Sandria L. Godwin

Comparison of a Rapid ATP Bioluminescence Assay and Standard Plate Count Methods for Assessing Microbial Contamination of Consumers' Refrigerators

The feasibility of using an ATP bioluminescence assay for assessing microbial contamination of home refrigerators was evaluated and compared with the standard culture methods. Samples of refrigerator surfaces were collected from 123 households by swabbing an area of 100 cm2 on three locations in the refrigerator with premoisturized sterile swabs. Microbial contaminations were determined by aerobic plate count (APC; incubated at 35 degrees C for 48 h) and psychrotrophic plate count (PPC; incubated at 7 degrees C for 10 days) on plate count agar. The results were compared to the readings from the microbial ATP (mATP) bioluminescence assay. The correlation coefficient (r) between mATP and PPC (r = 0.851) was slightly higher than that between mATP and APC (r = 0.823). Our results indicated a potential discrepancy in the population of mesophilic and psychrotrophic bacteria in the refrigerator samples. Nevertheless, mATP appeared to be a reliable indication of the average of APC and PPC (r = 0.895). The mATP bioluminescence assay would provide a rapid and convenient test for researchers in field studies to assess microbial contamination in refrigerators.

Consumer Home Refrigeration Practices: Results of a Web-Based Survey

To reduce bacterial growth and to ensure the quality and safety of food products, the U.S. Department of Agriculture and the U.S. Food and Drug Administration advise consumers to clean their refrigerators regularly, use a refrigerator thermometer, and keep refrigerator temperatures at 40 degrees F (4.4 degrees C) or below. We conducted a nationally representative Web-enabled survey (n = 2,060) to collect data on refrigerator thermometer ownership, home refrigerator temperatures, and the frequency of home refrigerator cleaning. We stratified the sample to provide results for pregnant women, older adults (60 years or older), and the remaining population. About half of all respondents had cleaned their refrigerators at least 1 month before the survey. Only 11% of all respondents had a thermometer in their refrigerator before the survey. Older adults (77.5%) were more likely than the remaining population (70.4%) to have their refrigerators at the recommended temperature (P < 0.01). Older adults who were not married and who lived alone were less likely to have refrigerator thermometers and to have their refrigerators at a recommended temperature (P < 0.05). For all respondents, those who had previously owned a refrigerator thermometer were more likely to have their refrigerators at the recommended temperature than were respondents who did not previously own a thermometer (P < 0.01). Food safety educators can use the survey findings and results of previous research to target educational materials and help consumers, especially those at risk for listeriosis, to safely store refrigerated foods at home.

Efficacy of home washing methods in controlling surface microbial contamination on fresh produce.

Much effort has been focused on sanitation of fresh produce at the commercial level; however, few options are available to the consumer. The purpose of this study was to determine the efficacy of different cleaning methods in reducing bacterial contamination on fresh produce in a home setting. Lettuce, broccoli, apples, and tomatoes were inoculated with Listeria innocua and then subjected to combinations of the following cleaning procedures: (i) soak for 2 min in tap water, Veggie Wash solution, 5% vinegar solution, or 13% lemon solution and (ii) rinse under running tap water, rinse and rub under running tap water, brush under running tap water, or wipe with wet/dry paper towel. Presoaking in water before rinsing significantly reduced bacteria in apples, tomatoes, and lettuce, but not in broccoli. Wiping apples and tomatoes with wet or dry paper towel showed lower bacterial reductions compared with soaking and rinsing procedures. Blossom ends of apples were more contaminated than the surface after soaking and rinsing; similar results were observed between flower section and stem of broccoli. Reductions of L. innocua in both tomatoes and apples (2.01 to 2.89 log CFU/g) were more than in lettuce and broccoli (1.41 to 1.88 log CFU/g) when subjected to same washing procedures. Reductions of surface contamination of lettuce after soaking in lemon or vinegar solutions were not significantly different (P > 0.05) from lettuce soaking in cold tap water. Therefore, educators and extension workers might consider it appropriate to instruct consumers to rub or brush fresh produce under cold running tap water before consumption.

Consumer knowledge and use of open dates: results of a WEB-based survey.

