Progress 04/01/13 to 03/31/18
Outputs
Target Audience:farmers, researchers and consumers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Students learned to design a horticultural field experiment, measure fresh weight, soluble solids and fruit firmness, analyze and interpret data How have the results been disseminated to communities of interest?A presentation will be given February 5, 2019 at the NJ Vegetable Grower's Meeting in Atlantic City, NJ What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Essential Oils and their Encapsulation in Cyclodextrin. Herbs such as thyme, oregano, cinnamon and garlic have been used throughout history to not only add flavor to foods but to preserve their shelf life. The essential oils (EOs) found in herbs was later shown to be responsible for anti-microbial effects. In addition, EOs typically act as growth inhibitors. Monoterpenes from a variety of plants are known to inhibit respiration and act as uncoupling agents for ATP production. This coincides nicely with the two most important factors for increasing postharvest shelf life: reduction in disease and reduced respiration. The major difficulty in using monoterpene EOs for reducing disease and inhibiting the deleterious effects of respiration on shelf life is that the compounds are volatile. Volatility makes the compounds difficult to apply and their effective treatment time is limited, nevertheless; a volatile compound can coat the surface of a the plant cuticle much more effectively than a compound dissolved in water. The strategy we have adopted is to encapsulate the EOs in cyclodextrin (CD). CDs are cage-like compounds with the ability to sequester small molecules. Beta-CD is relatively inexpensive, has GRAS status and is used in the food industry. The release of encapsulated compounds from CD involves the absorption of water by CD. This changes the conformation of the complex and releases the EO. The CD-EO complex is sealed in a Tyvek sachet. Tyvek is permeable to water vapor but impermeable to liquid water. The fruit is packaged in 1-lb vented plastic clamshell containers. Fruit transpiration provides the water to change the conformation of the CD-EO complex, and results in a slow-release of EO. Modified Atmosphere Packaging (MAP). The second component to our system is to use MAP to wrap the clamshell packages. The MAP has microperforations in the packaging to create an atmosphere modified by the amount and type of fruit in the package. During storage, the fruit respires, reducing the oxygen, and increasing the carbon dioxide content of the package. Some water vapor exits the package preventing condensation that can promote disease. The optimal oxygen content of the package for a variety of fruits and vegetables is about 5%, and carbon dioxide from 5-10%. Without the microperforations oxygen content can drop below 1% creating an anaerobic environment resulting in off-flavors and aroma along with fruit deterioration. MAP also maintains water content of the fruit. This is important because strawberry is typically 92% water when ripe. Losses of as little as 2% are significant because they change color and texture of fruit and increase consumer rejection. Treatments. Cooled fruit were added to each package (6 replicates /treatment) and weighed. Strawberry fruit were maintained for 7 days at a temperature between 0-4 C. There were 4 treatments in each experiment. These treatments consisted of some combination of thyme (Thymus vulgaris) EO and MAP in a 2x2 complete factorial experimental design. The treatments were: +EO +MAP, - EO +MAP, +EO - MAP, - EO- MAP. Two Tyvek sachets containing CD (with /without EO) were taped to the inner bottom of the containers in some experiments, or a coating of the CD-EO complex was prepared with soy protein isolate and glycerol. Results. 'Chandler' strawberries were picked directly into clamshell containers at a commercial farm in NJ. After 7 days, the fruit was evaluated and then again after 1 additional day at 11 C to simulate a retail display. The fruit were evaluated for changes in fresh weight, disease incidence and two quality parameters, firmness and Brix. It was clearly evident that enclosing the clamshell packaging containing fruit in MAP reduced water loss. Treatments without MAP lost 5.4% fresh weight whereas with MAP treatments lost 0.4% or less fresh weight. At $4/lb., this loss of fresh weight translates directly into an economic loss. EO had no effect as expected on fresh weight loss. In contrast, disease incidence was significantly reduced by treatments containing thyme EO. The best treatment was TO:CD +MAP with the lowest percentage of disease fruits. Fruit quality parameters such as firmness and Brix (soluble solids) were in the range for acceptable ripe fruit with all treatments. Fruit firmness slightly increased during storage, whereas mean Brix only increased in the treatments without MAP. This may have been due to the loss of fresh weight. After 7 days in cold storage, the fruit were stored at 11 C for one additional day to simulate retail shelving conditions. All treatments were stored without MAP. The higher temperature resulted in a loss