Tag: food

Science News 2025

On By Catherine HausteinIn Uncategorized2 Comments

1. Weather related heat shortens lives and accelerates aging. Being outside in the heat for an extended period of time is as bad for your health as smoking and drinking.

Hot weather will also disturb the sex ratios of reptiles, which depend on temperature instead of x and y chromosomes to determine if they will be male or female.

Sadly (unless you want to be a female turtle) , experts predict the weather will get even hotter in the next five years.

Changes in glacial ice means faster melting in the coming years, too.

(more here)

2. Ulcerative Colitis, a form of Irritable Bowel Syndrome appears to be caused by a bacteria found in fresh and brackish water, at least in some cases. The bacteria (Aeromonas) produces a toxin which kills intestinal macrophages, large germ-eating cells. This leaves the intestine vulnerable to inflammation and damage. (Bacteria are also implicated in colon cancer.)

3. Nitrate sensing drones are coming! Nitrates come from fertilizer and fecal matter among other sources and are associated with cancer including ovarian cancer. They are known to cause poor thyroid function. Even low level exposure to nitrates disrupts thyroid function.

Nitrates are water soluble and that’s where they pose damage to populations. They are not hard for a chemist or even an amateur to detect but getting to the polluted waterways isn’t easy. Iowa has a sensor network but since ignorance is bliss for some of our elected officials, it is not going to be funded beginning this July. Also, local elected officials have claimed that geese are the source of the pollution (probably at least true in part) and that the majority of the local lake water is not polluted—only the shoreline where people take water samples (and go swimming). A few drones can at least overcome some of our misconceptions and shoreline sampling issues.

4. There’s no doubt about it. Doge and the reckless firings of government scientists, grant cuts, and misinformation pouring from the White house has been an epic tragedy for science in the US. However, there’s hope. Lawmakers are poised to restore science funding. And if you want to read about and follow a champion, Patty Murphy is the GOAT.

5. I’ve written a novel based on gene editing. The current technique, relying on cutting genes out and inserting new ones, might have a breakthrough gene-modifying partner to fight genetic diseases. This new technique relies on silencing bad genes without removing them all together.

Meanwhile, the first gene edited baby is taking his first steps.

6. Smiling Medusa artifact has been found in Amastris, Turkey. I’m a Medusa fan. A gorgon professor is part of my Monster College Chronicles series. Book 2, Monsters Play the Field, has been accepted for publication. All you monster romance and dark academia fans–I’ll keep you posted!

7. A long-lost coffee bean has been rediscovered in Sierra Leone. Coffea stenophylla produces coffee that’s “sweet with notes of chocolate and caramel and a hint of jasmine.” In addition to containing our favorite drug—caffeine—it also holds another stimulant, theacrine. It can grow at warmer temperatures, too. (read about it here and here.)

These were the top midyear science news stories:

1. Many men wish to control their fertility, and a few new products might be on the market soon. Some work by changing hormone balance, including a cream, and a newly developed pill might block the gene that directs sperm production. The later has just passed human safety standards in clinical trials.

2. July was one of the worst flooding seasons in global history. At last 134 people were killed in Texas, 34 in China,69 in the Himalayas, and in early August, hundreds were missing in Pakistan and India. The chemistry of why flash flooding is getting worse is outlined here. “Though floods naturally occur, increased moisture and rising temperatures from climate change are in some cases supercharging storms. According to a study in Nature, between 2020 and 2100, the size of the global population exposed to flood hazards is estimated to increase by 15.8%.”

3. Uncontrolled rage has sweeping societal consequences. A new study confirms that childhood aggression that persists into adulthood can be caused by early trauma. “Trauma during childhood can alter brain circuits that regulate attention and impulse control, increasing the risk of pathological aggression and cognitive decline in adulthood.”

5. The mysterious Shroud of Turin has captivated Christians for a long time. Is it really the burial garment laid over Jesus following his crucifixion? Radiocarbon dating has been inconclusive. Now, the art world steps forward to suggest that the image was made from a statue and not a body.

6. Trump is dismantling science in the US . Why do we have a government that no longer serves the people and our futures? Because this is the will of at least one political party.

