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Irradiation as a Processing Aid

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Food Safety and Inspection Service (FSIS), USDA.


Notice of availability of petition and public meeting; request for comments.


The Food Safety and Inspection Service (FSIS) is announcing that it has received a petition from the American Meat Institute (AMI) to recognize the use of low penetration and low dose electron beam irradiation on the surface of chilled beef carcasses as a processing aid. Based on its consideration of the data and information contained in the petition, FSIS believes that the petition has merit. FSIS will hold a public meeting on September 18, 2008, to review the information contained in the petition and to receive public comments on what action it should take with respect to the petition. A copy of the petition is available on the FSIS Web site.


The public meeting will be held on September, 18, 2008. Comments must be received by October 18, 2008.


The public meeting will be held from 9 a.m. to 1 p.m. at: L'Enfant Plaza Hotel, 480 L'Enfant Plaza, SW., Washington, DC 20024, (202) 484-1000.

FSIS invites interested persons to submit comments on the petition and its reaction to the petition. FSIS will finalize an agenda on or before the meeting date and will post it on the FSIS Web page​News?​Meetings_​&​_​Events/​. The petition discussed in this notice is available for viewing by the public in the FSIS Docket Room and on the FSIS Web site​News?​Meetings_​&​_​Events/​ and​regulations_​&​policies/​Petitions/​index.asp. The official transcript of the meeting will be available for viewing by the public in the FSIS Docket Room and on the FSIS Web site​News?​Meetings_​&​_​Events/​ when it becomes available.

Comments may be submitted by either of the following methods:

Federal eRulemaking Portal: This Web site provides the ability to type short comments directly into the comment field on this Web page or attach a file for lengthier comments. FSIS prefers to receive comments through the Federal eRulemaking portal. Go to and, in the “Search for Open Regulations” box, select “Food Safety and Inspection Service” from the agency drop-down menu, then click on “Submit.” In the Docket ID column, select the FDMS Docket Number FSIS-2008-0028 to submit or view public comments and to view supporting and related materials available electronically. After the close of the comment period, the docket can be viewed using the “Advanced Search” function in

Mail, including floppy disks or CD-ROMs, and hand- or courier-delivered items: Send to Docket Clerk, U.S. Department of Agriculture, Food Safety and Inspection Service, FSIS Docket Room, 1400 Independence Avenue, SW., Room 2534, Washington, DC 20250.

All submissions received must include the Agency name and docket number FSIS-2008-0028. Documents referred to in this notice, and all comments submitted in response to this notice will be available for public inspection in the FSIS Docket Room at the address listed above between 8:30 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments also will be posted on the Agency's Web site at​regulations_​&​_​policies/​2008_​Notices_​Index/​index.asp.

Individuals who do not wish FSIS to post their personnel contact information—mailing address, e-mail address, telephone number-on the Internet may leave this information off of their comments.

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For technical information, Patrick Burke: telephone—202/720-7974 and e-mail—

Pre-registration for this meeting is recommended. To pre-register, please contact Robert Tynan by telephone at (202) 720-3884 or by e-mail at, Persons Start Printed Page 52002requiring a sign language interpreter or special accommodations should contact Robert Tynan as soon as possible.

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I. Background

A. Food Irradiation

Food is most often irradiated commercially to extend shelf-life, eliminate insect pests, or reduce numbers of pathogenic microorganisms. Food irradiation for these purposes is practiced in many countries, including the United States. Food irradiation is the process of exposing food to high levels of radiant energy. One form of radiant energy used commercially is electron beam (e-beam). Energy from accelerated electrons is absorbed as they enter the surface of the product being irradiated. The electrons cause chemical bond breakage in the microorganisms immediately, in addition to damaging their deoxyribonucleic acid (DNA). However, not all microorganisms are destroyed at the same energy dose because of the differences in the amount of genetic material or their ability to repair their genetic material.

In 1999, FSIS amended its regulations (64 FR 72168, December 23, 1999) to permit the use of ionizing radiation for treating refrigerated or frozen, uncooked meat, meat by products, and certain other meat food products to reduce levels of foodborne pathogens and to extend shelf-life. The FSIS regulations require the use of sources of ionizing radiation identified in FDA's regulations (21 CFR 179.261(a)). These sources include gamma rays, electrons generated from machine sources (e-beam), and x-rays. In 9 CFR 424.22(c), FSIS details the requirements for the use of irradiation by official establishments, including the labeling requirements for irradiated meat (9 CFR 424.22(c)(4)). The Agency requires that labeling for packaged meat food products irradiated in their entirety bear the radura logo along with a statement such as “Treated with radiation” or “Treated by irradiation.” FSIS requires that the logo be placed prominently and conspicuously in conjunction with the required statement, and that the statement appear as a qualifier contiguous to the product name (9 CFR 424.22(c)(4)(i)). Also, FSIS requires that inclusion of an irradiated meat food product ingredient in any multi-ingredient product be reflected in the ingredient statement on the finished product labeling (9 CFR 424.22(c)(4)(iii)). FSIS requires that for unpackaged meat food products irradiated in their entirety, the logo and a statement be prominently and conspicuously displayed to purchasers either through labeling on a bulk container or some other appropriate device (9 CFR 424.22 (c)(4)(iii)).

