The holiday season is marked by traditions, like family gatherings, gift-giving and, of course, seasonal foods people look forward to all year round. Treats like pumpkin pie, eggnog and cranberry sauce bring back memories of holiday feasts and large gatherings for many people. But do you know what it takes to place these traditional dishes on your table?
Here’s how these favorite wintertime dishes are processed:
Milk products sold in the U.S. must be pasteurized before being packaged and stocked on store shelves. Pasteurization is the process of heating the product to a temperature and for a length of time known to kill harmful organisms like E. coli, salmonella or Coxiella burnetii, which can cause Q fever in humans, according to Milk Facts.
Eggnog is made by combining eggs with milk or cream. Both the eggs and the milk have the potential to contain dangerous bacteria. To offset the risk, the mixture needs to be heated to either 155 degrees Fahrenheit for 30 minutes for large-batch vat processing, or 175 degrees Fahrenheit for 25 seconds for continuous high-temperature, short-time processing.Eggnog must be pasteurized to ensure it’s free of harmful bacteria.
Did you know your pumpkin pie might be more like squash pie? According to the Food & Drug Administration, it’s perfectly acceptable for Cucurbita pepo as well as varieties of Cucurbita maxima to be mixed together in the can of delicious creamy pumpkin puree you poured into your pie shell this winter. The former is commonly called a field pumpkin and isn’t as bright as the jack-o’-lantern you carved for Halloween, while the latter is firm-shelled, golden-fleshed, sweet squash.
Regardless of what’s technically in the can, there are two truths almost everyone can agree on: pumpkin pie is delicious, and it’s important that the ingredients are prepared safely to prevent foodborne illnesses. An important aspect in implementing controls in processing to prevent bacterial growth is knowing the product’s pH. Different pH levels contribute to varying levels of bacterial growth; lower acidity, found in Low-Acid Canned Foods, generally means the product isn’t required to go through a hazard analysis or be subject to risk-based preventative controls, according to the FDA. Foods that have a final acidity of more than 4.6 are considered LACF; since pumpkin averages a pH of 4.9-5.5, it’s considered a LACF.
A critical distinction between LACFs and high-acidity foods is the potential for Clostridium botulinum, the bacterium that can cause botulism to grow, according to William McGlynn, a food scientist at Oklahoma State University’s Robert M. Kerr Food & Agricultural Products Center. pH levels of less than 4.6 don’t allow for this dangerous spore to grow, which means that LACF’s must undergo intensive heat treatments to kill any spores. Pressure cooking inside the can is one effective way to rid the puree from harmful bacteria.
As Forbes contributor Nadia Arumugam explained, the journey from field to can is a long one that involves heavy-duty machinery to wash, sanitize, remove the stem, seeds and pulp, chop, steam, condense and finally mash the squash. Each of these steps is critical in creating that consistent texture you imagine when you think of pumpkin pie.
While pumpkin has a low acidity, cranberries fall on the higher end of the scale, with cranberry sauce having an average pH of 2.4 and cranberry juice a pH of 2.3-2.5, according to the Robert M. Kerr Food & Agricultural Products Center. While this may mean Clostridium botulinum has a very low chance of surviving in these environments, other toxins like salmonella can thrive in this level of acidity, and pasteurization is necessary to make sure they’re safe to consume.
According to the FDA, fruit juices need to either be pasteurized or labeled with a warning message stating that the product has not gone through a pasteurization process and could be a health risk to consumers, particularly those who have weak immune systems. As is dairy processing, heat pasteurization is a common practice among juices and fruit juice products.
High-quality equipment matters
When pasteurizing milk, fruit or vegetable products, it’s not just factors like temperature and process duration that makes a difference, but also the equipment in use. Some materials are naturally less prone to contamination than others.
Stainless steel is one material that is well-suited for food processing because of its resistance to fouling, corrosion and pitting. Alloys that contain copper, which naturally has antimicrobial properties, can also be good choices for food processing equipment, according to Antimicrobial Copper. As such, stainless steel and copper alloys are commonly used in food processing operations.
If your food processing plant is in need of new stainless steel shell and tube heat exchangers for your pasteurization process, reach out to the experts at Enerquip.