7. mRNA vaccines are being badmouthed for no good reason. A detailed analysis of their promises and mild perils is presented here.

8. As the saying goes, we are done with COVID but COVID is not done with us. Since the government no longer approves COVID vaccines for many of us despite CDC warnings, the pharmaceutical industry is coming up with a new anti-viral drug, ibuzatrelvir. (Perhaps not in time for the COVID vaccine to be banned altogether!)

A scientist’s guide to refrigeration: Will freezing kill bacteria in food?

On By Catherine HausteinIn UncategorizedLeave a comment

A well-publicized recall of frozen foods due to bacterial contamination lead a friend to ask a question: why didn’t the freezing kill the bacteria?

My first thought was the somewhat well-known idea (among science types) that freezing doesn’t kill the bacteria, only slows it down. The answer, however, is more complex.

It’s logical to think that putting food into the freezer or buying frozen foods will cut down on the bacteria and thus the food poisoning. However, freezing doesn’t kill the bacteria in foods.Freezing and thawing cycles can reduce the number of bacteria but doesn’t kill them all. Bacteria can respond to freezing by producing a type of antifreeze or by forming a biofilm. The susceptibility of the bacteria to freezing varies across the type of bacteria correlates to the freezing and thawing cycles as well.

In a study of soil bacteria exposed to freezing and thawing conditions, freezing reduced the number of bacteria but did not totally eliminate them. When numerous freezing and thawing events occurred, damage to the bacterial colonies was significant. However, cold-resistant bacteria developed. Quick freezing and thawing reduced bacterial levels less than slow freezing and thawing. This was due to the type of ice formed—slow freezing produces larger ice crystals which are more damaging to bacteria. What does this have to do with a frozen food recall? Consumers don’t like big ice crystals and often additives such as xanthan gum are added to food to prevent them. ( reference here)

Common food related bacterial contamination comes most often from these four horsemen: Campylobacter, E. coli, Listeria, and Salmonella.

Most of the 2025 frozen food recalls have been due to Listeria. Frozen peas and carrots, ice cream bars, and the more extensive Chicken Fettuccini Alfredo are recent examples. Listeria is the third most deadly bacterial food toxin here in the US.

Listeria grows best under warm conditions but even continues to grow under refrigeration. It isn’t killed by freezing and in fact, is one of the most freeze resistant bacteria around. Listeria will cause flu-like symptoms and can even lead to seizures since it primarily attacks the central nervous system. It can be deadly for older people, immunocompromised folks, and infants. The mortality rate is as high as 20% in vulnerable populations. It causes miscarriages and stillbirths, too.

Food poisoning is the most common way to encounter Listeria. Listeria is a persistent bacteria and commonly found in slaughter houses, especially on conveyor belts for carcasses. Listeria forms a biofilm, often working symbiotically with other bacteria to strengthen this pervasive film. (reference)

One way for you to keep ahead of Listeria is to keep your refrigerator clean and to wipe down surfaces and cutting tools after use. Washing produce with warm water before eating it is another recommendation, although produce is not major carrier for Listeria. Use leftovers within three to four days and don’t just let them sit in there until you find time to throw them out. Toss them immediately—they could contaminate other food. Be sure to cook foods thoroughly, even leftovers. (reference)

I don’t eat lunch at work anymore but I’m a fan of frozen burritos. What should I do? A food thermometer is more than a luxury–it’s an important safety tool. Don’t simply reheat a frozen meal. Make sure to cook your frozen meals that least 165 degrees F. Steam should rise from the product. If storing a heated up frozen meal, put it in the refrigerator within two hours and eat it promptly.

Besides contaminated frozen foods, Listeria can be found in soft cheeses and raw milk products. (reference) It’s even been found in ice cream bars this year. Sugar helps it grow! Vinegar and low pH can discourage it. 

Taking a step back, frozen foods have only been around for about 100 years. They were introduced to Western society by Clarence Birdseye, who leaned techniques from Inuit and Metis communities in Labrador, where he appropriated their knowledge while failing to acknowledge their contributions. Beginning with frozen fish in 1922, Birdseye moved on to become synonymous with frozen foods, thanks to the quick freeze technique he learned in Canada. Freezing prevents food waste. About 30% of all food in the US becomes waste while only 6% of this is frozen foods. Freezing food preserves nutrients, especially Vitamin C and when used within a year.

