(Table of Contents)

CFSAN Regulatory Codes: I.C; III.A; III.C
CFSAN Program Priority Codes: none
Start Date: 10/01/1998    Completion Date: 09/30/2002

Statement of Research Problem:
This project will validate new approaches for controlling a variety of microbial contaminants in fruits, vegetables, processed food products and for reducing organisms or toxins that may cause food borne illnesses from these products. Several intervention strategies will be explored to improve the safety of fruits, vegetables, and processed food products. These strategies include improved sanitation techniques, alternative technologies (high pressure, ultrasound, and ultraviolet light processing), and irradiation.

Statement of Project Objective(s):
Investigate new methods and technologies to improve the safety of raw agricultural products and processed commodities.

Anticipated Impact on FDA Regulatory Program:
This project will provide the Agency with a substantial scientific basis for establishing future FDA policies. Workshops and symposia will be organized to communicate the results of these studies.

Project Priority Changes During FY2000:


1. Component 3, Effectiveness of Intervention Strategies to Control Biofilms, is a JIFSAN collaborative project. Due to higher priorities, the biofilm project is no longer a separate collaborative project at the NCFST.
   
2. Component 4, Safety Assessment of Pulsed Electric Field Processing Technology, was discontinued as an NCFST collaborative project effective in FY 2001.
   
3. Three new NCFST collaborative projects will be initiated in FY 2001: Bacterial Pathogen Surrogate Evaluation (Component 10), In-Shell Pasteurization of Eggs Utilizing Microwave and/or Ultrasonic Energy (Component 11), and Chemical Changes of Polymer Additives during Irradiation (Component 12).

Administrative Liaison(s): Richard E. McDonald: 708/728-4154

Research Personnel:


Name	Office/Division	FTE [00, 01, 02]	Components
S.E. Keller	OPDFB/DFPP	1.0,1.0,1.0	1,10
G. Fleishman	OPDFB/DFPP	1.0,1.0,1.0	1,4,5,11
R. Reddy	OPDFB/DFPP	1.0,1.0,1.0	4,6
V. Komolprasert	OPDFB/DFPP	1.0,1.0,1.0	8,12
E.G. Murakami	OPDFB/DFPP	1.0,1.0,1.0	7
M. Pascall	OPDFB/DFPP	0.5, 0.5,0.5	9
L. Jackson	OPDFB/DFPP	0.5,0.5,0.5	7
C. Warner	OPA/DPMU	0.8,0.8,0.8	2
L. Ali	OPA/DPMU	1.0,1.0,1.0	3
H. Solomon	OPDFB/DMS	0.5,0.5,0.5	6
T. Tran	OPDFB/DMS	0.5,0.5,0.5	2
R. Thunberg	OPDFB/DMS	1.0,1.0,1.0	2
T. Lilly	OPDFB/DMS	0.5,0.5,0.5	6
Additional Chem Support	OPA/DPMU	0.5,0.5,0.5	8,12
	Total FDA FTE's	10.8, 10.8, 10.8
Non-FDA NCFST support (technicians, graduate students, post-docs)		4.5,6.5,5.5	1,4,6,7,8,9,10,12
Non-FDA JIFSAN graduate student		1.0,1.0,1.0	3
Non-FDA visiting scientist at OPA/DPMU		0.5,0.5,0.0	8
Collaborators:
A. Paradis, Praxair			1,5
K. Taylor, Eldorado County California Department of Agriculture			1
H. L. Tan, University of California			1
P. D. Schreuders, University of Maryland			3
V. M. Balasubramaniam, NCFST/IIT			4,6
H. Wallace, Ultrasonic Energy Systems			5
E. J. Rhodehamel, Cryovac, Sealed Air Corp.			6
T. Koutchma, NCFST/IIT			7
G. Sadler, NCFST/IIT			8
K. Ghiron, Megtherm			9
C. Sizer, NCFST/IIT			9
P. Slade, NCFST/IIT			10
R. Abshire, Applied Microwave Technologies LLC			11
B. A. McNulty, Applied Microwave Technologies LLC			11

Several intervention strategies will be explored to improve the safety of fruits, vegetables, and processed food products. These strategies include improved sanitation techniques, alternative technologies (high pressure, ultrasound, and ultraviolet light processing), and irradiation. This project will validate new approaches for controlling a variety of microbial contaminants in fruits and vegetables and processed food products and for reducing organisms or toxins that may cause foodborne illnesses from these products.

Component 1 Objectives:


1. Fruit used for juice will be examined to determine factors that effect microbial levels and increase the risk of pathogen contamination.
   
