and 760 nm, respectively, during storage were minor and there was little effect of the honey treatments on these parameters. Overall, the shelf life of fresh-cut persimmon cubes was extended by honey solution dips, which delayed off-aroma development, firmness loss and jelling.

PRACTICAL APPLICATIONS

New products and changing trends make today's food marketplace alive, and fresh-cut fruits and vegetables seem to be on top of list of these products. Although fresh-cut produce has been on the market for a long time, preserving their quality attributes has not been completely successful especially in the case of fruit. This study focuses on a new alternative fresh-cut produce, fresh-cut persimmon, with adapting a potentially safe organic method, use of honey dips. The present study demonstrated that honey solution dip treatments could preserve the fresh-like quality of typical flavor or aroma of persimmon fruit by causing no changes in aroma and taste attributes and extending shelf life. Therefore, honey dip treatment may be used, depending on commodity, to preserve and extend shelf life of fresh-cut produce in fresh-cut processing industry.     

Cassava Starch Coating and Citric Acid to Preserve Quality Parameters of Fresh-Cut “Tommy Atkins” Mango

Abstract: Combination of citric acid dipping (5 g/L) and cassava starch coating (10 g/L), with and without glycerol (10 g/L), was studied to verify the effectiveness of these treatments to inhibit enzymatic browning, to reduce respiration rate, and to preserve quality parameters of “Tommy Atkins” fresh-cut mangoes during storage at 5 °C. Color characteristics (L* and C*), mechanical properties (stress at failure), weight loss, β-carotene content, sensory acceptance, and microbial growth of fruits were evaluated during 15 d. The respiration rate of fruit subjected to the treatments was also analyzed. Nontreated fresh-cut mango was used as a control sample. Cassava starch edible coatings and citric acid dipping promoted a decrease in respiration rate of mango slices, with values up to 41% lower than the control fruit. This treatment also promoted better preservation of texture and color characteristics of mangoes and delayed carotenoid formation and browning reactions during storage. Moreover, the treated fruit showed great sensory acceptance by consumers throughout the whole storage period. However, the use of glycerol in the coating formulation was not efficient in the maintenance of quality parameters of fresh-cut mangoes, promoting a higher weight loss of samples, impairing fruit texture characteristics, increasing carotenogenesis, and favoring microbial growth during storage. Practical Application: Consumer demand for tropical fresh-cut products is increasing rapidly in the world market. Fresh-cut mangoes are appreciated world-wide for its exotic flavor. However, its shelf life is limited by changes in color, texture, appearance, off-flavors and microbial growth. The edible coatings act as gas and water vapor barrier, extending the storage time of fresh-cut fruit and vegetables. Thus, cassava starch is an alternative to preserve minimally processed mangoes and the quality parameters of fresh fruit. The information of this work is useful for the fresh-cut produce industry to increase shelf life of fresh-cut mangoes, which can be considered an alternative to fast food and other ready-to-eat products, attending the demand for healthy and convenient foodstuffs.     

Factors affecting quality and safety of fresh-cut produce

The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail.     

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.     

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.     

Modified Atmosphere Packaging of Pomegranate Fruit and Arils: A Review

Ongoing global drive for a healthier diet has led to a rise in demand for convenient and fresh food produce, with high nutritional value and free of additives. Minimally fresh processed fruits and vegetables, satisfies the consumers’ perception of a high nutritional quality and convenience produce. Minimally processed fruit and vegetables are susceptible to increased deterioration in quality and microbial infestation due to increase in endogenous enzymatic processes and respiration rate. Modified atmosphere packaging (MAP) technology offers the possibility to retard produce respiration rate and extend the shelf life of fresh produce. However, it is important to correlate the permeability properties of the packing films with the respiration rate of the produce, in order to avoid anaerobic conditions which could lead into fermentation of produce and accumulation of ethanol. Hence, mathematical prediction modelling is now widely applied in the design and development of effective MAP technology in both whole and minimally processed fresh produce. With increasing global interest in postharvest handling and nutrition value of pomegranate, MAP of minimally processed pomegranate arils offers additional innovative tool for optimal use and value addition, including the utilization of lower-grade fruit with superficial peel defects such as; cracks, splits, and sunburnt. This review paper highlights the current status and applications of modified atmosphere packaging in whole fruit and minimally processed pomegranate arils and identifies future prospects.     