Consumers are relying increasingly on ready-to-eat (RTE) foods because they are convenient, quick, and easy. Open dates let consumers know by which date to purchase or use RTE foods for best quality. To further characterize consumer knowledge and use of open dates for specific refrigerated RTE foods (smoked seafood, cooked crustaceans, bagged salads, prewashed cut produce, soft cheeses, frankfurters, deli meats, fermented sausages, and deli salads), we conducted a nationally representative web-enabled survey (n=2060). Before purchasing RTE foods, 48 to 68% of respondents check open dates all or most of the time. Before preparing RTE foods, 43 to 64% of respondents check open dates all or most of the time. Nearly two-thirds of respondents reported that their senses were the most important factors in deciding whether to eat a refrigerated food, which is an unsafe practice. About one-third of respondents reported that an open date is the most important factor in deciding whether to eat a refrigerated food. Many respondents, however, do not understand the meanings of the different types of dates. Only 18% correctly defined the use-by date. The findings suggest consumers could benefit from education regarding open dates and recommended storage times for RTE foods.

Evaluation of nutrient intakes of rural elders in eleven southern states based on sociodemographic and life style indicators

Nutrient intakes of 2893 rural free-living elderly persons aged 65 and older residing in 11 southern states were studied. Data being reported herein include food intake by a 24-hr recall, meal preparation settings and use of dietary supplements and socioeconomic variables. High percentages of monthly income were spent on food, particularly among black females and participation rates in community service programs, including senior centers and home delivered meals, were low. Caloric intakes by rural males were 1603 and 1365 kcal, respectively, for whites and blacks; 1270 and 1259 kcal for white and black females, respectively. Means for most of the nutrients equalled or exceeded the RDAs for this age group except energy and calcium. Age had little influence on nutrient intake. Race showed as a significant determinant on the nutrient intake index computed from 11 key nutrient intakes; however, the significant effect of race disappeared when either income or educational level was used as covariate. Thus, the disparities in intakes between the black and white elders were due partly to income rather than race. Of these rural elders, 46.5% consumed meals alone. Eating alone per se did not have a significant impact on nutrient consumption, but 35.2% of those eating alone indicated that they ate less, had fewer choices or ate more. Dietary supplements were used by 33.9% of rural elders, and their intakes of several nutrients were higher than by nonusers. More effort by community services to reach rural elders is needed, particularly those in the low socioeconomic spectrum.

Evaluation of portion size estimation aids used for meat in dietary surveys

Abstract In three studies, individuals used various PSEAs (bean bag, peg board, ruler, sausage diagram, and size grid) to estimate portion sizes for three different categories of meat (intact cuts of meat, ribs, and link-type sausages). For intact cuts of meat, individuals generally were able to estimate length and width accurately, but had more difficulty estimating thickness regardless of the PSEA used. For ribs, while no PSEA provided an average estimation error less than +40%, a correlation existed between the portion size and average perceived size category (r = +0.89). For link-type sausage portions, a sausage diagram provided average estimations within 15%, decreased the variability of individual errors when compared to a ruler, and was used more frequently than any other PSEA. Results indicate that using PSEAs in conjunction with other estimation strategies for portion estimation is likely to be an effective way to collect consumption data for meats in large-scale dietary surveys.

Food safety behaviors observed in celebrity chefs across a variety of programs

Background Consumers obtain information about foodborne illness prevention from many sources, including television media. The purpose of this study was to evaluate a variety of cooking shows with celebrity chefs to understand their modeling of food safety behaviors. Methods Cooking shows (100 episodes) were watched from 24 celebrity chefs preparing meat dishes. A tabulation of food safety behaviors was made for each show using a checklist. Results Proper modeling of food safety behaviors was limited, with many incidences of errors. For example, although all chefs washed their hands at the beginning of cooking at least one dish, 88% did not wash (or were not shown washing) their hands after handling uncooked meat. This was compounded with many chefs who added food with their hands (79%) or ate while cooking (50%). Other poor behaviors included not using a thermometer (75%), using the same cutting board to prepare ready-to-eat items and uncooked meat (25%), and other hygiene issues such as touching hair (21%) or licking fingers (21%). Conclusions This study suggests that there is a need for improvement in demonstrated and communicated food safety behaviors among professional chefs. It also suggests that public health professionals must work to mitigate the impact of poorly modeled behaviors.