2. Traditional and novel methods of disinfection will be investigated to determine the best methods to achieve a 5-log reduction in the appropriate target pathogen in fresh juices.
   
3. Methods of pathogen reduction will be examined singly and in combination to determine most appropriate methods.
Component 1 FY 2000 Deliverables:

1. Finish evaluation of higher Chlorine levels.
   
2. Begin evaluation of chlorine dioxide.
   
3. Examine use of detergents and/or surfactants in conjunction with other treatments.
Component 1 FY 2000 Progress:

1. Evaluation of Chlorine will be completed by Oct 1 2000. Results to date show minimal effects of chlorine on the reduction of pathogens on fruit used for juice processing or in juice.
   
2. Chlorine dioxide, as well as the use of detergents and surfactants will not be examined due to changing project priorities.
   
Technical Barriers to Meeting Component 1 Objectives or Deliverables:

1. Proper evaluation of intervention techniques requires that each method be tested first in the laboratory and under field conditions. Field conditions require the use of a non-pathogenic surrogate that will mimic the pathogen under similar conditions. At the beginning of this project no such microorganism was available and considerable time was devoted to development of one. At this time, additional work is still required in this area before other interventions can be examined.
   
2. During the course of this study, several results were obtained that indicate biofilms may play a role in survival of pathogens. This may be an obstacle to interventions and needs further examination.
Component 1 FY 2001 Deliverables:

1. Finish wrap up of Placerville juice project. Provide final report on results of background microflora and interventions used.
   
2. Develop method for examination of biofilms on fruit and vegetable surfaces. Begin examination of attachment.
Component 1 FY 2002 Deliverables:
Project should be completed by end of FY 2001

This project will validate new approaches for controlling a variety of microbial contaminants in fruits and vegetables and processed food products and for reducing organisms or toxins that may cause food borne illnesses from these products. Washing techniques will be developed using sanitizing agents or disinfectants that will reduce or eliminate the microbiological burden on fruits and vegetables meant to be consumed raw. In addition to microbiological analysis to determine the efficacy of the washing procedures, chemical and organoleptic analyses will be done to ensure that the procedure under study does not render the food unfit for consumption. Initial studies have dealt with the use of chemical disinfectants to reduce total aerobic plate counts (APCs). Fresh produce, such as broccoli, mung bean sprouts, celery, lettuce and green onions, have been treated with chlorine, chloramine, ozone and 10% ethanol in water.

Component 2 Objectives:


1. Evaluate the effectiveness of chemical agents in reducing APCs.
   
2. Determine if injury to the produce would prompt consumer rejection of the product.
   
3. Develop chemical tests to determine if residues or chemicals derived from the reaction of the disinfectant with the food components are left on the produce.
   
Component 2 FY 2000 Deliverables:

1. Determine the reductions in APCs after treatment with disinfectants, such as chlorine, and ozone.
   
2. Study the effects of metal ions, short chain fatty acids, surfactants, and other chemicals on the potency of ozone and chemical disinfectants.
   
Component 2 FY 2000 Progress:

1. Studies of chlorine, chloramine, ozone, and 10% ethanol in water with broccoli, mung bean sprouts, celery, lettuce and green onions have been completed. Reductions in APCs ranging from a low of about 0.3 log for ozone at 1-2 ppm to a high of 1 log for 10% ethanol were realized. The 10% ethanol in water also appeared to extend the shelf life of the produce.
   
2. Exploratory studies with an oxalic acid, microwave pre-treatment, and pH buffering were carried out to determine if the effectiveness of ozone could be increased. No improvements in the APC reductions were noted.
Technical Barriers to Meeting Component 2 Objectives or Deliverables:
Further studies with adjuvants for the ozone treatment were re-scheduled for FY 2001 because it was decided to pursue the promising results with the 10% ethanol in water.
Component 2 FY 2001 Deliverables:

1. Select the most promising disinfectant procedure and study the effectiveness of the procedure in eliminating or reducing pathogen surrogates deposited on the produce.
   
2. Determine if ozone efficacy can be increased by preliminary rinses with solutions of short chain fatty acids, enzymes, chelating reagents, or surfactants that would be expected to disrupt biofilms.
   
3. Develop marker compounds that occur naturally on produce or can be deposited there to measure cleaning effectiveness.
Component 2 FY 2002 Deliverables:

1. Develop a cleaning formulation consisting of a surfactant, a chelating agent and buffer for cleaning produce. Evaluate cleaning effectiveness with cleaning formulation by noting reduction in APCs and marker compounds.
   
