Progress 05/03/17 to 09/30/21
Outputs
Target Audience:Food industry, specifically ready-to-eat deli meats and fresh minimally processed produce, and consumers. In addition, dairy products such as fresh milk producers, particularly small dairies could benefit from the results of our research. Since this research focuses on ways to make food stay fresher longer and add a hurdle for potential pathogens, it is hoped this work will beneft companies such as Charter Next Generation, Smithfield, and Happy Cow Dairy. Work on antimicrobial film could also benefit packaging converters such as Sonoco. Changes/Problems:Nisin's work was completed and tested as planned but the Chlorine dioxide work needed to be limited to strawberries using the existing clamshell with a delivery system. We first needed to optimize the system to determine the best location for the delivery widget. This information can be used for other produce in future projects. What opportunities for training and professional development has the project provided?Two PhD students were able to successfully defend their dissertations and publish their work. Some papers are still in process but at least one from each project has been published so far. Both were also able to find jobs in the professional field, working for companies where they will use their training and skills. How have the results been disseminated to communities of interest?Papers were presented at the Clemson University Center of Excellence for Flexible Packaging and Professional conferences such as International Association for Food Protection and International Association of Packaging Research Institutes. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Nisin research was involved in the development of a material that was tested for effacy using turkey bologna. The following is an abstract from the published paper: Training alone cannot stop the spread ofL. monocytogenes; antimicrobial packaging using nisin is an excellent approach to control this microorganism. While research indicates that progress is being made towards the commercialization of nisin-based films, there is still a gap between what can be done in research laboratories and what current packaging companies are capable of or willing to do. After 7 days, levels of nisin were observed for coating A and coating B in polymer (PA: 2617.83 IU/mL, PB: 1699 IU/mL) and wax paper (WA: 1075 IU/mL, WB: 1699 IU/mL) using the agar well diffusion method. For the spot on lawn, 2291IU/mL levels of nisin were observed on PA, WA, PB, WB. Findings from our current research suggest that the developed coatings demonstrated antimicrobial activity againstL. monocytogenes. All treatments (PA, WA, PB and WB) were statistically different from treatment C (control) in the reduction ofL. monocytogenes. All treatments had a range of two to four log reduction compared with control over 63 days. The developed coatings were food safe, colorless and within the commercial range for viscosity and percent solids. Research performed with Chlorine dioxide changed from examining a wide variety of produce with cellulose fiber pads to strawberries using a ClO2 delivery system. The following is an abstract for one of the papers published on the ClO2 work: Chlorine dioxide gas treatment has been proven to increase the shelf life of fresh strawberries. Treatment strategies often involve the addition of a generating sachet into the clamshell packaging. However, gradients exist within the package, resulting in uneven treatment of the contents. Indicators utilizing iodometric chemistry were used to determine the relative distribution of chlorine dioxide within the package. Using a nonreactive substrate (marbles) and a reactive substrate (fresh strawberries), the impacts of package dimensions, substrate size, substrate reactivity, sachet release rate, sachet placement, time, temperature, and humidity on gas distribution were investigated. Models were created to statistically analyze the influence of these packaging considerations on gas distribution. Insights gleaned from these analyses were used to drive the development of a three-dimensional printed widget facilitating improved gas distribution. The prototype system outperformed the traditional treatment strategy, resulting in significantly more oxidizer being detected by the indicator (p< 0.05).
