Influence of different concentrations of 1-methylcyclopropene on the quality of tomato harvested at different maturity stages

BACKGROUND: A wide range of 1‐methylcyclopropene (1‐MCP) concentrations as well as various treatment durations have been studied in tomatoes by different researchers. However, little is known about interaction of 1‐MCP doses and maturity stages of tomatoes. Therefore the effects of different concentrations of 1‐MCP on storage and postharvest quality of ‘Zorro’ tomatoes harvested at mature green or pink maturity stages were investigated in a 2‐year trial study. RESULTS: Higher concentrations of 1‐MCP delayed and/or inhibited all parameters related to fruit ripening, such as lycopene, chlorophyll, surface color, polygalacturonase (PG) activity and soluble solids content/titratable acidity (SSC/TA), and these effects were greater in tomatoes harvested at the mature green stages. Lower concentrations of 1‐MCP slightly reduced the loss in general quality features compared with untreated tomatoes. CONCLUSION: The results suggest that 1‐MCP, especially at higher doses, is effective for delaying ripening of mature green tomatoes. Mature green fruits treated with 1000 nL L^?1 1‐MCP were stored for 35 days without significant decreases in quality characteristics such as elasticity, surface color and SSC/TA with certain physiological processes (ethylene production, PG activity, lycopene synthesis). Copyright © 2011 Society of Chemical Industry     

How to prevent ripening blockage in 1-MCP-treated 'Conference' pears

BACKGROUND: Some European pear varieties treated with 1‐methylcyclopropene (1‐MCP) often remain ‘evergreen’, meaning that their ripening process is blocked and does not resume after removal from cold storage. In this work this was confirmed also to be the case in ‘Conference’ pears. To reverse the blockage of ripening 1‐MCP treatments combined with external exogenous ethylene were tested. RESULTS: 1‐MCP treatment of ‘Conference’ pears is very effective in delaying ripening and, more specifically, softening. The same 1‐MCP concentration in different experimental years caused a different response. The higher dose of 1‐MCP (600 nL L^?1) always resulted in irreversible blockage of ripening, whereas the behaviour of fruit receiving a lower dose (300 nL L^?1) depended on the year, and this did not depend on maturity at harvest or on storage conditions. Simultaneous exposure to 1‐MCP and exogenous ethylene significantly affected fruit ripening, allowing significant softening to occur but at a lower rate compared with control fruit. CONCLUSION: The application of exogenous ethylene and 1‐MCP simultaneously after harvest permitted restoration of the ripening process after storage in ‘Conference’ pears, extending the possibility of marketing and consumption. Copyright © 2011 Society of Chemical Industry     

The effects of 1-methylcyclopropene treatment on the shelf life and quality of cherry tomato (Lycopersicon esculentum var. cerasiforme) fruit

The use of 1‐methylcyclopropene (1‐MCP) to extend the shelf life of cherry tomato (Lycopersicon esculentum var. cerasiforme) was investigated. Higher concentrations of 1‐MCP delayed the ethylene induced climacteric peaks in mature green (MG) and breaker (BR) fruits. Thirteen days after treatment, control fruits were 55% as firm as fruit treated with 0.11 μL L^?1 1‐MCP. The initiation of fruit softening, chlorophyll degradation and accumulation of lycopene and carotenoids was delayed in treated fruits. Higher 1‐MCP concentrations inhibited the accumulation of lycopene and carotene such that the colour of the fruit did not reach that of control fruit. Treatment of MG cherry tomatoes with 1‐MCP enhanced shelf life optimally, while treatment of BR fruits was beneficial where full colour and high content of lycopene and carotenoids is important. Differentiation of the different stages of ripening before application of 1‐MCP is needed in order to succeed in accomplishing different postharvest objectives.     