2. Deposit pathogen surrogates on produce and determine the effectiveness of the optimum disinfecting procedure (to be selected after review of the work in FY 2000 and FY2001).
   
3. Determine if byproducts derived from the disinfecting agent are deposited on the food.

Bacteria adhere to many surfaces involved in food processing and storage, and with time, form a biofilm. Biofilms are composed of two major components: microbial cells and bacterial extracellular polymers (EPS). The microbial species and their morphology as well as EPS composition largely determine the physical properties of the biofilm. Thus, the biofilm can be considered as an organic polymer gel with living microorganisms embedded in it thus making their removal an even more difficult task. The Calgary Biofilm Device (CBD) has been introduced to determine the minimum inhibitory concentration (MIC) of antibiotics against biofilms on in-dwelling medical devices.
It is well documented that current methods of testing the efficacy of antimicrobials/sanitizers using planktonic cells do not reflect the true efficacy of these substances against microbes that are present as biofilms in the environment including on foods. This absence of methodology has adversely affected the regulatory agencies in assessing the real-life usefulness of antimicrobials.

Component 3 Objectives:


1. Investigate the suitability of the Calgary Biofilm Device (CBD) for assessing the antimicrobial efficacy of sanitizing agents.
   
2. Evaluate the effects of different disinfectants and cleaning methods on biofilms cultured on polished, brushed stainless steel, glass, and polyethylene film.
Component 3 FY 2000 Deliverables:

1. Evaluate the relative effectiveness of different sanitizers to reduce/eliminate the microbes using the CBD as a biofilms model.
   
2. Develop techniques for growing E. coli strain K12 biofilms on glass as well as polished and brushed 316 stainless steel slides.
   
Component 3 FY 2000 Progress:

1. The efficacies of different disinfectants were tested (e.g., bleach, phenol, and hydrogen peroxide).
   
2. Examined the effectiveness of multiple strategies to mitigate the risk associated with biofilms containing the pathogen of Escherichia coli 0157:H7.
   
3. Grew the biofilm for E. coli 0157:H7 strain #1224 and Listeria innocua strain #1240 for 24 hours.
   
4. The outgrowth medium was applied for recovery purposes (with and without 10 min. sonication). Three-fold dilution of TSBYE worked best in building a reproducible and uniform biofilm, 10 min. sonication was needed for optimal release of biofilm for both strains, and approx. 3.3X reduction in counts after multiple washed.
   
5. Scanned electron micrograph of an E. coli biofilm was examined. The total percent biofilm coverage was calculated from images obtained when using a FITC filter.
Technical Barriers to Meeting Component 3 Objectives or Deliverables: none listed
Component 3 FY 2001 Deliverables:

1. Validate the method refined earlier. Continue inoculated biofilm studies to determine the effect of washing/sanitation using a variety of disinfectants and assess their effectiveness on biofilm elimination and reduction of potential microbial contaminants.
   
2. Complete the study to eliminate E. coli 0157:H7 biofilm on glass, as well as brushed and polished stainless steel slides using different disinfectants before and after applying ultrasound on the surface of the biofilm.
   
Component 3 FY 2002 Deliverables:

1. Incorporate method in the Agency's policy guidelines to industry and use in setting performance standards for putative antimicrobial agents.
   
2. Develop guidelines to improve sanitation practices for use in HACCP.

Pulsed Electric Field Processing (PEF) is a promising alternative method of preserving foods, which could be used to complement or replace traditional thermal processing methods. Previous studies have shown that PEF is capable of producing a pasteurization-type of effect on liquid foods to reduce the number of microorganisms present. However, different implementations of PEF technology result in varying lethality indicating a lack of sufficient understanding of the basic effect of PEF on microorganisms. This understanding is vital if PEF is to be commercialized. The goal of this project is to therefore quantify lethality as function of PEF process variables. This allows for the prediction of lethality, which is necessary for process design and process monitoring to assure that lethality is established and maintained.

Component 4 Objectives:


1. Develop static chamber and experimental protocol to study the inactivation of pathogenic microorganisms by PEF energy
   
2. Determine the effect of elevated but microbially sublethal temperatures on PEF lethality.
   
3. Correlate energy input with lethality for each microorganism.
Component 4 FY 2000 Deliverables:

1. Measure the effect of thermal energy and determine its effect on bacterial lethality to isolate the electric field contribution to lethality.
   
