USA CUN 16 POST HARVEST

-- Dry, Cured Pork Products Page 1



### METHYL BROMIDE CRITICAL USE RE NOMINATION FOR POST

HARVEST

-- DRY CURED PORK PRODUCTS

NOMINATING PARTY : The United States of America

FILE NAME : USA CUN 1 6 POST HARVEST

-- DRY, CURED PORK PROD UCTS

BRIEF DESCRIPTIVE TI TLE OF NOMINATION : Methyl Bromide Critical Use Nomination for Post Harvest Use on Dry Cured Pork Products (Submitted in 20 1 4 for 201 6 Use Season)

STRUCTURE, COMMODITY OR OBJECT TREATED:
This sector is for the production of dry cured pork products, such as country hams. The se are produced primarily in the southern U.S. This sector has no known viable alternative currently

available.

QUANTITY OF METHYL B ROMIDE REQUESTED IN EACH YEAR OF

NOMINATION:

T ABLE 1 : Q UANTITY OF M ETHYL B ROMIDE R EQUESTED IN E ACH Y EAR OF N OMINATION

Y EAR N OMINATION A MOUNT ( KILOGRAMS )

201 6 3,240 kg

(Details on this page are requested under Decision Ex. I/4(7), for posting on the Ozone Secretariat website under Decision Ex. I/4(8).)

In assessing nominations submitted in this format, TEAP and MBTOC will also refer to the original nomination on which the Party’s first

- year exemption was approved, as well as any supplementary information provided by the Party in relation to that original nomination. As this earlier information is retained by MBTOC, a Party need not

re

- submit that earlier information.

NOMINATING PARTY CONTACT DETAILS:

Contact Person: Federico San Martini, Ph.D.

Title: Foreign Affairs Officer

Address: Office of Environmental Policy U.S. Department of State
2201 C Street, N.W. Room 2657 Washington, D.C. 20520

U.S.A. Telephone: (202) 647

- 3819

Fax: (202) 647

- 1052

E

- mail: SanMartiniFM@state.gov

Following the requirements of Decision IX/6 paragraph (a)(1) United States of America has determined that the specific use detailed in this Critical Use Nomination is critical because the lack of availability of methyl bromide for

this use would result in a significant market disruption

. 

### ■ Yes  NoUSA CUN 16 POST HARVEST

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Signature Name Date

Title:

CONTACT OR EXPERT(S) FOR FURTHER TECHNICAL DETAILS:

Contact/Expert Person: Yu

- Ting Guilaran

Title: Director

Address: Biological a nd Economic Analysis Division Office of Pesticide Programs

U.S. Environmental Protection Agency 1200 Pennsylvania Avenue, N.W. Mailcode 7503P Washington, D.C. 20460

U.S.A. Telephone: (703 ) 308

- 0 052

Fax: (703) 308

- 8 0 91

E

- mail: Guilaran.Yu

- Ting @epa.gov

LIST OF DOCUMENTS SENT TO THE OZONE SECRETARIAT IN OFFICIAL NOMINATION PACKAGE:

1. PAPER DOCUMENTS: Title of paper documents and appendices No. of pages Date sent to Ozone

Secretariat

2. ELECTRONIC COPIES OF ALL PAPER DOCUMENTS: *Title of each electronic file (for naming convention see notes above) No. of kilobytes Date sent to Ozone

Secretariat

USA CUN1 6 Post Harvest Ham

* Identical to paper documentsUSA CUN 16 POST HARVEST

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### METHYL BROMIDE CRITICAL USE RE NOMINATION FOR POST

HARVEST

-- DRY CURED PORK PRODUCTS

1. SUMMARY OF NEED FOR METHYL BROMIDE AS A CRITICAL USE

Currently there are no viable alternatives to methyl bromide for the dry cured pork industry . The United States has an active research program on methyl bromide alternatives for dry

- cured pork products. Through that program, researchers have investigated all the avenues recommended by MBTOC, but none have demonstrated commercial viability at this time. Final results are not yet

available and research on the se suggestions recommended by MBTOC continues. Preliminary work by Zh ao et al (2012a) indicates that there may be other methods to control mites. The United States is committed to continued research in this area and remains hopeful that such research efforts will help identify and develop commercially viable alternatives t o methyl

bromide for use in this sector. At the time of this nomination

, there are no known registered

alternatives for use on dry cured pork in the U nited S tates that provide the same level of mite control as methyl bromide. U.S. regulations do not per mit the introduction into interstate commerce of dry

- cured pork products contaminated with mites. Therefore, methyl bromide remains critical to this industry.

T ABLE 2. N OMINATION A MOUNT

2. SUMMARIZE WHY ALTERNATIVES ARE NOT FEASIBLE

This industry currently has no viable chemical or non

- chemical alternative available . Although

IPM measures ha ve minimized the frequency fumigation is needed, it has not eliminated the need for fumigation. Therefore, methyl bromide remains critical to th is industry.USA CUN 16 POST HARVEST

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3. UPDATE OF RESEARCH RESULTS SHOWING EFFICACY OF ALTERNATIVES

University r esearchers in Kansas, Mississippi and Oklahoma are investigating the management
and control of arthropod pests that infest dry cured pork products during the aging process. This interdisciplinary and multi

- institutional group is funded primarily by the USDA competitive grants program titled “Methyl Bromide Transitions.”

