[Carol Shirk, Dodge County Master Gardener Association]

Good evening, I’m Carol Shirk with the Dodge County Master Gardener Association, and tonight our guest is Amy Freidig with the U.W. – Wisconsin Master Gardener Volunteer Program. She’s going to be talking to us about plant pigmentation, where beauty meets science. Plant colors are a vibrant part of gardening, the gardening experience, and there’s a fascinating science behind that display. We’re gonna learn about five common plant pigments in your garden, and I think there’s something about lobsters in there too. Amy has a master’s in horticulture and plant breeding, where she researched her favorite and very colorful plants: red beets.

Please join me in welcoming Amy.

[applause]

[slide featuring the title slide for the presentation – Plant Pigments: Where BEAUTY meet Science – Amy Freidig, UW-Extension, Cooperative Extension, Master Gardener Program]

[Amy Freidig, Program Assistant, Mater Gardener Program, University of Wisconsin-Extension]

Well, thank you guys for having me out here tonight. I actually do have a Dodge County connection.

[Amy Freidig, on-camera]

I married a guy from Beaver Dam. So, I’ve spent a fair amount of time in this county, so it’s kind of cool to be able to talk to you all tonight.

So, we’re gonna be talking about plant pigments, and when I create a talk, a lot of research goes into it. So, it’s got to be something that I find interesting. And I’m a very visual person. I – I really love things that I find beautiful. And besides plants, I also find science beautiful.

So, talking about plant pigments really holds my interest because it kind of unites –

[return to the title slide, described above]

– both science and beauty.

[new slide featuring a macro photo of crayon tips in an open crayon box]

So, you all have your set of, what is it, eight – eight colors in front of you. You have your crayons and your coloring sheet, and you’re probably wondering, Okay, why – why did she do this?

[Amy Freidig, on-camera]

Well, I want you, today, to experience pigment firsthand. So, throughout the course, I’m gonna be talking to you for about 45 minutes, and that’s a long time. And I want you to be able to just doodle and color and feel creative. This isn’t meant to be – make you feel childish or patronizing. I really am a strong believer in that when your – your hands are busy, then your mind is just kind of free and better able to absorb information. So, I want you, as I’m talking and as you feel ready to, take up whatever pigment stick you wish, color the rabbit, color in the vegetables, or you can –

[return to the slide featuring the crayon tips in the open crayon box]

– flip over your sheet and it’s a very, very open-ended note sheet. So, if I say anything that interests you that you want to remember, draw a picture, doodle something, take notes. It’s very open-ended so –

[Amy Freidig, on-camera]

– that you can be as creative as you want to be.

So tonight, we’re going to talk about –

[slide featuring the word Color in orange on a light green background]

– color. And my – my ultimate goal that when you leave tonight is that when you walk outside and it’s still, you know, it’s still August, things aren’t, it’s not November. We have vibrant colors surrounding us when we’re –

[Amy Freidig, on-camera]

– outside, and you’re all gardeners, you all love plants, so I want you to leave in – in more awe of plants than when you came in, if that is possible. And I want you to think about pigment, which is everywhere, in a – with a little bit more awe.

So, color. In your garden –

[slide featuring rows and rows of tulips in different colors from yellow to red to purple to violet to orange to pink]

– I mean when this picture pops up here, maybe you noticed the design, maybe you noticed the texture, but, wow, that color, it just pops.

[new slide featuring several vegetables and fruits in a plastic container – cherries, red pepper, cherry tomatoes, and white feta cheese]

And nowadays you’re hearing were – it’s recommended that you eat a more colorful diet. Now, that does not mean that you go out and you get the green food dye, and you turn your oatmeal green.

[laughter]

That – that means that you want to increase your consumption of fruits and vegetables.

[new slide with five colored tables for each of the associated pigments and their health benefits (right to left, top to bottom) – Chlorophyll (green table) – Decrease blood pressure, Contribute to blood sugar control; Carotenoids (orange table) – Antioxidant, Protect against macular degeneration, Decrease heart disease risk; Lycopene (red table) – Antioxidant, Decrease cancer risk, Decrease heart risk; Betalains (maroon table) – Antioxidant, Anti-inflammatory ability, Anticancer effects; Anthocyanins (blue table) – Antioxidant, Cancer prevention, Enhance immune function, Protect against neurological disorders, Decrease heart disease]

And here up on the screen are a series of plant colors and health claims associated with eating that – that pigment in a – in a food. And I’m not gonna go into detail about all of these health claims associated with these plant pigments because I am not a physician. I’m a horticulturist so that’s not in my wheelhouse.