Role of biological control agents and physical treatments in maintaining the quality of fresh and minimally-processed fruit and vegetables

Abstract

Fruit and vegetables are an important part of human diets and provide multiple health benefits. However, due to the short shelf-life of fresh and minimally-processed fruit and vegetables, significant losses occur throughout the food distribution chain. Shelf-life extension requires preserving both the quality and safety of food products. The quality of fruit and vegetables, either fresh or fresh-cut, depends on many factors and can be determined by analytical or sensory evaluation methods. Among the various technologies used to maintain the quality and increase shelf-life of fresh and minimally-processed fruit and vegetables, biological control is a promising approach. Biological control refers to postharvest control of pathogens using microbial cultures. With respect to application of biological control for increasing the shelf-life of food, the term biopreservation is favored, although the approach is identical. The methods for screening and development of biocontrol agents differ greatly according to their intended application, but the efficacy of all current approaches following scale-up to commercial conditions is recognized as insufficient. The combination of biological and physical methods to maintain quality has the potential to overcome the limitations of current approaches. This review compares biocontrol and biopreservation approaches, alone and in combination with physical methods. The recent increase in the use of meta-omics approaches and other innovative technologies, has led to the emergence of new strategies to increase the shelf-life of fruit and vegetables, which are also discussed herein.     

鲜切果蔬微冻技术的研究进展

鲜切果蔬具有天然、便利、营养、保健以及口感清脆爽口等优点,深受国内外快餐业、旅游业、零售业等行业青睐。但鲜切果蔬贮藏品质损耗严重,保鲜期限短,一直是困扰其工业化发展的瓶颈因素之一。目前,国内外研究者试图采用各种物理、化学方法改善果蔬的贮藏品质问题。虽然这些方法在杀菌或在改善质量方面取得一定成效,但在满足人们对果蔬天然、高营养、安全、较长的保鲜期限等综合品质的需求方面存在局限。微冻技术以其突出的保鲜效果,成为低温保鲜领域的研究热点。而关于微冻技术在果蔬保鲜上应用效果的报道还很少。基于此现状,本文从果蔬保鲜技术的研究现状、微冻保鲜作用效果及组织损伤机制3方面,探究了微冻技术在鲜切果蔬上的应用前景。     

Quality Measurement of Intact and Fresh-cut Slices of Fuji, Granny Smith, Pink Lady, and GoldRush Apples

ABSTRACT: Development of fresh-cut apple products requires consideration of cultivars that store well as both intact and fresh-cut fruit. We compared the instrumental and sensory quality of 2 apple cultivars, Granny Smith and Fuji, that are used for fresh cutting with 2 new cultivars, Pink Lady and GoldRush, which were considered to have quality characteristics suitable for fresh cutting. Firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration were measured in intact fruit of the 4 cultivars during 12 mo storage in air at 0 °C and during 3 wk storage at 5 °C as fresh-cut slices. After 1 wk storage as fresh-cut slices, sensory evaluations for acceptability of flesh and peel appearance, flavor, texture, and overall eating quality were performed. During storage, GoldRush apples maintained > 80 N firmness, approximately 17% SSC, > 0.5% TA, and had high aromatic volatile production, that is, maintained quality better than the other cultivars. The quality and shelf stability of GoldRush slices were also as good as or better than slices from the other cultivars, whereas Granny Smith slices generally rated lower than the other cultivars. The acceptability of flavor, texture, and overall eating quality of GoldRush slices was as good as that for Pink Lady and Fuji. The quality of GoldRush apples can be maintained throughout the year in refrigerated air storage and still remain suitable for fresh-cut processing. The results indicate that GoldRush and Pink Lady are 2 promising new, high-quality apple cultivars for fresh cutting. Keywords: fresh-cut fruit, Malus × domestica , postharvest quality, respiration rate, shelf life     