2. Perform experiments to measure the influence of PEF parameters on the electric field lethality.
   
3. Develop equations to define the kinetics of PEF.
Component 4 FY2000 Progress:

1. A static chamber was designed, constructed and successfully tested.
   
2. Both Escherichia coli O157:H7 and Listeria monocytogenes were treated with PEF energy at different intensities. Current and voltage wave forms of the treatments were recorded for the correlation of total energy with the degree of microorganism destruction. It was found that PEF energy alone produced a maximum reduction of 3 logs in E. coli and 1 log in L monocytogenes. Thermal energy applied simultaneously with PEF energy to E. coli produced additional, but nonsynergistic, reductions. However, when applied to L monocytogenes, the added thermal energy produced a clearly synergistic reduction. The effectiveness of PEF energy was decreased in food-based gel (as opposed to water based gel normally used in this study).
   
3. We expect to complete the development of equations to define the kinetics of PEF before the end of FY2000.
Technical Barriers to Meeting Component 4 Objectives or Deliverables: This component is being discontinued as an NCFST collaborative project effective in FY 2001.
Component 4 FY 2001 Deliverables: None -- Project completed in FY2000
Component 4 FY 2002 Deliverables: None -- Project completed in FY2000

Conventional ultrasound (20 kHz) has a partial bactericidal effect. Physical restrictions at this frequency require a metal tip transducer to contact the fluid for efficient delivery of sonic energy. Furthermore, a complete bactericidal effect is realized only in conjunction with other lethal agents, making this a challenge to use in food systems. High frequency ultrasound, operating at a frequency of 600 kHz, delivers sonic energy without physical contact of the transducer. Furthermore, it may impart a greater bactericidal effect on the basis that it produces smaller cavitation bubbles, on the order of the size of a bacterial cell. This project will determine if significant lethality can be obtained using high frequency sonication (HFS).

Component 5 Objectives:


1. Determine if high frequency ultrasound has a bactericidal effect.
   
2. Using non-pathogenic bacteria (Lactobacillus planterum, E. coli K12), determine the effect of temperature, gas sparging, and treatment parameters (treatment duration, energy intensity) on HFS lethality.
   
3. Using a pathogenic bacterium (E. coli O157:H7), determine the effect of temperature, gas sparging, and treatment parameters (treatment duration, energy intensity) on HFS lethality.
   
4. Determine the effect of food-based suspending media (e.g., apple juice) on HFS lethality.
Component 5 FY 2000 Deliverables:

1. Determine the effect of HFS parameters (intensity, processing time) on lethality in non-pathogenic bacteria.
   
2. Investigate the use of gas sparging, temperature and other parameters on the efficacy of HFS on non-pathogenic bacteria.
Component 5 FY 2000 Progress:

1. HFS runs were made with Lactobacillus planterum suspended in sterile distilled water. Consistent reductions in microorganism count were observed, although the actual log reduction varied between 1 and 5 logs. This variation was attributed to difficulty in sampling. A redesign of the chamber closure to address this problem is underway.
   
2. In addition to the basic runs, modifications to the treatment approach involving recirculation and sparging with air, along with temperature variation, showed that lower temperatures and air sparging produce greater reduction in microbial count.
Technical Barriers to Meeting Component 5 Objectives or Deliverables:
Lack of an onsite machine shop has hampered the implementation of the design (and redesign) of various custom components of the sonication system. This project was not funded as a collaborative NCFST project.
Component 5 FY 2001 Deliverables:

1. Redesign and implement a chamber closure to better isolate chamber contents. Design and implement a new sparging reservoir to allow better contact between sparging gas and liquid.
   
2. Develop experimental approach, defining treatment parameters to achieve consistent reductions using recirculation and argon sparging, for the application of HFS to Lactobacillus planterum.
   
3. Quantify effect on HFS lethality of treatment intensity, recirculation rate and sparging gas.
Component 5 FY 2002 Deliverables:

1. Study HFS lethality on the gram negative bacterium, E. coli K12, establishing, as with Lactobacillus planterum, a basic treatment, then examining treatment parameters.
   
2. Evaluate containment issues of the HFS apparatus for the eventual use of E. coli O157:H7 and establish protocol for the safe treatment of E. coli O157:H7.

