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    Food waste strategies for home: The Latest From Science with Dr Polly Burey [Ep. 23]

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    Hello, I'm Michelle Tapper with the Latest from Science Food waste is a major global problem with about one third of all food that's produced ending up as waste

    In Australia, it costs the economy about $20 billion a year, and it also has serious environmental consequences Joining us today to discuss these issues is Dr Polly Burey, a food scientist from the University of Southern Queensland Hi, Polly Thanks for joining us Hi Michelle

    Thank you for having me along to talk about a topic that's quite near and dear to me, and probably affects quite a few people out there as well Now, a lot of people are probably unaware, just how much impact food waste has on greenhouse gas emissions How bad is it here in Australia? So in Australia with all our activity, we produce about 500 million tonnes of CO2 equivalent per year In Australia, in terms of food waste, we produce about 8 million tonnes of food that might be wasted And off that 8 million tonnes, we're generating 15 million tonnes of that CO2 equivalent, contributing to that 500 million

    So it's only like a few percent, but putting it in perspective, it's actually more than what our steel and iron ore industries produce, which is really quite significant when you think about it And when you think of how much energy and effort goes into producing those things, our food waste actually produces more greenhouse gas emissions than that does What can people do at home to reduce their own food waste? Okay, well, there's a few strategies you can use at home And I guess the first one is prevention is better than cure So one of the first things you can actually do is try and prevent food waste being generated

    So you can do a lot of planning for your shopping for the week or the fortnight for your food usage and only buy or source o what you need and use it up while it's fresh or while it's within the date of usage One of the issues typically is that things like fresh produce tend to spoil quite quickly So your berries, they really only last a couple of days or so in terms of quality, some veggies can last about a week or so and some a little bit longer So first of all, try and use everything that you buy Second of all, if you still have stuff left over, there's a few things you can do

    And you can borrow some processes from the past, and from the food industry So there's a few things you can do You can cook and chill your food, and then eat that over the week And it's lasting a little bit longer than just your fresh produce You can cook and freeze and that lasts a couple of months or so, depending on what it is that you're actually cooking

    Now freezing can work for quite a few foods, but for some things like tomatoes, it's not ideal because they turn out pretty mushy and horrible Some of the things you can do, if you're into that kind of thing, you can do some canning or preserving, and that can work for both fruit and vegetables as well With your meats, you can make things like beef jerky and so on, and they last a lot longer than just fresh meat You can do things like fermentation and pickling, and the good thing about fermented foods as well There's a lot of healthy compounds in there as well

    Not just that your food's shelf, life is lasting for quite a while And then another thing that you can actually do is dry your food And that way you're reducing the level of water in there So your nasty bacteria and all sorts of things that would spoil the food otherwise can't do their job And so that means your food quality and your food safety is prolonged

    However, you might still have some stuff that actually did spoil and get a little bit horrible, and that's when you can start getting into things like producing compost But typical backyard compost, you've got to do it properly If you just dump it on there and just leave it, that's actually not going to do much good, it's just as bad as a landfill Because you're going to be producing some methane and all those other little greenhouse gases and things So if you're going to do compost, make sure you learn how to do it properly

    It does need to be turned and aerated Sometimes you see those barrel-type compost bins that tumble, and that's the reason for it to keep it aerated and to keep it healthy Well, that's all really helpful advice, but what about supply chains and grocery stores? What issues do they have and how can they help produce food waste? So supply chains in Australia can be quite tricky sometimes It can be quite a bit of distance from where the food is produced to where it ends up being sold And so during that journey along the supply chain there's actually quite a lot of points where there could be waste generated

    So it might be generated on farm, which I'll talk about in a moment, it might be generated while it's travelling on the truck and stuff got thrown around a bit and maybe bruised that can affect quality and it might not be saleable Then, you know, they're obviously packed a certain way to try and prevent that, but there's always a little bit of damage Once it hits the shops, there's a little bit more handling to get your food out on the shelves and so on Sometimes things get dropped, sometimes things are left too long People in the supermarket tend to, and they say they don't, but they tend to pick over to get the nice looking apple or the nice looking tomato and so on

    So if you saw for example, a cut on something, and you're worried about what that might mean for safety or how it looks or how it will taste, people do tend to avoid that, for the most part, so that's one of the issues Probably the major issue with a large sort of grocery store chains is that they've got a lot of food there, potentially it could be waste Some of the worst categories are actually a fresh produce, which I mentioned earlier, because it can go off quite quickly And bread is one of the other big categories as well That can be wasted too

    So I think with grocery stores, it's the collation or the collection of a heap of food, all in the one place trying to be distributed quite quickly sometimes And if it isn't in time or then yeah, it just ends up being wasted There'll be going back to the beginning of the supply chain from a farming perspective, how can food waste be improved upon there? Okay, now farming can be really tough And sometimes the issues that cause food waste on farm are actually outside of the farmer's control So one thing a farmer can't control, they can't control the weather

    So if it gets hot too soon, that means their produce may ripen or mature sooner than planned, which means that their scheduled pickers can't arrive in time, which means the produce is ripening and it's extending into getting towards spoilage, and that's something they can't control What we need to do to maybe tackle that is to in a way, and this is where my research starts getting into it, bring a processing or preservation capability to the farm, where there is the tonnes of food being produced that may become waste So one of the issues, and this is when I first started working on this problem, with the pineapple industry every few years, the weather patterns caused them to ripen quite quickly and quite early And that means that they end up with a glut at which might not be usable in time And one of the criticisms sometimes is that our factories won't take these