But, tonight, we are going to first start out by talking about four of these plant colors, and I’m gonna tell you some of the really cool science stories behind them. And then, at the end, we’re going to kind of pull back and talk about –

[Amy Freidig, on-camera]

– the relationship between eating a colorful diet and human health cause I have – I also have a strong interest in plants and human health.

So, tonight, we’re going to talk about the colors green, red –

[slide featuring two photos – one of a broad leafed green plant and one of a sliced tomato]

– orange –

[the slide animates in a photo of an orange flower and then animates in a photo of sliced beets]

– my favorite beet red –

[the slide finally animates in a photo of blueberries]

– and we don’t have time to talk about blue tonight, that – that’ll take us into too long of a time. But –

[new slide posing the question – So what gives a plant (in orange lettering) COLOR with each letter in the word colored with a different color – C = green O = orange L = red O= maroon R = blue with all the letters outlined in orange]

– we need to start out by with – with kind of a baseline here in talking about what gives a plant color.

[new slide with the word – Pigment and its definition – A compound that contains a chromophore capable of harvesting light. The slide also features a photo of an artists table filled with 16 small round containers filled with various pigment colors – greens, yellows, pink, reds, blues, maroons, and greys]

And that’s pigment. So, the definition of pigment is a compound that contains a chromophore capable of harvesting light. And to pick apart this definition a – a little bit, we need to start by talking about light. And to do that we have, you know –

[Amy Freidig, on-camera]

– it’s a little bit of physics. So, if that gives anybody heart palpitations, I’m sorry. [laughs] But here we go.

[slide featuring a visual of the electromagnetic spectrum of visible light – going from ultraviolet to infrared and indicating the wavelengths of the various colors in nanometers from 400 (UV) to 700 plus (IR)]

So, how do things have color? Well, it has to do with light. So, light comes in, visible light comes in, and they – the wavelengths of light that make up the visible light spectrum are 400 to 700 nanometers. So, light comes in in waves. A wavelength is the distance between the waves. So, like, the bottom of one wave trough to the bottom of the other. That’s a wavelength. And the different widths or different wavelengths correspond to different colors of light.

So, when light comes in, some of those wavelengths –

[Amy Freidig, on-camera]

– of light are absorbed and some are reflected. The wavelengths of light that are reflected are what we see and perceive as color.

So, when all the visible light comes in and hits the apple –

[slide featuring a photo of a Red Delicious apple and an illustration of the rainbow of visible light hitting the apple and an red arrow reflecting off of the apple and hitting a statement that – We see red.]

– some wavelengths of light are absorbed, the red is reflected, and that’s what we see, and our brain perceives as the color red.

[return to the slide with the definition of Pigment, described above]

So, coming back to this definition, a pigment is the compound that contains a chromophore capable of harvesting light. So, it’s really just a compound that has a part of it, a chunk of it, called the chromophore, that is responsible for harvesting that light. So, I think that it’s really cool to think about color and pigment, which is so bold and so vibrant, is actually –

[new slide still under the title of Pigment showing a molecular representation of a chromophore with red and black spheres connected together with white bars to represent a chemical compound]

– controlled kind of on a molecular level. It’s very, very small.

[new slide with a lime green background]

So, that’s our baseline just talking about where –

[Amy Freidig, on-camera]

– where color comes from. And now we’re going to launch into talking about some specific plant pigment colors, starting with green. And green is the pigment chlorophyll.

[slide titled – Chlorophyll – featuring a photo of a plant with broad green leaves]

I’m sure you’ve all heard that name before.

[new slide featuring five photos of plants and vegetables that are green – spinach, broccoli, kiwi, lime, and Brussels sprouts]

And it’s found in anything that’s green. So here are some edible crops. Some leaf crops, broccoli, Brussels sprouts on the right, and it’s in fruits, like kiwi and lime. That’s chlorophyll.