High Pressure Processing (HPP) can be used to inactivate microorganisms in certain foods or food ingredients without a substantial decrease in product quality. Currently, HPP is used in Japan as a commercial processing method for extending shelf life of acid foods such as fruit products. There are no published reports on the resistance of C. botulinum spores to HPP. Biological validation of a HPP process can be very time consuming. There is a need for a kinetic based process delivery calculation procedure. Process establishment would then be a function of process conditions and the resistance of the appropriate organism of concern. Previously we found that: (1) HPP can be used to inactivate (over 5-log) spores of C. botulinum type E in a model buffer (phosphate buffer, 0.067M, pH 7.0) or a food system such as crabmeat blend, (2) up to 3-log unit reduction of type A strains in a model buffer can be obtained at a maximum pressure (827 MPa) and temperature (75°C) combination for 15-20 min, and (3) HPP was ineffective in reducing spores of nonproteolytic type B strains (17-B and KAP9-B) in either of the systems (phosphate buffer and crabmeat blend at maximum operating conditions (827 MPa, 75°C, and process time of 10 min). Results of this study at higher processing temperatures (>75°C) will benefit the FDA, industry, and NCFST in the application of HPP for inactivation of C. botulinum spores of type A and nonproteolytic type B in various low-acid foods and food ingredients.

Component 6 Objectives:


1. Determine D- and Z_p-values of type E spores in a model phosphate buffer system with previously obtained data and additional experiments.
   
2. Evaluate the effect of high pressure (up to 827 MPa) and high temperatures (up to 120°C) on inactivation of spores of C. botulinum type A and proteolytic and nonproteolytic type B strains in a model buffer system as well as a low-acid food product.
   
3. Determine D- and Z_p-values of spores of C. botulinum type A and nonproteolytic type B strains in a model buffer system.
Component 6 FY 2000Deliverables:

1. Continue to study inactivation of C. botulinum spores of strains proteolytic type A and nonproteolytic type B in a model food system.
   
2. Determine D- and Z_p-values of type E spores in a model phosphate buffer system.
Component 6 FY 2000 Progress:
Inactivation experiments were conducted with type A spores of 62-A and BS-A strains in model food system (Crabmeat blend) using (60, 65, 70, and 75°C), pressure (827 MPa), and time (up to 20 min) combinations. Inactivation of type A strains spores in crabmeat blend increased with increase of time (5 to 15 min) and temperature (60 to 75°C) at a pressure of 827 MPa. Only partial inactivation (2 to 3 log reduction) of type A strain spores in crabmeat blend was obtained at high pressure and temperature combinations with time of 15 min. Some experiments with type E spores of Alaska and Beluga in model buffer system were conducted. Results for these experiments will be available in next two months.
Technical Barriers to Meeting Component 6 Objectives or Deliverables:
Experiments related t the inactivation of spores of nonproteolytic type B strains other than KAP9-B and 17-B will be conducted during August 2000. Previously we conducted some experiments with 2-B and KAP8-B in model buffer system. Completion of deliverables for FY 2000 is dependent upon the proper functioning of the High Pressure Processing Unit.
Component 6 FY 2001 Deliverables:

1. Continue D- and Z_p-values of type E spores in a model phosphate buffer system.
   
2. Determine the effect of high pressure (up to 827 MPa) and high temperatures (up to 120°C) on inactivation of spores of C. botulinum type A and proteolytic and nonproteolytic type B strains in a model buffer system as well as a low-acid food product.
Component 6 FY 2002 Deliverables:

1. Complete studies related to the effect of high pressures (up to 827 MPa) and high temperatures (up to 120°C) on inactivation of spores of C. botulinum type A and proteolytic and nonproteolytic type B strains in a model buffer system as well as in a low-acid food product.
   
2. Determine D- and Z_p-values of spores of C. botulinum type A and nonproteolytic type B strains in a model buffer system.

The Federal Register (April 24, 1998) reported several cases of illness resulting from consumption of various types of juices, mostly unpasteurized orange and apple juices. The FDA conducted public meetings and a majority of the comments indicated opposition to mandatory pasteurization due to the high cost and degradation of flavor and quality. Consequently, it was recommended to use safety performance criteria which allows for the application of technologies (i.e., UV, chemical approach, HACCP) other than pasteurization which are capable of controlling the vegetative form of the target bacteria. It was suggested that a tolerable level of risk may be achieved by requiring a 5-log reduction in the target pathogen.

Manufacturers claim that continuous UV disinfection systems can be effective in low and high acid juices. The use of UV light for liquid disinfection is not new. Its application in disinfecting wastewater has grown in popularity in the last 10 years (Loge et al., 1996). Compared to chlorine, UV light is superior due to low cost, absence of toxic byproducts and effectiveness. When used in disinfection of liquid foods, UV light may have the added benefits of retention of fresh quality and simplicity of operation. Although, it has been reported that UV light is ineffective against Cryptosporidium in apple cider (Pargas, 1998), some UV light manufacturers claimed that their equipment is effective against it. Studies must be done to corroborate those claims and establish effective operating conditions.

