Luncheon meat, hotdogs: Here's how your favourite processed foods are really made

A show of hands if you enjoy Korean army stew piled high with sliced luncheon meat and hotdogs. Let’s have a count, too, if you can’t resist ordering salted egg and pickled mustard with congee for supper. Your favourite weekend activity is checking out the latest cafe for a brunch of bacon or sausages? Got it.

It’s no secret we’ve all got a complicated relationship with processed meats. They’re either a guilty pleasure or our go-to comfort food. At the same time, we’ve been warned about eating too much of these items because of what they contain.

For instance, what do they add to ham to make it look pink? How do they get the meat in hotdogs so finely minced and compacted, you can’t tell it’s meat? And do they really smoke bacon and beef jerky to create that smoky flavour? Just how dangerous are the additives used in these – and should you be worried about cancer in the long run?

CNA Lifestyle reached out to a dietitian and a gastrointestinal surgeon to find out more about what goes into some of our favourite foods.

LUNCHEON MEAT AND HOTDOGS

As tasty as they are in your hotdog bun or between slices of bread, these items are actually made from the leftover bits found on chicken or pork bones.

After the valuable cuts (such as chicken breasts, thighs, drumsticks, pork loin and pork belly) have been removed, the carcass is forced through a high-pressure sieve to create a meat paste consisting of remnant meat, cartilage and other tissues. Yummy.

What follows is a cocktail of chemicals: Nitrates such as sodium nitrate to preserve as well as enhance flavour and colour, according to Jaclyn Reutens, a clinical and sports dietitian, and the founder of Aptima Nutrition and Sports Consultants.

Lactate and phosphate compounds may also be added to regulate acidity and provide further preservation. And finally, flavour enhancers such as MSG and dextrose to make the meat product tasty, she said.

The additives with the highest quantity used are typically listed first on the ingredient list, so that’s how you watch out for them, said Reutens.

“From a nutritional perspective, these foods are normally high in sodium and saturated fat, which can increase the risk of blood pressure and heart disease if consumed frequently,” she said.

GROUND MEAT

Yup, even supposedly “natural” food such as ground meat can be cause for suspicion. That tray of minced beef or pork looks pink and fresh for a reason – carbon monoxide or CO could be introduced under the plastic wrap to keep the meat from oxidising and turning brown.

As alarming as it sounds, CO-treated meats are safe for consumption, said Reutens, and “not associated with any health risks”.

“It is difficult to detect the use of carbon monoxide as it’s an odourless gas. But it should not matter because there is no risk posed to humans,” she said.

MEAT PATTIES AND NUGGETS

Back in 2012, 70 per cent of ground beef in the US was said to contain pink slime or, if you want to put it more delicately, finely textured meat. It is generally used as a filler by food manufacturers when making burger patties – or the chicken version of pink slime when manufacturing chicken patties and nuggets.

By 2013 though, pink slime use dropped to about 5 per cent – a significant reduction caused in part by the US media’s coverage of the additive.

What exactly is pink slime? It is made from cooking remnant bits of fatty meat to separate the fat from the meat. Gaseous ammonia is then added to “disinfect” the resulting pink meat product before it is flash-frozen and shipped to food manufacturers.

You might pick up on pink slime if you see “lean finely textured meat” on the ingredient list, said Reutens. “Apart from that, it is hard to tell.”

But is it safe to eat pink slime? There is ammonia used after all. “It is not the most nutritious form of meat but it is safe to eat pink slime,” said Reutens.

“Ammonia is added to such meat products to prevent the growth of potentially harmful bacteria and pathogens,” said Reutens. This is, of course, different from the ammonia that we use to disinfect bathrooms and are “regarded as safe in small quantities by the US Food and Drug Administration”.  

DELI MEATS SUCH AS HAM

Viruses are not good news (think: COVID-19). So when you hear about spraying viruses onto ready-to-eat deli meats, alarms inadvertently go off in your head.

More accurately, the food industry uses bacteriophages or phages, which are viruses that infect and kill bacteria that cause food poisoning, such as salmonella, E coli, camphylobacter, listeria and pseudomonas, said Reutens.

“Bacteriophages are safe for use on food. They only attack bacteria and are harmless to humans. If anything, they are protective,” she said.

Furthermore, you cannot tell if phages have been sprayed onto your ham, she added.

BACON AND OTHER SMOKED MEATS

That lovely smokiness you smell when you fry up bacon? It’s courtesy of the liquid smoke used to flavour it and other BBQ foods, said Reutens.