[new slide titled – Chlorophyll – and featuring the chemical structure of Chlorophyll made of Nitrogen (in blue), Manganese (in green), Hydrogen (in black), and Oxygen (in red)]

And here is the structure of chlorophyll on the screen. And one thing that I want you to note, and I – I – I think I’m supposed to stay here, but you can see the blue there. Those are Ns. Is there a, yep, okay. See, those Ns? That stands for Nitrogen. So, it – it – within the chlorophyll molecule there’s nitrogen. So, when you’re out there fertilizing with a nitrogen-based fertilizer, you are providing some of the nitrogen that goes into manufacturing this chlorophyll. So, if you’ve got a plant that’s yellowing –

[Amy Freidig, on-camera]

– that’s why you need to add this nitrogen so it has some of those raw materials so that it can manufacture this molecule.

And it’s obviously found in a lot of above-ground structures –

[slide featuring a photo of several potted plants that are overflowing with green leaves]

– like leaves, stems, and petioles, and that makes sense –

[animation to a new slide titled – Photosynthesis – featuring an illustration of a large yellow Sun in the upper right and a green oak leaf in the middle. In the upper left are the chemical formulas for Water (H2O) and Carbon Dioxide (CO2) and a blue arrow crossing through the leaf diagonally with the word Energy above the leaf and then at the end of the arrow is the word Sugar and the chemical formula for Oxygen (O2)]

– because it has to do with photosynthesis.

So, photosynthesis is a really, really, super complex process that I think is really, really fascinating, but I’m not going to go into a lot of detail about it tonight. The 10 seconds elevator speech about photosynthesis is that it takes in carbon dioxide and water as raw materials, and energy from the sun and a series of chemical reactions occur and out comes sugar, which the plant uses for energy or for food, you can think of it like that, and the byproduct of oxygen.

[Amy Freidig, on-camera]

So, what I want to talk to you about, though, is where chlorophyll actually is in this. So, when you go outside and you look at that green grass, you’re going to be able to remember and – and think back, Oh, yeah, that’s – thats where the chlorophyll actually is located. So, we’re going to pretend like you have – we’re going to zoom in, okay? So, we have a plant. We have our leaf here. We’re going to zoom into a cell, and –

[slide featuring a microscopic cross-section of a plant cell that looks like a pea pod with wavey lines shaped like two- toned scarves moving back and forth within it]

– we’re gonna look inside a plant cell right now. So, this structure right here is called a chloroplast. And you’re thinking, Well, where’s the green in this image? This is an electron micrograph, and the nature of these images is that they are black and white. So – but this, we’re – were going to hone in on where the chlor-chlorophyll is in this chloroplast. So that’s the structure, and within the chloroplast you see these lines going back and forth. These are membranes called –

[the slide animates on the words – Thylakoid membrane – to the left of the microscopic image]

– thylakoid membranes. And they’re – theyre a membrane that kind of weaves throughout and forms also these little brown –

[the slide animates on three arrows emanating from the word – Granna – that point to the dark grey sections of the two-toned scarf-shaped wavy lines]

– stacks called granum. And – and in botany class they tell you to think about it like they’re kind of stacked like pancakes.

[Amy Freidig, on-camera]

So, we need to eat – go inside these membranes to continue our hunt for the chlorophyll.

[slide featuring an illustrated cross-section of a thylakoid membrane with the membrane shown as a structure of Q-tips lined up side-by-side-by-side with the tips of the Q-tips in yellow. Along the length of the Q-tip shape are other oval shapes labelled PSII, b6f, and PSI along with various chemical reactions that occur when light hits these objects]

So here, on this slide, it’s really, really complicated slide, but I don’t want you to worry about too much on it. So here, you see that – those little yellow circles on top and bottom? That is the membrane, okay? So, we’ve cut it in half, and we’re looking inside, and embedded –

[the slide animates off all of the other parts of the previous illustration except for the area between the ovals labelled PSII, b6f, and PSI]

– within those membranes are these two structures. They’re called PSII and PSI, which stands for Photosystem II and Photosystem I. So, those are embedded within those thylakoid membranes. And, finally, now, we have zoomed in far enough –

