Duration and concentration of 1-methylcyclopropene treatment: impact on ripening and shelf life of partially ripened bananas

In order to improve the quality and extend the shelf life of bananas after gassing with ethylene at commercial treatment during transportation and storage the simultaneous application of ethylene and 1-methylcyclopropene were examined. Fruit were treated with 100 μL L-1 of ethylene for two consecutive days as a control, followed by 20 min ventilation each day, or simultaneously exposed to 1-MCP at different concentrations (30, 100 or 300 nL L-1 on the first day or second day, or treated with 1-MCP alone on the third day at 22ºC. Fruit from each treatment were used to evaluate external and internal quality parameters and shelf life. The results showed that shelf life increased significantly, compared to the control when 1-MCP was applied coincidently with ethylene in the second day and reapplied alone in the third day. The highest increase in shelf life (125%) was obtained when 1-MCP was applied on the second day at 30 nL L-1 simultaneously with ethylene and at 300 nL L-1 alone on the third day, compared to the control in both harvest months. We conclude that simultaneous application of 1-MCP is more effective than the more common method of extending banana shelf life through application of 1-MCP after ethylene treatment

Physicochemical traits of seedless barberry (Berberis vulgaris L.) fruits stored under refrigeration as affected by heat and calcium chloride treatments

The loss of chemical characteristics and quality of the fresh seedless barberry fruit during storage and qualitative losses of its dried fruit are the most important postharvest challenges in barberry industry and its exports. The fresh harvested fruit samples were dried using an electrical drier at 50°C to 50% moisture content. Thereafter, the effects of hot water alone (65°C for 45 sec), and hot water + 2% calcium chloride were carried out on the quality maintenance and chemicals during the cold storage of seedless barberry. The results showed that the samples treated with calcium chloride stored at 2°C had the highest TSS over time, whereas the titratable acidity of barberry fruits was not significantly affected by postharvest treatments. Hot water alone or in combination with calcium chloride treatment increased redness and chroma values result in better appearance quality than control. In addition, the treatments reduced the variable L* and thereby enhanced fruit lightness. The highest antioxidant content (% 77.92) was observed in hot water treated samples and the lowest (% 54.28) was obtained on control. Also, the highest amount of anthocyanins and antioxidants were obtained from samples treated with hot water. Only calcium chloride treatment had a significant effect on Ca content of the samples. The results revealed that postharvest application of hot water and calcium chloride treatments improved the appearance quality and nutritional values of fresh seedless barberry fruit, as well as extend the cold storage life, likely due to reduced pathogen contamination

Concentration and duration of ethylene treatment influences the response of banana to 1-methylcyclopropene

Proceedings of IV International Conference on Managing Quality in Chains - The Integrated View on Fruits and Vegetables QualityWe examined the effect of ethylene concentration and duration on 1-MCP efficacy with regards to shelf life and fruit quality in bananas (cv. Williams) from the middle section of bunches harvested during winter 2004 and summer 2005. Before storage, fruit was treated with ethylene (2, 20, 50 or ¹00 µL•L⁻¹) for two consecutive days or 100 µL•L⁻¹ for the first and 2 µL•L⁻¹ for the second day, prior to 1-MCP (300 nL•L⁻¹) exposure for 24 hrs at 22ºC. To examine the effect of duration, bananas were treated with 100 µL L⁻¹ ethylene for 30, 40 or 50 hrs prior to 1-MCP treatment (300 nL•L⁻¹) at 22 °C. 1-MCP was most effective at increasing shelf life and firmness when fruit were treated with 100 µL•L⁻¹ ethylene for the first day and 2 µL•L⁻¹ for the second day. Interestingly, fruit harvested in winter initially treated with ethylene at the lowest concentration (2 µL•L⁻¹) or exposed to the shorter duration of ethylene (30 hrs) did not ripen and remained green when treated with 1-MCP. However, winter-harvested bananas that were exposed to ethylene for 50 hrs had a longer shelf life compared to bananas treated with ethylene for 40 hrs. 1-MCP was only more effective in summer-harvested fruit when they were exposed to ethylene for 40 hrs with an increase in firmness. The discolouration index (DI) of 1-MCP treated fruit increased significantly when fruit were exposed to the ethylene for shorter durations than 50 hrs in winter, but no differences were observed in DI of 1-MCP treated bananas that were ripened with ethylene at different concentrations. These observations suggest that the efficacy of l-MCP to improve shelf life and quality of bananas is reliant on not only the harvest season of fruit but also the concentration and duration of ethylene application prior to 1-MCP usage.http://www.actahort.org/books/712/712_96.ht