鲜切果蔬的加工工艺和保鲜技术

鲜切果蔬是指为消费者提供新鲜、方便的产品,加工鲜切果蔬包括清洗、去皮、切分、去心(核)、修整、包装等。鲜切果蔬的加工引起新陈代谢加快,从而导致果蔬腐败变质,加工时的机械损伤,增加呼吸强度和乙烯产量,伴随着影响色、香、味和营养价值的生化反应的加速。本文介绍了鲜切果蔬的加工工艺和保鲜技术的生产现状和应用研究情况。     

鲜切果蔬品质劣变影响因素及其可能机理

鲜切果蔬是指新鲜果蔬原料经预处理、清洗、切分、保鲜、包装和贮藏等多道工序制成的不影响其鲜活状态的一种制品。品质快速劣变是影响其货架寿命的主要原因。本文综述鲜切果蔬品质快速劣变的影响因素及其可能机理,旨在为鲜切果蔬贮藏保鲜新技术的建立和应用提供理论依据。     

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.     

Influence of Heat Treatments on Quality Retention of Fresh and Fresh-Cut Produce

Postharvest decay and insect infestation are two major causes that contribute towards higher postharvest losses during the fresh produce supply chain. Although decay and pest infestation could be controlled successfully via pesticide applications, the use of chemicals at the postharvest stage is becoming limited due to the strict regulations regarding pesticide residue levels enforced by importing countries. Heat treatments are environmentally friendly and recommended as alternative treatments to replace pesticide applications, especially with regard to fresh produce. These treatments help to eradicate pathogens or pests that are present on the fruit surface while maintaining the overall quality of the fresh produce during the supply chain. Browning is regarded as an economically important physiological disorder that causes detrimental effects on the quality maintenance of fresh-cut produce. Contamination of fresh produce by foodborne pathogens could occur at any stage during the production, harvesting, postharvest chain, or processing, and heat treatments could be recommended as an antibrowning or disinfection treatment for the fresh-cut industry. In light of the above, this review summarizes the effects of postharvest heat treatments on postharvest decay, insect infestation, physiological disorders, fruit ripening, retention of color, and bioactive compounds.     

Retention of quality and nutritional value of 13 fresh-cut vegetables treated with low-dose radiation

Improving the microbial safety while maintaining quality of fresh fruits and vegetables will increase consumer confidence in fresh produce. This study was conducted to investigate the effects of irradiation at 1 kGy, a dose that potentially inactivates E. coli O157:H7 by 5 logs, on the quality of 13 common fresh-cut vegetables: iceberg, romaine, green and red leaf lettuce, spinach, tomato, cilantro, parsley, green onion, carrot, broccoli, red cabbage, and celery. The results showed that the appearance of irradiated samples was similar to the nonirradiated ones except that irradiated carrots, celery, cilantro, and green onions had higher appearance scores than corresponding nonirradiated vegetables. There was no difference in the instrumental texture between irradiated samples and nonirradiated ones. The aroma of several irradiated vegetables was significantly better than controls after 14-d storage, because these control samples decayed or senesced. The 1 kGy irradiation did not affect vitamin C content of most vegetables; however, irradiated green and red leaf lettuce had 24% to 53% lower vitamin C contents than the controls. Our results suggest that most fresh-cut fruits and vegetables tested can tolerate up to 1 kGy irradiation without significant losses in any of the quality attributes.     