In 21 CFR 179.26 (b), FDA lists the conditions under which ionizing radiation can be safety used. For the control of foodborne pathogens in, and extension of the shelf-life of, refrigerated uncooked meat, the amount of irradiation is not to exceed 4.5 kGy maximum for refrigerated products. The regulation does not list a minimum dose.

B. Processing Aids

Under FDA's regulations, processing aids include substances that are added to a food for their technical or functional effect during processing but are present in the finished food at insignificant levels and do not have any technical or functional effect in that food (21 CFR 101.100 (a)(3)(ii)(c)). FDA's regulations provide that processing aids are not required to be included on product labels.

FSIS has relied on the FDA regulations on processing aids in regulating the labeling of meat and poultry products (​PDF/​Determination_​of_​Processing_​Aids.pdf). FSIS does not require that the use of substances determined to be processing aids be declared on product labels. For example, for over a decade, the Agency has permitted the use of lactic acid and certain other organic acids as antimicrobial carcass washes applied post-slaughter but pre-chiller. In this application, lactic acid and the other organic acids are classified as a processing aid, and no labeling is needed, because the effect of application of the substance is momentary and not lasting.

AMI Petition

On July 8, 2005, AMI submitted a citizen's petition to FSIS requesting that the Agency officially recognize low dose, low penetration e-beam irradiation applied to the surface of chilled beef carcasses as a “processing aid.” The petition requested that information concerning irradiation treatment not be required on the label of any products derived from the carcass.

The petition argues that low dose (≤ 1.0 kGy surface dose), low penetration (20mm) e-beam irradiation is a processing aid because the electron beam has a functional effect of reducing pathogens on the carcass surface, but that once the energy from the electrons is absorbed, there were no further functional effects from the irradiation. According to the petition, low dose, low penetration e-beam application results in only a small portion of the carcass receiving the e-beam irradiation exposure. The petition presents evidence that the use of e-beam irradiation is effective in reducing levels of Escherichia coli O157:H7 on the carcass; has no effect on organoleptic properties or appearance of the carcass; has no lasting effect on shelf life of the carcass or of product derived from the carcass; and produces no significant loss of either macro- or micro-nutrients in the carcass or the product derived from the carcass. A summary of the scientific data presented in the petition follows:

1. The Process Is Effective at Reducing Levels of E. coli O157:H7

The USDA Agricultural Research Service's Meat Animal Research Center (MARC) conducted a study on the effectiveness of low-dose, low penetration e-beam irradiation in reducing levels of E. coli O157:H7 on chilled beef carcass surface cuts. (Arthur, Terrance M. and et al. 2005. Effects of Low-Dose, Low-Penetration Electron Beam Irradiation of Chilled Beef Carcass Surface Cuts on Escherichia coli O157:H7 and Meat Quality. Journal of Food Protection, Vol. 68, No. 4 2005, Pages 666-672.)

In the study, portions of beef cutaneous trunci muscle were selected to represent the carcass surface because the muscle, which covers portions of the beef plate and beef flank, is the outermost surface muscle and thus approximates the surface matrix of a beef carcass. Forty cutaneous trunci pieces were inoculated with E. coli O157:H7, twenty with a high concentration of 6 log cfu/cm2 (high inoculation) and twenty with a low concentration of 3 log cfu/cm2 (low inoculation). The forty samples were cut into equal portions for a total of eighty samples. One half of the high inoculated and low inoculated samples were treated with surface dosage of 1 kGy with approximately 15 mm of penetration. The remaining samples were not treated.

Results for direct cell count plating show that while the E. coli O157:H7 contamination of the untreated samples remained around the high inoculation level (7.2 logs after attachment, 6.6 logs at 48 hours and 5.9 logs at 120 hours) and the low inoculation level (3.9 logs after attachment, 2.9 logs after 48 hours, and 2.6 logs after 120 hours), E. coli O157:H7 was undetectable after 48 hours in irradiated samples that had been inoculated at the high level and was present at approximately 0.1 log after 120 hours. For the low inoculation level, the irradiation treated samples Start Printed Page 52003were undetectable for E. coli O157:H7 after 48 and 120 hours. In addition to direct plating, researchers conducted enumeration of positive samples using the most probable number (MPN) technique. The results of the MPN analysis were similar to that from direct plating, indicating that the numbers of viable E. coli O157:H7 cells following irradiation were very low. There was no low-inoculation sample at 48 hours and only one low-inoculation sample at 120 hours that had a MPN value above the limit of detection (minimum level of detection was 0.036 CFU/cm2). All of the high-inoculation samples were above the limit of detection.