Latest Research Results

Tyrophagus putrescentiae , the ham mite, is the most serious arthropod pest of souther n dry cured hams in the USA. Work at Kansas State University (KSU) developed a trap for use in integrated pest management, IPM (summarized recently by Amoah et al. 2013). The trap consists of a 90 mm disposable plastic Petri dish that is painted black on the entire outer surface. Around the sidewall of the dish are eight evenly spaced holes, approximately 0.5 mm in diameter, at 2 mm

above the bottom of the dish for entry of responding mites. The lure or bait, consisting of a 10 mm high by 25 mm dia circular plug of mite rearing diet jelled in agar, is placed inside the center of the trap. Mites respond to the baited dishes, enter the holes in the side wall , and feed on the diet plug where they also mate and lay eggs. Laboratory studies confirmed that traps baited with food diet were very effective at detecting mites compared to unbaited traps. During 2012

- 2013 mite populations were monitored in three comm ercial ham curing/aging facilities using 20 traps distributed evenly throughout the buildings for consecutive one

- week periods. Mite numbers in traps varied from zero to several hundred in each week, consecutive weekly trapping suggested a

seasonal variat ion in mite populations, and the spatial distribution of traps with or without mites demonstrated that certain areas of a given facility consistently had higher mite activity than other areas. Mite numbers in traps confirmed that fumigation in certain cir cumstances caused severe reduction in mite populations, and showed that mites would slowly increase in numbers and activity following fumigation.

KSU research in 2013 focused on the sensitivity for mite detection with these traps and the role

of environm ental factors such as temperature, relative humidity, trap placement relative to structural features, proximity of traps from a source of mites and general trap design on trap efficacy (Amoah et al. 2013) . The standard trap was deployed in four retail fac ilities close to

K ansas State University , including a pet store, an organic grocery store, a large “big box” department store and a farm supply store in order to have a near

- by study site. Mites were detected only at the farm supply store. Of twenty trap s evenly spaced throughout the retail area, mites were consistently trapped only in one specific area. Traps were also deployed in three small rooms at our KSU laboratory in which we released an open colony of mites at one end of the floor and traps were arranged in three consecutive 1 m intervals away from the food source, either along one side wall or in the center of the floor. Results suggest that mites can be detected 3 m from a population source within minute s to hours from the time of deployment an d that

room wall edges may be important for orientation of mites to traps. Experiment s are planned that will evaluate various commercial designs of stored product beetle traps that should also capture mites. Simple laboratory rooms and the farm supply st ore with a localized mite population will be used to correlate mite trap counts to direct measures of mite density derived

from defined f

loor samples of mites and dust collected in a defined area. Monitoring data of T.USA CUN 16 POST HARVEST

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putrescentiae populations using trap s will be important information to aid in IPM decision

making.

To date very little information is available on the potential for non

- fumigant chemicals to control

ham mites. Laboratory studies were conducted to assess the potential of food grade

preserva tives to function in coatings on hams to prevent mite infestation and also for registered and experimental pesticides for applying a residual treatment to environmental surfaces to kill mites (reported by Abbar et al. 2013). A bioassay with food preservat ives was conducted, in which pieces of ham or whole hams were dipped in or sprayed with a given compound and then exposed to 20 adult mites for 14 days, after which the total resulting population of surviving nymphs and adults was determined. Propylene gl ycol, the preservative ethoxyquin and a mixture

of short

- chain hydrocarbons proved effective at preventing mite reproduction on small ham pieces. A simulated field study was conducted in which whole 27

- lb green hams were coated

with cure mix from Rebel Bu tcher Supply and then each sprayed with 28 g of 100% propylene glycol, PG. Hams were again treated with cure mix at 8 and 18 days after the first application

then washed and cold

- smoked at day 21. After smoking, single hams were sprayed with PG

either 4 times at 4

- week intervals, at 3 week intervals for 5 times and most frequently at 2

- week intervals for 7 sprays. One

- inch cubes were taken from outer slices of each ham and subjected to mite reproduction challenge. The non

- PG hams and those treated at 4

- week or 3

- week intervals produced high numbers of mites, but cubes from the ham treated at 2 week intervals produced significantly fewer mites.

Laboratory experiments of registered and experimental pesticides utilized a bioassay in which 20

adult mites we re released inside a ventilated glass vial that had been previously treated with 35 ul of a diluted test compound. Mites were allowed to walk on the treated surface for 24 hrs, after which they were moved to clean vials with food for 24 hrs and then asses sed for mortality. Each experiment had a solvent

- only control and up to 3 concentrations of the test compound (0.5 X, 1 X and 2 X the EPA label rate). Of eight active ingredients tested an experimental mixture of

short

- chain hydrocarbons and registered f ormulations of deltamethrin, chlorfenapyr and a mixture of deltamethrin with chlorpyrifos

- methyl had very high mite mortality at the recommend

label rates and at half the label rates. Results to date with food

- safe preservatives and with commercial pestic ides currently registered by EPA for surface treatments in storage facilities show great promise for IPM of ham mite ; however, further work is needed to validate the effectiveness of these potential alternatives.