Component 7 Objectives:


1. To evaluate the effectiveness of UV light in delivering a 5-log reduction on a target microorganism.
   
2. To develop a technique for determining applied dosage during UV processing.
   
3. To determine factors affecting effectiveness of UV light in disinfecting juices.
   
Component 7 FY 2000Deliverables:

1. Determine the germicidal effectiveness of UV on surrogates of E. coli 0157:H7 and other pathogens in water and several fruit juices.
   
2. Evaluate various compounds that are present in commercially prepared juices for use in chemical actinometry.
   
Component 7 FY 2000 Progress:

1. It was found that the E. coli K12 was a good surrogate for E. coli O157:H7 in UV processing.
   
2. Results showed that a commercial UV reactor from FPE Inc. (NY) was capable of more than 5 log reduction after 2 passes in both apple cider from Placerville, CA and Mott's dark apple juice.
   
3. The FPE UV reactor was also tested at Placerville, CA. The variables were surrogate types, apple variety, inoculation procedure, and apple condition. Results are being analyzed.
   
4. The effectiveness of UV light was also tested on apple cider inoculated with Cryptosporidum. Results were not conclusive.
   
5. Several chemical compounds were evaluated for use as chemical actinometer and currently HMF (Hydroxymethyl furfuraldehyde) is found to be the most promising.
Technical Barriers to Meeting Component 7 Objectives or Deliverables: none listed
Component 7 FY 2001 Deliverables:

1. Determine the inactivation curve of E. coli K12 as a function of pH, BRIX, Titratable acidity and total solids.
   
2. Investigate reciprocity of intensity and time in evaluating dosage.
   
3. LC/MS study of HMF degradation in a model system.
Component 7 FY 2002 Deliverables:

1. Develop computer model for evaluating intensity distribution in a reactor and predicting dosage delivery.
   
2. Identify critical design parameters for UV reactors.
   
3. Study the effect of UV treatments on light sensitive nutrients of several fruit juices.
   

The selection and approval of polymeric packaging material for use in food irradiation (or other applications) depends on the resistance of the packaging to chemical or physical/ mechanical changes when subjected to applicable doses of radiation. This study will investigate the effects of ionizing radiation on several polymeric packing materials to determine the relationship of polymer structure to the extent to which irradiation either generates products in the polymer or alters the functionality of the polymer so that compounds migrate into food products. Effects of gamma and e-beam irradiation at various doses on chemical changes in the model test materials will be determined. Several test packaging materials of industry interest will be selected, irradiated at various conditions and subsequently analyzed to identify and quantify radiolytic products that may be generated. The results obtained will aid the petition review process of approving new packaging materials for food irradiation applications.

Component 8 Objectives:


1. To determine if the effects of gamma and e-beam radiation on the test materials are equivalent or different
   
2. To determine the suitability of non-FDA approved test materials for irradiation at wide applicable doses
   
3. To help develop test protocol for assessing other packaging materials, and assist the Office of Premarket Approval in developing guidelines or a points-to-consider document for industry to follow.
Component 8 FY 2000 Deliverables:

1. Continue analytical methods development and validation
   
2. Continue e-beam and gamma irradiation experiments using the selected test materials.
   
3. Continue analysis of the irradiated test materials compared to the nonirradiated
Component 8 FY 2000 Progress:

1. Completed gamma and e-beam irradiation of PET test specimens at 5, 25 and 50 kGy doses.
   
2. Completed developing anal validating analytical methods for quantifying non-VOCs compounds present in 10% ethanol and 100% heptane food-simulating solvents, and in PET polymers.
   
3. Completed analysis of non-VOCs migrating from PET test specimens into the 10% ethanol and 100% heptane food simulating solvents.
   
4. Irradiated EVOH and ionomer with 5, 25 and 50 kGy gamma irradiation.
   
5. Completed analysis of VOCS present in EVOH and ionomer before and after 5-50 kGy gamma irradiation.
   
6. Began developing analytical methods for analyzing non-VOCs in EVOH and ionomer.
Technical Barriers to Meeting Component 8 Objectives or Deliverables: none listed
Component 8 FY 2001 Deliverables:

1. Complete data analysis and evaluation of the selected food packaging materials
   
2. Determine whether the effects of e-beam and gamma irradiation on the test materials are equivalent
   
3. Develop test protocol for assessing packaging materials and assist the Office of Premarket Approval in developing guidelines or a-point-to consider document for industry
Component 8 FY 2002 Deliverables: None, Component 8 will be completed in FY 2001.