These data appear to support the conclusion that a low dose (≤ 1.0 kGy surface dose), low penetration (20mm) surface e-beam irradiation process will produce a significant surface reduction of E. coli O157:H7 on chilled beef carcasses. FSIS solicits comment on whether this conclusion is correct, and on whether there are data available that would support a different conclusion.

2. The Process Does Not Have Any Affect on Quality or Appearance

The MARC's study also addressed effects of low dose, low penetration e-beam process on organoleptic properties of treated product. Spilt beef carcasses have thin external muscles that may be partially exposed from the carcass splitting process. During low dose e-beam irradiation of carcass sides, these muscles will receive various doses of radiation depending on their location and the extent of fat cover. In MARC's assessment of organoleptic impact, the flank steak was used as the model muscle because it is partially surface exposed; consistent in size, shape, and location; easy to access and remove; and possesses sufficient surface fat and surface layer molding to achieve variable penetration.

None of the flank steak sensory attributes (aroma intensity, off-aroma, tenderness, juiciness, flavor intensity, and off-flavor) were affected by any penetration treatment (10%-75% penetration). Three Hunter Color measurements (lightness, redness, and yellowness) were made in the MARC study, and all showed some treatment effects. However, the effects on lightness and yellowness were not linear with dose, and thus the investigators did not consider them to be meaningful treatment-related differences. The effects of treatment on redness values were linear. However, the researchers concluded that the magnitude of the effect was slight and would likely have no impact on consumer acceptance.

These data appear to support that a low dose, low penetration surface e-beam process does not have any affect on quality or appearance. FSIS asks for comment on whether the available data support this conclusion.

3. The Process Does Not Have an Effect on Shelf Life

A study of the effects of low dose, low-penetration e-beam surface exposure on the shelf life of beef was performed by Silliker Inc.

Twelve chilled beef plates from a commercial beef slaughter facility were removed from beef carcasses and transported to a commercial irradiation facility. Six beef plates were designated “air-exposed,” and three of these six were left untrimmed. Six beef plates were designated “vac-pac,” and all were trimmed. Six of these twelve were treated with low level (1 kGy), low penetration (15 mm) surface e-beam irradiation. The other six were left untreated as controls.

After the six beef plates were irradiated, the irradiated and control plates were randomly subdivided into four equal segments. Each segment was allocated into time slots of 1, 3, 6, and 9 days for air exposed, and 1, 10, 20, and 30 days for vac-pac. The following microbiological tests were performed at each measurement time: total aerobic plate count (APC) (35°C with aerobic atmosphere), hetero- and homo-lactic acid bacteria (LAB) (30°C with micro-aerobic atmosphere), total coliforms (35°C with aerobic atmosphere), and Biotype I E. coli (35-45°C with aerobic atmosphere). To provide a measure of oxidative rancidity, thiobarbituric acid (TBA) was analyzed throughout shelf life.

For APC, LAB, and total coliform counts of air-exposed beef after nine days, the irradiated samples were within 1.5 logs of the non-irradiated samples. For APC and LAB counts of vacuum packed beef after thirty days, the irradiated samples were within 1 log of the non-irradiated samples, while the total coliform counts were equivalent. The vacuum packed beef TBA values ranged from limited, tolerably oxidized to somewhat oxidized over 30 days of shelf life. The air exposed beef TBA values ranged from limited, tolerably oxidized at 2 days of shelf life to oxidized at 9 days of shelf life. All samples were below the range of rancidity.

Based on the results of this study, the initial antimicrobial effects of the treatment appear to have been minimal, and over the course of shelf life, the APC and LAB counts on the surface e-beam treated product increased to the point that quantitative levels nearly approximated the non-treated controls at the end of the storage period. In addition, one of the principal measurements of shelf life and product spoilage—rancidity—as measured by TBA indicated that the treated samples would turn rancid slightly before the non-treated controls. These data appear to demonstrate that the e-beam surface treatment of beef plates does not have a lasting effect on the product shelf-life.

Based on all of these data, a low dose, low penetration surface e-beam process appears not to have any affect on shelf-life. FSIS asks for comment on this tentative conclusion.

4. The Process Does Not Produce Significant Losses of Nutrients

A literature review and analysis on the effects of low dose, low-penetration e-beam irradiation on the levels of micro and macro nutrients was conducted by Dr. Donald W. Thayer, a retired USDA—ARS researcher (Thayer, Donald. 2004. Literature Review and Analysis of the Effects of Beef Carcass Surface Irradiation on Micro- and Macro-Nutrients).