Food Safety: Recommendations for Determining Doneness in Consumer Egg Dish Recipes and Measurement of Endpoint Temperatures When Recipes Are Followed

Many consumers do not follow recommended food safety practices for cooking egg dishes, such as pies, quiches, and casseroles, potentially leading to foodborne illnesses such as Salmonellosis. The United States Department of Agriculture (USDA) recommends cooking egg mixtures until the center reaches 71 °C (160 °F). The objectives of this study were to determine what endpoint temperature information consumers receive from egg dish recipes, and if recipes would lead to safe temperatures when followed. Egg dish recipes (n = 226) from 65 websites, 50 cookbooks, and nine magazine titles (multiple issues of each) were analyzed. Time was the most frequently used indicator, given in 92% of the recipes, with 15% using only time. Other indicators included: set (89), browned (76), clean toothpick/knife (60), puffed (27), and jiggled (13). Only two recipes indicated final endpoint temperatures. Three recipes (a pie, a quiche, and an egg casserole) were chosen and prepared in triplicate to see if they would reach recommended temperatures. The pie and quiche were still liquid at 71 °C, and were well over the recommended temperature when cooked according to instructions, but the egg casserole was not consistently above 71 °C, when the recipe instructions indicated it was done and the center was light brown and “jiggled” This research indicates that consumers are not receiving information on endpoint temperatures in egg recipes, but the likelihood of foodborne illness is low since most dishes probably be cooked past the recommended temperature before the consumer considers them done unless there are many inclusions that may absorb liquid and reduce the appearance of liquid in the dish.

An Immunoassay for Quantification of Contamination by Raw Meat Juice on Food Contact Surfaces

Raw chicken products often are contaminated with Salmonella and Campylobacter , which can be transmitted from packages to contact surfaces. Raw meat juices from these packages also provide potential media for cross-contamination. There are limited quantitative data on the levels of consumer exposure to raw meat juice during shopping for and handling of chicken products. An exposure assessment is needed to quantify the levels of transmission and to assess the risk. An enzyme-linked immunosorbent assay (ELISA) was developed and validated for quantitative detection of raw meat juice on hands and various food contact surfaces. Analytical procedures were designed to maximize the recovery of raw meat juice from various surfaces: hands, plastic, wood, stainless steel, laminated countertops, glass, and ceramics. The ELISA was based on the detection of a soluble muscle protein, troponin I (TnI), in the raw meat juice. The assay can detect levels as low as 1.25 ng of TnI, which is equivalent to less than 1 μl of the raw meat juice. The concentrations of TnI in the raw meat juices from 10 retail chicken packages, as determined by ELISA, were between 0.46 and 3.56 ng/μl, with an average of 1.69 ng/μl. The analytical procedures, which include swabbing, extraction, and concentration, enable the detection of TnI from various surfaces. The recoveries of raw meat juice from surfaces of hands were 92%, and recoveries from other tested surfaces were from 55% on plastic cutting boards to 75% on laminated countertops. The ELISA developed has been used for monitoring the transfer of raw meat juice during shopping for and handling of raw chicken products in our studies. The assay also can be applied to other raw meat products, such as pork and beef.

Food Handling Behaviors Observed in Consumers When Cooking Poultry and Eggs.

Previous research has shown that many consumers do not follow recommended food safety practices for cooking poultry and eggs, which can lead to exposure to Salmonella and Campylobacter. Past research has been done primarily through surveys and interviews, rather than observations. The objective of this project was to determine through observations whether consumers follow food safety guidelines. Consumers (n = 101) divided among three locations (Manhattan, KS; Kansas City, MO area; and Nashville, TN) were observed as they prepared a baked whole chicken breast, a pan-fried ground turkey patty, a fried egg, and scrambled eggs. The end point temperature for the cooked products was taken (outside the view of consumers) within 30 s after the consumers indicated they were finished cooking. Thermometer use while cooking was low, although marginally higher than that of some previous studies: only 37% of consumers used a thermometer for chicken breasts and only 22% for turkey patties. No one used a thermometer for fried or scrambled eggs. Only 77% of the chicken and 69% of the turkey was cooked to a safe temperature (165°F [74°C]), and 77% of scrambled and 49% of fried eggs reached a safe temperature (160°F [71°C]). Safe hand washing was noted in only 40% of respondents after handling the chicken breast and 44% after handling the ground turkey patty. This value decreased to 15% after handling raw eggs for fried eggs and to 17% for scrambled eggs. These results show that there is a high prevalence of unsafe behaviors (undercooking and poor hand washing technique) when cooking poultry and eggs and a great need for improvement in consumer behavior with poultry and eggs.