Enhancing Safety and Aroma Appealing of Fresh-Cut Fruits and Vegetables Using the Antimicrobial and Aromatic Power of Essential Oils

ABSTRACT:  Microbial and aroma attributes are within the most decisive factors limiting safety and sensory appealing of fresh-cut fruits and vegetables. Alternatively, several plant essential oils (EOs) are constituted of several volatile active compounds and most of them present antimicrobial potential and had different aroma profile. Considering these premises, this hypothesis article states that safety and aroma appealing of fresh-cut produce could be improved with EO treatment. EOs could prevent fresh-cut fruit decay; however, their volatile constituents could be sorbed by the produce, and according to the aroma notes of the antimicrobial oil, sensorial appealing of odor, and flavor of the treated produce might be affected positively or negatively. Specifically, garlic oil is a natural antimicrobial constituted by sulfur compounds, which are responsible for its odor and antimicrobial properties. Besides, fresh-cut tomato is a highly perishable product that needs antimicrobial agents to preserve its quality and safety for a longer period of time. From the sensorial point of view, aroma combination of garlic and tomato is a common seasoning practice in Europe and America and well accepted by consumers. Once the right combination of flavors between the EOs and the fresh-cut produce has been selected, safety and quality of the treated fruit could be improved by adding antimicrobial protection and extra aroma. Therefore, other combinations between EOs and fresh-cut produce are discussed. This approximation could reinforce the trends of natural food preservation, accomplishing the demands of the increasing sector of consumers demanding tasty and convenient fresh-cut produce, containing only natural ingredients.     

The use of ozone to extend the shelf‐life and maintain quality of fresh produce

Fresh produce has been recognised as a healthy food, thus there is increasing consumer demand for fresh fruit and vegetables. The shelf‐life of fresh produce, however, is relatively short and is limited by microbial contamination or visual, textural and nutritional quality loss. There are many methods to reduce/eliminate microorganisms present in food and ozone treatment is one of them. The use of ozone by the fresh produce industry is a good alternative to chemical treatments, e.g. the use of chlorine. The effectiveness of ozone as an antimicrobial agent has previously been reviewed and has been updated here, with the latest findings. The main focus of this review is on the effects of ozone on the fresh produce quality, defined by maintenance of texture, visual quality, taste and aroma, and nutritional content. Furthermore, ozone has been found to be efficient in reducing pesticide residues from the produce. The treatments that have the ability to reduce microbial contamination of the product without having an adverse effect on its visual, textural and nutritional quality can be recommended and subsequently incorporated into the supply chain. A good understanding of all the benefits and limitations related to the use of ozone is needed, and relevant information has been reviewed in this paper. © 2014 Society of Chemical Industry     

鲜切果蔬中生物保鲜剂的研究进展

随着人们对食品质量与安全的要求日益提高,鲜切果蔬保鲜技术迅速发展,生物保鲜剂因具有安全、高效等特点成为鲜切果蔬保鲜的研究热点。鲜切果蔬经分级、清洗、修整、去皮、切分、保鲜、包装等过程处理后,机械损伤、生理代谢、病原微生物污染等问题会引起鲜切果蔬腐烂、品质下降,给鲜活农产品的经济贸易带来了巨大损失,并对人类生命安全造成了重大威胁,因此本文综述了温度、气体环境、生理生化反应、微生物等几项能够导致鲜切果蔬褐变腐烂、品质下降的重要影响因素;总结了3种生物保鲜剂在鲜切果蔬保鲜中的应用,包括植物类天然保鲜剂、动物类天然保鲜剂和微生物保鲜剂;讨论了生物保鲜剂的不足,并对今后生物保鲜剂的发展进行了展望。     

Determination of O2 and CO2 transmission rate of whole packages and single perforations in micro-perforated packages for fruit and vegetables

Microperforated packages are in widespread use for whole and fresh-cut fruit and vegetables, and there is a need for a simple and cost efficient methodology to accurately determine gas transmission rates for different packages. This work demonstrates a static technique using a low cost gas analyser for determining the O₂ and CO₂-transmission rates and permselectivity for whole perforated and non-perforated packages stored at different temperatures. The work further demonstrated the possibility to calculate the transmission rates for single holes, and results for single perforations agreed well with results in other studies. The O₂- and CO₂-transmission rates in perforated packages were not significantly affected by temperature in the range 5–23 °C, whereas transmission rates increased with increasing temperature for non-perforated packages. Gas transmission measurements can be used within quality control, in the choice of appropriate packaging for different fruit and vegetables and as an important parameter in EMAP modelling.     

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。