Garlic lovers have long faced a dating dilemma. Do they reach for the delicious dips and hope their date does the same, or do they give up garlic for romance?
Luckily for all of us gourmands – and our partners, Ohio State University food scientists say they have found a remedy for garlic breath – yoghurt. More specifically, Greek yoghurt. In their study, published last year in research journal Molecule, Professor Sheryl Barringer and her PhD student, Manpreet Kaur, showed that high protein yogurt can physically trap the stinky sulphides found in garlic.
Frying tonight?
According to their experiments if you want to get the best effect on your breath, frying garlic reduces the starting amounts of smelly volatile compounds. The evidence says you should also go for a high protein content yoghurt and avoid the fat-free varieties.
The fat and protein work together to keep the stinky molecules mouth bound. All in all, the researchers discovered that whether the garlic was raw or fried, the fat and protein in yoghurt reduced the concentration of pungent molecules dramatically compared to no yoghurt. Time for tzatziki to go with your hummus?
Passing the Smell Test
So how do we know this is for real? Are Barringer and Kaur shills for big yoghurt? Opinions on odours are subjective, right? Well, the duo skipped subjective sniff tests and went straight to the science of smell. They used objective measures to test the amounts of scent-causing chemicals in raw and fried garlic that they had mixed with yoghurt, and compared them to raw or fried garlic alone.
The two took a batch of freshly prepared garlic, chopped or fried and placed them in special plastic bottles. They then added yoghurt to some samples keeping identical specimens with no yoghurt as controls. Next, the scientists used a special machine that sucks up all the air in the ‘empty’ space of the bottle and measures the concentration of volatile compounds using mass spectrometry. Volatile compounds are the molecules that float around in the air creating smells.
First they found that frying diminishes the potency of garlic smells. Importantly for us, though, they discovered that when you add yoghurt to garlic, raw or fried, the yoghurt reduced the concentrations of the most pungent aroma producing molecules in the air by up to 99%.
Fat or Protein?
Next, the researchers looked into what it was about yoghurt that made it so successful in trapping the garlic smells. First they examined whether fat was responsible for the effect. They found that when they added butter with little protein in it, or fat-free milk powder instead of yoghurt, they each were effective at grabbing a different subset of fragrant compound types. When they were put together, fat and protein worked collaboratively to compensate for each other’s weak spots. Yoghurt, they found, contains just the right ratio of fat, water and protein to snatch the garlic smells out of the air.
They also looked at how much protein and fat you need to get the effect. Strikingly they found that Greek yoghurt, with its characteristic high protein content, was significantly superior at reducing odours than its French-style plain yoghurt competitor. Could low-fat or fat-free yoghurt get the job done? The experiments showed that the more fat, the better.
Here Comes the Science Part
This all goes back to the chemistry of smells and taste. The flavour of food is created by a mixture of volatile fragrance compounds, texture and taste: sweet, sour, salty, bitter, etc. While it feels like we are experiencing the flavour in our mouths, actually most of the work is happening in our nose. When we eat something, once it is in our mouth, the volatile chemicals that make different flavours float around in the air inside our mouth. They drift up the back of our throat and into our nose where our smell receptors trap them and send a message to our brain. Our brain then combines all the different complex signals from our supersensitive smell receptors and mixes it up with the sensations we get from our mouth. The more fragrant the food, the better the taste.
Food scientists noticed as far back as the 1980s that adding protein to a food can make it taste more bland or give it funny flavours. When they used mass spectrometry to see what was going on, they found that the aroma producing compounds were getting stuck on the protein. Once they were stuck, they couldn’t float up out of the food and into the air any more.
Fat and Protein – The Anti-Garlic Dream Team
The protein in yoghurt works much the same way. Milk proteins specifically, it turns out, are really good at capturing volatile compounds. Fat also has a smell damping effect. Most aroma creating molecules are derived from fat, and, as we know, oil and water don’t mix. In the case of full-flavoured oils and fried food it makes the fat taste good. In contrast, if the fat is blended evenly with protein as it is in milk and yoghurt, the fat actually makes it easier for the volatile compounds to come into contact with the protein and get stuck.
So what does this mean for yoghurt? Well, if you want to mitigate lingering smells in your mouth, taking a spoon full of yoghurt quickly after eating a stinky meal can beat bad breath. As Professor Barringer said in a press release for Ohio State University, “have your garlic and eat the yoghurt right away”.
References
Kaur M, Barringer S. Effect of Yoghurt and Its Components on the Deodorization of Raw and Fried Garlic Volatiles. Molecules. 2023;28(15):5714. doi:10.3390/molecules28155714
Overbosch P, Afterof WGM, Haring PGM. Flavor release in the mouth. Food Reviews International. 1991;7(2):137–184. doi:10.1080/87559129109540906
Semenova MG, Antipova AS, Misharina TA, Golovnya RV. Binding of aroma compounds with legumin. I. Binding of hexyl acetate with 11S globulin depending on the protein molecular state in aqueous medium. Food Hydrocolloids. 2002;16(6):557–564. doi:10.1016/S0268-005X (02) 00017-6
Kühn J, Considine T, Singh H. Interactions of Milk Proteins and Volatile Flavor Compounds: Implications in the Development of Protein Foods. Journal of Food Science. 2006;71(5): R72-R82. doi:10.1111/j.1750-3841.2006.00051.x
Yoghurt may be the next go-to garlic breath remedy. EurekAlert! Accessed July 2, 2024. https://www.eurekalert.org/news-releases/1001868