SEQUENTIAL TREATMENTS OF HOT WATER AND MODIFIED ATMOSPHERE PACKAGING IN CHERRY TOMATOES

ABSTRACT

The effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on the storage and fruit quality of cherry tomatoes (Lycopersicon esculentum Mill. cvs. “Alona” and “Naomi”) were investigated. For this purpose, light‐red cherry tomato fruits were dipped in hot water (54C for 5 min) and subsequently stored in plastic film materials with various O₂ and CO₂ permeabilities. The cultivars used in the study were stored in a cold room at 5–7C and 90 ± 5% relative humidity (RH). The changing gas composition within the films and quality changes of the fruits were evaluated during the storage period. At the end of the study, HWT combined with MAP produced better results than MAP alone in both cultivars. Therefore, the HWT + MAP treatment proved effective with regard to fruit quality and delaying the maturity of cherry tomatoes during storage. HWT + 50 micropolyethylene (μPE) treatment produced the best result in the two cultivars at the end of the 28‐day storage with respect to the parameters evaluated in the study.

PRACTICAL APPLICATIONS

Tomato is considered a climacteric fruit, in which ripening is accompanied by a peak in respiration and a concomitant sharp increase in ethylene production, which accelerates quality loss through the physicochemical changes related to this process, such as softening and color evolution. Postharvest heating is a noncontaminating physical treatment that delays the ripening process, reduces chilling injury and controls the activity of pathogens. Because of these beneficial effects, heat treatments are currently used commercially for quality control of fresh products. Modified atmosphere packaging is another technique that has been used to prevent or retard postharvest fruit ripening and its associated biochemical and physiological changes by favorably altering the O₂ and CO₂ levels around the products. In recent years, the use of combined techniques in the postharvest handling of fresh products is increasing, and numerous authors have obtained good results using a combined treatment. Diseases have the potential to destroy the market value and utility of large amounts of fresh tomato annually. The present work evaluated a prestorage conditioning treatment to protect against these losses. The results will allow the long storage of cherry tomato, benefiting the growers, exporters, shippers and distributors of this horticultural product.

     

Effect of pre‐ripening chilling temperatures on ripening,shelf life and quality of bananas treated with 1‐methylcyclopropene

Ethylene production, shelf life and fruit quality of Cavendish bananas (cv. Williams), held at different pre‐ripening storage temperatures (5 °C, 10 °C or 15 °C) prior to ethylene and/or 1‐methylcyclopropene (1‐MCP) application, were determined and compared. Levels of ethylene production during ripening were highest for control fruit that had been stored at 5 °C followed by 10 °C and then 15 °C. 1‐MCP treatment (at 300 nL L^?1) had no effect on ethylene production of fruit that had been stored at 10 °C by day 10 of storage, but ethylene production was significantly higher for fruit that had been stored at 15 °C and lower for those stored at 5 °C before 1‐MCP treatment. 1‐MCP also increased shelf life to a greater extent when applied to fruit that had been stored at 10 °C or 15 °C. Even though 1‐MCP had no significant effect on under peel chilling injury, it increased discolouration significantly, regardless of storage temperature. Firmness of 1‐MCP‐treated fruit decreased significantly compared to the control when fruit were held at 5 °C or 15 °C prior to ripening (and 1‐MCP application) but had no effect on fruit stored at 10 °C before ripening. These results indicate that pre‐ripening storage temperature affects ripening, shelf life and quality in both ethylene and 1‐MCP‐treated bananas.     

1‐METHYLCYCLOPROPENE DELAYS POSTHARVEST RIPENING AND REDUCES DECAY IN HAMI MELON

ABSTRACT

The effects of 1‐methylcyclopropene (1‐MCP) on postharvest ripening and fruit decay in Hami melon were investigated. Melons were treated with 0, 0.1, 1, or 5 µL/L 1‐MCP at 25C for 24 h and then stored at 25C for 16 days. 1‐MCP treatment significantly inhibited respiration rate and ethylene production and delayed their climacteric rise. The treatment also significantly inhibited the decrease of firmness and the increase of electrolyte leakage. Moreover, treatment with 1 or 5 µL/L 1‐MCP maintained significantly higher total soluble solids, vitamin C and chlorophyll contents. In addition, 1‐MCP treatment significantly delayed the incidence of fruit decay and inhibited the increase of decay index. The efficacy of 1‐MCP on delaying postharvest ripening and controlling fruit decay increased with increasing concentration. These results indicate 1‐MCP treatment has great potential to extend shelf‐life and maintain quality in Hami melon during distribution at ambient temperature.