of fresh weight. Treatments without MAP lost an additional 4% of their fresh weight to a total fresh weight loss of 7-8%. Treatments that had been enclosed in MAP now lost a total of 2-3% of their fresh weight. The presence of MAP was a significant factor in reducing total fresh weight loss. Disease increased across all treatments, but disease incidence was lowest with the with the treatments containing thyme EO . Mean firmness and Brix was not significantly different across all treatments from initial harvest values. The results clearly indicate the value of thyme EO for disease control and MAP for reducing weight loss. What are the active components of thyme EO? GC/MS analysis of the thyme EO used in the experiment indicated the presence of more than 20 mono and sesquiterpenes. The most abundant compounds were thymol (44%), p-cymeme (27%), gamma-terpenene (5%), linalool (4%) and carvacrol (4%). In our system, the fruit are not directly treated with the EO; the EO is released in volatile form from the CD-EO complex when water vapor from transpiration enters the sachet or coating and alters CD conformation. In this experiment, the individual components of thyme EO were applied to a filter paper disc attached to the inner lid of a sealed container containing strawberry fruit. Disease incidence was monitored at both 4 and 22 C. Control fruit, thymol, p-cymene and gamma-terpenene treated fruit exhibited symptoms of disease after 11 days at 4 C; however, fruit treated with carvacrol was disease free. The results indicate that carvacrol is likely to be the component in thyme EO responsible for disease control in this system. Thymol is well-known for its antimicrobial properties, but is probably not volatile enough at 4 C to significantly reduce disease symptoms. At 22 C, thymol was inhibitory to disease development, but p-cymene and gamma-terpenene were not, despite their greater volatility. The results also indicate that the monoterpene phenols are more inhibitory to fungal growth than hydrocarbon monophenols. Future work should test other EOs that are high in carvacrol such as Greek oregano (Thymus capitatus) and common oregano (Origanum vulgare) for both disease resistance and the ability to inhibit fruit respiration. • Thyme oil (TO) can be encapsulated with cyclodextrin (CD) for postharvest disease control in strawberry fruit • TO-CD is most effective when combined with MAP • Carvacrol appears to be the most important active ingredient at the cold storage temperature
Publications
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Businesses involved in the cut-flower and fruit export trade Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We are finalizing the results of this five year study in the final months of research.
Impacts
What was accomplished under these goals?
Results Regarding the effects of thyme oil (TO) sachets and MAP bags on 'Chandler' strawberry fruit quality after 6 days storage at 3°C and 4 days at 10 ºC at the farm located near Hackettstown, NJ. Harvest Date June 9, 2017. Variety: Chandler There were four treatments: Thyme oil (TO) sachets plus Multisorb MAP bags, TO without MAP bags, No TO with MAP bags and no TO without MAP bags. Fruit weight loss after six days at 3C and four days at 10C was 13.9% for -TO+MAP, 15.5% for +TO+MAP, whereas weight loss was 17.7% for -TO -MAP, and 16.6% for +TO-MAP. The fruit weight loss was significantly different between + and - MAP. Disease incidence was 24.7% for -TO+MAP, 15.7% for +TO+MAP, whereas disease incidence was 25.5% for -TO -MAP, and 16.0% for +TO-MAP. The fruit disease incidence was significantly different between + and - TO. Conclusions There was a very low incidence of disease in all treatments after six days storage at 3°C. Disease incidence increased significantly when fruit were stored at 10°C for four days to simulate market shelf conditions. There were two important conclusions: (1) Multisorb MAP packages during the 6-day cold storage period reduced shrinkage (weight loss of fruits) significantly compared to fruit stored in clamshells without MAP. This was true when clamshells were weighed after 6-days (data not shown) and after the additional 4-day market shelf storage, even though the clamshells were all removed from MAP before the 4-day market shelf storage, (2) Thyme oil (TO) sachets significantly reduced disease incidence by about 10% compared to fruit stored without TO sachets. The +TO+MAP treatment resulted in the lowest disease incidence and lowest fruit weight loss during the 10-day postharvest storage. There were no treatment effects on fruit firmness or soluble solids content (TSS).
Publications
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:Discussion of results with businesses involved in the cut-flower and fruit export trade Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Discussion of results with companies interested in licensing technology What do you plan to do during the next reporting period to accomplish the goals?Experiment with different coating technologies to increase disease control effectiveness. For blueberry commercial use, disease will need to be reduced to 5% or less.
