HACCP AND SLOW-ROASTING TURKEYS..

[daveomak]

HACCP AND SLOW-ROASTING TURKEYS
by O. Peter Snyder, Jr., Ph.D
Hospitality Institute of Technology and Management
November 2008 edition
Introduction
Slow roasting turkey overnight seems to be a very common practice dating from the 1930s.
There has been a persistent question, however, about the microbiological safety of slow-roast
poultry, especially in terms of the production of Staphylococcus aureus toxin. In 1988, a well-
done study was run at the University of Minnesota, Department of Food Science, by Eckner,
Zottola, and Gravani, which provided the answer to the question of safety.
The study
Four frozen turkeys were used in the study. The turkeys were thawed in a refrigerator. The
weight of the turkeys ranged from 11.7 to 25.5 pounds. Hence, they would take different times
to cook. The carcasses were thoroughly washed, dried with a paper towel, and were stuffed with
stuffing prepared using a standard recipe formulation. Cultures of Staphylococcus aureus,
Salmonella typhimurium, and Clostridium perfringens were added to the stuffing of two turkeys.
The population of each organism ranged from 100,000 per gram to 10,000,000 per gram of
stuffing.
The stuffed turkeys were placed in a preheated, 350°F oven and baked for 1 hour. A cooking
curve for a 29-lb. turkey is shown at Figure 1 (Eckner, et al., 1988).
Figure...

Figure 1. Rate of heat penetration at the slowest heating points in 29-lb. turkey
OPS-papers-

The temperature of the oven was then reduced to 225°F, and the turkeys were roasted an
additional 12 hours. If the juice of the turkeys was pink. The turkeys were roasted an additional 1 to 2 hours at 300°F, or 1 hour at 350°F. A critical fact was that the final temperature of the stuffing was 165°F. The longest time between start of cook and getting to above the safe temperature of 130°F for the slowest cooking / largest turkey was about 8 hours.
As expected, no salmonellae or staphylococci was recovered. They were killed above 130°F as
the turkey was cooking. Actually, if the stuffing had been sampled at 140 to 150°F, they would
have found that these organisms would be dead, considering that 140°F for 12.7 minutes gives a
7D reduction of Salmonella in beef.
At the end of cooking, the stuffing and turkey were still positive for C. perfringens, as expected.
Temperatures above 130°F are lethal for salmonellae and staphylococci, as these are vegetative
pathogens. However, the spores of C. perfringens survive 165°F. Some of the C. perfringens
spores may germinate to vegetative cells during a slow cook, but vegetative C. perfringens is
very easy to inactivate. Therefore, when the turkey reaches 140°F, the vegetative C. perfringens,
if produced, is destroyed. Once cooked, the turkeys cooked in this manner would be safe as long
as they are above 130°F. Of course, uneaten portions of the stuffing (and turkey) must be
handled properly to prevent C. perfringens "toxinfection" from the outgrowth of the spores
during inadequate hot holding below 130°F or cooling too slowly to refrigeration temperatures.
How long does one have in cooking to get above the safe temperature of 130°F?
Willardsen et al. (1978) reported on the multiplication of the C. perfringens vegetative cells in precooked
hamburger during slow come-up in cooking. If the time to go from 50 to 130°F was about 7.6
hours, the vegetative cells might multiply 10,000 to 1. If the time was 5.8 hours, the
multiplication would be about 1,000 to 1. If the time was 3.5 hours, the multiplication would be
about 10 to 1. So, slow cooking might permit C. perfringens vegetative cell multiplication. By
the time the hamburger reached 140°F, all of the C. perfringens vegetative cells that had
multiplied will be destroyed. They used C. perfringens strains that multiplied about one every
7.5 minutes at 113°F. Common illness strains multiply more like once every 15 minutes at
113°F. Hence, this experiment was looking for extremes of safety. The times would probably
be twice that reported for more "normal" C. perfringens.
From a HACCP perspective, what would be our concern? It would be toxin production from S.
aureus growth during cooking. However, in raw turkey / food, S. aureus does not multiply,
because there are competitive spoilage microorganisms. Therefore, with raw turkey, it would not
multiply during cooking. Even if it did, as on cooked turkey with 100 S. aureus per gram, which
was slowly reheated, the fastest I have found S. aureus to multiply is about once every 20
minutes in milk--3 times slower than the C. perfringens experiment by Willardsen et al.
Staphylococcus aureus would have to multiply at least 1,000 to 1, or 10 generations, to make
enough toxin to make anyone ill. The danger time to go from 50 to 130°F in cooked food
starting with 100 S. aureus per gram would be expected to be approximately 3 times that of C.
perfringens, or 15 hours. Note, this shows that the FDA-required food reheating to 165°F and
holding for 15 seconds in less than 2 hours has absolutely no scientific validity. There is a small
reason to set a minimum time for raw food cook come-up, but no justification for reheating as a safety control.
OPS-papers-