PRACTICAL APPLICATIONS

1‐Methylcyclopropene (1‐MCP) has been commercially used to delay postharvest ripening and extend the storage life on some climacteric fruits. Hami melon has a very short shelf‐life mainly due to fruit ripening and decay, which causes significant economic losses. In this study, a postharvest application of 1‐MCP significantly delayed ripening and reduced fruit decay while maintaining overall quality during storage at 25C. The results will allow long‐distance transportation and marketing of Hami melon and benefit growers, shippers and distributors of this melon fruit.     

Effect of 1-methylcyclopropene on tomato flavour components, shelf life and decay as influenced by harvest maturity and storage temperature

BACKGROUND: In Florida, tomatoes are harvested green (GR), which includes mature green (MG) and immature green (IG) fruits, and stored at low temperature (13 °C), resulting in poor flavour. Flavour improvement might be achieved if fruits were harvested with some colour (to eliminate IG fruits) and/or stored at higher temperature with the ripening inhibitor 1‐methylcyclopropene (1‐MCP). RESULTS: ‘Florida 47’ tomatoes were harvested at GR (MG + IG), breaker (BR), turning (TR) and pink (PK) stages, treated (+) or not (?) with 1‐MCP and stored at 13 and/or 18 °C. 1‐MCP treatment resulted in a gain of up to 6 days of shelf life depending on harvest maturity and storage temperature. Storage at 18 °C rather than 13 °C resulted in an increase in internal red colour, soluble solids (SS)/titratable acidity (TA) ratio and levels of many volatiles studied. The shelf life of BR (+) MCP fruits stored at 13 °C was similar to that of MG fruits. IG fruits exhibited lowest levels of SS, TA and ten volatiles compared with BR fruits. CONCLUSION: Harvesting tomatoes with colour (BR), thereby eliminating IG fruits, and treating with 1‐MCP resulted in better quality with adequate shelf life. Published 2011 by John Wiley & Sons, Ltd.     

Effects of stage II and postharvest deficit irrigation on peach quality during maturation and after cold storage

Effects of regulated deficit irrigation (RDI) on the quality of a mid–late maturing peach (Prunus persica L Batsch cv Andross) were determined at commercial harvest as well as 1 week before (early pick‐up) and after 1 week of cold storage. Respiration and ethylene evolution were measured during 96 h on fruits sampled at early pick‐up and at harvest. Fruits from a well‐watered irrigation treatment (Control) were compared with a treatment of RDI during stage II of fruit growth (RDI‐SII) and with RDI applied postharvest (RDI‐PH). A fourth treatment received a combination of deficit irrigation applied during stage II and postharvest (RDI‐SII‐PH). Higher soluble solids content (SSC) amd SSC/titratable acidity (TA) ratio for RDI‐SII were already noted at early pick‐up and these differences were enhanced after cold storage (RDI fruits having higher SSC, lower TA and higher SSC/TA ratio than Control fruits). This improvement in quality (high SSC/TA ratio) was also correlated with a more reddish colouration in the fruit skin. Moreover, ethylene production indicated different behaviour of the physiological evolution for fruits from the different treatments. Copyright © 2004 Society of Chemical Industry     

RESPONSE OF 1-METHYLCYCLOPROPENE TREATED "GRANNY SMITH" APPLE FRUIT TO AIR AND CONTROLLED ATMOSPHERE STORAGE CONDITIONS

ABSTRACT

In the study, the efficacy of 1‐Methylcyclopropene (1‐MCP) on the quality of apples cv. “Granny Smith” was examined. Fruits were stored for 120 and 180 days at 0 ± 0.5C and 90 ± 5% relative humidity (RH) under normal (NA) and controlled atmosphere (CA), and samples taken at 120 and 180 days of storage were kept at 20 ± 2C and 60 ± 5% RH for 7 days. Weight loss was higher in fruits stored under NA. The lowest respiration rates were in CA while the highest rates were found in NA‐stored fruits without pretreated. 1‐MCP + CA reduced the internal ethylene concentration from 10.63 µL/L to 0.60 µL. The incidence and severity of superficial scald was 68.10 and 77.00% in fruits stored in NA. 1‐MCP consistently suppressed the expression of superficial scald. 1‐MCP maintained the quality fruit kept in CA and NA environments to a higher degree than nontreated apples over a 180‐day storage period. The results indicated that cv. “Granny Smith” could be stored successfully under 1‐MCP + CA conditions and that 1‐MCP + NA may be a viable alternative to CA for optimal eating quality.

