Effect of Antimicrobial Starch Edible Coating on Shelf‐Life of Fresh Strawberries

Strawberry is a very sensitive fruit and presents a short post‐harvest shelf‐life. Among the factors responsible for strawberries' quality loss are high metabolic activities and mold decay. To increase product shelf‐life, cassava starch–based edible coatings (3%), added or not with potassium sorbate (0.05%), were applied on minimally processed strawberries. Uncoated minimally processed strawberries were used as control samples. Physical and chemical properties, respiration rate and sensorial acceptance of uncoated and coated strawberries stored up to 15 days at 5°C were monitored. The results showed that coatings had no significant effect on soluble solids, titrable acidity, pH and colour of strawberries. Besides reducing the respiration rate of samples, cassava starch edible coatings were efficient in delaying weight and firmness loss of strawberries during storage. In the studied conditions, potassium sorbate was not efficient in controlling microbial growth. Strawberries coated with cassava starch without the antimicrobial agent showed good conditions for consumption and good sensorial acceptance up to 12 days of storage, whereas the control samples and the samples treated with the coating containing potassium sorbate achieved a shelf‐life of 9 days because of microbial spoilage. Copyright © 2011 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.     

Combined effect of chill storage and modified atmosphere packaging on mussels (Mytilus galloprovincialis) preservation

Changes in biochemical indices, microbial growth, headspace and sensory quality of mussels which had been packaged in two modified atmospheres [Modified atmosphere packaging (MAP) 1: 60% CO₂/20% N₂/20% O₂ and MAP 2: 60% CO₂/40% N₂] and under vacuum (VP) were studied for 14 days. The results showed better quality retention and greater shelf life of mussels packaged under MAP 1 as compared to MAP 2 and VP samples. Increase in total volatile basic nitrogen followed the order: MAP 1 < MAP 2, VP < air (control) samples while increase in trimethylamine nitrogen followed the order: MAP 1 < air < MAP 2 < VP. The 2‐thiobarbituric acid (TBA) values of MAP 1 and air samples were significantly higher (p < 0.05) than the TBA values of VP and MAP 2 samples. MAP 1 showed a greater (p < 0.05) inhibition effect on total viable count of mussel samples than all other packaging conditions. Based primarily on odour scores, the MAP 1 samples remained acceptable up to ca. 10–11 days, the MAP 2 and VP up to ca. 7–8 days while the air‐packaged samples up to ca. 5–6 days of storage. Copyright © 2007 John Wiley & Sons, Ltd.     

The Applications of ‘active packaging and chlorine dioxide’ for extended shelf life of fresh strawberries

Fresh strawberries are highly perishable because of their high respiration rates. Three alternative packaging approaches were investigated to maintain the high quality and to extend the shelf life of strawberries. These were active packaging using chlorine dioxide (ClO₂) and ethylene‐moisture sachets. The quality properties of four groups of samples were measured over 3 weeks at 4°C. The groups were: control, active packaging without ClO₂ treatment, active packaging with low‐dose (5 ppm) ClO₂ treatment and active packaging with high‐dose (10 ppm) ClO₂ treatment. Measured properties were weight loss, gas concentration, pH, titratable acidity (TA), soluble solids content, texture profile and colour. Active packaging with low‐dose (5 ppm) ClO₂ treatment was found to be the most effective for TA retention and for maintaining (L) brightness values. The control group showed the largest total soluble solids reduction from 7.60 to 6.57. Active packaging without ClO₂ treatment showed the lowest weight loss (0.33%), while the control group showed the highest (1.86%) at the end of the storage. Active packaging with high‐dose ClO₂ treatment showed the highest preference value in global appearance, colour and firmness properties. The low‐ and high‐dose active packaging groups had greater firmness, gumminess and chewiness than that of all other treatments. The results from this study showed that active packaging treatment with ClO₂ and the ethylene‐moisture sachets had a beneficial effect on the quality of strawberries and could be used commercially. Copyright © 2010 John Wiley & Sons, Ltd.     