[new slide featuring a group of green circles at the bottom of the slide labelled – Pigment molecules (of chlorophyll) – and showing a reaction wherein a red arrow labelled – Photon – points down and hits the chlorophyll pigment molecules and bounces around them – shown by a red line going through five molecules ending in a darker green molecule labelled the – Reaction center – which ejects an electron (shown as a light blue arrow pointing up and out of the molecule cluster and labelled – Primary acceptor]

– that we can finally find the chlorophyll pigment molecules. So that’s pretty far. We’ve gone from leaf to cell to chloroplast to the membrane, cut the membrane in half, and with, you know, look in there for the – the – the photosystems, and those are where the pigment molecules are. And what happens is the light comes in, indicated by that arrow, and remember, pigment molecules contain that chromophore which is capable of harvesting the light. So, they’re harvesting that light coming in. They’re bouncing it around, kind of like a pinball machine, to various pigment molecules until it hits the reaction center. And the reaction center is a special place where an electron is hanging out. An electron is the negatively charged particle. And what happens is the energy, just think of it kind of like a packet of energy is given to that electron, and that elevates the energy status of that electron –

[Amy Freidig, on-camera]

– which really is – what it does is it starts a chain reaction of chemical reactions that cascade down and eventually produce the end product of photosynthesis: sugar. So, this is kind of like the very start of everything, and chlorophyll is right there facilitating this.

But, for something –

[slide with white words on a green background which are – Chlorophyll problems!]

– that is so vital to the plant, to the plant life, chlorophyll can actually kind of be a liability for the plant –

[slide featuring an illustration of a single chlorophyll molecule as a half a green circle and a yellow arrow pointing down into the molecule from a yellow box labelled – Light Energy]

– and here’s how. So, this – this is our pretend chlorophyll molecule. So, when light comes in and elevates that electron –

[the slide animates in a dark purple arrow emanating out of the molecule with an electron at the end indicated by a circle with an e- in it and also animating on the following statement – Excited electrons can react with oxygen resulting in damaging free radical molecules]

– remember it elevated the energy status of that electron, sometimes things don’t go as planned. So, in theory, the electron gets its energy, and it causes the right chemical reactions to occur. But sometimes that doesn’t happen, and the electron reacts with something that it’s not supposed to. For example, oxygen. And when that happens, that creates something called a free radical molecule. Has anybody heard that before?

[Amy Freidig, on-camera]

Free radicals, yep. So, these – these are molecules that can cause damage within a cell because they’re highly reactive.

And so, when that happens within a plant, that problem is called –

[slide with the word – phototoxicity – on it]

– phototoxicity. When those free radical molecules are reacting with things that they aren’t supposed to be and are causing damage. And they cause damage on a – a cellular level. Like they react with nucleic acids, with proteins, with membranes. That’s the level at which they do their damage.

[new slide featuring a photo of dark purple leaves nestled within a plant that has bright green leaves]

[return to the slide with the word – phototoxicity – on it]

And in a minute, we’re going to talk about –

[Amy Freidig, on-camera]

– kind of what I consider the elegant ways that plants have of dealing with this problem cause it’s a big problem if you think about it, that your – that your green blade of grass, that’s a lot of chlorophyll and that’s a lot of phototoxicity issues that could be going on.

A cool story about chlorophyll has to do with purple plants.

[return to the slide with the plant with the purple leaves nested in the bright green leaves]

And I don’t know if any of you have personal experience with this. I’d be interested to hear. So, we have – this is a sweet potato vine. A really pretty purple one. So, it’s a sun-loving plant. When it’s grown in the – in the proper light conditions, looks great. You take that plant, and you move it to the shade. It’s going to turn kind of a browner, muddier color. Not that really true purple color. And that’s because it’s upping its level of chlorophyll production. You take that sun-loving plant, you put it in the shade, it needs to increase the amount of chlorophyll it’s producing so that it can kind of compensate for how it’s not – it – it – compensate so that it has enough – it’s harvesting enough light to get enough energy to perform photosynthesis the way that it needs to.