It is true that there is a phenomenon whereby Salmonella can double or triple in resistance to
inactivation if it spends some time at about 110F, which it will during slow cooking. However, it
makes no difference; 12.7 minutes at 140°F gives a 10,000,000-to-1 kill (7D reduction). Assume that the time becomes 45 minutes. During slow cooking, the food still spends plenty of time at lethal temperatures above 130°F to kill all vegetative pathogens.
As a final point, remember, the code says that raw, potentially hazardous food must be held at
41F. There is no science for any temperature by itself. There must be time factored in, because
Listeria monocytogenes, Yersinia enterocolitica , and Aeromonas hydrophila all begin to grow at
29.3°F. If we choose 7 days at 41°F as a control, which actually allows for about 10
multiplications of L. monocytogenes in 7 days, or if 45°F, 4 days, or if 50°F, 2.4 days, and if
110°F, 4.5 hours, all of these times and temperatures allow for the same amount of growth
(Snyder, 1998). When we use HACCP in retail food operations, no one needs to measure the
refrigerators again in terms of raw food hazard control. The vegetative pathogens will be killed
in cooking.
There is getting to be an extensive body of science indicating that below about 55 to 60°F, food
"spoils safe." The FDA has provided no justification for imposing a raw food 41°F cold-holding
temperature. Epidemiological experience of the last 100 years suggests that food held at 55 to
60°F has limited pathogen growth and spoils safe. There are many quality reasons for keeping
raw food at 28 to 32°F. However, this is shelf life and quality, and not safety.

 

[SmokinAl]

It was a long read, but quite interesting Dave!
Thanks!
Al

 

[oldsmokerdude]

Thanks, Dave. I always like digging in to the technical details (must be the nerd in me). Was a great and informative read.

 

[daveomak]

Cook 'em slow like granny did and all's well....

 

[chef jimmyj]

Good stuff! I read that some time ago but hesitated to post it here at the risk of getting into an argument. The article pretty much describes how, contrary to the USDA guidlines, Grandma defrosted on the counter for a day. Stuffed the bird and Slow roasted it overnight with no family deaths...But, it fails to take Into consideration the High Risk Population that may be eating this bird. The average family of healthy adults and kids will have no issues. Very old, very young or sick members of the family, face at least some risk mild to severe illness.
Is it a good idea to stuff a Twenty Five Pounder and smoke it all night a 225? This study indicates there " should " be no issue. As long as nothing ELSE goes wrong. Power out, fire dies and so on.
I got my system down and I'll stick with it...JJ

 

[noboundaries]

That article described exactly how turkeys were cooked by my family and extended family each TG and Christmas. Thawed on the counter, stuffed, then roasted overnight. Driest friggin' birds imaginable. Breast was like eating chalk. Tons of gravy was required. But now I know why we didn't all die. :)

 

[robertjohn2]

These precautions in keeping a good track of roasting turkeys. Its overall good. Hope to see more recipes for foods.

 

[Jabiru]

Ok, I have had to many beers to read through that

What’s the conclusion daveomak ?

 

[DanMcG]

There must be time factored in, because
Listeria monocytogenes, Yersinia enterocolitica , and Aeromonas hydrophila all begin to grow at
29.3°F.

Can that be right? 29.3f

 

[chef jimmyj]

Yes Sir. But the growth is slow. This is why prompt cooling and refrigeration is important. Get potentially hazardous foods from, Hot to 70°F in 2 hours and under 40°F in the next 4 hours or less.
Buffets like at the Holidays, Game Day and Summer Parties are the biggest concern, because foods can sit out for Hours risking contamination from the air and guests...JJ

 

[daveomak]

Ok, I have had to many beers to read through that

What’s the conclusion daveomak ?

Food held at an appropriate temperature for a long time, any pathogens will be killed...
I interpret the article..... It's a method to use to pasteurize the bird and stuffing...

This article talks about chicken but..... it's poultry......