Concerning macro-nutrients, Dr. Thayer found that there were no significant differences in the peroxide and iodine values of lipids following irradiation up to 10 kGy of the m. longissimus dorsi of beef. Also, there were no significant changes following irradiation in the malonaldehyde concentration in beef m. longissimus dorsi (Hampson, J.W., et al., 1996. Effect of low dose gamma radiation on lipids in five different meats. Meat Science. 42:271-276). Concerning micro-nutrients, Dr. Thayer found that several authors studied the effects of sterilization doses of gamma irradiation on vitamins in ground beef at 1 kGy dose. According to Dr. Thayer's review, the water soluble vitamins in beef (niacin, vitamin B12, chorine, instill, and folacin) were “unaltered.” One water soluble and one fat soluble vitamin (thiamin and tocopherol) would likely be decreased. For these two vitamins, Dr. Thayer estimated, worse case, that the maximum net decrease in the U.S. diet would be only 0.021% for thiamin and 0.014% for tocopherol.

Dr. Thayer concluded that “beef carcass surface, low dosage (1.0 kGy) electron beam irradiation will not produce a significant loss of either micro- or macro-nutrients from the U.S. diet.”

Based on these findings, it appears that a low dose, low penetration surface e-beam process does not have any significant effect on micro and macro Start Printed Page 52004nutrients. FSIS asks for comment on this tentative conclusion.

Processing Aid

The AMI petition raised the issue of considering low dose, low penetration e-beam irradiation of the surface of beef carcasses to be a “processing aid” whose use would not need to be disclosed in the labeling of products derived from the carcasses that were irradiated. FSIS has consulted with FDA about this issue, and FDA has advised FSIS that, tentatively, it would not object to treating low dose, low penetration e-beam irradiation on the surface of chilled beef carcasses as a processing aid. FDA is still considering this issue and will likely consult further with FSIS.

Issues To Be Discussed at the Public Meeting

After considering the AMI petition, FSIS has tentatively concluded that there is merit to consider low dose (≤1.0 kGy) and low penetration (20mm) e-beam irradiation on the surface of chilled beef carcasses as a processing aid.

Data submitted showed that low dose, low penetration surface e-beam irradiation will produce a significant surface reduction of E. coli 0157:H7 on chilled beef carcasses. The e-beam treatment does not appear to have a lasting antimicrobial effect that would extend the shelf-life of the products, and it appears that there is no significant difference in color, odor, or taste between treated and untreated products. Relevant studies appear to support the assertion that the low dose, low penetration e-beam irradiation treatment would not produce any significant changes in the macro and micro nutrient content of the treated products. Further, the entire beef carcass is not irradiated, only the surface of the carcass.

Public Meeting and Comments

FSIS is seeking comment both at the public meeting and during the comment period on the following questions and those raised throughout this document:

  • Is there any additional evidence to support or contradict the evidence presented in the AMI petition on the specific application of a low penetration of 20mm and low surface dosage of ≤1.0 kGy electron beam irradiation on the surfaces of chilled beef carcasses as a processing aid?
  • Is there any evidence indicating that FSIS should consider the cumulative effects of the absorbed dose delivered in accordance with the AMI petition and any subsequent absorbed dose, such as a result of further irradiation of ground beef?
  • Should FSIS consider requiring irradiation process controls if irradiation is considered a processing aid? If so, what would they be and what impact would they have on the low dose irradiation of chilled carcasses?
  • Are there factors that FSIS has not considered? If so, what are they and what impact would they have?

Additional Public Notification

Public awareness of all segments of rulemaking and policy development is important. Consequently, in an effort to ensure that minorities, women, and persons with disabilities are aware of this notice, FSIS will announce it on-line through the FSIS Web page located at​regulations/​2008_​Notices_​Index/​.

FSIS also will make copies of this Federal Register publication available through the FSIS Constituent Update, which is used to provide information regarding FSIS policies, procedures, regulations, Federal Register notices, FSIS public meetings, and other types of information that could affect or would be of interest to constituents and stakeholders. The Update is communicated via Listserv, a free electronic mail subscription service for industry, trade and farm groups, consumer interest groups, allied health professionals and other individuals who have asked to be included. The Update is available on the FSIS Web page. Through the Listserv and the Web page, FSIS is able to provide information to a much broader and more diverse audience.

In addition, FSIS offers an e-mail subscription service which provides automatic and customized access to selected food safety news and information. This service is available at​news_​and_​events/​email_​subscription/​.

Options range from recalls to export information to regulations, directives and notices. Customers can add or delete subscriptions themselves and have the option to password protect their account.

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Done at Washington, DC on: September 2, 2008.

Alfred V. Almanza,


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[FR Doc. E8-20653 Filed 9-5-08; 8:45 am]