Pint of Science Day Two - The Future of Food

Rotten tomatoes on a compost heap. photo: Paul Glazzard

First up is Matt who is enhancing plant defences using UV light.

We live in a world of food safety and security challenges - climate change, pathogens, pests. And yet we throw away 45% of the fruit and vegetables in grow. In Europe half of this is during production. Can we reduce loss in three key areas - production, post-harvest and distribution? Specifically, Matt is focusing on spoilage fungus. This led to losses of £88 million last year in tomatoes alone. Also known as noble rot, this grey mould is actually good for grapes as it intensifies the flavour of wine but isn't good for most fruit and veg and can infect over 235 different species. The main issue is where it attacks the stem rather than just a single fruit. It reduces yields and shelf life and is resistant to all know fungicides.

The solution is to increase plants' natural defences. The aim is to use UV light to improve the defences and then try to find a way to commercialise this treatment. UV light is dangerous to all organisms - it causes mutations and cancer. It is also used in sterilisation. So, how does UV induced resistance work? Plants can "see" UV light and they "memorise" that they have seen it. They adapt to it by producing sunscreen molecules, antioxidants and phytoalexins. More importantly, since they can't move, they change their metabolism. Responses to environmental stress can be entwined with responses to pathogens.

UV poses stress to the plant so this can generate a response that can deal with the spoilage fungus. However, the right level of UV is vital as too much can kill the plant. Matt and his team still aren't totally sure how the mechanism in the plant actually works but it seems to be very effective on tomatoes. This could be because greenhouse plants never normally interact with UV light - most is filtered out by the atmosphere and the rest by the glass planes in greenhouses. Longer term, there's a possibility that an alternative method to using UV light could be used to stress the plants.

In the middle of the night’s food sandwich is Tom, who is getting creative about conservation.

Constructed wetland

There's a "conservation crisis" - destruction on a global scale caused by humans. Habitat loss, over exploitation and climate change are all immense challenges, but how can we solve them? Do we try prohibition like Kenya have recently enforced with their ivory burning? Do we create more protected areas such as nature reserves? Do we implement rewilding such as the reintroduction of beavers in Scotland? Most pertinent - is it a hopeless case? If we look at the UK, do we really have a natural environment? We have a monoculture of oil seed rape - we're growing so much because we need food. While there are questions about whether these crops encourage bio-diversity, it does at least represent the creation of a habitat.

Are there any lessons that we can learn from the rest of the world? The Sinai is a war-torn and troubled peninsular that is home to many endemic creatures such as butterflies and reptiles. However, the bio-culture is under threat from drought, over grazing, tourism and over-exploitation. But it is also where you can find the Bedouin gardens. These feature diverse planting, water and nutrient management and minority crops such as fruit, nuts and herbs. But do these gardens take away pollinators from outside the gardens? No, they actually lead to an abundance of diversity and functional richness. There are plants found in the gardens that were not planted by humans. The pollinator visits to the gardens lead to more complexity and abundance within the gardens. This benefits the crops and the native plants and so leads to better seed sets which leads to better almond crops. So, the gardens have conservation value, cultural value and economic value. This allows for optimism that we can create better habitats.

But what about artificial habitats - are these of any benefit? In industry there are thousands of wetlands created by reed beds used to capture water where microbes are then used to treat the water (a better alternative to treating water with chemicals). These wetlands can be used to capture things such as mine water, domestic waste, airport run-off or farm run-off. Very good for water treatment, but they don’t attract larger vertebrates such as the bearded tit and the bitten because the reed beds aren't as large as natural ones. However, there is hidden diversity such as a breed of wasp which lays its eggs in maggots that are plentiful in the wetlands. These maggots are also eaten by harvest mice. So, constructed reed beds can have the same diversity as natural ones despite all of the inherent nastiness such as heavy metals. Other artificial habitats can also be of value such as urban gardens, golf courses, old factory sites and railway verges. Maybe there is some hope yet.

Crispy...

Before the last speaker, there is an opportunity for the Pint of Science to win some bees by guessing how many bits of pollen are in a bag. There is also a chance to try eating some insects. I go for the grasshopper and it actually isn't that bad. It doesn't really taste of much, it's just very crispy.

After my snack, it was on to Andy, who talked about food sources for an increasing global population. Are we really going to be eating bugs?

Why are we going to need more food? There are four key drivers: population growth, increased life span, obesity and improved economic stability. Overall population growth comes from less well developed countries. As these countries become wealthier, there is an increase in life expectancy and also in their desire to ape our western diet. So far, we have managed to respond to an increase in food requirements, especially in the west, by producing more crops and more livestock (largely, more maize and chickens) However, where it is being produced is changing. For example over the last twenty years:

• India has doubled its milk production
• Brazil has doubled its production of beef
• USA has more than doubled its chicken production
• China has seen a three to four fold increase in chicken production
• China has doubled pork production (and now has 60% of global production)

The big problem is that it takes 5-6kg of grain to produce 1kg of pork - we could be eating that grain. In the UK a third of wheat grown is used to feed animals. In fact 70% of the cost of raising livestock for meat is animal feed. Growing populations are likely to want to eat meat and we are going to have to feed those extra animals. Modern breeds are very efficient at utilising very high nutritional value feed, they are bred specifically for growth on high quality plant material. There has also been a huge growth in fish aquaculture over the last ten to fifteen years, especially in freshwater fish. Most marine fish are still caught rather than farmed but ironically enough, aquaculture is making this worse as fish meal is being fed to the farmed fish. However only 70% of this remains in the fed fish - this is completely unsustainable.

 

So, why don't we just stop eating animals? Well, eating them helps prevent protein-energy deficiency, iron deficiency and vitamin A deficiency. A billion households around the world rely on livestock for their income and a lot of people just like eating meat. Really, we need to find alternate feeds for animals. Options could include waste and by-products (such as bio-energy co-products, brewer's waster or household waste), novel and under-utilised crops (those that can be grown on land unsuitable for conventional crops) or insects. Could insects really present an alternative source of energy, protein and other nutrients for livestock production? Insects contain up to 70% protein and examples such as the black soldier fly can grow on anything (although in Europe they couldn't be grown on animal waste due to regulations put in place after the BSE outbreak, they would have to be grown on plant waste). But there are still questions - what would we feed the insects? Are there any issues with disease transmission? Can we produce insects cheaper than we produce current feed?

How about insects as human food? Two billion people worldwide already eat them, although they are supplementary rather than a main source of protein for those humans. While the large parts of the world producing insects for humans has a very low carbon footprint, in the UK we would require a lot of energy to produce them, especially in the winter. There is still a lot that the European Food Safety Authority do not yet know about insects as food. Can they pass on pathogens? Can they accumulate heavy metals or other chemical contaminants? Would they set off anyone's allergies? (the audience at Rough Trade were advised to not eat any of the insects if they had any allergies to shellfish but this is just a best guess at the moment)

There are a lot of countries that already eat too much protein - here in the UK we eat twice as much animal protein than we need on average. A lot of people are already trying to reduce their meat intake, although this is mainly due to health concerns or to reduce weight - it's clear that the environmental message isn't getting through. As we've seen the global demand for meat is going to increase and as the cost goes up and availability goes down, it will impact those who need it the most. Insects could be part of the solution. Since we're going to need Omega 3 from fish, perhaps the best use of insects will be to feed the fish.

So, that's the future of food washed down with a pint of science. For the final night of the festival, I'm off to Spanky Van Dyke's to hear about "Space: What's Out There?"

Pint of Science Day Two took place on Tuesday 24 May 2016.

Pint of Science website