Some meat products, especially those considered as ready to eat (RTE), are advised to be avoided during pregnancy. Likewise, all kinds of raw and undercooked meat are deemed unsafe for consumption by pregnant women.
Prosciutto, just like salami, chorizo and pepperoni, are cured and fermented but not cooked. Therefore, there is a risk of bacterial contamination that may be harmful for pregnant women and their unborn babies. Prosciutto is recommended to be avoided during pregnancy, unless it has been cooked or heated to a safe temperature.
In this article, we will talk about what prosciutto is, its origin and its varieties. We will also discuss the evidences linking prosciutto consumption to Listeriosis, as well as the devastating effects that this infection can have on pregnant women and babies. Lastly, we will be giving some ideas on ways to eat prosciutto safely during pregnancy.
What is Prosciutto?
Prosciutto in Italian means “ham.” It originated in Italy where villagers dry-age pork legs to lengthen their supply of meat for long winters. To make prosciutto, pork leg meat is covered in salt and left to age for several weeks (60 to 90 days).
Salting draws out blood and moisture from the pork leg, preventing bacteria from causing spoilage of the meat. After salting, the pork legs are washed and seasoned by hand. Then, they are to left to air-dry for 12 to 36 months. This gives prosciutto its distinct sweet and delicate flavor.
In Italy, prosciutto crudo refers to raw, cured ham, while prosciutto cotto refers to cooked or baked ham. But in the United States, prosciutto is generally the term used for uncooked, dry-cured ham.
Prosciutto is typically served in paper-thin slices and eaten raw. The meat is left in the mouth to let the fat melt on the tongue. It can be eaten on its own, or paired with fruits, vegetables, toasted bread, cheese (chunks of Parmigiano-Reggiano), fresh figs, ripe melon, or wine. It can also be used as an ingredient in cooked dishes like pasta, pizza, soups, stews, stuffing or bread.
Prosciutto offers a taste between sweet and salty. Its thin texture, while melting in the mouth, also allows a different series of sensations.
Varieties of Prosciutto
The two most popular varieties of prosciutto are Prosciutto di Parma and Prosciutto di San Daniele. Both are under the Protected Designation of Origin (PDO) of the European Union.
Prosciutto di Parma is exclusively made from heritage breed pigs and aged in Parma province in Italy, in the region of Emilia-Romagna (the same region where Parmigiano-Reggiano cheese is also well known).
Parma ham keeps its rounded mandolin-like shape and removes the animal hoof.
Meanwhile, Prosciutto di San Daniele is processed exclusively in San Daniele, in the Friuli-Venezia Giulia region of northeastern Italy. It undergoes pressing after salting, which flattens the ham and gives the appearance of a guitar, while also retaining the hoof of the animal attached to the leg. The higher altitudes and colder climate give a darker and sweeter flavor of its meat.
Both varieties must be aged for a minimum of 13 months but can be as long as 3 years. The breeze during drying, that is particular in the two production areas, creates the significant difference between the two hams. Other varieties in Italy include Prosciutto di Modena, Prosciutto Toscano and Prosciutto di Carpegna.
Listeriosis from Consumption of Prosciutto
Listeria monocytogenes is an opportunistic pathogen that is often implicated in food borne illnesses (Franciosa et al., 2001). It causes Listeriosis, a severe and often invasive infection associated with a hospitalization rate of 60 percent and a mortality rate of 11 to 42 percent (Reimer et al., 2019).
Listeriosis can result in severe illness, especially among pregnant women and their fetuses (Barkley et al., 2016). In pregnant women, Listeriosis manifests in two forms (Franciosa et al., 2001):
- Non-invasive – manifested as gastroenteritis with fever and vomiting
- Invasive – characterized by bacteremia and meningitis
In unborn fetuses, Listeriosis can lead to adverse pregnancy outcomes, including spontaneous abortion and stillbirth. In newborns, this disease often results in septicemia or central nervous system (CNS) infection. Reported overall feto-neonatal fatality rate was as high as 57.1 percent (Li et al., 2020).
L. monocytogenes is ubiquitous in the environment and can be found in many food products, including vegetables, milk, dairy and meat (Iacumin et al., 2016). It can survive at high salt concentrations and grow at refrigeration temperatures. It is also able to persist in food processing plants for decades of years. (Ferreira et al., 2014).
It is able to grow and multiply in temperatures as low as 1 to 4 degrees Celsius (Iacumin et al., 2016). This makes contamination in ready to eat foods, such as cooked, raw-cured and dry-cured salted meat products, prevalent (Gomez et al., 2015).
Although dry-cured hams are an RTE meat product, their process of production is identified as not being able to support the growth of L. monocytogenes. However, it is still possible for this pathogen to be introduced in different phases, including during deboning or slicing (Iacumin et al., 2016).
In 2015, Gomez et al. examined different RTE meat products to check for the occurrence of L. monocytogenes. Their study detected the presence of Listeria in 17 percent of cooked meat, 36 percent of raw-cured meat, and 24 percent of dry-cured, salted meat.
The world’s first ever documented Listeriosis outbreak that was definitively linked to a food source happened in Canada in 1981. It was linked to consumption of contaminated cabbage used in coleslaw and caused 41 confirmed cases, of which 17 pregnant women, fetuses and newborn babies died (Reimer et al., 2019).
In 2008, one of the largest recorded Listeriosis outbreaks in Canada occurred and was linked to nationally distributed contaminated RTE deli meats. Another outbreak was associated with consumption of prosciutto in 2010 (Reimer et al., 2019).
Learn More: Can You Eat Deli Meat While Pregnant?
Retail food establishments can be a potential source of L. monocytogenes because they keep ready to eat items in refrigeration temperatures. L. monocytogenes is able to persist in food processing sites and food service establishments for long periods (Barkley et al., 2016).