PRACTICAL APPLICATIONS

1‐Methylcyclopropene (1‐MCP) is an effective inhibitor of ethylene action and it binds irreversibly to ethylene receptors. 1‐MCP delays the onset of the climacteric ripening of fruits. Recently research has been conducted on the effects of 1‐MCP on postharvest behavior of fruits and vegetables with the objective of reducing physiological disorders and quality losses to prolong their commercial life. The use of 1‐MCP is easy. It is important that the fruit treated with 1‐MCP reach a good sensory quality at the commercial level. Superficial scald of apples is a physiological disorder, which following long‐term storage has the potential to destroy the market value and utility of millions of tons of fresh apples annually. The present work evaluated a prestorage conditioning treatment to protect against this physiological disorder. Results will allow the long storage of apple cv. “Granny Smith,” benefiting growers, exporters, shippers and distributors of this horticultural product.     

Extending the Shelf Life of Edible Flowers with Controlled Release of 1‐Methylcyclopropene and Modified Atmosphere Packaging

Abstract: Edible flowers have great sensory appeal, but their extremely short shelf life limits their commercial usage. Postharvest 1‐methylcyclopropene (1‐MCP) treatment is used to counter ethylene activity and delay senescence in fresh produce; however, its potential application in edible flowers has not been tested. The objective of this study was to investigate the effect of 1‐MCP treatment with modified atmosphere packaging (MAP) on the shelf life of edible flowers. Freshly harvested carnations and snapdragons were packaged in trays with or without 0.5 μL/L of 1‐MCP, sealed with a gas permeable film, and stored at 5 °C. Package atmospheres, tissue electrolyte leakage, and flower quality were evaluated on days 0, 7, and 14. Treatment with 1‐MCP resulted in significantly slower changes in package headspace O₂, CO₂, and C₂H₄ partial pressures, maintained higher overall quality of both flower species and reduced electrolyte leakage and abscission in snapdragon. All samples prepared with MAP had significantly reduced dehydration and higher overall quality compared to flowers packaged commercially in plastic clamshell containers. Treatments with controlled release of 1‐MCP and MAP significantly extended storage life of edible carnation and snapdragon flowers. Practical Application: Edible flowers are currently shipped via air cargo due to their extremely short shelf life. The technology developed in our research significantly extended the storage life of edible flowers, making it possible to ship the edible flowers via ground transportation with significant cost savings.     

Effects of 1‐methylcyclopropene and gibberellic acid on ripening of Chinese jujube (Zizyphus jujuba M) in relation to quality

Overripening of Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage usually results in a dramatic decline in quality. The role of 1‐methylcyclopropene (1‐MCP) and gibberellic acid (GA) in fruit ripening of Chinese jujube during storage in relation to quality was investigated. Fruit ripening of jujube was significantly enhanced by ethylene, whereas rates of respiration and ethylene production of the fruit were reduced by 1‐MCP. Treatment with 1‐MCP or GA delayed the decreases in firmness and vitamin C and reduced the level of ethanol. Furthermore, the effectiveness of 1‐MCP was improved by replicate treatments during storage at 20 or 2 °C. In addition, treatment with GA + 1‐MCP resulted in additive beneficial effects on ripening inhibition of the fruit. Copyright © 2003 Society of Chemical Industry     

Controlled‐atmosphere storage of tomato fruit: low oxygen or elevated carbon dioxide levels alter galactosidase activity and inhibit exogenous ethylene action