Timing of 1-methylcyclopropene exposure in relation to ethylene application influences shelf life of cavendish bananas

We examined the response of shelf life and fruit quality of banana ('Williams') from the middle of the bunch to the application of 1-MCP and ethylene simultaneously as well as the effect of pre-and early-climacteric application of 1-MCP on bananas harvested from the top or bottom of bunches. Fruit were treated with ethylene at 100 μl L-1 for two consecutive days as a control or simultaneously with 1-MCP at different concentrations (30, 100 or 300 nl L-1) on the first day or second day, or treated with 1-MCP alone on the third day. To examine the effect of low concentrations of 1-MCP in the pre-climacteric stage fruit were treated with 1-MCP at (0, 2, 4, 5, 6 or 10 nl L-1) for 6h at 22°C followed by ethylene at 100 μl L-1 for two consecutive days (control) or ethylene followed by early-climacteric 1-MCP application at 300 nl L-1. Shelf life increased significantly compared to the control when 1-MCP was applied coincidently with ethylene in the second day and reapplied alone in the third day or applied only in the third day. Application of 1-MCP at the lower concentrations at the pre-climacteric stage in combination with reapplication of 1-MCP in the early-climacteric stage increased shelf life significantly in both fruit from the top and bottom of the bunch. We conclude that simultaneous application of 1-MCP is more effective than the more common method of extending banana shelf life through application of 1-MCP after ethylene treatment.F. Moradinezhad, A. Klieber, A. J. Able and M. Sedgleyhttp://trove.nla.gov.au/work/3865037

Effect of ripening temperatures on shelf life and quality of partially ripened 1-MCP-treated bananas

Also published as a journal article: Acta Horticulturae, 2010; 877(353-357)We examined the effect of ethylene and 1-MCP treatment on shelf life and fruit quality in bananas ('Williams') ripened at different temperatures. Fruit was treated with ethylene at 100 μl L-1 for two consecutive days and then were exposed to 1-MCP at 0 or 300 nl L-1 for 24h at 22°C. Thereafter, bananas were placed into temperature controlled rooms at 16, 19, 22 and 25°C with approximately 90% RH. 1-MCP was most effective at increasing shelf life and firmness when fruit were ripened at 16°C. The results showed that response of fruit to 1-MCP treatment was dependent on storage temperature after ripening initiation by ethylene. These observations suggest that a combination of optimum ripening storage temperature and application of 1-MCP to partially ripened bananas will further extend shelf life and also improve fruit quality.F. Moradinezhad, A. Klieber, A. J. Able and M. Sedgleyhttp://trove.nla.gov.au/work/3865037

Distribution and amount of stresses caused by insertion or removal of orthodontic miniscrews into the maxillary bone: A finite element analysis

Objective > Initial stability of miniscrews is an important factor in their success as orthodontic anchorages. One of the factors affecting this stability is the stresses exerted to the bone by the screw. Since the distribution and extent of stresses and strains produced during insertion or removal of miniscrews had not been measured before, this study used finite element analysis (FEA) to measure these parameters in tapered versus cylindrical screws with or without pilot sockets. Materials and methods > An FEA model of maxilla, pilot hole, and tapered/cylindrical miniscrews were created from 875 CT scan data. The bone cortex was considered 2 mm thick. The cancellous bone was reconstructed below the cortical bone. Miniscrews were modelled on the basis of commercial titanium tapered and cylindrical miniscrews (1.6 mm wide, 8 mm long). The diameter and length of the guiding hole were considered to be 1.1 and 1.5 mm, respectively. The miniscrews were inserted (and removed) between the maxillary second premolar and first molar. Stress/strain produced in the bones or screws were measured. Results > During screw insertion, in all setups, the highest stress existed within both the bone and screw, when the screw was in the cortical bone; after insertion into the cancellous bone, the stress suddenly dropped. In cylindrical screws, the highest amount of stress was distributed around the neck which was used for screw driving. In tapered screws, the stress was mostly distributed around the front one-third of the screw. During screw removal, the results of four setups were rather similar with stresses concentrated around screw necks, in the depth of the screw hole, and around the bone surface. The greatest bone stress during insertion was caused by the pilot-less tapered screw (10.18 MPa) and the lowest stress was exerted by a pilot-less cylindrical screw (0.74 MPa). Conclusion > Most of the stress and strain is tolerated by the cortical bone and not the cancellous one. Using cylindrical miniscrews might be more bone-friendly. However, all cases had stresses below tolerable thresholds, and hence are safe