CFSAN is experiencing diminishing expertise with a working knowledge of inspection methods for metal cans, glass containers, paperboard and plastic containers. These resources are necessary, especially when investigating post-process contamination, outbreaks and recalls. The FDA regulations for all metal double seamed cans are clearly stated in 21 CFR 113.60(a), but the regulations for heat sealed flexible and semi-rigid plastic packages are not clearly specified. The inspection of semi-rigid plastic containers is mostly subjective and done primarily by visual inspection. This procedure is in contrast to the much more objective tear-down procedures for metal double-seamed cans. During the training of our FDA inspectors, the severe limitations of our current inspection techniques for plastic containers have become apparent. This reality, coupled with the increased use of plastic packaging for LACF foods makes it necessary to investigate the seal integrity of currently used plastic materials and packages. The results from the research work will suggest appropriate methods for inspection of heat-sealed (fusion and peelable) plastic packages. These methods will then be published and incorporated into the inspection protocols for plastic packages.

Component 9 Objectives:


1. Establish testing and inspection protocol for selected flexible and semi-rigid food packaging systems.
   
2. Evaluation of existing packaging integrity inspection systems (pressure differential, magnetic resonance and ultrasound).
   
3. Participate in training exercises for FDA field inspectors and investigators.
Component 9 FY 2000 Deliverables:

1. Complete distribution testing.
   
2. Complete container integrity testing using different container types from those already tested.
   
3. Write testing protocol and findings to help develop new FDA inspection guidelines.
   
4. Participate in training exercises for field inspectors and investigators.
Component 9 FY 2000 Progress:

1. Completed bench-top pressure differential evaluation.
   
2. Completed pinhole size evaluation of polymeric trays by online pressure differential system.
   
3. Bio-challenge analyses of polymeric trays are currently in progress.
   
4. Distribution test on polymeric trays analyzed by bench-top pressure differential unit is completed.
   
5. Gave lectures and laboratory training exercises on metal, semi-rigid and flexible packaging for an Advance LACF course for FDA field inspectors.
   
6. Seal strength analysis of polymeric trays using ultrasonic imaging is in progress.
   
7. Completed preliminary MRI analysis on polymeric trays for channel leaks and spoilage identification in brick-type packages.
Technical Barriers to Meeting Component 9 Objectives or Deliverables:
(Logistics note) This project was not funded as a collaborative NCFST project for FY 2000. It will be funded as a collaborative NCFST project for FY 2001 and 2002.
Component 9 FY 2001 Deliverables:

1. Complete leak detection and contamination identification in packaged foods using MRI system.
   
2. Complete non-destructive packaging leak detection using on-line pressure differential system.
   
3. Complete non-destructive analysis of food packaging seal strength using ultrasonic imaging.
   
4. Publish results of pressure differential, MRI, ultrasonic and bio-challenge testing on food packages.
   
5. Participate in training exercises for FDA field inspectors and investigators.
   
6. Continue writing packaging integrity testing protocol.
Component 9 FY 2002 Deliverables:

1. Complete packaging integrity testing protocol.
   
2. Determine the effect of high pressure processing on packaging integrity and seal strength.
   
3. Conduct research relating to packaging integrity using gas leak detection method. The results will be used in teaching appropriate methods for inspection of heat-sealed packages and incorporated into inspection protocols for plastic packages.
   
4. Participate in training exercises for FDA field inspectors and investigators.

Use of pathogens to evaluate the efficacy of intervention strategies in food processing operations can be hazardous because of the potential risk presented to both research workers and the production environment. It is, therefore, essential to use non-pathogenic bacterial surrogates in-lieu of pathogenic microorganisms. However, the adequacy of the surrogate(s) for the intended purpose has rarely been systematically and comprehensively evaluated. Moreover, no standard pool of organisms has been developed to serve as surrogates in investigations of diverse intervention strategies including traditional processing techniques (e.g., antimicrobial rinses, pasteurization, use of preservatives, adjustment of pH and a_W, combination treatments, etc.), and novel processing techniques [e.g., high pressure processing (HPP), and UV treatment]. This project aims to evaluate, in a systematic and comprehensive manner, a number of different bacterial species for use as surrogates for a diverse range of bacterial pathogens, under certain food processing parameters. A standard set of surrogate organisms will be developed for use in process development and validation.

Component 10 Objectives:


1. Evaluate, in a systematic and comprehensive manner, a number of different bacterial species for use as surrogates for a diverse range of bacterial pathogens, under certain food processing parameters.
   