[Amy Freidig, on-camera]

So, I don’t know, has anybody ever experienced that? Off the top of their head, no? It’s – its something worth experimenting with to see if you can – to see if the color change does happen. And of course –

[slide featuring a photo of a leaf covered path in the forest in the fall with red and orange leaves on the trees and on the path]

– we talked about how chlorophyll can be produced by plants. It can also be degraded. So, in a little while we’re going to start to see this, and that’s because as trees start to go dormant, they are starting to break down their chlorophyll for the season. That’s part of the going dormant process, and we’ll start to see other pigment shining through.

[Amy Freidig, on-camera]

Okay, our next pigment, our next color is orange.

[slide with an orange background color]

[new slide labelled with the next pigment – Carotenoids ex. Beta-carotene – in an orange box to the left of the chemical composition of Beta-carotene made up of many Hydrogen atoms in a long row]

Orange is the family of compounds called carotenoids. You may have heard of beta-carotene. This is a member of this large family of compounds. There’s over 600 compounds are in the carotenoid family.

[the slide animates off the ex. Beta-carotene under the label – Carotenoids – and replaces it with a small, bulleted list under the words – Two big groups – Carotenes (with an orange stripe next to this word) and Xanthophylls (with a yellow stripe next to this word)]

And there are two big groups, the orange carotenes and the yellow xanthophylls.

[new slide with the following bulleted list – Lipid soluble; Molecules occur in crystals, surrounded by lipids, in association with proteins]

And these type of molecules are lipid soluble. That means they don’t like to be free-floating in water. They want to be surrounded by a lipid or a fat kind of protective bubble. And these molecules, carotenoid molecules, will occur a lot of times as something else, like in a crystal –

[Amy Freidig, on-camera]

– form surrounded by lipids or fats or in association with other proteins. And now here comes the lobster story.

So, lobsters really illustrate –

[slide featuring a photo of a bunch of live lobsters in a bin]

– this well. How carotenoids don’t like to just hang out by themselves. They like to be in association with something else. So, when you have a live lobster like this, its shell is kind of a darker color. Alright, a variation on these – this type of color. But their shells are still really high in carotenoids. So, I like to think of it like this. You have the carotenoid, and you have the – the protein that it’s in association with, but then –

[new slide featuring a photo of a red cooked lobster on a plate next to melted butter and a lemon]

– when you cook it, you heat the lobster shell and protein doesn’t like heat. It gets destroyed by – by heat. So, you take away that protein and all that’s left is the carotenoid shining through in this –

[Amy Freidig, on-camera]

– oops, sorry, wrong button – in this shell. So, that’s why shells of lobsters change color when they’re cooked because the carotenoid is shining through cause you took away the protein.

Carotenoids are found in a lot of flower petals, like those –

[slide featuring two photos – one of orange Asiatic lilies on the left and one of yellow Marigolds on the right]

– lilies, marigolds, also dandelions. They – they have those luteins in them.

[new slide featuring three new photos of things that contain carotenoids – one of a Flamingo, one of a cooked Salmon, and one of a shrimp]

We already talked how they’re found in the shells of crustaceans, but shrimp also have it, salmon, and the feathers of flamingos contain carotenoids.

[new slide with three new photos of vegetables that contain carotenoids – one of a cooked sweet potato, one of a bowl of carrots, and one of a line of pumpkins labelled Squash]

And, talking about human health, here are some healthy carotenoid-containing foods, sweet potatoes, carrots, and squash.

[new slide featuring three green vegetables that all have carotenoids in them – one of a leaf of Collard greens, one of a bowl of Spinach leaves, and one of three Kale plants]

And now, here are some green things that actually contain carotenoids: collard greens, spinach, and kale. And there is –

[Amy Freidig, on-camera]

– so, you’re thinking, Well, we’re talking about orange. Why are we talking about green now? Well, it has – the reason why is that carotenoids actually have something in common with chlorophyll, and it has to do with what they do for the plant.

So, one reason plants have carotenoids is that they are – they also play a role in photosynthesis. They’re an accessory pigment.