The FDA Food Code recommends cooking chicken to 165°F (74°C). But the pasteurization of chicken is actually a function of both temperature and time. If you can hold your chicken at 145°F (63°C) for 8.5 minutes, you can achieve the same bacterial reduction as at 165°F (74°C). In his new book Kenji López-Alt uses this principle along with the principle of carryover cooking in large masses of meat to achieve succulent, perfectly safe results at a dramatically lower pull temp. To learn the necessary thermal secrets, keep reading.
The Food Safety Culprit: Salmonella
Verifying the internal temperature of chicken is particularly important given the threat of salmonella bacteria in poultry. Why is there so much concern with this particular bacteria? Salmonella is a very hardy bacteria. It lives in the temperature range of 35-117°F (2-47°C) which is beyond what most other common food bacteria can tolerate. According to the CDC, 1 in 6 Americans gets sick from foodborne illness each year, and about one million of those cases can be attributed to salmonella.
Proper cooking and refrigeration temperatures when dealing with chicken are critical to avoid foodborne illnesses.
Food Safety is About Temperature and Time
The FDA Food Code suggests cooking chicken to 165°F (74°C) to be sure all bacteria is killed and safe to eat. This temperature is suggested because at 165°F (74°C) the chicken achieves a 7-log10 reduction—meaning that 99.99999% of the bacteria present are destroyed—instantaneously: a foolproof rule to follow for safety. Salmonella isn’t anything to be trifled with, and 165°F (74°C) is indeed the temperature to target if preparing food for individuals at higher risk of illness (older adults, pregnant women, young children, and others with compromised immune systems).
Not widely known is the fact that chicken can achieve the same 7-log10 reduction at temperatures as low as 136°F (58°C) as long as that temperature is held at 136°F (58°C) for at least 63.3 minutes. As the internal temperature increases, the holding time for a 7-log10 reduction decreases.
In a document from the USDA on Time and Temperature Tables for Cooking Poultry Products, the time cooked chicken must be held when brought to an internal temperature of 145°F (63°C) is 8.4 minutes. At 150°F (65.5°C) the time is reduced to only 2.7 minutes!
Chicken as the Temperature Rises
In The Food Lab, Kenji breaks down what is going on with the protein as the internal temperature of poultry rises:
⦁ Under 120°F: The meat is still considered raw. The muscle cells are bundled up in long, thin fibers giving the meat its “grain.”
⦁ At 120°F: The protein myosin begins to coagulate, forcing out some liquid that remains within the protein sheaths at this point.
⦁ At 140°F: The remaining proteins within the muscle cells of the breast meat coagulate, forcing all of the liquid out of the cells. The coagulated proteins make the meat firm and opaque.
⦁ At 150°F: Proteins in the sheaths themselves rapidly coagulate and contract. Water that was forced out of the cells and collected within the sheaths is squeezed out of the breast meat.
⦁ Above 150°F: Muscle fibers in breast meat have become almost completely squeezed dry. Meat is dry and chalky.
⦁ 160-170°F: When held in this temperature range for ten minutes, collagen in the leg meat will begin to convert into rich gelatin, keeping the meat moist and juicy even after the muscle fibers have expelled most of their liquid.
Chicken Texture at Different Pull Temps
Below is a breakdown of what the texture of the breast meat of chicken will be at different pull temperatures:
⦁ 140°F: Pinkish-tinged and almost translucent; extremely soft, with the texture of a warm steak; fleshy.
⦁ 145°F: Pale, pale pink but completely opaque; very juicy, a little soft. This is Kenji’s favorite doneness temp.
⦁ 150°F: White and opaque, juicy, and firm.
⦁ 155°F: White and opaque, starting to turn a little bit stringy; bordering on dry.
⦁ 160°F and higher: Dry, stringy, and chalky.
According to this temperature guide, the breast meat will become dry if taken too far above 150°F (65.5°C), while the leg meat needs to reach the temperature range of 160-170°F (71-77°C) in order for the connective tissue to dissolve into mouthwateringly rich gelatin. Knowing that salmonella has been scientifically proven to be safely eliminated at temperatures lower than 165°F (74°C), we followed Kenji’s recipe for Simple Whole Roast Chicken to the finest detail, including the 145°F (63°C) pull temperature.
Tracking the Cook
Using ThermaData Thermocouple Loggers, we placed thermocouple needle probes in four locations: the standard recommended location at the deepest point in the breast avoiding bone (the lowest temperature found in the chicken), one in the breast toward the shoulder, another closer to the top of the breast about 1/2” below the skin, and the last probe in the center of the thigh. The data loggers enable us to see how all the temperature gradients rise over time as the lowest temperature reaches our pull temperature, and monitor the carryover cooking through a 30 minute rest to be sure it stays at or above 145°F (63°C) for at least 8.5 minutes.
Thermal Tip:
Your chicken is only as safe as the lowest temperature found in the breast meat. Use an instant read digital thermometer like a Thermapen® to find the lowest temperature to spot-check once the 145°F (63°C) alarm sounds.
Ingredients
—1 whole chicken, 3-1/2 to 4 pounds
—1-2 tablespoons vegetable oil or olive oil
—Kosher salt and ground black pepper
Instructions
• Line a sheet pan with heavy-duty foil and place a V-rack or cooling rack on the pan. Suspending the chicken above the pan is important to allow for air circulation around the entire bird.
• Preheat oven to 500°F (260°C).