2. Develop a standard set of surrogate organisms for use in process development and validation.
Component 10 FY 2000 Deliverables:
Project commences on 10-01-00
Component 10 FY 2000 Progress:
Project commences on 10-01-00
Technical Barriers to Meeting Component 10 Objectives or Deliverables: none listed
Component 10 FY 2001 Deliverables:

1. Identify and characterize microorganisms to use as surrogates for E. coli O157:H7.
   
2. Assess performance of surrogates under food processing conditions, with multiple stresses.
Component 10 FY 2002 Deliverables:

1. Identify and characterize microorganisms to use as surrogates for Salmonella spp.
   
2. Assess performance of surrogates under food processing conditions, with multiple stresses.

In-shell pasteurization is currently carried out using hot water immersion of eggs. This process relies on heat conduction, an inefficient method of energy transfer. The use of microwave or ultrasonic energy, both providing excellent energy penetration and direct heat generation inside the egg, could make significant improvements in the efficiency of the process.

Component 11 Objectives:


1. Measure or obtain from the literature the thermal, sonic and dielectric properties of egg components.
   
2. Development and implement of techniques to inoculate eggs in the yolk while maintaining shell integrity for the purpose of providing experimental validation of the planned theoretical work.
   
3. Conduct a mathematical analysis of the heat transfer phenomenon occurring within the egg while being heated with microwaves.
   
4. Conduct experiments on microwave-based in-shell heating using a specially designed applicator to determine the efficacy and quality of heated eggs.
   
5. Conduct an experimental study to determine the effect of ultrasound in inoculated eggs.
Component 11 FY 2000 Deliverables:
Project commences on 10-01-00
Component 11 FY 2000 Progress:
Project commences on 10-01-00
Technical Barriers to Meeting Component 11 Objectives or Deliverables: none listed
Component 11 FY 2001 Deliverables:

1. Measure or obtain properties of egg components.
   
2. Develop a method and validation of method for inoculation of eggs.
   
3. Conduct mathematical analysis of microwave heating in eggs.
   
4. Begin design of custom cavity for the purpose of heating eggs.
   
5. Develop experimental protocol for sonication of eggs.
Component 11 FY 2002 Deliverables:

1. Construct and test custom microwave cavity.
   
2. Determine the ability of microwave energy to pasteurize eggs and evaluate quality.
   
3. Determine the ability of sonic energy to pasteurize eggs and evaluate quality.

Additives are used to protect polymers from undesirable reactions during packaging material production and subsequent food processing operations such as irradiation. It is possible that the base polymer itself may degrade by irradiation, producing radiolytic products that could subsequently interact with the other by-products generated by the additives. As a result, secondary by-products may be formed and these compounds could be different from the primary degradation products of the polymer and additives. There are pending petitions seeking FDA approval to extend use of irradiation from uncooked red meat products to cooked meat products including hot dogs, sausages and bologna. Since these food products are generally packaged in high barrier laminates before irradiation, the primary and secondary by-products generated in these packages must be investigated to ensure the packages safety. The study will determine the effects of irradiation on additive(s) incorporated in polymers intended for irradiated pre-packaged food, and the interactions between the additive(s) and base polymer during irradiation.

Component 12 Objectives:


1. Identify and quantify volatiles and non-volatiles generated by exposure of the polymer additives to different irradiation conditions.
   
2. Assess the effects of the irradiation on chemical changes in the selected additives.
   
3. Determine the possible interaction between additives and with those generated by the base polymer corresponding to the additives being studied.
Component 12 FY 2000 Deliverables:
Project commences on 10-01-00
Component 12 FY 2000 Progress:
Project commences on 10-01-00
Technical Barriers to Meeting Component 12 Objectives or Deliverables: none listed
Component 12 FY 2001 Deliverables:

1. Select one or two polymer additives in the study
   
2. Prepare experimental design for polymer additive irradiation
   
3. Perform preliminary irradiation experiment
   
4. Begin to develop analytical methods for analysis of VOC and non-VOC in the additives
Component 12 FY 2002 Deliverables:

1. Continue irradiation experiment using test systems containing additives alone and with polymer typically used with the selected additives.
   
2. Continue analytical methods development for analysis of VOC and non-VOC in the test systems.

Reddy, N.R., Solomon, H.M., Fingerhut, G.A., Rhodehamel, E.J., Balasubramaniam, V.M., and Palaniappan, S. 1999. Inactivation of Clostridium botulinum type E spores by high pressure processing. J. Food Safety 19:277-288.

Table of Contents

Hypertext updated by dav 2001-OCT-02