A perhaps disconcerting study has been recently publicized. It promotes—of all things—microwaving your tea so that you obtain more of its health benefits.
Moreover, scientist Dr. Quan Vuong asserts that this technique yields a better-tasting cup.
Anathema! Nuke my tea? No way!
But why was Dr. Vuong microwaving his tea anyway?
As reported by ABC News–Australia on April 10, Vuong focuses on how to best extract components from foods and beverages—so that these compounds can be added to other food products or used in supplements.
And tea is simply loaded with highly beneficial stuff:
Yes, caffeine has plenty of real health benefits (click here to see why we might want to embrace it). Extracted caffeine is also added to other beverages and to medicines.
This highly desirable amino acid, found nearly exclusively in tea:
- Gives tea its umami flavor. (Shade-grown tea has more theanine than tea grown in sunlight, driving up both tea quality and price.)
- Increases alpha wave activity in our brains. These are the brain waves that relax us (think meditation or mindfulness).
- Works synergistically with caffeine to improve brain function and attention.
- May prevent some cancers and heart disease, boosts our immune system, and helps us lose weight (Vuong et al. 2011).
And of course tea is loaded with phenols, which are incredibly good for us in myriad ways (may prevent cancer, heart disease, diabetes, dementia, etc.).
Vuong and his colleagues (2010:3426) speculate, however, that just drinking tea “may not provide a sufficient level of catechins to achieve these health benefits”—hence his efforts on extracting and concentrating phenols so they can be added to other foods.
(While not negating the benefits of consuming more phenols, I would say that there are other research studies that indicate that drinking tea does have measurable effects.)
Which brings us to:
Extracting these elements
When we make a cup of tea at home, we use hot water to extract flavor, caffeine, theanine, and polyphenols from the tea leaves.
For extraction on a large scale and for commercial applications, however, methods must be as efficient, reproducible, safe (for employees, consumers, and environment), and cost effective as possible.
Therefore Vuong and his colleagues (2010, 2011) experimented with multiple ways (including with a microwave) to extract theanine and polyphenols, using varying solvents, temperature, time, and so on.
They found that the process was most efficient with ground dried tea. They also learned that they could extract the most theanine at 176°F for 30 minutes and a ratio of about 6 ounces of water to 0.035 ounces of tea (20 ml water per gram tea) (Vuong et al. 2011:2474).
Needless to say, extracting bulk theanine to add to other products is a whole different thing than extracting it in your teapot where the goal is largely to make a great cup of tea!
Which brings us to the microwave
For immediate home use, Vuong (Hoh 2017) asserts that you can obtain 80% of tea’s caffeine, theanine, and polyphenols—and the best flavor—by making tea this way:
- Put hot water in the cup with your teabag.
- Heat in the microwave for 30 seconds on half power.
- Let it sit for a minute.
Does it work? Well-l-l-l-l . . . .
Well, as far as health benefits go, that depends on whether you believe the science is correct, and as consumers, this is difficult to verify. For one, we must watch for additional research that supports Vuong’s claims.
I would say, however, that the “half power” thing is extremely non-scientific! Microwaves vary in wattage levels so half power of a small microwave will not be the same as that of a more powerful microwave. So how do we know if we are getting the 80% or not?
And as far as flavor goes, I’ll let you know in my next post!
–Boros, K. et al. “Theanine and caffeine content of infusions prepared from commercial tea samples,” Pharmacognosy Magazine 12(45):75–79. January–March 2016.
–Hoh, A. “Microwaving tea the best way to brew and extract health benefits,” ABC News, April 10, 2017.
–Vuong, Q. V., et al. “Extraction and isolation of catechins from tea,” J. Sep. Sci. 33:3415–28. 2010.
–Vuong, Q. V., et al. “Optimum conditions for the water extraction of L-theanine from green tea,” J. Sep. Sci. 34:2468–74. 2011.