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Romero, A., Sharp, J., Dawson, P. and Darby, D. and Cooksey, K. 2021. EVALUATION OF TWO INTELLIGENT PACKAGING PROTOTYPES WITH A PH INDICATOR TO DETERMINE SPOILAGE OF COW MILK. Food Packaging and Shelf Life. 30: 100720
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Progress 10/01/19 to 09/30/20
Outputs
Target Audience:Food industry, specifically ready-to-eat deli meats and fresh minimally processed produce, and consumers. In addition, dairy products such as fresh milk producers, particularly small dairies could benefit from the results of our research. Since this research focuses on ways to make food stay fresher longer and add a hurdle for potential pathogens, it is hoped this work will beneft companies such as Hormel, Smithfield, and Happy Cow Dairy. Work on antimicrobial film could also benefit packaging converters such as Sonoco. Changes/Problems:Nisin containing film reserach was completed in the last reporting period so work using active packaging was directed toward development and implementation of a spoilage indicator film. What opportunities for training and professional development has the project provided?Two PhD students were given opportunities to complete their degrees and gain experience in developing, implementing and defending their research. How have the results been disseminated to communities of interest?Papers were presented at the Clemson University Center of Excellence for Flexible Packaging and Professional conferences such as International Association for Food Protection and International Association of Packaging Research Institutes. What do you plan to do during the next reporting period to accomplish the goals?Continue work on chlorine dioxide as antimicrobial treatment. Work on nisin film is currently completed, but if an appropriate student is found, more work on different foods or challenges against different bacteria could be pursued.
Impacts
What was accomplished under these goals?
One of the graduate students that worked on Chlorine dioxide treatment of strawberries completed their work and has graduated. The following is a summary of their work: Strawberry waste occurs at all lifecycle stages from production, distribution, retail, and household handling; this is an estimated 640 million pounds of strawberries lost valuing at $1.4 billion dollars. Active packaging strategies based on the generation of gaseous chlorine dioxide in the primary package have potential to provide to preserve strawberries in storage extending the shelf life. Benchtop studies have shown significant bactericidal activity of chlorine dioxide and quality preserving effects. As chlorine dioxide travels from the source through the package, the concentration decreases as it acts at the surface of the food product. As a result, the dose is uneven in the package. A multifactorial model was created to determine how the packaging environment influences the distribution of chlorine dioxide gas. A prototype package insert was developed to improve the gas distribution within the primary package system. When tested in a food trial challenge, chlorine dioxide was able to extend the shelf life of strawberries in simulated distribution conditions. The chlorine dioxide releasing widget increased shelf life beyond what was seen with the sachet alone, extending shelf life by 3 days vs 1 day. Localized bleaching was observed near the site of the sachet, these bleaching effects were mitigated when the widget was utilized. High doses of chlorine dioxide were utilized to recreate the bleaching observed in the food trial study and strawberry analyes were analyzed to determine the chemical changes occurring during these events. Work on nisin containing film was completed in the last report period so active packaging reserach on meat products was directed toward spoilage indicators. Asummary is provided as follows: A pectin-based coating solution was created with a color pH indicator extracted from purple cabbage. The coating was applied to a packaging film used to contain a 10g slice of beef semitendonosis sample and vacuum packaged. Beef samples were evaluated for pH and bacteria counting, and film samples were evaluated for color in three-day intervals: 1, 4, 7, 10, and 13 days. Film samples were evaluated for mechanical properties (tensile test), water and oxygen barrier and thermal properties (DSC).The color indicator film changed color parameters when the pH changed. The mechanical properties of the color indicator film were similar to the control film. The thermal properties of the color indicator film were different to the control film due to the volatilization, crystallization and other properties of the coating materials. Future research should be testing other types of meats such as chicken, pork, fish and shrimp with the color indicator film. Finally, it can be said that this study presents a new aspect of intelligent sustainable films.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2021
Citation:
Romero, A., Cooksey, K., Dawson, P. and Darby, D. EVALUATION OF TWO INTELLIGENT PACKAGING PROTOTYPES WITH A PH INDICATOR TO DETERMINE SPOILAGE OF COW MILK. Food Packaging and Shelf Life. in progress
Romero, A., Cooksey, K., Dawson, P. and Darby, D. CREATION AND CHARACTERIZATION OF A FILM WITH A PH COLOR INDICATOR TO DETERMINE THE SPOILAGE OF BEEF, USING SUSTAINABLE MATERIALS. Food Packaging and Shelf life. in progress