The effects of 3% O₂ and 20% CO₂, both alone and together with 100 µg g⁻¹ C₂H₄, on ethylene production, chlorophyll degradation, carotenoid biosynthesis and α‐ and β‐galactosidase activity in breaker tomato (Lycopersicon esculentum Mill) fruit were investigated. The low O₂ and high CO₂ atmospheres prevented the rise in ethylene production, total carotenoid and lycopene biosynthesis and α‐ and β‐galactosidase activity and slowed down chlorophyll degradation and loss of firmness (P < 0.05). These suppressive effects were not reversed, or only in part – in the case of chlorophyll breakdown – by addition of 100 µg g⁻¹ C₂H₄ to said controlled atmospheres. After transfer from the various atmospheres to air, flesh firmness decreased and ethylene production, total carotenoids, lycopene and β‐galactosidase II activity increased but these parameters were, in all cases, still significantly different from those of fruit held in air. Keeping tomatoes in controlled atmospheres, even in the presence of ethylene, had marked residual effects. Results suggest an antagonism between elevated CO₂/low O₂ and exogenous ethylene which could determine most of the ripening parameter behaviour under controlled‐atmosphere storage, though a direct regulatory mechanism by O₂ and/or CO₂ should not be discarded. © 1999 Society of Chemical Industry     

Oxidative behaviour of Blanquilla pears treated with 1‐methylcyclopropene during cold storage

The increasing use of 1‐methylcyclopropene (1‐MCP) to extend the commercial life of fruit constitutes an attractive way of improving packing house competitiveness. This compound prevents the effects of ethylene in a wide range of fruit and vegetables. However, despite the extensive literature relating to this action on ethylene, little is known about its other physiological effects. In this work, pears (Pyrus malus L cv Blanquilla) were treated with 100 ppb 1‐MCP immediately after harvest and stored in air for 5 months. Differences in oxidative stress and in antioxidant potential between controls and 1‐MCP‐treated fruits were established, determining the changes in the levels of hydrogen peroxide, ascorbate content and ionic leakage during storage. Activities of the H₂O₂‐generating enzyme superoxide dismutase (EC 1.15.11) and the H₂O₂‐scavenging enzymes catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11) and unspecific peroxidase (EC 1.11.1.7) were also determined. 1‐MCP‐treated fruits exhibited lower levels of hydrogen peroxide, ascorbate and lower ionic leakage during storage. In accordance with this result, 1‐MCP‐treated fruits also exhibited higher enzymatic antioxidant potential. These results challenge the hypothesis that the beneficial effects of 1‐MCP on ripening were not exclusively due to its action on ethylene but also to an increase in antioxidant potential in pear. Copyright © 2004 Society of Chemical Industry     

INFLUENCE OF 1-METHYLCYCLOPROPENE AND NATURESEAL ON THE QUALITY OF FRESH-CUT "EMPIRE" AND "CRISPIN" APPLES

Wounding during processing triggers physiological reactions that limits shelf life of fresh‐cut apples. Exposure of “Empire” and “Crispin” apples at harvest to the ethylene antagonist, 1‐methylcyclopropene (1‐MCP), on the maintenance of fresh‐cut quality was evaluated in combination with post‐cut dipping of NatureSeal^TM Efficacy of 1‐MCP on fresh‐cut physiology and quality depended on the storage duration and apple cultivar. Ethylene production of apple slices was inhibited by 1‐MCP but not by NatureSeal. Total volatiles produced by fresh‐cut apples were not affected by NatureSeal but by 1‐MCP when 1‐month stored “Crispin” apples were used. 1‐MCP influenced the quality attributes of fresh‐cut slices prepared from apples stored either 4 months in cold storage or 6 months in controlled atmosphere. Enzymatic browning and softening of the cut‐surface, TSS and total microbial growth were suppressed by 1‐MCP in “Empire” apples. The influence of 1‐MCP on quality attributes in “Crispin” apple slices was marginal.     