One recent study found that improper storage and handing of foods was responsible for the most food poisoning deaths. (reference) For mass produced foods, food safety regulations and well-paid, well-trained employees are an essential part of food safety. (reference) The infamous deli meat Listeria outbreak was linked to poor plant hygiene. It’s important to have proper regulations and to enforce them. However, e have taken a step backwards since November 2025. Thanks to lobbying from the grocery and restaurant industries, our food is now inspected less and outbreaks not tracked.

The frozen food industry has a new trick for keeping ahead of bacteria without adding additives to prevent large ice particles–Freezing in the presence of a magnetic field to reduce ice formation. However, the effect on bacterial formation hasn’t yet been determined.

As for me, I’m making ample use of my food thermometer and cleaning out my refrigerator! 

Oil’s long, dirty, and highly useful fingers

On By Catherine HausteinIn chemistryLeave a comment
Do you think most acetic acid comes from fermented apples? Think again.

Saudi Arabia is going to cut oil production and although they say they are not doing it for political reasons, we can see our politicians here vocalizing what could be their wishes such as finishing the Keystone pipeline which would bring crude to their refinery in Texas. It’s hard to imagine that some US pols even speak against electric cars made in the USA. Or maybe not. If we all switched immediately to electric vehicles powered by wind and solar energy, would we still need oil? The answer is, yes.

Fuel oil and gas are not the only petroleum based products. The paving and roofing material asphalt is a complicated mixture of large hydrocarbons and plenty of sulfur, vanadium, and nickel impurities and is petroleum based. Tar can be made from coal or found naturally, as in the La Brea Tar Pits in Los Angeles where fossils of mammoths and dire wolves have been found. But tar and asphalt are not the only additional uses for petroleum.

Petroleum is the starting material for most of our plastics and synthetic materials, everything from fibers to pharmaceuticals, starts out as a form of oil.

Hydrocarbons can be chains or rings, and are distinguished by their composition-molecules made from just two elements, carbon and hydrogen. These materials can be light and flammable like naptha and gasoline or heavier as with asphalt and tar. Although they are useful in their own right, organic chemistry can step in and add elements to the hydrocarbons to make them into entirely new compounds. But they are the necessary beginning–the feed stock so to speak.

Here is an example of making something simple, acetic acid, as found in vinegar. Acetic acid contains oxygen in addition to hydrogen and carbon. It can be produced by fermentation as in this reaction where the acetic acid is bolded.

2 CO2 + 4 H2 → CH3COOH + 2 H2O.

It can also be made from alcohol, something you don’t want happening to your wine, for example, in this reaction starting with ethanol (as in wine) and adding oxygen naturally. It’s why you need to carefully control the amount of oxygen when wine making.

C2H5OH + O2 → CH3COOH + H2O

With the proper catalysts, acetic acid can easily be made from oil, for example as in this reaction:

2 C4H10 + 5 O2 → 4 CH3CO2H + 2 H2O

Why would anyone do this when acetic acid can be made from fermentation? We need a lot of it. Non-food acetic acid has been produced industrially since the 1960s and accounts for 90% of the usage world-wide. Over 5 million tons are produced each year. It’s a high demand chemical used to make coatings, paints, inks, and plastics such as PET. It’s one example of how we use chemical feed stock petroleum to make products we use every day.

Twenty percent of each barrel of oil is used as a chemical feed stock and when oil goes up in price, so does anything made from oil.

There are biological ways to make synthetic materials as discussed here and in my novel Lost in Waste. But as long as there is plenty of oil available, it has a long history of being used as a fuel and a feed stock and this isn’t likely to change anytime soon. Kicking the world’s oil addiction won’t be easy, unless we want to go back to life as it was 100 years ago. And we all know how some politicians love plastic bags. Fortunately, crude oil prices are still much lower than their highest point in 2008 so don’t despair. We will have plenty of low cost cigarette butts other plastics in the near future. In fact, the petrochemical industry will no longer be investigated if a plant catches on fire. That’s bad for people who lives near the plants, most on the Gulf Coast, but good for plastic prices.