Methyl b romide has been the most effecti ve, and essentially the only, pest control method used by the dry cured ham industry to manage ham mite infestations. The potential loss of methyl

bromide calls for an effective alternative in the form of a fumigant that can be applied over a few days at most , has no negative impact on food quality and can effectively reduce or eliminate mite

infestation and other arthropod pests with minimal cost relative to the benefit of protecting the ham products. In past years the fumigant sulfuryl fluoride was eval uated for the ham mite at 25 o

C for 48 hrs and did not eliminate the egg stage to the level that would effectively control pest mite populations. However, in laboratory testing, phosphine was effective against all life stages

within the label rates of the fumigant, and dried meats are already listed on the application label.USA CUN 16 POST HARVEST

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Drs. Schilling and Phillips participated in a commercial fumigation of a working ham production facility with phosphine gas in early 2013 (Phillips 2013)

. Two rooms were selected for treatment and each had several hundred hams that were in the late first or second year of aging. Magnesium phosphide was chosen as the application material because it produces twice as much hydrogen phosphide, PH3, and at a faster rate, than does aluminu m phosphide. Each room was well sealed and access of gas was restricted to exclude electrical and heating

- air conditioning

systems from exposure

. Gas concentrations of 1500 ppm and 700 ppm were reached within 12 hours of initiation in each room, and these levels were maintained for the duration of the 48 hr

treatment. Another full day was required for de

- gassing and clearance of the facility before

workers were allowed back in. Ventilated mite colony jars placed in treated and untreated spaces during the PH3 application confirmed that mortality of ham mites was very high in the treated

rooms. Unfortunately, corrosion to electrical wiring and equip ment was discovered as unacceptably high about 21 days after the fumigation

. Because of this corrosion issue with phosphine, it is not considered a viable alternative for the industry at this time. Future w ork needs to be done to properly prepare ham pro duction facilities for the corrosion potential of phosphine gas before application of this fumigant is recommended as a methyl bromide alternative for country hams

.

Research continues on fumigation alternatives for ham mites. The researchers have revisit ed sulfuryl fluoride to determine if its efficacy against mite eggs could be improved at higher fumigation temperatures and longer gas exposure times. Preliminary studies suggest that a treatment temperature of 35 o C for 48 hrs at a high sulfuryl fluoride concentration can co ntrol all ham mite life stages.

A New Methyl Bromide Transition Grant

The USDA

- Methyl Brom ide Transition program funded a multi

- institutional and multi

disciplinary project led by Dr. Phillips (KSU), Dr. Schilling (Mississippi State Univ.) and Dr. Adam (Oklahoma State University) for an Integrated Project to both conduct research into various methods of integrated pest management (IPM) of southern dry cured hams that include methyl bromide alternatives, and to develop educational materials and deliver extension

programs for producers and the pest control industry to implement dried ham IPM programs. Results from this project will benefit the southern dry

- cured ham industry in the U nited S tates

.

Grant Goals and Objectives

The long

- term goals of this project are to provide cost

- effective and legal methyl bromide alternative fumigants that can serve as definitive control agents in an IPM program that combines sanitation, prevention and monitoring in a decision

- ma king process. New information generated from recent work and from that proposed on suppression products and IPM methods in this project will be the subjects of one or more educational products such as a training manual or website, and that these education al products can also be used in extension programs during and soon after this project. Researchers hope to meet these goals by addressing the following six objectives in the current project.USA CUN 16 POST HARVEST

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1. Conduct laboratory studies of ham mite mortality or ham protection using sulfuryl fluoride at high temperatures, MITC as a new fumigant, and GRAS food additives as ham coatings; determine food safety and market quality of hams treated with these compounds.

2. Do field validation of phosphine fumigations with cyli nderized PH3 and special precautions to avoid electrical damage. Conduct at least one commercial fumigation of sulfuryl fluoride at a high temperature if results from objective 1 are positive.

3. Sample hams and ham production and aging environments to dete rmine mite density and correlate these direct population measurement with capture numbers in mite traps to develop predictive models of mite population size based on trap count.

4. Conduct field

- scale efficacy trials of food

- grade coatings to protect against mites, and also of space sprays with registered pesticides to reduce mite populations.

5. Conduct an economic feasibility study and articulate cost

- benefit scenarios for IPM and related alternatives for the dry cured ham industry

.

6. Develop and deliver dry

- c ured ham IPM programs via educational materials, field demonstrations and outreach to industry groups.

4. REGISTRATION UPDATE

No new chemicals have been registered or de

- registered since the last nomination.

5. ECONOMIC INFEASIBILITY OF ALTERNATIVES

An economic analysis was not conducted because this sector has no technically feasible

alternatives at this time.