采后1-MCP和MAP处理对‘红富士’苹果冷藏和货架期品质的影响

对‘红富士’苹果进行1.0 μL/L 1-甲基环丙烯（1-methylcyclopropene,1-MCP）和自发气调包装（modified atmosphere package,MAP）处理,继而进行0 ℃冷藏和20 ℃货架贮藏。结果表明：贮藏期间,‘红富士’苹果果实硬度和可滴定酸含量下降,可溶性固形物含量升高,虎皮病和果心褐变增多。1-MCP处理能较好维持冷藏期间‘红富士’苹果果实硬度和可溶性固形物含量,降低了包装内CO2和乙烯含量。同时,1-MCP明显降低了冷藏期间虎皮病发病指数、果心褐变指数以及果柄端果肉褐变率,显著抑制果皮α-法尼烯及共轭三烯的生成。1-MCP＋MAP结合使用可较好维持果实可滴定酸含量和果皮色泽、抑制果柄端果肉褐变。综合分析认为,1-MCP＋MAP处理能较好维持‘红富士’果实冷藏和货架期间的品质,并显著抑制果实虎皮病的发生。     

Effect of hot air treatment on quality and ripening of Chinese bayberry fruit

BACKGROUND: Postharvest decay and softening are the major factors limiting the extension of storage life of Chinese bayberry fruit. To evaluate the effects of hot air treatment (HAT) on Chinese bayberry fruit, fruits were stored at 2 °C after exposure to 20 °C (control), 40 °C (HAT₄₀), 45 °C (HAT₄₅) or 50 °C (HAT₅₀) hot air for 3 h. The effects of HAT on firmness, disease incidence, soluble solid content (SSC), titratable acidity (TA), respiration, ethylene production, pectic substances and activities of pectinmethylesterase (PME) and polygalacturonase (PG) were examined. RESULTS: HAT inhibited decrease in firmness, SSC and TA and retarded increase in disease incidence, while it promoted decrease in respiration rate and ethylene production. HAT suppressed the activities of PME and PG, which resulted in delaying the depolymerisation of chelator‐soluble and alkali‐soluble pectic substances and reducing the increase in water‐soluble pectic substances compared with control fruits. CONCLUSION: The present findings show that HAT can maintain postharvest quality and delay ripening of Chinese bayberry fruit and suggest that HAT could be considered for commercial use to extend the postharvest life of Chinese bayberry fruit. Copyright © 2008 Society of Chemical Industry     

Expression of genes associated with ethylene-signalling pathway in harvested banana fruit in response to temperature and 1-MCP treatment

BACKGROUND: Little attention has been paid to characterising the ethylene‐signalling pathway genes in relation to abnormal ripening of harvested banana fruit during storage at high temperature. The aim of the present study was to investigate banana fruit abnormal ripening and the expression of ten genes associated with the ethylene‐signalling pathway, namely MaACS1, MaACO1, MaERS1–4 and MaEIL1–4, at high temperature. Changes in these parameters of banana fruit at high temperature in response to 1‐MCP pretreatment were also investigated. RESULTS: High temperature accelerated the decline in fruit firmness, increased ethylene production and inhibited degreening in banana fruit, resulting in fruit abnormal ripening. In addition, the expression of MaACS1, MaACO1, MaERS2, MaERS3, MaERS4, MaEIL1, MaEIL3 and MaEIL4 was enhanced in banana fruit stored at high temperature. However, application of 1‐MCP prior to high temperature storage delayed fruit abnormal ripening and simultaneously suppressed the expression of MaACS1, MaERS2, MaERS3, MaEIL1, MaEIL3 and MaEIL4. CONCLUSION: The findings of this study suggested that the expression of genes associated with the ethylene‐signalling pathway might be involved in banana fruit abnormal ripening at high temperature. Application of 1‐MCP suppressed the expression of genes associated with the ethylene‐signalling pathway, which may be attributed at least partially to 1‐MCP delaying fruit abnormal ripening at high temperature. Copyright © 2010 Society of Chemical Industry     

Pre‐ or post‐harvest applications of putrescine and low temperature storage affect fruit ripening and quality of ‘Angelino’ plum