Liquid smoke sounds like alchemy magic but according to Reutens, it is made by burning hickory or applewood chips or sawdust at high temperatures, then condensing the smoke into liquid. “Other ingredients like salt, molasses, vinegar and caramel colour can be added,” she said.

It is important that the liquid smoke is filtered twice, said Reutens, to remove cancer-causing polycyclic aromatic hydrocarbons. “You probably cannot tell if liquid smoke is used,” she said.

From the list above, you would already have a sense of what food additives do – and their functions aren’t just limited to processed meat. Food additives are needed to keep your bag of potato chips crisp. They play a role in sweetening and fortifying your orange juice with Vitamin C. They’re there to ensure the chilli sauce doesn’t come out of the bottle watery.

Additives let your chocolate melt in your mouth and not in your hand. They are the compounds that allow boba pearls to stay chewy, no matter how long they soak in the milk tea. So yes, as despised as food additives are by the health-conscious, they fulfil many functions.

As for regulatory measures, a spokesperson from the Singapore Food Agency (SFA) commented that "source accreditation, random inspections and sample testing" are in place. "Checks are also done on processes across the entire supply chain from pre-import to sale."

To help consumers make informed choices, all prepacked food products have to carry a listing of all the ingredients and additives used, added the spokesperson. For the list of approved additives, you can check the SFA website.

YES, FOOD ADDITIVES ARE GENERALLY SAFE BUT…

From the medical standpoint, it can be difficult "to prove that a certain additive causes cancer in humans" as "this is usually an epidemiological association, which can be influenced by other confounding factors", said Dr Melvin Look, a general surgeon from PanAsia Surgery with an interest in gastrointestinal surgery.

On the whole, it doesn't hurt to reduce the intake of processed foods as they typically contain high levels of salt, which has been linked to stomach cancer. “High salt levels damage the stomach lining and cause the cells to die,” said Dr Look.

This link between cancer and salt explains why people who eat more salt-preserved foods, such as the Chinese, Japanese and Koreans, have a greater chance of developing stomach cancer. Other risk factors include smoking, heavy alcohol consumption, a personal history of Helicobacter pylori infection, and a family history of stomach and gastrointestinal cancers, said Dr Look.

While stomach cancer ranks low in Singapore (seventh among men and ninth among women, according to the National Registry of Diseases), it is showing up in younger patients. The high-risk group actually consists of individuals above age 45 and they’re predominantly male, said Dr Look.

“Studies have found that people who consume large amounts of pickled vegetables and foods have about a 50 per cent increased risk of gastric cancer compared to those who consume them minimally,” said Dr Look.

Your diet should not be saltier than an auntie who missed out on a supermarket discount. But as you can already guess, Singaporeans salt their food way too liberally. For comparison, the recommended daily intake of salt is less than 5g a day or just one teaspoon full. However, the average adult in Singapore consumes about 8.3g of salt daily – more than 60 per cent above the recommended level, according to the 2010 National Nutrition Survey.

WHAT OTHER ADDITIVES COULD LEAD TO CANCER?

Processed meat such as bacon, sausages, ham and hot dogs typically use nitrates and nitrites as preservatives. They are the chemicals that keep these meat products looking pink and fresh instead of brown and old.

Interestingly, nitrates and nitrites can be found naturally in vegetables such as spinach, lettuce, celery, carrots, radish and beets. And they are actually advantageous for cardiovascular health and immunity, according to Dr Look.

But when nitrates and nitrites are used as preservatives in processed meat such as bacon and sausages, it’s a different story altogether. “Ingested nitrates can be converted into nitrites by the bacteria in our mouth,” explained Dr Look.

When these nitrites enter the acidic environment of the stomach, along with the amines found in protein-rich meat, they become harmful nitrosamines, he said. Sometimes, nitrites can directly transform into nitrosamines without entering our mouths, such as during high-heat cooking. And it is these nitrosamines that play a role in stomach cancer.  

“Besides stomach cancer, nitrates and nitrites play a role in increasing the risk of colorectal cancer as well,” said Dr Look. “It has been estimated that the risk of colorectal cancer increases by 18 per cent per 50g of processed meat intake per day.”

Pickling, which uses salt to preserve food, can also produce carcinogenic compounds such as nitrosamines. “Studies have found that people who consume large amounts of pickled vegetables and foods have an approximately 50 per cent increased risk of gastric cancer compared to those who consume this minimally,” cited Dr Look.