CITATIONS

Abbar, S., Y Zhao, MW Schilling, and T Phillips. 2013. Chemical Alternatives for Suppressing the Ham Mite, Tyrophagus putrescentiae . Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reduction s, San Diego, CA, Nov.4

- 6, 2013, (36).

Amoah, B, MW Schilling, and T Phi llips. 2013. Trapping the Ham Mite, Tyrophagus putrescentiae , with A Food Bait: Toward A Monitoring Tool for IPM . Annual International Research Conference on Methyl Bromide Alternatives and Emissions

Red uctions, San Diego, CA, Nov.4

- 6, (3 7 ).USA CUN 16 POST HARVEST

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Phillips, T W . 2013. Fumigation A lternatives for the Ham Mite, Tyrophagus putrescentiae : Challenges and Prospects. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, San Diego, CA, Nov.4

- 6, 2013, (3 8 ).

Zhao, Y., T.W. Phillips, S. Abbar, W.B. Mikel, M.W.Schilling . 2012a. E ffects of various food

grade coatings on mite mortality and sensory quality of dry cured ham

. Annual International Research Conference on Methyl Bromide Alternatives and Emission

Redu ction, Orlando, FL, November 6

- 8

, (77).USA CUN 16 POST HARVEST

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A PPENDIX A

Census of Pork Producers Repeated from the USACUN2015 for MBTOC’s convenience

In May 2012, Dr. Wes Schilling (Mississippi State University) had 26 country ham producers respond to his survey (U.S. Country Ham Facility Survey) concerning use of methyl bromide in their facilities. These data provide the size of the aging rooms, the y early amounts of methyl bromide used, and the number of fumigations per year, by facility as requested by MBTOC. Facilities use multiple treatments per year because new hams are brought into the aging rooms throughout the year and multiple outbreaks may o ccur.

The producers monitor the aging rooms for evidence of pests, and when signs of pests are present they make the decision to fumigate. Typically they clean and seal the aging room on Friday. Gas is introduced after workers leave on Friday afternoon. Aerat ion usually begins on Saturday afternoon.USA CUN 16 POST HARVEST

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Table 3. U.S. Country Ham Facility Survey Conducted by Dr. Schilling, May 2012

Footnote: These numbers were rounded by Excel spreadsheet after conversion from the original U.S. units.

The data in Table 3 r epresent responses by 26 country ham producers. We believe there are approximately 28 ham producers in the United States and that the survey therefore represents over 90% of the sector. The standard presumption for use in post

- harvest treatments is 20 kg /1000 m 3 (Handbook on Critical Use Nominations for Methyl Bromide, 2007). Several of the facilities listed in Table 3 appear to be conducting fumigations at rates that are higher than the standard presumption. Facilities can undertake efforts to maximiz e their gas tightness and thereby aim to bring their use rate to within the standard presumption. The United States nomination is calculated by reducing the use rate to 20 kg/1000 m 3 plus 10% as described by MBTOC “a dosage of 20 g/m3, plus a 10% allowanc e for occasional unforeseen requirement for additional MB due to inclement weather or the sudden need for an extra treatment at a particularUSA CUN 16 POST HARVEST

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facility or possibly for one or two facilities not included in, or responding in time to, the survey, summed up as 10% for contingency measures” (MBTOC 2012, pg. 56).USA CUN 16 POST HARVEST

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A PPENDIX B

Results Prior to 2013 Repeated from the USACUN2015 for MBTOC’s convenience

Researchers from Kansas State University and Mississippi State University began investigating the control of arthropod pests that infest dry cured pork prod ucts during the aging process prior

to the spring of 2007, when a proposal was submitted to the USDA CSREES Integrated Research, Education, and Extension Competitive Grants Program

- Methyl Brom ide Transitions by several meat scientists (Schilling and others) and an entomologist (Phillips) . This proposal

was funded from 2007 to 2010. A no

- cost extension was granted for 2010

- 2011, and additional funding was provided through the Southern Regions Integrated Pest Management Center to continue research efforts for 2010 and 2011. In addition, a grant was submitted to the USDA in summer 2011 to seek funds to continue research with respect to potential alternatives to methyl bromide for use in the dry cured pork industry. All of the research projects listed above and below are being conducted in conjunction with the National Country Ham Association, The American Association of Meat Processors, individual ham producers, and the fumigation and

pest contr ol industries.

There were several objectives to the research project that was funded by the USDA MBT program from 2007

- 2010. The first was to determine the effectiveness of chemical controls (sulfuryl fluoride, phosphine, and methyl bromide) against al l life stages of both mold mites ( Tyrophagus putrescentiae ) and red legged ham beetles ( Necrobia rufipes ). The second objective was to determine the effectiveness of carbon dioxide and ozone against all life stages of both mold mites and red legged ham be etles. The third objective was to test the effects of sulfuryl fluoride, phosphine and methyl bromide on the quality and safety of the dry cured hams. The fourth objective was to conduct an economic analysis of the alternatives demonstrated to be

technic ally viable alternatives for methyl bromide in this industry.