BACKGROUND: Plum has a very short storage life. The role of pre‐ or post‐harvest applications of putrescine (PUT) and low temperature storage on fruit ripening and quality was investigated in plum fruit (Prunus salicina Lindl. cv. Angelino). RESULTS: Pre‐ or post‐harvest PUT treatments [(0.1, 1.0 or 2.0 mmol L^?1) + 0.01% Tween‐20 as a surfactant] delayed and suppressed the climacteric ethylene production and respiration rate irrespective of the method used to apply PUT. PUT‐treated fruit following low temperature storage (0 ± 1 °C; 90 ± 5% RH), at the ripe stage exhibited higher fruit firmness and titratable acidity (TA), while soluble solids content (SSC), levels of ascorbic acid, total carotenoids and total antioxidants were lower than in untreated fruit. Fruit both sprayed with PUT and stored in low temperature for 6 weeks, at the ripe stage showed reduced respiration rate, delayed changes in the SSC:TA ratio and levels of total carotenoids compared to post‐harvest PUT application. CONCLUSION: Pre‐harvest application of 2.0 mmol L^?1 PUT 1 week before the anticipated commercial harvest was more effective in delaying plum fruit ripening and can be used to extend the storage (0 ± 1 °C) life of plums for up to 6 weeks with minimum losses in fruit quality. Copyright © 2008 Society of Chemical Industry     

EFFECTS OF NISIN AND MODIFIED ATMOSPHERE PACKAGING (MAP) ON THE QUALITY OF EMULSION‐TYPE SAUSAGE

ABSTRACT

The aim of this work was to study the effects of nisin (30 ppm) and modified atmosphere packaging (MAP) on the chemical, microbial and sensory properties of emulsion‐type sausage stored under two different atmospheres (%CO₂/%N₂/%CO/%O₂): 39.5/60/0.5/0 and 39.5/20/0.5/40. The samples were stored at 3 ± 1C for 42 days. Microbial count, values of pH, CIE L*, a* and b* color parameters, lipid oxidation, production of nitrosomyoglobin and sensory properties were assessed throughout the storage period. The data showed that nisin was able to reduce the growth of mesophilic, psychrotrophic and lactic acid bacteria. In addition, the MAP did not show any significant effects on microbial growth. However, free O₂ MAP, in combination with nisin, reduced the growth of yeast and mold. MAP could produce a stabilized red color and minimize the oxidative reactions in the samples. Packaging conditions had no significant effect on pH and sensory properties.

PRACTICAL APPLICATIONS

The results of this study confirmed that nisin can reduce the growth rate of lactic acid bacteria, psychrotrophic and mesophilic bacteria in emulsion‐type sausage, and free O₂ MAP, in combination with nisin, inhibits the growth of yeast and mold. The use of 30 ppm nisin, in combination with MAP containing 39.5% CO₂ and 0.5% CO gases, can lead to better quality preservation of the emulsion‐type sausages stored at low temperature and can extend their shelf life.     

Combination of 1-methylcyclopropene treatment and controlled atmosphere storage retains overall fruit quality and bioactive compounds in mango

BACKGROUND: Postharvest application of fungicide prochloraz and hot‐water dip are commercially practiced to control postharvest diseases in mangoes. Owing to the increasing consumer demand for organically produced fruit, the search for natural environmentally friendly alternative products and processes has become important for the fruit industry. This study evaluated the combined effect of 1‐methylcyclopropene (1‐MCP) (500 nL L^?1) and controlled atmosphere storage conditions (CA‐1, 5% O₂ + 5% CO₂ or CA‐2, 3% O₂ + 8% CO₂) on the maintenance of fruit quality and bioactive compounds on hot‐water treated mangoes (cv. Kent) during postharvest storage. RESULTS: In comparison to the 1‐MCP + CA‐1 treatment, 1‐MCP + CA‐2 reduced the incidence of anthracnose, weight and firmness loss; delayed the skin and flesh colour development; prevented the increase of soluble solids concentration/titratable acidity ratio, ethanol and acetaldehyde content; and maintained the ascorbic acid, carotenoid, total phenolic and flavonoid contents, and antioxidant scavenging activity in hot‐water treated mangoes. The untrained panel preferred 1‐MCP + CA‐2 treated fruit to the fruit subjected to other postharvest treatments adopted in this investigation. CONCLUSION: Our investigation suggests that the combined effect of 1‐MCP and CA‐2 storage can be recommended as an alternative treatment to replace prochloraz application for hot‐water treated mangoes and can be adopted commercially for organic export markets. Copyright © 2011 Society of Chemical Industry