Effects of Packaging and Preservation Treatments on the Shelf Life of Murtilla Fruit (Ugni molinae Turcz) in Cold Storage

Murtilla (Ugni molinae Turcz) fruit has a unique aroma; along with its pleasant sweet flavour, this has stimulated its commercial development in international markets. This development, however, requires the application of suitable conservation methods. Five different packaging treatments for murtilla fruit (Red Pearl‐INIA variety) conservation were evaluated at 0 °C for 60 days. The treatments consisted of two types of packaging [polyethylene terephthalate (PET) punnets and low‐density polyethylene (LDPE) bags] and the application of an edible coating of carboxymethyl cellulose to the fruits. The incorporation of the aqueous extracts of murtilla leaves from the 18‐1 and 27‐1 ecotypes into the carboxymethyl cellulose edible coating was also evaluated for its antimicrobial effects. There was a significant (p < 0.05) reduction in the moisture content, a significant weight loss and an increase in soluble solids when the murtilla fruit was packed only in a PET punnet. However, with the other four treatments, in which an LDPE bag and edible coating were used, the moisture content (76.8–74.4 g/100 g) and soluble solids (15.6–17.8 ºBrix) in the fruit remained stable during storage. Low weight loss (1.64–2.25%) occurred in the fruits that received treatments with the LDPE bag and edible coating. Under experimental conditions and from operational facilities, packaging in PET punnets with an LDPE bag was the best alternative to preserve the murtilla fruit at 0 °C for 60 days. Copyright © 2013 John Wiley & Sons, Ltd.     

Effectiveness of modified atmosphere packaging in preserving a prepared ready‐to‐eat food

The effectiveness of modified atmosphere packaging (MAP) was evaluated for a combination prepared food (Korean braised green peppers with dry anchovies). From a preliminary storage test of the ready‐to‐eat dish at 10°C, the aerobic bacterial count on the green peppers was selected as a primary quality index. The effect of MAP with different CO₂ concentrations on the product quality at 10°C was also studied. MAP with a CO₂ concentration of ≥30% extended the lag time and/or reduced the growth rate of bacteria. Finally, the effect of different storage temperatures (5, 10, 15 or 20°C) on the shelf life of the product was investigated. Mathematical modelling of bacterial growth curves under stretch‐wrap air packaging and MAP with 60% CO₂/40% N₂ showed that MAP increased the hypothetical minimum temperature in the square root model that describes the temperature dependence of the lag time and growth rate. MAP conditions of 60% CO₂/40% N₂ extended the shelf life at 10°C by 130% (to 18.4 days) relative to that achieved with stretch‐wrap air packaging (7.9 days) based on the time taken to reach the quality limit of an aerobic bacterial count of 10⁵ CFU/g. The relative extension of shelf life achieved with MAP was greater at lower temperatures. Copyright © 2008 John Wiley & Sons, Ltd.     

抗菌涂层和抗菌塑料在食品包装中的研究发展

目的从可食用抗菌涂层和食品抗菌塑料包装的角度出发提升食品的品质安全,满足消费者对安全优质食品的追求。方法根据食物的腐烂周期和保质方式的特点,系统性地总结目前可食用抗菌涂层的几种主要覆盖技术,以及非食用性抗菌塑料的载体和制备方法,并将其运用到食品的包装设计中。结论针对保鲜周期短的易腐食品和保质期较长的常规食品提出了可行的包装方案,对可食用抗菌涂层和非可食用性抗菌塑料在未来食品包装领域的发展和研究做了指向性分析。     

Effect of chitosan coating and vacuum packaging on the quality of refrigerated grilled pork

The effects of chitosan coating and vacuum packaging on the quality and shelf‐life of retail packaged grilled pork in a PVDC/nylon pouch during refrigerated storage at 2 ± 1°C were investigated. Grilled pork without chitosan coating and packaged in 100% air was used as the control sample. Firmness, pH, colour, peroxide values, microbial population and shelf‐life (as determined by sensory characteristics) of the samples were determined during the storage. The results showed that colour, peroxide values and microbial population coincided with sensory characteristics. The delayed growth of microbes in vacuum packaging can be attributed to inhibition by low levels of O₂. Chitosan coating was shown to minimize oxidation, as reflected by the peroxide values, colour changes and microbial counts of the samples. Vacuum‐packaged chitosan‐coated grilled pork showed negligible microbial growth and was found to be organoleptically acceptable throughout the storage period. Chitosan coating along with vacuum packaging provided a type of active packaging to maintain quality and extend the shelf‐life of grilled pork. Copyright © 2006 John Wiley & Sons, Ltd.     

