United States Department of 

Agriculture

Food Safety and Inspection Service

Office of Policy and Program 

Development

Washington, DC 20250-3700

REGULATIONS AND DIRECTIVES DEVELOPMENT

Protocol for Evaluating Retained Water

in the Following Single Ingredient Red Meat Product: 

Steer/Heifer Carcasses

Note: The following is an example protocol and should not to be used verbatim. Because 

each establishment is unique, each establishment should design their protocol to reflect the 

individual characteristics of their operations.

1.0 Purpose Statement

 1.1 The purpose of this protocol is to determine the amount of

 water absorption and retention in Steer/Heifer carcasses that

 is unavoidable while achieving the regulatory pathogen

 reduction performance standard for Salmonella (as set forth

 in the PR/HACCP regulations – 9 CFR 310.25(b).

2.0 Type of washing and chilling system

 2.1 The facility slaughter/dressing line utilizes a final carcass

 washer at the end of the dressing procedures. This is 

 followed by a carcass rinses that includes the antimicrobial

 intervention (*insert example) prior to entry into the carcass

 cooler. The carcass cooler is maintained around 34 °F.

3.0 Configuration and modification of the chiller system

 components

 3.1 The establishment uses a carcass water spray system in the

 carcass cooler to chill carcasses rapidly. The carcass water

 spray system consists of intermittent sprays of water during

 the carcass cooling process.

4.0 Special features in the chilling process:
4.1 Chlorine is added to the carcass water spray as an

 antimicrobial intervention at 20-50 PPM. The carcasses

 freely drain before exiting the carcass cooler and prior to

 further processing in the establishment or prior to shipping.

5.0 Variable factors that affect water absorption and retention

5.1 The final carcass wash cabinet consists of a number of spray

 nozzles at a selected pressure at selected spray directions by

 the establishment. The final carcass wash water is the normal

 ambient water temperature from the municipality or of the

 well water. The number and size of spray nozzles, direction

 of nozzles, water pressure, and the length of time in the final

 wash cabinet may be changed depending upon the size of the

 carcasses, season of the year, and changes in the dressing

 procedures. The carcasses are in the chiller system (cooler)

 usually from 18 to 24 hours. The carcass cooler temperature

 is usually maintained around 34 °F. The temperature of the

 water in the carcass water spray is the normal ambient water

 temperature from the municipality or of the well water. The

 frequency and length of intermittent sprays of water per bay

 during the carcass cooling, the carcass cooler temperature

 and the drain time from the last spray prior to exiting the

 cooler may be varied.

6.0 Standards to be met by the chilling system:

 6.1 The current FSIS Salmonella pathogen reduction

 performance standards, as set forth in the PR/HACCP final

 rule, will be met.

7.0 Testing methodology

 7.1 Water absorption and retention

 7.1.1 Samples will be collected immediately prior to the final

 carcass wash on the slaughter/dressing line to

 determine the "green" weight of the carcasses.

 7.1.1.1 *(insert number) random carcasses will be

 tagged and weighed in *(insert number)

 groups of *(insert number) carcasses. The

*(insert number) groups will be distributed

 evenly throughout the production period

 (beginning, middle, and end) with the
 production period being defined as

 sanitation to sanitation.

 7.1.2 Samples will be collected from carcasses at point

 exiting the cooler.

 7.1.2.1 The tagged carcasses from 7.1.1.1 will be

 weighed immediately prior to further

 processing or shipping.

 7.1.2.2 These post-cooler weights will be

 compared to the pre-final carcass wash

 weights to determine the retained water

gained using a mathematical difference

calculation (cooler exit weight minus "green"

weight [pre-final carcass wash weight]) as a

 percentage.

 7.2 Pathogen reduction measurement

 7.2.1 *(insert number) groups of *(insert number) carcasses

 will be randomly selected post-cooler from the same

 lots as those tested in Section 7.1. The *(insert

 number) groups will be distributed evenly throughout

 the production period (beginning, middle, and end)

 with the production period being defined as sanitation

 to sanitation.

 7.2.1.1 The percent Salmonella positive rate will 

 be determined using the post-cooler

 carcass swabs Salmonella performance

 standard methodology.

 7.3 Evaluation of cooler factors

 7.3.1 The frequency and length of intermittent carcass

 sprays per cooler bay

 7.3.1.1 Three frequency and length of sprays will be

 evaluated.

 7.3.1.1.1 Fifteen minute interval: Spray for

 1 minute, spray off for 14

 minutes.
 7.3.1.1.2 Thirty minute interval: spray for

 3 minutes, spray off for 27

 minutes.

 7.3.1.1.3 Sixty minute interval: spray for 3

 minutes, spray off for 57

 minutes.

 7.3.2 The carcass cooler temperature will remain around

 34° F.

 7.3.3 The drain time from the last carcass spray until exit

 7.3.3.1 Two drain times will be evaluated.

 7.3.3.1.1 4 hours after last spray

 7.3.3.1.2 6 hours after last spray

 7.3.4 Study design

 7.3.4.1 A three-by-two factorial table will be used

 to evaluate the effect of these cooler factor

settings on the percent moisture retention

(Section 7.1) and on the pathogen reduction

measurements (Section 7.2).

 7.3.4.2 Each of the six cooler setting combinations

 will be evaluated for three processing

periods (defined as sanitation to sanitation).

Each processing period will be considered

a replicate.

8.0 Evaluation and Reporting of Data

 8.1 The results achieved from the three replicates per cooler

 setting combination will be averaged and reported as the final

 result for each cooler setting combination.

 8.1.1 Carcass weight differences will be determined using a

 mathematical difference calculation (cooler exit

 weight minus "green" weight) for each carcass group

 resulting in recorded weight difference results. The

 weight difference obtained per carcass group will be

 divided by the "green" weight per carcass group to

 determine the % moisture retention cooler exit per
 group. The results will be averaged to obtain the

 estimated average % moisture retention at point of

 cooler exit.

 8.1.2 The Salmonella data will be reported as the number

 of positive samples/number of samples tested x 100

 (% positive).

9.0 Explanation of how the conclusions will be determined.

 9.1 Conclusions will be determined by comparing the baseline

 pathogen reduction levels achieved pre-protocol

 implementation with the post-protocol implementation

 pathogen reduction results. This comparison will be evaluated

 according to the specifications detailed in section 6.1.

 9.2 The amount of moisture retention that is unavoidable to

 achieve the above food safety criteria will be reported.

(*) Each establishment should insert statistically significant and verifiable information that 

reflects their unique operations.

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Food Safety and Inspection Service

Regulations and Directives Development Staff

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Last modified: February 09, 2004