    They just won't take them But the reason being is that they're scheduling in these factories and there's limited factories as well So at the moment in our, I guess, processing side of our food's supply chain, there, isn't the flexibility to deal with something like this So one way to get around this is you can have, I guess, mobile processing in a way to deal with an unexpected glut for that period of time And then it goes away and can be used to deal with another problem

    That's one strategy Another is the farmer themselves can start moving towards value-added products So not necessarily just fresh produce, but they could have some of those things we talked about Like they could be making pickles, they could be making preserves they could be drying, et cetera And some farmers are actually already doing these kinds of things and solving some of their waste problems themselves

    So those are some ways that could be used to use up the waste As to how to reduce it Well, there are some sad stories out there So a couple of years ago there was a study done on Sunshine Coast, where some of the tomato growers had more than 80% of the produce didn't meet spec So that meant 80% of it didn't get sold, didn't get eaten

    Now, as you can imagine, that's quite significant And as a result, some of them actually stopped growing tomatoes, not an ideal strategy for reducing waste But it is one that has been used in the past to say, we don't want this to happen again, the way to stop it might actually be to stop growing up And then there's a couple of other reasons that can cause waste So a couple of years ago we had the strawberry issue in Queensland with the needles found in strawberries

    That was not the farmer's fault And that was something that was not foreseen Problem was not only the farms that had the issue were affected, but all strawberry growers were affected So again, something outside of their control, what can they do? So the only thing they can do is check all their produce, potentially send it to you know, a second tier product, like a powder or a jam or something like that, and try and recover something, in terms of value and in terms of the food being eaten as well, You do a lot of research and creating value from food waste Can you tell me about some of the innovations that you've come up with? Okay

    So my research team focuses on ending value to food to the point that there's no waste at all So just thinking, you know, for example, for your potatoes, a lot of people tend to peel the potatoes So there's what we call a byproduct where, you know, you don't typically tend to eat peel even though you can And so we focus on not only the, the edible part, but the part that people sometimes don't consider edible and what can be done with that So the areas that my team tend to focus on—we have our first stage, which is normally the capturing of the food to prevent it being wasted and preserving it

    And there's a few technologies we work on without industry collaborators So some involve special drying technologies, which don't affect the nutritional content of the food So typically if you dry a piece of fruit in an oven, you've lost pretty much all the, a lot, of the useful vitamins that would eat otherwise get from a fresh piece of fruit, but there's ways to do that and still preserve that So that's the first stage of our research We have a second stage, which actually focuses on extracting compounds that are useful for nutritional and pharmaceutical uses in some cases

    So there's some compounds and things like apples and bananas and strawberries, which in some research studies, admittedly lab bench studies, that have some activity on conditions like diabetes, like cancer, like heart disease, et cetera And so on and so forth Some of these compounds are actually well-established as having medicinal properties and are out there in the market and synthetic forms, but our foods that doesn't don't get eaten, can actually be a source of these and how to extract these, I guess, in an economically viable way, it's one of the challenges, where us engineers and scientists deal with So that's the second tier One arm of it also is fermentations

    So, I did some calculations a while ago and said, if we took all our potatoes and we turned them all into gin, we would have several million litres and we'd be literally drowning in gin That's wonderful, but it's not ideal So one thing we can actually do with fermenting, something like potatoes or another starchy or sugary type produce, is actually produce ethanol Now ethanol has a few uses You can use it as a biofuel

    You can use it for a clean product You can use it in hand sanitiser as we've found most recently But one thing with the ethanol is we can actually feed it back into our second stage process to do the extraction So one thing we do in our modelling, as we can say, okay, we have a waste stream, we can dry part of it And that's one of our products and it's worth X amount

    We can take that dry product and we can extract something else out of it and that's worth Y dollars And then we can take another part of it, produce that ethanol to extract that compound, and that produces a certain amount of value as well Those are some amazing products Now you also make bio-plastics from food waste How does that help the environment? So your food wastes have a few substances in there called biopolymers and your traditional plastics are just normal polymers from petroleum

    Now one of the things we can do is we can extract some of these biopolymers from our food waste and turn them into films So a couple of years ago I had a student working with some orange peel, and she extracted some pectons and some cellulose, which has some of those biopolymer molecules in them And she made some bioplastics Now I've got some right here So this one here was made from orange peel

    Now, when she was doing that project, she said, "Oh, I think I've failed a bit as a plastic It's not very dry" Some of the samples she created were actually like a hydrogel, and hydrogels have really good applications in wound healing and medicine as well So not only can we use it for a packaging-type application, but we can also go so far as using it for a medical application as well Now, obviously these are great and creative uses of food waste, but are they a sustainable solution to the problem? Or do we just need to go back to the very beginning and reduce our food waste in general? So some of these solutions, if we overcome the cost of producing some of these materials and substances, then they would be a sustainable solution

    And that's part of the, I guess, technology and research development to get to that point where it's competitive with alternatives, which are a lot cheaper So thinking about your bioplastics, your bog standard, just plastic bag is really quite cheap compared to how to produce a bioplastic So that's one of the challenges to overcome And once that is, then yes, it would be a sustainable solution But your point about reducing food waste in general, that's definitely a very wise one

    So if we stop creating the problem in the first place, that means we don't have to deal with amount of stuff down the line there And in fact, in the hierarchy of dealing with waste, reduce is probably at the top And then we start getting down into some of the strategies that I talked about today Thanks so much for all of that really important information and for stressing the importance of reducing, reusing recycling and repurposing Dr Polly Burey thank you for your time

    Okay Thank you for having me, Michelle And don't forget for regular video updates from the Australian Academy of Science, make sure to follow us on social media I'm Michelle Tapper, see you soon

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