Influence of Pullulan‐Based Edible Coating on Some Quality Properties of Strawberry During Cold Storage

Pullulan‐based edible coatings were used to extend the shelf life of strawberries (Fragaria ananassa cv. Camarosa) under cold storage conditions in perforated package. Some physicochemical properties of the strawberry fruits such as weight loss, firmness, colour, ascorbic acid, total carotenoids and fungal decay were determined during the storage. The coatings delayed mould formation and decreased weight loss, softening and degradation of ascorbic acid and carotenoids in the fruits. The most marked difference was recorded in the firmness value of the fruits coated with a 10% pullulan‐based emulsion. Coating with a 10% pullulan‐based emulsion successfully extended the shelf life of the strawberries for 5 days longer under cold storage conditions. Copyright © 2014 John Wiley & Sons, Ltd.     

Modelling a modified atmosphere packaging system for fresh scallops (Argopecten purpuratus)

Seafood is a highly perishable food, which has a relative short shelf‐life. Modified atmosphere packaging (MAP) is a system that offers a way of extending the shelf‐life of seafood products, maintaining quality and inhibiting bacterial growth. The objective of this research was to study and determine the optimal conditions for packaging scallops in a modified atmosphere system, which includes CO₂/O₂/N₂ mixture, headspace:food ratio and storage temperature, utilizing an integrated mathematical model for MAP systems with its respective experimental validation. For validation purposes, two experiments were conducted, using gas mixtures of: (a) 45% CO₂/10% O₂/45% N₂; and (b) 60% CO₂/10% O₂/30% N₂. In addition, two experiments, at 6°C and 20°C, were conducted to obtain the shelf‐life model, utilizing the following gas mixtures: 30% CO₂/10% O₂/60% N₂; 45% CO₂/10% O₂/45% N₂; 60% CO₂/10% O₂/30% N₂; and 75% CO₂/10% O₂/15% N₂. Gas mixtures with CO₂ concentrations between 30% and 70% and different headspace:food ratios were tested during simulations. The optimal conditions for scallop storage were a 60% CO₂/10% O₂/30% N₂ gas mixture and a headspace:food ratio of 2:1. With these conditions, a simulated shelf‐life of 21 days was obtained. Optimal conditions consider maximum shelf‐life, an adequate film collapse criterion, and time to reach the pseudo‐equilibrium condition. The predictive mathematical model, coupled with experimental studies for specific products, can be efficiently utilized to evaluate packaging alternatives (size, material and selected thickness) for different temperatures and initial gas concentration scenarios of MAP products. Copyright © 2006 John Wiley & Sons, Ltd.     

Shelf life extension of fresh asparagus using modified atmosphere packaging and vacuum skin packaging in microwavable tray systems

Asparagus (Asparagus officinalis L.) is one of the most popular vegetables because it contains a wealth of fiber and several essential nutrients. It is a very perishable commodity due to its very high respiration rate. To maintain product quality and to satisfy consumer demand as a convenient food, modified atmosphere packaging (MAP), vacuum skin packaging (VSP), and microwaveable containers were used to extend the shelf life of fresh-cut asparagus as a ready-to-eat food product. The objective of this study was to determine the shelf life of fresh-cut asparagus packed in MAP and VSP microwaveable tray systems at commercial storage conditions, 4°C, 80% RH. Weight loss, moisture content, O₂/CO₂ concentration in the package headspace, product pH, microbial growth, and sensory evaluation were used to determine the product quality and shelf life. Moreover, the preference of product appearance and the quality of the cooked asparagus in both microwaveable tray systems at different cooking times and microwave power levels was also sensorially evaluated. During storage for 21 days, there was no significant difference (p > 0.05) in weight loss, moisture content, and pH. Sanitation and packaging techniques also helped to retard the microbial growth. Both techniques, combined with refrigeration, help to maintain the freshness and product shelf life up to 21 days for MAP and 18 days for VSP. On the basis of hedonic scale results, consumers preferred the appearance of both packaging types. Both microwavable tray systems, thus, can help to prolong the shelf life of fresh-cut asparagus and can be eaten directly from the package.     