Impacts
What was accomplished under these goals?
In these experiments, blueberry fruit were harvested from local farms, cooled to 5°C using forced air and packed in 170 g plastic clam shells. A coating containing thyme oil encapsulated in cyclodextrin (TO:CD) was applied to the inner lid. There were 12 reps/tmt for blueberry. For the treatments with modified atmosphere packaging film (MAP), 12 treatment reps were placed in a box, wrapped and heat-sealed with MAP. Experiments with blueberries were done to evaluate the antimicrobial effectiveness of a ratio of 16:84 thyme oil (Thymus vulgaris) (TO) cyclodextrin (CD) capsules in a coating, on blueberries stored for 30 d at -1 °C with 94% humidity, with or without MAP (View Fresh A bag), or TO:CD. We found that fruit stored using MAP (VFA bag) and TO:CD sachets had significantly less decay and less weight loss. There were four treatments: TO:CD + MAP, TO:CD -MAP, CD +MAP, and CD -MAP with 12 clamshell packs per treatment. All treatments that were enclosed in MAP, had significantly less weight loss than treatments without MAP. This is important since weight loss reduces yield and quality of blueberry independently of disease incidence, and is an important problem during long term storage during shipping common to this fruit. In fact, MAP is not used commercially because of disease incidence. There were no significant treatment effects on firmness or soluble solids. These results indicate that the anti-microbial essential oils in the TO:CD capsules can successfully be applied as a coating to the clamshell package, which may be a more desirable delivery system for TO:CD than sachets. For blueberry, stored for long periods (30 d), the addition of MAP seemed essential for disease control and to avoid fruit shrinkage. We are making headway in our efforts to develop innovative packaging systems for fresh blueberries and other fruits to enhance quality and safety, and to extend shelf-life. We are developing an approach to extend the shelf life of fresh blueberries, and other small fruit using packaging as a delivery system to minimize microbial contamination through the controlled release of natural antimicrobials, and to extend shelf life using modified atmosphere packages (MAP).
Publications
- Type:
Other
Status:
Other
Year Published:
2015
Citation:
HERBAL ESSENTIAL OIL FOR BIOMATERIAL PRESERVATION - PATENT
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:Postharvest horticultural industry Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One part-time non-salaried scientist and one student have participated in the project and have received training in microbiology, cyclodextrin encapsulation chemistry, postharvest handling of horticultural products and chemical analyses of essential oils. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?The next series of experiments will be designed to determine the active ingredients within thyme oil that contribute to its anti-microbial activity. Based on this information other essential oils high in the ingredients active in our system will be tested for disease control.
Impacts
What was accomplished under these goals?
Impact Statement The results of this research will help to reduce the postharvest losses of fruit, vegetables and flowers estimated to be 25% of the total value of these horticultural commodities in the US. This research will also open new markets to US Horticulture because it will be possible to ship a greater number and variety of fruits, vegetables and flowers to overseas markets that are currently limited by our ability maintain fresh quality during lengthy shipping periods. Project activities and Accomplishments Strawberry fruit were harvested at commercial ripeness with an average firmness of 10.0 N/cm2 and a Brix of 6.21 degrees, within the range normally considered for ripe strawberry. The fruit were cooled to 5 C within two hours of harvest and placed in 454 gram plastic clamshell packs and weighed. In this experiment the thyme oil:cyclodextrin capsules (TO:CD) were formulated into a coating made with food grade natural products and dried onto the inner upper lid of the clamshell packs. For a control, CD was coated onto the inner upper lid but without TO. Modified atmosphere packaging (MAP) was another treatment. The MAP film chosen contained micro perforations to prevent water vapor condensation and to maintain a low oxygen but high carbon dioxide content within the package. There were four treatments: TO:CD + MAP, TO:CD -MAP, CD +MAP, and CD -MAP with 12 clamshell packs per treatment. The treatments were maintained at 4 C for seven days and evaluated for disease incidence, weight, firmness and soluble solids. Samples were also evaluated after an additional day at 11 C to simulate conditions in a supermarket display case. After seven or eight days, disease incidence was significantly reduced for the TO:CD + MAP treatment compared to treatments without TO:CD. Disease incidence with the TO:CD -MAP was intermediate, but not significantly different from the CD alone treatments. After an additional day at 11 C, disease incidence was greater for all treatments but the TO:CD + MAP treatment had significantly less disease than the others. All treatments that were enclosed in MAP on both evaluation dates, had significantly less weight loss than treatments without MAP. This is important since weight loss reduces yield and quality of strawberry independently of disease incidence. There were no significant treatment effects on firmness or soluble solids. These results indicate that the anti-microbial essential oils in the TO:CD capsules can successfully be applied as a coating to the clamshell package, which may be a more desirable delivery system for TO:CD than sachets. In the next phase of the project we will determine the effects of other essential oils encapsulated with cyclodextrin and additional delivery systems to increase disease control.