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:Food industry, specifically ready-to-eat deli meats and fresh minimally processed produce, and consumers. In addition, dairy products such as fresh milk producers, particularly small dairies could benefit from the results of our research. Since this research focuses on ways to make food stay fresher longer and add a hurdle for potential pathogens, it is hoped this work will beneft companies such as Hormel, Smithfield, and Happy Cow Dairy. Work on antimicrobial film could also benefit packaging converters such as Sonoco. Changes/Problems:Additional work on nisin containing film will require a student with microbiological skills in handling pathogenic bacteria. Currently our Class II biohazard lab is not safe to work in with regard to exposed asbestos. Our work this period had to shift to a non-pathogen work in a lab currently vacated by a retired faculty. Our current work still involves food safety related work but just doesn't involve innoculation with pathogenic strains. What opportunities for training and professional development has the project provided?Graduate students learned lab techniques such as microbial plating, dilution and reporting methods.The work on chlorine dioxide required consultation withan industry expert and learning design of experiments. How have the results been disseminated to communities of interest?This work has been presented at the International Assocation for Food Protection in July 2019, International Assocation of Packaging Research Institutes in Erding, Germany in November 2019. It has also been presented at the Fall and Spring meetings for Center for Flexible Packaging (CEFPACK) Annual Members meetings in 2018 and 2019. What do you plan to do during the next reporting period to accomplish the goals?Work has shifted to spoilage sensors for dairy and meat products. Nisin containing antimicrobial film still needs to be tested further so recruitment of a student can perform this work. Chlorine dioxide releasing packaging will be completed within the next reporting period.
Impacts
What was accomplished under these goals?
Results of the antimicrobial film are as follows: Evaluation of a flexographically applied antimicrobial coating for ready-to-eat turkey deli meat packaging. With an increase in demand for fresh, ready-to-eat meats, the use of antimicrobial food packaging could help reduce food waste by prolonging and decreasing growth of spoilage bacteria thereby, extending the shelf-life and enhancing food quality and safety. Nisaplin®, is a commercially available antimicrobial peptide that is approved by the FDA and GRAS as a food additive. This additive has the potential to be commercially added into antimicrobial packaging applications, specifically, ready-to-eat meat packaging. This study was conducted to determine if a coating containing Nisaplin® could be commercially applied to a polymer film substrate using large scale production equipment while still maintaining antimicrobial efficacy. A flexographic printing press was used to apply a liquid coating containing Nisaplin® to a PET/LLDPE laminate, non-forming web film substrate. pH and viscosity testing of the liquid coatings was conducted prior to applying the coating. Heat seal tests were conducted to determine if the coated film could be commercially converted into a package. Basis weight tests were conducted to determine the weight of the coating applied, and for determining the total cost of the converted package. Tests were also conducted using a colorimeter to determine if the liquid coatings caused a change in the overall appearance and clarity of the coated films. Antimicrobial efficacy and inhibition of aerobic bacteria, coliform bacteria, and staph growth were performed. Preservative and additive free sliced turkey deli meat was inserted into the treated and untreated converted pouches over an 11- day trial period. Inhibition testing was conducted on dry coated films to determine the maximum length of time in days that Nisaplin® proved effective in the inhibition of aerobic bacteria growth. Control films did not contain Nisaplin®. Uncoated films containing no coating were used as a second control set of pouches. The pH of he antimicrobial film was found to be 7.27 with a viscosity of 19.53 when tested with a #3 Zahn cup. Peel-able seals for all three tested films (nisin coated, coating only, and uncoated film) were achieved at 300F, with seal properties for the treatment cottoning containing Nisaplin® showing an increase in strength as temperature increased. Coated films without Nisaplin® also achieved inhibition against the growth of aerobic bacteria with statistical difference between the coating with Nisaplin® and the two control groups (the coating without Nisaplin® and the uncoated film) on Day 5 (2-log reduction) and Day 9 (1-log reduction), 45 days after the coating was applied to the film. No statistical difference in the inhibition of coliform colony growth between the two coatings (with and without Nisaplin®) throughout the sample periods. Thus, the application of the coating, as well as converting and efficacy of the antimicrobial coating process that it is possible to commercially produce an effective antimicrobial coating contain Nisaplin®. Showing that the antimicrobial coating containing Nisaplin® reduced the overall aerobic microbial population of the refrigerated ready-to-eat turkey