In 2014, one restaurant in Rhode Island, USA was implicated as the source of an outbreak of Listeriosis. Investigations found sanitation issues and improper storage of sliced meat as likely causes. A sample of sliced prosciutto was found to be positive for L. monocytogenes (Barkley et al., 2016).
Any kind of uncooked prosciutto is not safe for pregnant women to eat because of the potential risk for Listeria and other bacterial contamination. On the other hand, cooking prosciutto kills any potential bacteria, including Listeria. Therefore, cooked prosciutto can be safe to eat during pregnancy, as long as it was thoroughly heated or has been crisped up.
Dishes with Cooked Prosciutto
According to the U.S. Food and Drug Administration (US FDA, 2020), the minimum cooking temperature that would be hot enough to kill harmful pathogens in pork, including fresh ham, is 145 degrees Fahrenheit (or 63 degrees Celsius) with a rest time of 3 minutes. Resting time allows the juices and heat to disperse across the meat.
Thus, prosciutto and other cured pork should be heated to the same internal temperature (or until steaming hot) and thoroughly cooked in order to be safe for consumption during pregnancy. Moreover, once cooked, any perishable food left at room temperature should be fully consumed within 2 hours (US FDA, 2018).
The following are some dishes that use cooked prosciutto and can be safely eaten during pregnancy:
- Prosciutto crisps – baked until crunchy and eaten like fries, or sprinkled on salads, soups, pasta, eggs, potatoes (just like bacon)
- Prosciutto as topping on pizza – make sure that the prosciutto was cooked until steaming hot (instead of being placed raw on top of the pizza after cooking)
- Prosciutto as vegetable or fish wrapping – wrapped around asparagus, green beans, artichokes, scallops, fish fillets, then broiled until crispy
- Prosciutto on kebabs – placed on skewers alternating with veggies or meat then grilled
- Deep-fried prosciutto – add flavor to cooked vegetables, risottos, salads, soups
Final Thoughts
Prosciutto is a type of dry-cured pork leg or ham, which is popularly sliced very thinly and eaten raw. It has been linked to several occurrences of Listeria contamination. Listeriosis can have serious adverse effects on pregnant women and their babies. Therefore, eating raw prosciutto has been advised to be avoided during pregnancy.
Meanwhile, cooking to a safe internal temperature can effectively kill Listeria and render prosciutto safe to eat. Prosciutto can, therefore, be crisped up and eaten on its own or added to cooked dishes like pizza, pasta, and others, and be safe for consumption during pregnancy.
Pregnant women should be careful when dining out as retail food establishments have been linked to Listeria contamination. Any prosciutto they serve must be checked for thorough cooking before consumption.
Pregnant women should have the means to be able to communicate their dietary concerns appropriately. Following the advice of a health physician or specialist is the best way to make informed choices regarding food intake throughout pregnancy.
References
- https://www.eataly.com/us_en/magazine/how-to/what-is-prosciutto/
- https://www.thespruceeats.com/what-is-prosciutto-1328662
- https://www.cdc.gov/media/matte/2011/05_listeriapregnant.pdf
- Barkley, J., Gosciminski, M., & Miller, A. (2016). Whole-genome sequencing detection of ongoing Listeria contamination at a restaurant, Rhode Island, USA, 2014. Emerging Infectious Diseases 22(8), 1474-1476. doi: 10.3201/eid2208.151917
- Ferreira, V., Wiedmann, M., Teixeira, P., & Stasiewicz, M. J. (2014). Listeria monocytogenes persistence in food-associated environments: Epidemiology, strain characteristics, and implications for public health. Journal of Food Protection 77(1), 150-170. doi: 10.4315/0362-028X.JFP-13-150
- Franciosa, G., Tartaro, S., Wedell-Neergaard, C., & Aureli, P. (2001). Characterization of Listeria monocytogenes strains involved in invasive and noninvasive listeriosis outbreaks by PCR-based fingerprinting techniques. Applied and Environmental Microbiology 67(4), 1793-1799. doi: 10.1128/AEM.67.4.1793-1799.2001
- Gomez, D., Iguacel, L. P., Rota, M. C., Carramiñana, J. J., Ariño, A., & Yanguela, J. (2015). Occurrence of Listeria monocytogenes in ready-to-eat meat products and meat processing plants in Spain. Foods 4(3), 271-282. doi: 10.3390/foods4030271
- Iacumin, L., Manzano, M., & Comi, G. (2016). Phage inactivation of Listeria monocytogenes on San Daniele dry-cured ham and elimination of biofilms from equipment and working environments. Microorganisms 4(1), 4. doi: 10.3390/microorganisms4010004
- Li, C., Zeng, H., Ding, X., Chen, Y., Liu, X., Zhou, L., …, & Yin, C. (2020). Perinatal listeriosis patients treated at a maternity hospital in Beijing, China, from 2013-2018. BMC Infectious Diseases 20, 601. doi: 10.1186/s12879-020-05327-6
- Reimer, A., Weedmark, K., Petkau, A., Peterson, C., Walker, M., Knox, N., …, & Gilmour, M. (2019). Shared genome analyses of notable listeriosis outbreaks, highlighting the critical importance of epidemiological evidence, input datasets and interpretation criteria. Microbial Genomics 5(1), e000237. doi: 10.1099/mgen.0.000237
- U.S. Food and Drug Admnistration. (2018). Cooking from food safety for moms to be. https://www.fda.gov/food/people-risk-foodborne-illness/cooking-food-safety-moms-be
- U.S. Food & Drug Administration. (2020). Food safety: For pregnant women, their unborn babies, and children under five. https://www.fda.gov/media/83740/download