Shellfish supercharged with vitamins

21 July 2020

Interview with 

David Aldridge, University of Cambridge


Mussels on the seashore


Researchers in Cambridge have developed what they’re calling ‘vitamin bullets’ - but they’re not for shooting, and nor will you find them at the pharmacists! These capsules are designed to be fed to shellfish to make them more nutritious. Joining us is the vitamin bullet farmer himself, David Aldridge…

David - Thanks very much, Chris. Well, a vitamin bullet is a tiny particle. It's about 20 microns in size. So you can get about 50 of these lined up along one millimetre, and inside these particles are nutrients. Things like vitamins vitamin A, vitamin D, which are wrapped up in a tasty coating. And the idea is that these particles are made just the right size and shape for mussels, and clams, and scallops, and oysters, to filter out of the water column. And by doing that, they concentrate those particles inside their guts. And then when we eat those shellfish, we get that nutritional benefit.

Chris - Can you actually demonstrate though, that whatever's packaged up in your magic bullets is absorbed by the creatures and then gets into their bodies so their bodies become enriched for those substances?

David - Well, actually what' we've done is quite clever in that what we've designed these particles to do is to be dosed just at the end of the production system for commercial shellfish. So whenever people farm mussels, or clams, or scallops, or oysters, they have to go through, what's called a depuration stage. And this typically lasts about 48 hours. And this is the stage where ultraviolet light is shone into the water so that all the nasties, all the bacteria are removed from inside the bivalves. And what we've found is that if we just dose the particles at the very end, the last eight hours of that process, just before the bivalves are then removed and sent off to the shops, then the bivalves keep those particles in their guts. And because we eat the entire animal guts and all, when we eat bivalves, then we actually know for sure that those particles are going into the people that consume them. And another important thing with this is that by fortifying something where you actually eat the animal flesh and tissue, we know that that makes it much more bioavailable to the consumer than having it just added in a pill.

Chris - Will it work for any vitamins and minerals David, or are there specific ones that work best like this?

David - Well, the beauty of this technology. If you like, the world is our oyster, we can put whatever we like in these particles. I couldn't resist. We can tailor the nutrient profile that we put in these particles to whatever is limiting in a particular geographic location. So we know for instance, that vitamin A and vitamin D are particularly important nutrients in terms of global deficiencies. So for instance, over 85% of people in India are vitamin D deficient, and that can cause osteoporosis and rickets. So we know that perhaps if we target species in India, we should put vitamin D in, and actually even in North America, 40% of the population is vitamin D deficient, but there are other regional nutrient deficiencies globally. And we can tailor our formulation to whatever the local need might be.

Chris - Does it effect the creature itself, when it ingests these particles? Does it affect the flavour? That's very important, but does it also affect the health of the organism? And also in terms of storage, when we put these things into storage and transport them, are there any risks through doing this where it may have a health dis-benefit?

David - The products we use are a hundred percent food grade, we actually manufacture them on a plant that makes encapsulated particles for the food industry. So, there's absolutely no reason to think it would actually have a negative impact on the animals. And actually another avenue of our research is - actually relates to putting flavourings in these particles so we can make the bivalves more tasty.

Chris - What sort of flavours are we talking? Do your mussels come pre-loaded with garlic? Is this what you mean?

David - You could do whatever you like. Yeah. So we've actually tried garlic butter. Another potential thing would be to have chilli flavourings. So you could bring your mussels back from the supermarket and you could put them in some water and get some to take up chilli and have a game of Russian roulette with your mussels [giggle].

Chris - But more seriously, what you're showing is that this works across a repertoire of different things that you could put in. How much does it cost though? Because obviously if it hits the bottom line in a big way, it's just not going to be practical for people who are earning a dollar a day. Whereas if it's very, very cheap and it can sort out their diet, then that's wonderful. So what's the price?

David - Yeah, absolutely. That's the crucial thing. And for that reason, we’ve started from the top down and we actually manufacture our products on a commercial scale and have sort of tailored commercial scale systems down to meet our needs. And so we can produce 5,000 tons of product very cheaply, on our UK plant and because we only dose these products for eight hours, you need next to nothing. And so we estimate that perhaps our products might add less than one pence onto the cost of an oyster. And so it will be very, very acceptable. It's also been shown that actually in a lot of developing countries, that fortified foods carry an acceptable price premium, which people are willing to pay, much more so than eating a vitamin pill, which is less good anyway. A good example is nutrient-enriched rice for instance in a lot of the developing world, where people recognise it as being healthier and are prepared to pay a slightly higher premium, but the cost is really, really small.


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