Publications
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Postharvest horticultural industry Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The research provided training to two students duringthe summer who assisted with the project activities How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? The next steps will be to continue optimization of thyme oil/cyclodextrin encapsulation ratio for disease control technology
Impacts
What was accomplished under these goals?
Progress to date proves the technology that we have developed to reduce post harvest disease development in small fruits is effective for strawberry, blackberry and blueberry. This technology will benefit growers, processors and shippers of fresh fruit by reducing losses due to disease. The technology will also extend the shelf-life of these commodites and benefit consumers as well. Experiments were conducted in 2014 with strawberries, blackberries and blueberries to determine optimal weight ratios for thyme oil/cyclodextrin (TO/CD) encapsulation and amount of TO/CD capsules used for each sachet. Disease control was optimal in each case with a 14/86 weight ratio and 0.5 g of capsule in each sachet. For raspberry, the fruit were stored for 5 days at 1 C and evaluated for disease incidence, weight loss during storage (shrinkage), firmness, soluble solids and anthocyanins. A second storage period consisted of 5 days at 1 C + 2 days at 10 C to simulate supermarket shelf storage. Fruit (120 g) were packed in 120x100x35 mm (LxWxD) plastic clamshells with 12 clamshells/treatment with or without TO/CD sachets and either wrapped in View Fresh A bags or simply placed in open cardboard boxes during storage. Data were subjected to statistical analysis. For each storage interval, disease incidence was signficantly reduced with the TO/CD sachets treatments, and weight loss was reduced for the treatments wrapped in View Fresh A bags. Fruit firmness was not different between control and treatment and not different from initial values after 5 d at 1 C. For the 5 days at 1 C + 2 days at 10C, firmness was unchanged for TO/CD treatment compared to initial values, but controls had signifcantly lower firmness levels. Soluble solids and anthocyanin content was unchanged for all treatments and statistically the same as the initial values. The data indicates that TO/CD sachets can reduce disease incidence and weight loss can be reduced using view Fresh A bags without effects on other quality parameters.
Publications
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Progress 04/01/13 to 09/30/13
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? An undergraduate student received training in postharvest pathology research. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Experiments were conducted with strawberry fruit to determine the effects of thyme oil:cyclodextrin ratio, and dusting versus sachet delivery systems, on the extent of fungal infection, firmness and brix value of the fruit. The cyclodextrin capsules can be loaded with different concentrations of thyme essential oil. In this experiment we compared 8:92 and 16:84 ratios of thyme oil to cyclodextrin by weight. We also delivered the capsules either in a sachet attached to the bottom of the clamshell package, or by dusting the capsules on the fruit before packaging. Fruit (about 300 g) were packaged in plastic clamshell containers used commercially to hold 1 lb. of fruit. Two sachets were attached to each container or the fruit were dusted with TO:CD (5 g). There were two control treatments for the sachet or dusting delivery methods that contained CD without TO. There were 8 replicate containers per treatment and the fruit were stored for 7 days at 1C before evaluation. RESULTS. Disease incidence was higher for the dusting treatments compared to the sachet delivery system. The 8:92 ratio treatments had higher disease incidence than the 16:84 treatments. The best treatment, the 16:84 TO:CD sachet treatment, was without disease, whereas more than 75% of the fruit were diseased with the CD sachet alone. Firmness was maintained in the 16:84 TO:CD treatment, but was less than 50% of this value for all other treatments. Brix values were greater than 9, indicating ripe fruit, but it did not differ significantly among treatments. Treatment effects were significant at the 5% level by LSD. The results provide new information on the importance of the sachet delivery system to control disease and indicate an effective TO:CD ratio, and the number of sachets needed for each package, to control disease and maintain firmness which leads to longer shelf-life.
Publications
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