Fumigants and Alternatives for Controlling Ham Pests

The results of sulfuryl fluoride efficacy investigations on Tyrophagus putrescentiae , ham mite,

and Necrobia rufipes , red

- legged ham beetle, were presented at the 2008 MBAO Conference, in Orlando, FL. The studies included eggs and a mixture of adults and large nymphs of mites and the eggs, large larvae, pupae and adults of beetles. The experiments were conducted for 48 hours

at 23°C a t various concentrations of sulfuryl fluoride. The investigators achieved 100% mortality of red

- legged ham beetle adults and pupae at about 4.0 g/m 3 , and 100% mortality of larvae at 5.7 g/m 3 . Eggs of red

- legged ham beetles died at 24.0 g/m 3 of sulfuryl f luoride, well below the maximum label rate (Phillips et al., 2008). Mortality of ham mites required much higher concentrations of sulfuryl fluoride. A concentration of about 100.3 g/m 3 was necessary to obtain 100% mortality of adults and nymphs under the test conditions. However, this concentration obtained only a 95% mortality of mite eggs. This is about three times the legal label rate of sulfuryl fluoride (Phillips et al., 2008) and thus indicates that sulfuryl fluoride is not

a viable alternative to methyl bromide for controlling ham mites. In addition, results also indicated that levels of residual fluoride ion and sulfuryl fluoride in the hams were linearly related to fumigant concentration and that use of high concentrations of sulfuryl fluoride (72USA CUN 16 POST HARVEST

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g/m 3 or greater) and multiple fumigations could potentially lead to high concentrations of sulfuryl fluoride and fluoride in the ham (Sekhon et al., 2010a).

The results of investigations with carbon dioxide, phosphine, methyl bromide and ozone

treatments on Tyrophagus putrescentiae , ham mite, and Necrobia rufipes , red

- legged ham beetle, were presented at the 2009 MBAO Conference, in San Diego, CA (Sekhon et al ., 2009a, b; Phillips, 2009, Phillips et al. 2011, Sekhon et al., 2010b, 2010c). The studies included eggs and a mixture of adults and nymphs of mites and eggs, large larvae, pupae and adults of beetles. The experiments were conducted for variable times at 23°C at various concentrations of carbon dioxide, phosphine, methyl bromide and ozone. The investigators achieved mortality of all life stages of m ites with a concentration of 60 % carbon dioxide with 144 hr of exposure (Sekhon et al., 2009a; Phillips, 2009; Sekhon et al., 2010b). However, fumigation with carbon dioxide would likely not be applicable since ham structures are not air

- tight and 144 hr is too long of a time to fumigate the hams. In addition, a car bon dioxide concentration (> 80 %) with an exposure time of 144 hrs was necessary to cause 100 % mortality for all life stages of red legged ham beetles (Sekhon, et al. 2009a; Phillips, 2009; Sekhon et al, 2010b). In addition, there may be higher numbers of ham mites that can hide in the crevices o f the ham that may be able to survive during CO 2 fumigati on. Investigators achieved 100 % mortality of all life stages of red

legged ham beetles and ham mites with 48 hours exposure of 400 and 1000 ppm of phosphine, respectively (Sekhon, et al. 2009b; Phil lips, 2009; Sekhon et al., 2010c). In addition, residual phosphine concentrations in dry cured hams that were fumigated for 48 hrs at 1000 ppm were below 0.01 ppm, the legal residual limit in stored food products (Sekhon, et al. 2009b; Sekhon et al., 2010 c), and consumer panelists could not detect differences between control and phosphine fumigated samples at 1000 ppm (Sekhon et al. 2009b; Sekhon et al., 2010c). Therefore, phosphine can now be considered a potential alternative to methyl bromide for contr olling arthropod pests of southern dry cured hams. Further testing with a greater number of mites has indicated that a greater concentration of phosphine (>1000 ppm) is likely necessary to kill substantial mite infestations. In addition, commercial appli cations of phosphine are planned for

2010

- 2011 to determine the efficacy of using phosphine at the plant level. The effectiveness of phosphine will be evaluated through the use of both bioassays (with ham present) and on hanging hams in a simulated dry cur ed ham aging room.

Other portions of this research include the economic analysis of using phosphine in comparison to methyl bromide, if it is effective at eradicating mites. Commercial applicators and agricultural economists are working with us on this p ortion of the research. Additional items that will be researched in the future (if funding is obtained) include the effect of multiple fumigations on the sensory quality and residual concentration of phosphine in ham, and the effectiveness of using phosph ine in dry cured ham facilities. Many processors have indicated that they would be willing to help evaluate the efficacy of phosphine (at controlling ham mite infestations) in their plant as part of a research project. In addition, we have commitments fro m Universities and a commercial applicator to help implement phosphine fumigation in dry cured ham facilities for this research to take place.