Variability of responses to 1-methylcyclopropene by banana: influence of time of year at harvest and fruit position in the bunch

To examine the effect of early-climacteric (postripening) 1-methylcyclopropene (1-MCP) exposure on the shelf-life and quality of green Cavendish bananas ('Musa acuminata' cv. Williams) from the middle section of the bunch, bananas were harvested bimonthly and treated with 100 μL L−¹ ethylene for 2 consecutive days prior to exposure to 0, 100, 300, 1000, 3000 or 10 000 nL L−¹ 1-MCP for 24 h prior to storage at 22°C. 1-MCP treatment at a concentration of 300 nL L−¹ or above increased banana shelf-life significantly compared with the control, regardless of the month in which fruit were harvested except March where a higher concentration was needed (3000 nL L−¹). Fruit harvested in May were the most responsive with a greater than twofold increase in shelf-life. To examine the effect of fruit position in the bunch on 1-MCP efficacy, green fruit from the top or bottom of bunches were treated with 100 μL L−1 ethylene for 2 consecutive days prior to early-climacteric 1-MCP (300 nL L−1) exposure for 24 h at 22°C. In spring and autumn but not in summer, application of 1-MCP to early-climacteric fruit was more effective in fruit from the top than in those treated from the bottom of the bunch, increasing shelf-life. Firmness of 1-MCP-treated fruit was up to 19% greater than that of the control across the year, except in fruit from the bottom of the bunch. Given that 1-MCP is less effective in extending the shelf-life of summer-harvested fruit (particularly those from the bottom of the bunch), we conclude that preharvest conditions and fruit position in the bunch affect their responsiveness to ethylene and their behaviour during the ripening process

Concentration and Duration of Ethylene Treatment Influences the Response of Banana to 1-Methylcyclopropene

We examined the effect of ethylene concentration and duration on 1-MCP efficacy with regards to shelf life and fruit quality in bananas (cv. Williams) from the middle section of bunches harvested during winter 2004 and summer 2005. Before storage, fruit was treated with ethylene (2, 20, 50 or 100 µL•L⁻¹) for two consecutive days or 100 µL•L⁻¹ for the first and 2 µL•L⁻¹ for the second day, prior to 1-MCP (300 nL•L⁻¹) exposure for 24 hrs at 22°C. To examine the effect of duration, bananas were treated with 100 µL•L⁻¹ ethylene for 30, 40 or 50 hrs prior to 1-MCP treatment (300 nL•L⁻¹) at 22°C. 1-MCP was most effective at increasing shelf life and firmness when fruit were treated with 100 µL•L⁻¹ ethylene for the first day and 2 µL•L⁻¹ for the second day. Interestingly, fruit harvested in winter initially treated with ethylene at the lowest concentration (2 µL•L⁻¹) or exposed to the shorter duration of ethylene (30 hrs) did not ripen and remained green when treated with 1- MCP. However, winter-harvested bananas that were exposed to ethylene for 50 hrs had a longer shelf life compared to bananas treated with ethylene for 40 hrs. 1-MCP was only more effective in summer-harvested fruit when they were exposed to ethylene for 40 hrs with an increase in firmness. The discolouration index (DI) of 1- MCP treated fruit increased significantly when fruit were exposed to the ethylene for shorter durations than 50 hrs in winter, but no differences were observed in DI of 1-MCP treated bananas that were ripened with ethylene at different concentrations. These observations suggest that the efficacy of l-MCP to improve shelf life and quality of bananas is reliant on not only the harvest season of fruit but also the concentration and duration of ethylene application prior to 1-MCP usage