deli-meat. Further work needs to be conducted to validate shelf-life extension and improved safety of ready-to-eat food products. Shelf Life Extension of Fresh Strawberries Through Chlorine Dioxide Generation in the Primary Package: Package Optimization, Model Validation, and Consumer Acceptance Approximately 1.6 billion pounds of strawberries are produced in the US annually, valuing $3.5 billion USD. An estimated 1/3 of food is wasted, equating to approximately 533 million pounds of strawberry waste and $1.17 billion dollars of lost revenue per year. Industry estimates assume that one day of shelf life extension is worth $1.8 billion USD. Strawberries account for 4.7% of all produce sales, therefore the shelf life extension of strawberries has an approximate value of $84 million USD/day. Chlorine dioxide fumigation is a GRAS and USDA organic intervention proven to preserve quality of fresh produce. Strawberries are packaged in the field and often sit for hours in high temperature detrimentally influencing shelf life. Generating chlorine dioxide in the primary package can intervene at the point of harvest and have continued action throughout the supply chain. Through the utilization of PRISMA systematic literature review methodology 64 papers were identified from 2004-2019. Factors influencing treatment were modeled in JMP. Data shows that strawberries are a promising target for chlorine dioxide treatment. Since high efficacy is observed at low doses treatment design and optimization requires consideration of influencing conditions. Insights from studies optimizing primary packages for forced air pre-cooling of strawberries and gradients observed in the literature leads to the hypothesis that package geometry will have an influence of sachet-based chlorine dioxide treatments. Through statistical modeling, in-depth food trial analyses, and consumer acceptance studies employing novel biometric methods, a comprehensive approach to data driven product development and optimization of chlorine dioxide based active packaging strategies will be discussed herein.
Publications
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:The proposed work addresses improvements in packaging that can help improve food safety but also food quality in terms of improving shelf life thus reducing food waste. According to the National Resource Defense Council, up to 40% of all food in the United States is uneaten and considered wasted annually, leading to a loss of $165 billion in natural resources such as freshwater, energy, and land (Gunders, 2012). The largest portion of food is lost at the consumer level which has raised concerns about consumers being confused about sell by or use by code dates. Antimicrobial food packaging could help extend shelf life and provide an extra level of assurance for companies regarding the quality of their products meeting code date requirements. Another significant area of loss is during distribution and retail sale of which fresh produce make up the largest category. The proposed work will include fresh produce which could impact local, rural grower get their products through the distribution cycle to market without serious loss of quality and overall shelf life. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate students were trained and developed skills in microbial techniques, biohazardous waste and hygiene. The postdoctoral assistant on the project helped provide training and developed lab methods for the experiments. They were also active in writing and presenting the work. How have the results been disseminated to communities of interest?Conferences where the work has been presented from the previous reporting period: AIPIA (Active and Intelligent Packaging Industry Association), IAFP (International Association for Food Protection) in June and July 2018, repectively. What do you plan to do during the next reporting period to accomplish the goals?Publish results from previous reporting period, plan to present at professional conferences appropriate to the content and write/submit a proposal for more work on chlorine dioxide antimicrobial packaging research.
Impacts
What was accomplished under these goals?
Aantimicrobial coatings containing P100 bacteriophage were developed. The base material for the coatings were pectin, methyl cellulose, aloe vera or polyvinyl alcohol. Zones of inhibition were performed with all coatings against Listeria monocytogenes and phage assays were performed. Aloe vera was eliminated as a film coating material due to the poor mechanical properties it exhibited. Peaches were coated with the antimicrobial coatings andinoculated with Listeria monocytogenes at a high and low inoculum level. Peaches were analyzed for microbial population after refrigerated storage over a period of 2 weeks. Data is being analyzed currently. Regarding research with chlorine dioxide, two packages for home storage of fresh produce were examined for their design and use for delivery of active packaging components. One package uses a vent system in the lidding to scavenge ethylene and the other package uses a carbon dioxide releasing sachet that is placed in a comparment in the lid. Both packages show promise as a method to release chlorine dioxide from sachets for fresh produce storage. Some preliminary work was performed using blueberries showing that chlorine dioxide slow release sachets reduced mold growth on the surface of the blueberries.