Ozone concentrations of greater than 150 ppm for 48 hrs were able to achieve 100 % mortality of

ham beetles and m ites at the bench top level (Sekhon et al., 2009b; Phillips, 2009; Sekhon et al., 2010b). Consumers also could not determine sensory differences between control hams andUSA CUN 16 POST HARVEST

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those that were fumigated with ozone at 175 ppm for 48 hrs (Sekhon et al., 2010b)). However, ozone is not able to penetrate surfaces well and therefore may not be effective in real world applications since ham mites could potentially penetrate into crevices in the meat and ham beetles bore through the meat tissue. Research that was conduc ted by one dry cured ham processor indicated that the use of ozone in a commercial setting was not effective at eradicating ham mite infestations, which was likely due to the inability of the ozone to penetrate the surface of the ham and the ability of mit es to find places to hide where the ozone did not reach. However, ozone may have use as part of hurdle technology to help minimize infestations and enhance sanitation since it would sanitize areas in the plant as well as equipment that could potentially h arbor bugs and pathogens.

Further research has recently been conducted on the effects of low pressure and low oxygen concentration on the mortality of Tyrophagus putrescentiae (mold mites). Exposure of mites to low oxygen with pressure (25 mmHg; approx. 3.0% O 2 ) at 23°C for 144 hrs or greater was

effect ive at eradicating more than 95 % of each mite life stage (Hasan et al., 2010). However, testing with a larger number of mites and under commercial conditions would need to be

conducted to determine if this technology could be considered a potential alternative to methyl bromide. Its limitations include length of application, ability of mites to hide within meat crevices, and difficulty in implementing at the commercial plant level.

Food

- safe Dips and Coat ings to Prevent Mites on Ham

In additional studies (Zhao et al 2012a), ham slices and 1

- cm square cubes were dipped directly into either mineral oil, propylene glycol, 10% potassium sorbate solution or glycerin for 1 minute and dripped on a mesh colander for another minute. Lard was applied directly by rubbing a thin layer to cover the whole piece. Ham cubes (2.5 cm ×2.5 cm × 2.5cm) were used for the mite infestation study. During the study, 20 mites (mostly adult female) were placed on one cube of

ham whi ch was placed in a ventilated, mite proof glass container and incubated for 21 days at 27oC and 70% relative humidity. Mite populations on ham cubes were counted every week. Coatings on ham slices were washed off before cooking. Ham slices were oven baked to internal temperature of 71 ̊C and served to trained panelists for sensory Difference from Control tests. A randomized complete block design with 3 replications was used to determine if differences (P<0.05) existed between treatments with respect to mite number and sensory differences between products.

Results indicated that both lard and propylene glycol were effective (P<0.05) at controlling mite reproduction. No difference was detected in sensory characteristics between control ham slices and samples t reated with food grade ingredients. In addition, potassium sorbate and mineral oil did not inhibit mite reproduction but slowed mite growth (P<0.05) when compared to the control, and glycerin was ineffective at lowering mite counts (P>0.05) when compared to the

control.

The majority of research that has been conducted on use of food grade ingredients with meat products has been to prevent water loss and reduce rancidity of meat products (Baldwin, 2007). However, a finished ham product needs to lose at le ast 18% of its original weight during aging (USDA, 1999). At the same time, the unique flavors of dry cured ham are caused by proteolysisUSA CUN 16 POST HARVEST

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and lipolysis with the presence of oxygen. In this case, water vapor permeability of the films and coatings needs to b e considered when choosing a proper coating. Current and future research is being conducted to develop a cost

- effective food grade coating with high oxygen and water vapor permeability.

Based on the research studies described above (Zhao et al 2012a), th e active ingredients that show the most promise as potential methyl bromide alternatives are propylene glycol, butylated hydroxytoluene (BHT), and lard. Propylene glycol (PG) is likely the most feasible food

- grade ingredient that could be used to control ham mites but is also very expensive. BHT is effective at controlling mites on 1 inch ham pieces at a concentration of 10%. However, 0.01 % BHT (by fat percentage) is the acceptable level in some meat products. This makes it unlikely that it would be

accep ted for use, but may have application if it can be washed off the surf ace and there is less

than 0.01 % BHT in the finished product. Lard was effective at controlling mites on ham pieces. However, use of lard may prevent moisture loss and transmission of oxygen which would prevent the preservation and flavor development of the ham. However, these 3 ingredients need to be evaluated on whole hams for their ability to control mite infestations. In December of 2012, research was started on whole hams such th at the hams are treated with BHT, lard, or propylene glycol. Hams will be infested with a known number of mites and evaluated over 3 weeks for the number of mites on the hams. In addition, propylene glycol will be used in food

grade gel coatings to determ ine if incorporating PG in a gel will prevent evaporation of the PG and prolong its effectiveness at controlling mites. We will also work with processors to implement PG and other food grade products that may control mites in their plants to determine

thei r impact in industrial settings.

A series of laboratory experiments (Zhao et al 2012a) were conducted in which 1

- cm square cubes of ham were dipped into a test compound of a given concentration for 1.0 minute and then placed in a ventilated glass jar and inoculated with 20 adult mites. Jars were held for 14 days to allow for mite reproduction and population growth, after which the total number of mite adults and nymphs were counted and compared to numbers produced on other treated ham pieces and

on contro l hams dipped in water only. Three groups of experiments were conducted that compared common food oils, synthetic polyols and common legal food preservatives. Among oils tested, 100% lard from pork fat completely prevented mite reproduction on treated ha m pieces, while vegetable oils such as olive, corn and soybean had minimal effects on mites. Of the polyols, glycerol had little effect on mites while propylene glycol at 100% or 50% prevented mite reproduction. Other short

- chain diols had significant ef fects on mite reproduction. Of the other food preservatives tested, the various salts of sorbic and propionic acids were effective at preventing mite growth when applied as 10% solutions in water. Research so far suggests that approved food oils and synt hetic food preservatives show potential for protecting dry cured hams from mite infestation, and future work will need to address the effects of these additives, if any, on the quality of hams during the aging process and on consumer acceptability.

