Executive Summary

The Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture 

(USDA) contracted with RTI International and its subcontractor North Carolina State 

University (NCSU) to conduct meal preparation experiments to evaluate consumer food 

handling behaviors in a test kitchen. The research team conducted five separate iterations 

of meal preparation experiments to address a specific consumer behavior and to determine 

the effectiveness of a behavior change intervention. The meal preparation experiments are 

part of a larger 5-year annual study that also includes focus groups (two iterations) and web 

surveys (two iterations). This report describes the results of the fifth iteration of the meal 

preparation experiment. 

ES.1 Study Methods 

RTI and NCSU conducted the study in a test kitchen facility located in Raleigh, North 

Carolina (Wake County), with three identical test kitchens. The study examined participants’ 

adherence to recommended food safety practices when the mandated Safe Handling 

Instructions (SHI) label has been removed from meat packaging and safe handling 

instructions are integrated into the manufacturer’s cooking instructions (MCI). Participants 

were randomly assigned to the (1) control group: separate SHI label and MCI on sausage 

packaging (n = 125) or (2) intervention group: intervention label with safe handling 

instructions integrated into the MCI (n = 126). For the outcomes of interest, we conducted 

statistical testing for the difference between the control versus the treatment group. 

Participants were observed (while being video-recorded) cooking breakfast sausage 

(inoculated with harmless traceable nonpathogenic E. coli strain DH5-Alpha) and shell eggs 

and preparing a fruit salad with cantaloupe. Participants’ behaviors were coded to measure 

adherence to recommended food safety practices, including thermometer use, 

handwashing, cleaning and sanitizing, safely preparing shell eggs, and washing produce. 

Following meal preparation, the study team collected microbiological samples from surfaces 

and cantaloupe from the prepared fruit salad and analyzed the samples for prevalence and 

level of DH5-Alpha. Participants participated in a post-observation interview to collect 

information on their usual food preparation practices and response to the intervention label. 

ES.2 Key Findings 

The key findings from the study are summarized below. 

Impact of Intervention Label 

▪ The intervention label did not impact the rate of food thermometer use for the sausage, 

the rate of handwashing attempts (before or during meal preparation), or the rate of 

cleaning/sanitizing attempts for the surface used to prepare the sausage. 

Food Safety Consumer Research Project: Meal Preparation Experiment on Breakfast 

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▪ The results of the microbiological analysis suggest that the intervention label did not have 

an impact on cross-contamination during meal preparation. 

▪ When asked about thermometer use in the post-observation interviews, 40% of treatment 

group participants reported using a thermometer because of the instruction on the label 

compared with 16% of the control group (the control group label provided the endpoint 

temperature in the MCI but did not have instructions to use a food thermometer). These 

results suggest that the intervention label may have influenced thermometer use in the test 

kitchen, although the rates of thermometer use were not significantly different for the 

treatment and control groups. 

▪ Most (59%) treatment group participants did not offer any suggestions for improving the 

intervention label; 79% said the length of the label was about right, and 20% believed it 

was too long. 

Thermometer Use 

▪ Fifty percent of the control group and 55% of the treatment group used a thermometer to 

check doneness of the sausage patties. The difference between the two groups was not 

statistically significant. Some participants reported that they used a thermometer in the test 

kitchen, although this is not their usual behavior when cooking at home. 

▪ Among participants using a thermometer, the mean number of sausage patties checked 

for doneness was three (most participants cooked four patties) for each group. 

▪ Among participants using a thermometer, most participants failed to insert the 

thermometer in the proper location when checking doneness of the sausage patties. 

▪ Comparing thermometer use among control group participants for Years 1 through 5 of the 

study, thermometer use varied by the type of product cooked. Excluding the not-ready-toeat frozen, breaded stuffed chicken breasts—given the different characteristics of this 

product—the rate of thermometer use was significantly higher for hamburgers (58%), 

bratwurst (55%), and breakfast sausage (50%) compared with turkey burgers (34%). 

Handwashing 

▪ Rates of handwashing attempts before meal preparation were similar for the two groups: 

44% for the control group and 42% for the treatment group. 

▪ Rates of handwashing attempts during meal preparation were similar for the two groups: 

17% for the control group and 18% for the treatment group. 

▪ As in Years 1 through 4, few handwashing attempts included all steps necessary to be 

considered an adequate handwashing event as defined by the Centers for Disease Control 

and Prevention’s (CDC’s) recommended steps, and the most documented reason for not 

successfully washing hands was failing to rub hands with soap for at least 20 seconds. 

▪ For handwashing before meal preparation, the rate of attempting handwashing for Years 4 

and 5 (44%) was significantly lower compared with rates observed for study 

Executive Summary 

ES-3 
Year 2 (74%) and Year 3 (71%) among control group participants.1 We speculate that the 

lower rate for Years 4 and 5 may be because participants used the hand sanitizer station 

upon arrival, which was not present in prior years, as a COVID-19 precaution. Other 

reasons are possible, such as differences in the characteristics of the study sample and 

social distancing measures during the participant introduction to the test kitchen, which led 

them to touch meal preparation surfaces (e.g., drawers/cabinets), thus commencing meal 

preparation before washing their hands. Additional analysis is needed to understand why 

the rates are different. 

Cleaning and Sanitizing 

▪ Attempts to clean and sanitize immediately after handling sausage were similar for the two 

groups (about one-third of participants), with over half of the attempts unsuccessful 

because the participant cleaned but did not sanitize the surface. 

▪ At the end of meal preparation, 65% of control group participants and 58% of treatment 

group participants attempted cleaning and sanitizing; the difference was not statistically 

significant. The rate of successful attempts (cleaned and then sanitized) was around 70% 

for both groups. 

Cross-contamination and Microbiological Analysis 

▪ Across all participants, the most often contaminated surface was the kitchen basin (38% of 

participants). The rate of contamination for the cantaloupe was the next highest, at 25%. 

▪ Rates of contamination were relatively low for the juice glasses used to plate the meal 

(9%), spice containers (5%), and the tablet (3%). No differences were observed by group 

for prevalence or level of contamination. 

Preparing and Cooking Eggs 

▪ Less than half (43%) of participants attempted to wash their hands after cracking eggs; of 

those, only 1% successfully did so according to CDC’s recommended steps. 

▪ Sixty-nine percent of participants who cooked scrambled eggs reported cooking them until 

the yolk was firm. Among participants who fried the eggs, only 20% cooked them until the 

yolk was firm, preferring instead for their eggs to be over easy or over medium, with the 

yolks still runny. 

Washing Produce 

▪ The rate of washing attempts for the cantaloupe among all participants was 25%; and 

among these, 75% were successful. 

▪ The rate of washing attempts for the mint among all participants was 43%. Of these, only 

29% rubbed the mint with their hands, the recommended practice.