Effect of Different Packaging Methods on Quality and Shelf Life of Fresh Reindeer Meat

The impact of different packaging methods [vacuum, modified atmosphere packaging (MAP) (60% CO₂ and 40% N₂) and MAP + CO₂ emitter] on the quality of fresh reindeer meat (M. semimembranosus) stored at 4°C for 21 days was investigated. Colour and odour of the meat, drip loss, pH, microbial content, antioxidant capacity and cooking loss were measured. The MAP + CO₂ emitter resulted in prolonged microbial shelf life compared with vacuum and MAP without CO₂ emitter as lower level of total viable counts was detected after 13 and 17 days. Samples stored with CO₂ emitter also had lower drip loss. Samples stored in vacuum had significant lower L*‐value, higher a*‐value and lower intensity of freshness (odour and colour) compared with those stored in MAP and MAP with CO₂ emitter. However, MAP with a gas‐to‐product volume ratio of 1 : 1 seems to be too low in quality preserving. Increased partial pressure by adding a CO₂ emitter improved bacterial inhibition compared with vacuum and traditional MAP. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of Antimicrobial Active Packaging to Increase Shelf Life of Gluten‐Free Sliced Bread

This paper presents a complete study and comparison of the efficiency of three types of packaging system: active packaging, modified atmosphere packaging (MAP) and combinations of both. To choose the best option, we must take into account microbiological results as well as sensory quality; therefore, a complete sensory study and an in‐depth statistical study were carried out, in order to evaluate each option and their interactions. The results showed that active packaging considerably increases the shelf life of packaged food, so it could be an attractive option to extend the shelf life. The active packaging provided better sensorial properties than the MAP option. Positive factors like characteristic flavour and spongy texture had higher values in the absence of MAP, and negative properties like cinnamon flavour, crumbly texture and hardness reached higher values when MAP was present in the packaged food. So when microbiological and sensorial properties are taken into account, the active packaging is a better option than MAP to increase shelf life because it inhibits microbial growth while maintaining the high quality of sensorial properties for gluten‐free breads. Copyright © 2011 John Wiley & Sons, Ltd.     

草莓贮存保鲜技术的研究进展

目的保鲜技术一直是延长草莓货架寿命、提高贮存时间的有效方法,总结当前先进保鲜方法,为研究学者提供研究方向和技术改进措施。方法文中主要在分析草莓如何快速腐烂变质原因的基础上,阐述目前国内外学者对于草莓贮存保鲜的先进技术方法和进展,介绍了气调、热处理、可食涂膜、瓦楞纸箱涂膜、辐照等保鲜技术的原理、特点、实现过程以及技术效果,对草莓保鲜技术的未来发展方向做出了展望。结论目前保鲜技术可将草莓的货架寿命延长至20 d以上,研究成果推动了草莓种植业的发展,提高了草莓的经济价值,并提升了我国对于草莓保鲜技术的研究水平。     

Use of Sodium Lactate and Modified Atmosphere Packaging for Extending the Shelf Life of Ready‐to‐Cook Fresh Meal

In this work, the combined effects of sodium lactate and modified atmosphere packaging (MAP) in extending the shelf life of a ready‐to‐cook fresh skewer, made up of raw pork chops and semi‐dried vegetable mix (i.e. zucchini, peppers and tomatoes), were investigated. In the first experimental step, a sodium lactate solution was used to dip pork chops at three different concentrations: 20, 40 and 60% w/w. The second part of the work was focused on the use of MAP. In particular, the following MAPs were tested: MA1 (50%O₂/30%CO₂/20%N₂), MA2 (70%O₂/30%CO₂), MA3 (30%O₂/70%CO₂) and MA4 (30%O₂/30%CO₂/40%N₂). Finally, the optimal concentration of sodium lactate and the best gas composition were combined. The samples were stored at 4 °C; their microbial and sensory qualities were monitored along the entire observation period. The results indicate that the shelf life of the investigated ready‐to‐cook meal can be extended by approximately 83%, if compared with the control skewer packaged in air. The best preservation strategy is the combination of dipping of meat pieces in 40% sodium lactate solution and packaging under MA1. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of modified atmosphere packaging and superchilled storage on the shelf‐life of farmed ready‐to‐cook spotted wolf‐fish (Anarhichas minor)

Modified atmosphere packaging (MAP) combined with superchilling (?1°C) was evaluated as a mild preservation method for farmed spotted wolf‐fish (Anarhichas minor). Portions were packaged in air and in CO2:N2 (60%:40%) atmosphere with a gas:product ratio of approximately 1, at superchilled (?1.0°C ± 0.2°C) or chilled (+4.0°C ± 0.2°C) temperatures. A reduced bacterial growth (p < 0.001), measured as aerobic plate counts (APC) and psychrotrophic bacteria, was observed in modified atmosphere (MA) packaged wolf‐fish at both ?1°C and +4°C, compared to portions in air. MA‐packaged wolf‐fish had improved odour and flavour scores (p < 0.05), but also a higher drip loss than fish stored in air. A shelf‐life of 15 days was obtained at ?1°C for MA‐packaged fish compared to 8–10 days in air, and at 4°C the shelf‐life was 13 days in MA and 6–8 days in air. Copyright © 2006 John Wiley & Sons, Ltd.     