A Simp le, L ow

- cos t Trap for Monitoring Ham Mites

Dr. Phillips’ research group (Zhao et al 2012b) developed a mite trap based on the basic design of a trap first developed in England. This trap consists of a 90 mm disposable plastic Petri dish that is painted black on the entire outer surface. Around th e sidewall of the dish are eight evenlyUSA CUN 16 POST HARVEST

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spaced holes, approximately 0.5 mm in diameter, at 2 mm above the bottom of the dish for entry of responding mites. A food bait was placed inside the middle of the dish and was a 25 mm diameter circular plug of mite diet, approximately 10 mm high. Mite diet was composed primarily of ground dog food with yeast, glycerin, anti

- fungal agent and gelled with 2% agar. Mites respond to the baited dishes, enter the holes in the side wall, and feed to the diet plug

where th ey mate and lay eggs. Laboratory studies confirmed that traps baited with diet were highly attractive to mites compared to unbaited traps. A study was initiated to monitor mite populations in which twenty traps were distributed evenly throughout each of three different ham production facilities for consecutive one

- week periods. Mite numbers lured to traps varied from zero to several hundred in one week, and seasonal trapping determined that certain areas of facilities had higher mite activity than other areas. Traps confirmed that fumigation in certain circumstances caused severe reduction in mite populations, and showed that mites would slowly increase activity following fumigation. Future work will attempt to correlate mite trap counts

with other direc t measures of mite density, and also utilize such information to aid in IPM decisions. In addition, mite traps will be placed in additional processing facilities to determine

mite numbers in facilities in different areas in the Southeastern United States both prior to and after fumigation.

Simulations of Commercial Ham Fumigations

Three fumigations trials (Zhao et al 2012b) were conducted in 1000

- cubic feet shipping containers intended to simulate dry cured aging ham houses with phosphine concentrations ranging between 1000

- 2000 ppm and exposure time of 48 hours. Ten dry cured hams were hung from racks in each shipping container to simulate dry cured aging conditions. Twenty Tyrophagus putrescentiae (ham mites) bioassay jars and ten Necrobia rufipes (red

- legged ham beetles) jars were placed in each shipping container for each trial. Five of these hams were used for mite inoculation and the other 5 hams were used for sensory analysis and phosphine residue testing. The lean portion of the dry cured hams (tha t were used for inoculation) was also inoculated with a mixed culture of approximately 1000 mites. Temperature was recorded in the ham houses during fumigation.

There were three treatments in each trial: control (no fumigation), low phosphine, and high ph osphine. Three shipping containers were used during each trial. Phosphine gas was produced in the shipping containers using magnesium phosphide cells that reached target fumigation doses at between 8 to 12 hours after the fumigation was started. Phosphine concentration was measured in the shipping containers using both Dräger tubes and a calibrated UV

- VIS detector after 48 hours fumigation. Average concentration of the three trials after 48 hours fumigation for low phosphine treatment (52 grams of magnesium phosphide) was about 1300 ppm. For high concentration fumigation treatment (140 grams of magnesium phosphide), average concentration was about 1600 ppm.

The mite mortality was 99.8 % in the bioassays at two weeks post fumigation when 2000 ppm phosphine was achieved, but not all eggs on either the hams or in the bioassays was controlled, even at concentrations as great as 2000 ppm. A lengthier fumigation time was attempted during

earl y November, but the ambient temperature was too cold (<15oC) to achieve successful control of ham mites. At temperatures of 20oC or greater, all life stages of red

- legged ham beetles wereUSA CUN 16 POST HARVEST

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controlled in all fumigation trials. Variations in test conditions i ndicated that temperatures and exposure time need to be optimized for fumigation since 48 hours was not long enough to control ham mites at 2000 ppm and ambient temperatures below 15oC decreased the effectiveness of the fumigation against both ham mites an d red legged beetles.

Ham slices were oven baked to an internal temperature of 71 ̊C and served to trained panelists. A randomized complete block design with three replications was used to determine if trained panelists (n=6

- 8) could detect a difference be tween fumigated and non

- fumigated hams in sensory difference from Control Tests. Sensory tests indicated that trained panelists could not determine differences (P>0.05) between phosphine treated dry cured hams and non

- fumigated hams In addition, residual p hosphine concentration was below the legal limit of 0.01 ppm in ham slices that were taken from phosphine fumigated hams. Further research is underway to determine if phosphine can be used at the plant level to control ham mite infestations.

