What's the current state of science on microgreens?
June 29, 2022 5:30 PM   Subscribe

I know the CDC doesn't think ANYONE should eat raw sprouts, least of all kids and the immunocompromised. I LOVE sprouts. But I have a kid so I don't buy them. I see lots more microgreens around these days. I feel like they're no sprout, but close enough, maybe? Are they safe? For adults? For kids? I know non-organic might be safer. I think I could probably have access to either organic or non-organic.
posted by If only I had a penguin... to Food & Drink (15 answers total) 4 users marked this as a favorite
 
I don’t have any science for you, but microgreens are just regular greens picked when they’re small. I’m not sure why you think organic would be less safe. Organic vs conventional doesn’t have anything to do with food safety.
posted by Comet Bug at 6:08 PM on June 29, 2022


It's easy to grow sprouts at home. You can buy kits, but back when we were hippies, mason jars were the preferred sprout ranches.

An important note: only purchase seeds specifically intended for sprouting. These seeds are chemical-free and cleaned so that they're pathogen-free. You don't want a side dose of salmonella or e. Coli with your sprouts! Sometimes you can find packets of sprouting seeds in garden centers, but if not, check your favorite seed catalog.

I'd guess sprouts grown commercially are exposed to unsafe water or unsafe harvesting. Your tap water is likely clean and safe; your water provider will post at least annual reports.
posted by theora55 at 6:14 PM on June 29, 2022 [6 favorites]


Sprouts grown at home can be safe and delicious! But you do want to be very careful, especially when starting out. See safety guidelines from University of California here.
posted by SaltySalticid at 6:57 PM on June 29, 2022 [6 favorites]


The reason sprouts (both conventionally farmed and organic) are susceptible to food borne pathogens is because the conditions to sprout the seeds are the perfect conditions for salmonella and e.coli - grown in dark and damp, plus the pathogens adhere well.

But micro greens are actually a different stage of the plant and are safer. Not perfect but safer. So I might go for those.
posted by warriorqueen at 7:22 PM on June 29, 2022 [8 favorites]


I find it hard to believe that microgreens could be any more dangerous than spinach and lettuce, because microgreens are at least generally farmed indoors on shelves and many greens growers don't provide even the barest minimum required toilet facilities for fieldworkers.

Growing your own microgreens, in coco coir or even on mesh screen, is fun and easy and if you wash your hands before handling likely a good bit safer than commercial.
posted by Lyn Never at 7:34 PM on June 29, 2022 [3 favorites]


To answer your title question directly, here's a nice recent (2019) scientific review article on farm-to-fork food safety issues for microgreens.
posted by SaltySalticid at 8:10 PM on June 29, 2022 [7 favorites]


theora55, Lyn Never,, there have been steady cases of Salmonella-contaminated seed from many sources since we were young hippies. The odds have changed. Which is why the UC guidelines tell you to treat the seed in 140°F hydrogen peroxide for five minutes, plus other care that’s a lot fussier than the windowsill jars of my youth.

There were enough surprising food-pathogen outbreaks in the 1990s-2000s that the US got a new Food Safety Modernization Act in 2015, much of which is tightening up practices that used to be good enough risks and now aren’t - big or small, organic or not.
posted by clew at 8:23 PM on June 29, 2022 [10 favorites]


Response by poster: I used to grow sprouts at home. But they're not particularly safer than store-bought sprouts since the danger, as I understand it, is salmonella on the INTERIOR of the seeds. You can't just wash it off like you can when foods are contaminated from the outside and of course you sit it around in a moist warm conditions, stuff will grow.

My thinknig was that microgreens aren't just regular greens at an earlier stage, they're also sprouts at a later stage. And unlike greens at a later stage, you're eating those little leaves that are basically just seeds (the things that can carry the salmonella). So just like with sprouts, you're eating the seeds. I thought non-organic might be safer because they might be treated/washed with some bacteria-killing agent or irradiated, which organic food might be less likely to be (not sure if irradiation is allowed for organic designation). (but I just looked it up and apparently you're not allowed to sell irradiated greens, so I guess it's irrelevant).
posted by If only I had a penguin... at 8:29 PM on June 29, 2022 [3 favorites]


Response by poster: SaltySalticid So it's not really clear from that. Can I eat them? Can I feed them to a small child?
posted by If only I had a penguin... at 8:31 PM on June 29, 2022


I dodge issues with pathogens by sprouting food grade dried lentils and peas. Dry chickpeas sprout wonderfully after a few hours soaking, as do lentil sprouts and mung bean sprouts. Dried mung beans are harder to get but I find them in kilo bags at my local South Asian grocer. Like my first round was just some soup mix lentils on a wet towel when I was kid.
posted by Jilder at 8:56 PM on June 29, 2022 [7 favorites]


Best answer: Sorry that link is wonky, it looked like full text when I commented but now I have to click around to get there.

Honestly the conclusion mostly supports your instincts: they are sort of between sprouts and regular vegetables in terms of safety risks.

Here is the conclusion section:

@The limited amount of data available suggests that microgreens may very well be of lower risk than sprouts in terms of food-borne illness, but the background level of bacteria is higher than that of conventional vegetables (Chandra et al. 2012, Lee et al. 2009) and is more similar to sprouts. Hydroponically grown microgreens appear to be much more susceptible to bacterial colonization compared to any solid media tested (Wang et al. 2016, Xiao et al. 2015). Spoilage and shelf life may be linked to contamination by pathogens (Gao et al. 2016, Kou et al. 2013, Kou et al. 2015, Xiao et al. 2014). The variety of microgreen and the serovar of the contaminant may influence risk. Post-harvest washes appear so far to be ineffective and may actually increase contamination risk due to tissue damage that invites pathogens among other microorganisms (Kou et al. 2015). Pre-harvest spraying with disinfectants may provide a valid alternative the post-harvest wash for ameliorating surface contamination. Seed decontamination appears to be a critical ongoing discussion (Kou et al. 2014)."
posted by SaltySalticid at 9:09 PM on June 29, 2022 [3 favorites]


This is wild guessing, but if field grown fresh greens are safer than sprouts (and AFAICT the evidence says they are) it’s not because they have been exposed to fewer microbes. I know we can plant lettuce without a hydrogen peroxide seed treatment and be both GAP and organic certified, for instance. And the fields are outdoors with wildlife.

So, hypothesis, field grown greens are safer because a whole suite of harmless microbes have elbowed aside the Salmonella. Which will be different in indoor grown micro greens, though it’s not obvious to me how - I would guess, when they carry Sslmonella it’s worse because theyre not being re-colonized by complete outdoors microbe communities. But perfect indoor control would reduce the number of cases that start, or catch them by sampling the wastewater.
posted by clew at 10:02 PM on June 29, 2022 [2 favorites]


If you happen to have access to greens from an indoor farm (eg Bowery in the NYC area, etc), I think there's almost zero chance of illness from their microgreens.
posted by pinochiette at 6:06 AM on June 30, 2022 [1 favorite]


Almost-zero based on what?
posted by clew at 12:38 PM on June 30, 2022 [2 favorites]


I grew up on mung bean sprouts. Those are going to be safer, if you decide to take the risk.
posted by liminal_shadows at 2:35 PM on June 30, 2022


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