As a teacher/​researcher, how many times have you cringed on hearing a piece of well-meant, but terrible advice?

Here’s an example: ​“Don’t eat Kurkure, it’s made of plastic!”

For the record, this rumour was started because of a video clip that showed a piece of Kurkure ​‘burning and melting’, which apparently meant that the popular snack contained plastic. 

Fact: Most snacks that contain high levels of carbohydrates and oil will​‘burn and melt’ just like Kurkure.

A downright dangerous challenge: ​“It’s dengue season…for all those who want to avoid dengue, or cure dengue in a day, drink papaya leaf juice.”

Fact: papaya leaf extracts do not prevent or even cure dengue (in a day?). Dengue fever causes a decrease in platelets in your body. Papaya leaf extracts boost your body’s ability to make platelets, and help mitigate the effects of dengue – if you get bitten by a dengue-carrying mosquito, even though you have drunk papaya leaf juice, you can still get dengue. 

When well-meaning friends or relatives, who are usually sharp enough to spot fake notes in a wad of money, believe in and pass on such messages, what do you do? Taking my responsibility as a former scientist and current science communicator very seriously, I decided to try and explain that this ​‘information’ was not true.

The most common response to my carefully collated research material (and rational thinking) was, ​“Yes, yes, but all of this is done by someone else! How do you know they’re telling the truth?”. This is in truth, a fair question. The only way to counter it is to test these so-called facts by carrying out and interpreting the results of experiments by yourself.

This is exactly what an Associate Professor, Evan Lampert, and a graduate student, Holly Munro, at the University of North Georgia made undergraduate students do. The students designed their own hypotheses and set up experiments to test the veracity of a well-known and widespread modern myth in the USA – that fast food does not decay.

In a study that they published in The American Biology Teacher, Lampert and Munro made students inoculate hamburgers and other fast food items with the fungus Rhizopus stolonifer (black bread mould) as a part of an introductory biology class. R. stolonifer is usually harmless, easily obtainable, and easy to culture. Students used a 3 mm plug of R. stolonifer cultured on potato-dextrose agar to inoculate 60 mm disks of different foods such as burger patties, chicken nuggets, bread, burger buns, biscuits, and other baked products. Petri plates with the inoculated foods were sealed and incubated at 25 ˚C for four days, following which, the diameters of the fungal growths on the food were measured. During the incubation period, students were given worksheets where they had to list out the ingredients, including antimicrobials and preservatives, in the foods they were testing. Using this information, they were asked to formulate a hypothesis on whether a particular food item would support fungal growth or not, and explain their reasons for the hypothesis. Since most undergraduate students usually have difficulties in differentiating between a question, hypothesis, and prediction, the exercise was useful in helping them understand these concepts. 

Through the experiments, the class observed that plain bread products, which contain the antifungal agent calcium propionate, seldom allowed fungal growth. Similarly, fungal growth was low in foods covered with condiments such as ketchup and mustard, which also contain high levels of preservatives. However, animal products like burger patties and chicken nuggets, and moist foods with sauces and glazes supported plentiful fungal growth. Overall, the experiments helped students understand that fungal growth depended on the moisture and preservative content of the food.

The entire exercise not only helped the class evaluate the reliability of online information, it also served as an introductory lesson on fungi. Using well-known foods boosted interest in the laboratory experiments, and promoted discussions of nutritional practices. The authors report that after the experiment, many students expressed interest in changing their eating habits for a healthier future. 

Lampert and Munro end their publication with thoughts on unlimited opportunities to examine online claims in lab courses. ​“We recommend that high school and college instructors seek out their own online stories and develop ways to test them or seek original information in peer-reviewed scientific literature. Such activities can be effective and engaging learning experiences,” they add.

“Popular myths can be busted through simple hypotheses-driven experiments in colleges and schools. Students can be asked to identify and list prevailing online information — for example, certain rice brands made of wax or Maggi noodles being coated in wax,” says Urmi Bajpai, an associate professor from the Acharya Narendra Dev college, New Delhi. ​“In testing such claims, students learn to prove/​disprove a ​‘known fact’ instead of doing cookbook-style experiments. They learn to question the credibility of unverified facts and understand the concepts of enquiry-based learning, along with learning experimental skills,” she adds.