One phosphin e fumigation trial (Zhao et al 2012b) was conducted in a 36,000 cubic foot processing facility at 1600 ppm. Ham mite assays with live mites were distributed throughout the aging room. After 48 hr of fumi gation at 1600 ppm (80 F, 70

- 80 % RH), there were no living ham mites in the assays. However, phosphine fumigation corroded the electrical switches to the fans, and these switches had to be replaced. In addition, the research needs to be repeated when many hams are infested with mites to determine if it is effective in real world situations. In addition, if phosphine is going to corrode and incapacitate electrical equipment, it will not be adaptable to the industry. Sensory panels were conducted to verify that fumigation with phosphine did not change the s ensory profile of the hams. In this testing, trained panelists could not determine differences (P>0.05) between phosphine treated dry cured hams and non

fumigated hams.

References:

Abbar, S., M. W. Schilling and T. W. Phillips. 2012. Protecting hams from the mite Tyrophagus putrescentiae using food

- safe approaches. Annual International Research Conference on Methyl Bromide Alternatives and Emission Reduction, Orlando, FL, November 6

- 8 , (44).

Amoah, B., M. W. Schilling, T. W. Phillips. 2012. IPM a s an alternative for the ham mite, Tyrophagus putrescentiae: monitoring with traps. Annual International Research Conference on Methyl Bromide Alternatives and Emission Redu ction, Orlando, FL,

November 6

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Hasan, M.M., Phillips, T.W., Aikins, J.M., Schilling, M.W. 2010. Controlled atmosphere treatments to control arthropod pests of American dry cured hams. Annual International Research Conference on Methyl Bromide Alternatives and Emission Reduction, Orlando, FL, November 1

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MBTOC, Han dbook on Critical Use Nominations for Methyl Bromide , 2007. Available at: http://ozone.unep.org/teap/Reports/MBTOC/MBTOC_Handbook_ver_6_Dec_07_final.pdfUSA CUN 16 POST HARVEST

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MBTOC. 2012. Report of the UNEP Technology and Economic Assessment Panel

. October

2012

. E valuations of 2012 critical use nominations for methyl bromide and related matters. Available at: http://www.unep.org/ozone/teap/Reports/TEAP_Reports/

Phillips, T.W. 2009. Personal Communication.

Phillips, T. W., M. M. Hasan, M. J. Aikins and R, Mahroof. 2011. Fumigation and IPM

. alternatives for arthropod pests of museums. J. Ent. Acarol. Res. 43: 205

- 210.

Phillips, T.W. M.M. Hasan, M.J. Aikens, M.W. Schilling

. 2008. Efficacy of sulfuryl fluoride to

control ham mites and red

- legged ham beetles. Annual International Research Conference on Methyl Bromide Alternatives and Emission Reduction, Orlando, FL, November 11

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, (89).

Rentfrow, G., Hanson, D.J., Schilling, M.W., Mikel, W.B. 2008. The use of methyl bromide to control insects in country hams in the Southeastern United States. Extension Publication. University of Kentucky Extension/National Country Ham Association. Publication # ASC

171. Pages 1

- 2.

Sekhon, R.K., Schilling, T.W., Phillips, Hasan, M.M., Aikins, M.J, Mikel, W.B. 2009.Chemical Compositio n of Dry Cured Hams Fumigated with Carbon Dioxide. Annual International Research Conference on Methyl Bromide Alternatives and Emission Reduction, San Diego, CA, November 10 th

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Sekhon, R.K., Schilling, T.W., Phillips, Hasan, M.M., Aikins, M.J, Mikel, W.B. 2009. Chemical composition of dry cured hams fumigated with phosphine. Annual International Research Conference on Methyl Bromide Alternatives and Emission Reduction, San Diego, CA,

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Sekhon, R.K., Schilling, M.W., Phillips , T.W., Hasan, M.M., Aikins, M.J. Mikel, W.B. 2010a. Sulfuryl fluoride fumigation effects on the safety, volatile composition, and sensory quality of dry cured ham. Meat Science. 84(3):505

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Sekhon, R.K., Schilling, M.W., Phillips, T.W., Hasan, M.M., Aikins, M.J., Nannapaneni, R., Mikel, W.B. 2010b. Effects of carbon dioxide and ozone treatments on the volatile composition and sensory quality of dry cured ham. J. Food Science. 75(5):C452

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Sekhon, R.K., Schilling, M.W., Phillips, T.W., Hasan, M.M., Aikins, M.J., Corzo, A. Mikel,

W.B. 2010c. Effects of phosphine and methyl bromide fumigation on the volatile flavor profile and sensory quality of dry cured ham. Meat Science. 86(2):411

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Schilling, W. and T. W. Phillips, 2011. Personal Communicatio n.

Zhao, Y., T.W. Phillips, S. Abbar, W.B. Mikel, M.W.Schilling . 2012a. E ffects of various food

grade coatings on mite mortality and sensory quality of dry cured ham

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Zhao. Y., T.W. Phillips, M.J. Aikins, W.B. Mikel, M. W.Schilling. 2012b. Sensory evalu a tion and pest mortality of dry cured ham fumigated with phosphine in a simulated ham aging

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