Publications
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Progress 05/03/17 to 09/30/17
Outputs
Target Audience:Food industry, specifically ready-to-eat deli meats and fresh minimally processed produce, and consumers. Since this research focuses on ways to make food stay fresher longer and add a hurdle for potential pathogens, it is hoped this work will beneft companies such as Hormel, Tanamura, Antle, WP Rawl, andr Prestage Farms. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Some training of undergraduates has occurred for the Creative Inquiry class. They have learned how to make diltuion fluid, aseptic technique, handline of biohazardous waste, food microbiological techniques and plating using Petrifilm. How have the results been disseminated to communities of interest?Presentations have been given at the Institute of Food Technologists meeting in 2017 and CEFPACK meeting. What do you plan to do during the next reporting period to accomplish the goals?Since we have had a full year to make progress on this project, our work will be presented at Ameripen in June 2018, the IFT annual meeting in July 2019 CEFPACK in March 2018, and AIPIA in June 2018.
Impacts
What was accomplished under these goals?
Accomplishments: Goals / Objectives Overall Objective: The overall objective of this work is to create safe, novel coatings and packaging materials that inhibit the development of foodborne pathogens and reduce local spoilage microflora in packaged foods. The proposed coating materials will combine controlled release of the antimicrobials from the coatings with specific polymer chemistry for food packaging. The coatings will be formulated with generally regarded as safe (GRAS) antimicrobials and food-grade plasticizers that will not alter the intrinsic properties of the packaged foods. Objective 1: To test film produced using the coating methods previously developed in our lab against a wider variety of bacteria to include pathogenic bacteria and spoilage flora typically found in ready-to-eat meat using film on lawn testing. Objective 2: To test the effect of the packaging material on shelf life of ready-to-eat meats and physical properties of coated material (Food Challenge study), Objective 3: To test different concentrations of nisin in the coating formulation to optimize for efficacy against spoilage and pathogenic bacteria depending upon outcome of food challenge study. If the food challenge study proves the existing formulation to be effective, process parameters for production of the film will be optimized. Objective 4: To evaluate process capabilities of converting material using form/fill/sealing operations. Objective 5: To examine optimal delivery methods for other antimicrobial agents such as chlorine dioxide using sachets, encapsulation and incorporation into cellulose fibers of purge pads. Testing will include effectiveness of chlorine dioxide incorporated packaging materials for improved safety and shelf-life of minimally processed produce such as sliced tomatoes, peppers and onions for bulk distribution and foodservice applications. These experiments will indirectly evaluate chlorine dioxide efficacy by quantifying the naturally occurring spoilage microflora including yeast and molds of the treated versus control samples. The long-term objective of this work is to develop stable, process scalable coating formulations that can be applied either on the surface of the packaging material (meats) or formulated as a wax (fruits) with an active antimicrobial agent incorporated in a sol-gel matrix that can prevent the growth of spoilage and background microflora via a control release process. Methods and Results The general approach is to extend the research in our laboratory about the immobilization of antimicrobial agents in various coating formulations. These formulations were based on film forming materials such as aloe, methyl cellulose, whey protein isolate, sodium alginate and polyvinyl alcohol. A general spot-on-the-lawn method was used to define antimicrobial spectrum of the tested antimicrobials and the formulated coatings. Briefly, the microorganism to be tested (indicator microorganisms) was grown to mid-exponential phase and then plated on the surface of nutritive agar plates. Tested antimicrobials and/or coating material were spotted as 10 microliter droplets on the surface of the lawn. After incubation, the antimicrobial activity was recorded as millimeters zone of inhibition of the lawn bacteria around the spot. Indicator microorganisms included Gram-negative and Gram-positive bacteria such as Pseudomonas aeruginosa, Escherichia coli, Salmonella Typhimurium, Micrococcus