• Remove the neck and giblets and pat the chicken completely dry with paper towels. Dry skin with be more crisp and brown evenly.
Food Safety Tip: Don’t Rinse
Rinsing the raw chicken will cause tiny droplets of contaminated water to spray all around your kitchen increasing the risk of spreading bacteria through cross-contamination.
• Using your hands, separate the skin from the meat.
• Apply oil both under and on top of the skin. Using oil rather than butter will yield crisper skin because butter is about 18% water, which will steam and then cool the skin as it evaporates, giving the skin a spotty appearance with soft spots as it browns.
• Season on all sides with salt and pepper.
To Truss or Not to Truss?
Trussing—the act of tying up the bird’s legs before cooking—is an oft-recommended but totally pointless exercise. It has the opposite effect of what you want for a bird, effectively shielding the inner highs and thereby making the slowest-to-cook part cook even more slowly. Chickens and turkeys should always be left as nature intended them: with their legs wide open, to allow for maximum heating via convection. —Kenji López-Alt, The Food Lab, pg. 587
• Place the chicken onto the prepared rack. Place the ChefAlarm probe into the deepest part of the breast to track the lowest temperature during the cook. Set the ChefAlarm’s high alarm to 145°F (63°C).
• Place the chicken in the 500°F (260°C) preheated oven and turn the oven temperature down to 350°F (177°C) as soon as the oven door is shut. Continue cooking until the high alarm sounds (cook time will be approximately 1 to 1-1/2 hours depending on the size of the bird).
• Once the alarm sounds, spot-check the breast meat with an instant read thermometer like a Thermapen to be sure the ChefAlarm’s reading is the lowest temperature (the exact location of the lowest temperature may shift during the cook). You need to verify that the lowest reading is 145°F (63°C). Check the temperature of the leg meat, as well. It should be in the perfect 170-175°F (77-80°C) range. If not, put the chicken back into the oven for a couple more minutes.
• Once final pull temp has been reached allow the chicken to rest, uncovered, for 15 minutes. This is critical. It must rest for a full 15 minutes for the full pasteurization of the meat to occur and for the chicken to be safe to eat. To be extra safe, you could use both the built in timer function in the ChefAlarm set to 15 minutes and the low temperature alarm feature unique to the ChefAlarm. Simply set the low temperature alarm to 145°F (63°C) during the rest to be sure your chicken doesn’t dip below the target temperature for at least 8.5 minutes.
Observing Temperature in Motion
The graph above shows the temperature changes at various points in the whole chicken as measured by our ThermaData Thermocouple Loggers. You can see exactly how the internal temperatures increased during the cook. The red horizontal line represents our pull temperature of 145°F (63°C). The most dramatic rises in temperature were, unsurprisingly, in the thigh and the outer breast meat which were most directly exposed to the hot air in the oven. Neither of those areas saw a temperature increase during the rest. Rather, you can see how they began to cool immediately once the inside breast meat reached 145°F (63°C) and the chicken was removed from the oven.
Most importantly, we found that the coolest breast meat (the internal reading above) did NOT cool when the chicken was removed from the oven. See how the purple line above continues to rise from 145°F (63°C) to a maximum temperature of 155°F (69°C) during the resting period—the most dramatic temperature increase due to carryover cooking during the rest.
It is important to note that this continuous rise in internal temperature after the chicken was removed from the oven is due to the significant mass of the whole chicken being cooked. We would NOT expect to see such carryover cooking in a single chicken breast, for example.
The thigh’s peak temperature, as shown above, of 200°F (93°C) occurred as the internal breast meat reached our pull temp, resulting in a gradient variance of 55°F (30.5°C) between the coolest and hottest parts of the chicken! Many different temperatures occurring in the same roast chicken.
In summary, we were able to observe that with Kenji’s recommended pull temperature the chicken remained in the necessary thermal range above 145°F (63°C) for a full 15 minutes (more than the required 8.5 minutes for pasteurization) after pulling the chicken from the oven, making it just as safe to eat as a piece of chicken that had reached the instantaneous pasteurization temp of 165°F (74°C).
The Real Test: How Did it Taste?
Because the chicken was cooked to a lower temperature, the meat retained more moisture and the result was a juicy and succulent piece of chicken—not a dry bit to be found! Not only was the meat extremely juicy, but the measures taken with drying the meat and separating, oiling and salting the skin, made for crackling-crisp skin. Some of our very willing taste-testing subjects commented this was the best roasted chicken they’d ever tasted.
Because of personal preferences and some individuals being more susceptible to contracting illness, this cooking method may not be for everyone. But with the right tools and expert advice, you can experience better tasting roasted chicken. With the ChefAlarm and Thermapen‘s precision and accuracy there is no need to question your chicken’s safety. Get roasting!

 

[chef jimmyj]

This is good info, Dave. Thanks for posting.
It should be Noted that the above was for safe elimination of Salmonella and completed in under 2 hours at 350 °F. There are other Toxin Producing Bacteria that become a concern Smoking a 20 pound, " Enhanced ", Whole Turkey at 225°F...JJ