Researchers have found that the enzyme polyphenol oxidase (PPO) in certain fruits like bananas can reduce the absorption of heart-healthy flavanols, especially when combined with flavanol-rich ingredients like berries. The study suggests choosing ingredients with low PPO activity, such as pineapple or oranges, when making smoothies to optimize flavanol absorption.
This article assumes I am drinking smoothies purely for the flavanoids.
Avoid the Noid
I mean, the #1 reason is because it makes it taste like banana.
Handful of strawberries. Handful of blueberries. Half cup of pineapple juice. Cup of crushed ice. 1 whole banana. Blended well.
Super smooth dairy free smoothie and all you taste is the other fruit.
i’m gonna go out on a limb and wager that this is an utterly insignificant effect compared to how healthy it is to eat fruits.
Like obviously people have been healthy while consuming banana smoothies, you’re probably going to suffer more from stressing out about minute stuff like this than any possible negative health effects consuming it could bring…
Yeah. I feel like somebody read enough to come up with a clickbait article but not enough to learn anything.
Sort of like when sci-fi writers have a very surface understanding of something, but it’s forgivable because they’re sort of close and it’s good for the story. Except here it’s just an article nobody really needed.
Ugh can’t even come to lemmy to escape real life - spent most of Monday morning denaturing/counteracting PPO in my uni food science lab!
Polyphenol oxidase is the enzyme responsible for browning in shit like apples and potatoes when cut and exposed to air.
I haven’t read the study linked in the OP yet (and I’m far too sad and intoxicated for it right now) but in other fruits/vegetables it’s pretty easy to deactivate PPO through application of some combination of Vitamin C (converts quinones back to their phenol form and reacts with oxygen before it can get to the PPO) and heat (which actually denatures the PPO enzymes).
When we were denaturing PPO in potatoes in a lab setting we simply blanched the sliced potatoes in 90°C water for 5 minutes before placing it in an ice bath until cool.
Right? Insert a little bit of lemon juice and the polyphenol oxidase shouldn’t be a problem anymore. Also, banana wouldn’t be the only problem (concerning high polyphenol oxidase activity), would it? Cut up an apple and it turns brown before you can push all pieces into a juicer. Literally, I’ve had a couple R&D projects at the juice company I used to work for and we had this small Angel Juicer and by the time all apple pieces were in, the juice was brown (provided I didn’t spritz in lemon juice at the beginning).
Submerging apple slices in water with a bit of salt prevents browning. Doesn’t change the flavour like lemon as not much salt needed.
Hey, I know I’m like two days late to reply, but you probably wouldn’t need the salt even. The polyphenoloxidase reaction is what the name suggests, an oxidation. So it requires plenty of oxygen to run, which probably is inaccessible in water, I would assume.
I actually wasn’t quite sure anymore if I had that right and when googling it, I managed to find an entire diploma thesis on the polyphenoloxidase reaction, so for anyone that’s interested in it more deeply (sorry, it’s in German aside for the abstract, which is in English, too), have fun c:
I’m not confident saying for sure without reading the actual paper - it really depends on how PPO interacts with the flavanols, but at the end of the day denaturing the PPO with heat should make it a non-issue. Keep in mind though that bananas are far from the only smoothie ingredient with PPO!
Ottaviani said tea is a major dietary source of flavanols and depending on how it is prepared, a different amount of flavanols would be available for absorption.
Dammit, you can’t just say that and not give any detail!
It’s not a big mystery. Green tea has the most amount flavanols. Fresh leaves also have more compared to aged leaves. Also, powered forms of tea release them more quickly compared to loose leaf. However, you could just steep regular leaf tea for longer as well. The key thing to remember is to not use boiling water, as that may degrade the flavanols, so select a temperature just-below boiling (80-90C / 175-195F).
I’m not in the right headspace to read any studies on it but based on my understanding of how food works on a chemical level I’d say it’s a safe bet to say that the difference in preparation is mostly down to heat and steeping time.
If you steep for longer it gives the water more time to absorb flavanols.
If you use a temperate that is too high you’ll denature or destroy the flavanols, whereas if you use a temperature that’s too low they may not dissolve into the water as readily necessitating a longer steeping time.
Yeah I was thinking temperature. For example, you’re not supposed to use boiling water for green tea, as it burns the tea. I’ve noticed this with many brands, however each brand tends to be a bit different - some are more tolerant to higher temperatures than others.
I imagine you can also do a multi-stage extraction, where you heat at a lower temperature and then at a higher temperature. This should avoid denaturing the lower temp compounds. It’s commonly done with alcohol when extracting sugars into the wort.