luteus, Listeria innocua and Listeria monocytogenes. Nisin was the primary antimicrobial incorporated because of our previous extended research. In addition, a novel coating was developed for stone fruits to contain bacteriophage P100 (Listex ™ P100) to be used for Listeria monocytogenes control on stone fruits. Listex ™P100, just as nisin are compounds with GRAS status. Results indicated that when used in a polyvinyl alcohol-based coating nisin has inhibitory properties against Gram-positive bacteria that can cause spoilage such as Micrococcus luteus and Listeria innocua. Listex ™P100 presented inhibitory activity against Listeria monocytogenes in all coating formulations suggesting that phage preparations can have active packaging applications. Challenge study- turkey meat active packaging polyvinyl alcohol containing nisin. The coating formulation developed previously in our laboratory is used for the study that involves objective 1 and 2. The coating solution was prepared by heating and simultaneously stirring 10 grams of 4-88 Mowiol PVOH resin in 30 mL of distilled water to 120°C for approximately 30-45 minutes until the resin dissolved into solution. Once the resin had dissolved, 3.2 mL of glycerin (40 parts per 100 grams of PVOH resin) and 185 µL of Tween® 80 (0.25% v/v) (Polysorbate 80, FCC, Spectrum Chemical Manufacturing Group, New Brunswick, NJ, USA) were then added to the cooling resin solution. In a separate beaker, 1 gram of Nisaplin ® (2.5% - 12,500 IU/mL in solution) (Danisco, Inc. Madison, Wisconsin, USA) was dissolved in 2 mL of 0.02 M acetic acid solution. (Franklin et al 2004) (Glacial acetic acid, Fischer Scientific, Waltham, MA, USA) 30 mL of 95% ethanol was then added, covered and stirred while adding both 0.3 g (0.4% w/v) ascorbic acid (ascorbic acid USP, Avantor Performance Materials, Inc. Center Valley, PA, USA) and 0.22 g (0.3% w/v) potassium sorbate. (Granular potassium sorbate, Spectrum Chemical Manufacturing Corporation, New Brunswick, NJ, USA) Both the resin solution and the ethanol solution were combined upon dissolving all components and cooling the resin solution. The material used for application of the coating was a multilayer, 2.5 mil thick, PET (polyethylene terephthalate) coextruded lidding material commonly used for hot dog packaging donated by Sealed Air Corporation. The sealant web of the material consisted of linear low density polyethylene (LLDPE). The web width of the donated roll of material was 17 inches and was slit down to 14.5 inches per the specifications of coating/laminating equipment to be used for the trial. Untreated material, 50 feet, was removed from the slitted roll as a control for future tests. After the slitting process, material was added to the front and back ends of the web to account for machine equipment set up and adjustments. This leader material was a 48 gauge PET. Approximately 400 feet was added to the front of the roll and 450 feet was added to the back. The roll totaling approximately 2250 feet was then taken to the Sonoco Institute of Packaging Design and Graphics for corona treatment. Preliminary work showed that the handheld corona treater yielded coating adhesion with a water soluble primer at 37 dynes/cm. The initial surface tension of the LLDPE sealant was 32 dynes/cm. Therefore, this same level of treatment was the goal level to be achieved at the Sonoco Institute. The corona treater on the OMET VaryFlex 530 was used to treat the material at a line speed of 150 ft/min at 1000 watt*min per m2. Heat seal curves were performed prior to making pouches following ASTM F1921 for the packaging of the deli turkey slices. Fresh, precooked turkey was obtained from Publix, Clemson SC and individually packaged into pouches made from the nisin coated PET material. On days 1, 3, 5, 7 and 10, each package of turkey was aseptically opened and 10mL of peptone dilution added to the pouch. Each pouch was hand massaged for 2 mins and 1mL removed to make serial dilutions ranging from 10-1 to 10-5 CFU/mL. Aliquots (1mL) from each dilution tube was plated onto the following Petrifilms: Aerobic Plate Count, Total Coliforms and Staphylococcus aureus. Petrifilm plates were incubated at 35oC for 48 h prior to enumeration.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Institute of Food Technologists Annual Meeting 2017 Active Packaging to Enable Clean Label, June 28, 2017, Las Vegas, NV
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Bacteriophage based antimicrobial food packaging systems: proof of concept and future directions CEFPACK Meeting, November 2017 Clemson University, Clemson SC
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