How many times have you dropped fries, cookies or the burger itself and picked it up and eaten it anyway applying the 5-second-rule?
Well, according to the “The Quick and the Curious” show aired on Discovery’s Science Channel last week, the rule actually works provided the surface the food falls onto is comparatively dry.
As an experiment to find out the real truth behind the rule, a NASA engineer Mike Meacham offered cookies to people in a park. The only catch being that the strangers had to pick up the cookie from the ground in about five seconds and have it anyway.
While most of them turned down the fallen cookie, one man agreed to eat it anyway, much to the annoyance of the woman with him.
Whenever a piece of food is dropped on the ground, small amounts of bacteria will settle on it immediately.
“Moist foods left longer than 30 seconds collect 10 times the bacteria than those snapped up after only three,” Meacham said.
Bacteria, such as “E-coli, salmonella & listeria, love wet environments. They absorb water for the nutrients they need to grow and multiply.”
So, the next time you drop your food and pick it up quickly, it is all right to consume it provided that the food and surface are both fairly dry.
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A crew member “drops” his or her sandwich aboard the International Space Station (ISS), and it hits a surface. Quick! Grab it within five seconds or it is spoiled?
If this rule really did apply, and the sandwich was picked up few seconds too late, not much bacteria would be found, according to the latest published results of the Lab-on-a-Chip Application Development – Portable Test System (LOCAD-PTS).
The paper, titled Rapid Culture-Independent Microbial Analysis Aboard the International Space Station (ISS) Stage Two: Quantifying Three Microbial Biomarkers, provided molecular data on the distribution of microbial molecules – parts of microbes that are single-cell organisms – in every livable space of the station.
“This means that the LOCAD-PTS analyzed samples collected from surfaces in every habitable module that was part of the ISS from 2007 to 2009,” said Heather Morris, LOCAD-PTS scientist at NASA’s Marshall Space Flight Center in Huntsville, Ala. “The molecules that it can detect are cell wall molecules of bacteria and fungi.”
The handheld LOCAD-PTS device rapidly detects biological and chemical substances on surfaces aboard the station. Astronauts swab surfaces within the cabin, mix swabbed material with a liquid before adding it to the LOCAD-PTS and obtain results within 15 minutes on a display screen. The lightweight system has three different types of cartridges for detecting endotoxin, a marker of gram-negative bacteria; glucan, a type of fungi; and lipoteichoic acid, a marker of gram-positive bacteria. The category of gram-positive bacteria includes multiple pathogens, specifically the well-known Streptococcus and Staphylococcus, making the identification of these bacteria important for crew health.
The study showed a rapid indication of biological cleanliness to help the crew monitor microorganisms in the space station environment. Likewise, this technology can provide a quick screen for bacterial/fungal contamination in a hospital or other clinical setting, particularly after cleaning, to assess the sanitization of the surface.
“The major benefits of the LOCAD-PTS are the low, relative cost and minimal crew time to operate with rapid results,” said Norm Wainwright, Ph.D., the principal investigator for the system from Charles River Laboratories in Charleston, S.C. “It can be used right at the place where contamination may have occurred, only requiring a small sample, and performs the analysis in a contained environment with no growth of organisms required.”
In the paper, investigators reported that most surfaces used by the station crew are relatively free of microbial molecules. However, the number of microbial molecules were elevated at sites frequently contacted by crew members, including the workout bike in the U.S. Laboratory module; the Japanese Experiment Module (JEM) airlock handle; and foot rests, drawers and the waste and hygiene compartments in the Zvezda and Tranquility modules.
The first molecular test of surfaces in the newly docked JEM were performed using the cartridges designed to detect gram-positive bacteria, including the microorganisms that can cause staph infections and strep throat. The results revealed relatively clean surfaces.
“By and large, we found that the station is a clean environment as the crew does have a stringent cleaning protocol,” said Lisa Monaco, Ph.D., scientist for the LOCAD-PTS at Marshall. “Our in-orbit testing revealed some areas of hardware/software/testing modifications that need to occur, and we’ve begun working on all of them, but overall we’re very satisfied with the results.”
original articles below
https://www.nasa.gov/mission_pages/station/research/news/locad_pts.html
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