Development of an active polylactic acid (PLA) packaging film by adding bleached bagasse carboxymethyl cellulose (CMCB) for mango storage life extension

This study aimed to determine the properties of a new active packaging film in order to extend the storage life of fresh mangoes by packing “Nam Dok Mai” mangoes (Mangifera indica Linn) with an active packaging film composed of biodegradable polymer and cellulose derivatives. A new packaging bag was produced primarily by blending polylactic acid (PLA) with spray‐dried carboxymethyl cellulose (CMC) from bleached bagasse (CMC_B) at various concentrations (0%, 1%, 2%, and 4% w/w). The film thickness of the PLA and PLA/CMC_B bags was 75 μm. Unpacked mangoes were used as control before the packaged ones were stored at export conditions (13 ± 1°C and 90 ± 5% relative humidity [RH]) to evaluate the efficiency of the PLA/CMC_B film. Mango respiration and ethylene production rate were measured periodically in a packaging atmosphere as an indicator of ripeness. Changing fruit physio‐chemistry parameters were also studied, including weight loss, peel and flesh colour, firmness, total soluble solid (TSS), and total acidity (TA). The capacity of PLA/CMC_B packaging to absorb water vapour and prolong mango shelf life was demonstrated, and active packaging function by control of RH was also demonstrated. The absorption of PLA/CMC_B packaging was increased dramatically at 4% (w/w) CMC_B mixed with PLA. At this CMC_B concentration, the packaging film could extend the shelf life of mangoes for 42 days in export condition as well as decrease the physio‐chemistry parameters and respiratory rate, which were significantly enhanced when compared with those of control mangoes or unpacked mangoes (P ≤ 0.05), which had a shelf life of approximately 3 weeks.     

PVA 活性包装膜对圣女果保鲜性能研究

目的研究常温贮藏条件下PVA活性包装膜对圣女果的保鲜性能。方法采用3种不同的包装膜(PE膜、PVA包装膜、PVA活性包装膜)对圣女果进行保鲜包装,通过对圣女果的感官评价,同时测定其失重率、腐败率、维生素C及总糖含量等各项指标的变化,比较3种不同包装膜对圣女果的保鲜效果。结果 3种包装膜均适用于圣女果的保鲜包装,可延长其货架寿命;通过对保鲜后圣女果各项性能指标进行检测,发现PVA活性包装膜能够更好地延缓圣女果的腐败,降低变质率,维持较高的维生素C及总糖含量,延长圣女果的保鲜期。结论 PVA活性包装膜将圣女果的保鲜期延长了6 d以上,达到了很好的保鲜效果。     

氩气MAP技术在樱桃保鲜包装中的应用

研究了氩气MAP与不同预处理组合对樱桃常温保鲜性能的影响,并与自然气调包装的保鲜效果进行了比较.结果表明,在相同的包装薄膜(LDPE袋)内,相同的包装期限,氩气MAP能有效的抑制樱桃的腐烂,降低樱桃果实中水分子的活力,延长了樱桃的货架寿命.其中,涂膜结合氩气MAP对樱桃的保鲜效果最佳.     

综合保鲜处理对草莓保鲜效果的影响

以草莓为试验对象,研究1-MCP,CaCl2和植酸以及气调包装对低温下草莓保鲜效果的影响。草莓经过质量浓度为1μL/L的1-MCP(分别处理6,12和24 h)、CaCl2(质量分数为0.5%,1.0%,1.5%)、植酸(体积分数为0.05%,0.10%,0.15%)处理,用气调(体积分数为9%~10%CO2+8%~10%O2)包装后于2℃下进行储存,结果表明,综合保鲜处理能够抑制草莓的乙烯释放量和失重率的上升,延缓硬度和VC含量的下降,其中1μL/L的1-MCP处理12 h后,1%CaCl2及0.1%植酸处理对草莓保鲜更为有效。