[return to the electro-microscopic image of the inside of a plant with the scarf-like structures shown previously but now with an information box on the left that asks the question – What do carotenoids do in plants? – followed by this list – Role in photosynthesis; Antioxidant]

So, while chlorophyll is doing the heavy lifting of the light absorption for the photosynthesis, carotenoids can also do that. And the other really fascinating thing that they do is they behave as an antioxidant, and this is getting back to earlier when I said we’re gonna kind of talk about that elegant way that plants have of dealing with that phototoxicity problem with those free radical molecules. We’re going to talk about that now.

[new slide asking the question – So, what is an antioxidant? – in orange lettering on a white background]

But first of all, what is an antioxidant?

[new slide featuring an illustration labelled – FREE RADICAL – showing a red nucleous in the middle surrounded by two rings of electrons. In the first ring are two blue circles representing two paired electrons; in the second ring are five blue circles – two pairs of paired electrons and one electron that is not paired labelled – unpaired electron]

So, we have to go back to free radical molecules to explain what an antioxidant is. This is a generic molecule that I invented, here on the screen. And the thing about free radicals – or the thing about molecules or atoms is – they don’t like to have unpaired electrons. They always want to have a pair. They always want to be in two. So, this unpaired electron is what makes this really highly reactive –

[the words – Oxidative damage – animate on to the left of the free radical illustration]

– and causes that damage. It’s called oxidative damage. But I just want you to really focus on the word damage. Remember that.

[Amy Freidig, on-camera]

So, an antioxidant molecule is able to –

[return to the Oxidative Damage slide which now animates off the words – Oxidative damage an replaces it with another illustration of another molecule with a red nucleolus and two rings of electrons labelled ANITOXIDANT – the first ring (like the other) contains two blue circles representing two paired electrons; the second ring contains thirteen blue circles that represent two paired electrons and nine electrons that are unpaired; it also has an arrow pointing to the unpaired electron in the first (right) molecule so that this free electron in the antioxidant pairs with the unpaired electron in the free radical molecule and makes it (the once free radical molecule) stable again]

– come over –

[the slide animates the free electron from the antioxidant travelling along the arrow and pairing up with the unpaired electron in the free radical]

– and donate one of its electrons to the free radical, so now it’s a pair. It’s neutralized it. It’s not gonna react and cause that damage. And the antioxidant also, even though it now has an unpaired electron, it’s not going to be reactive and damaging like a free radical molecule can be just by nature of its chemistry.

[new slide featuring a photo of an old car taken head on in which the hood of the car is coated with rust]

So, what kind of – what – what’s some oxidative damage you see every day?

[Female audience member, off-camera]

Rust.

[Amy Freidig, off-camera]

Rust. And I like this to think of it like – I like this picture cause it makes me think, Okay, oxidative damage caused by free radicals, you know, maybe within one cell, maybe it’s bad news for that –

[Amy Freidig, on-camera]

– one cell, but you think collectively, well, it’s bad news for that car. So, it’s a good example of types of oxidative damage.

But back to that phototoxicity problem.

[return to the slide with the word – phototoxicity – on it]

So, plants have carotenoids, and they have chlorophyll. And the chlorophyll is causing this problem ultimately, in a way, but – by creating these free radical molecules, but it’s got another pigment in it that’s able to act as an antioxidant and give – give those electrons to the free radical molecules it’s created and neutralize the problem. So, that’s why we don’t always sit here, you know, in – in –

[Amy Freidig, on-camera]

– in Master Gardener training or plant health adviser training, you’re not talking about phototoxicity issues because the plant can solve it for itself.

So, in the floor – fall we talked about –

[slide featuring a photo of a birch tree in the fall with yellow leaves next to the statement – In fall, the chlorophyll degrades and we see carotenoids! – in an orange text box]

– how chlorophyll degrades. Carotenoids one of the colors that you are gonna see coming through in just a little while. Those yellows and those oranges are gonna be due to carotenoids. So, sycamores, buckeyes, birches, all those and many more are caused by carotenoids.

[new slide titled – Carotenoids and Vitamin A – featuring a photo illustration of a carrot plus a bottle of olive oil (an arrow pointing right) absorbed and converted (another arrow pointing right) the chemical composition of retinol (with the statement – Active form of Vitamin A = retinol under the chemical formula)]

And to talk a little bit again about carotenoids in our diet. Carotenoids are precursors to vitamin A, which is an essential nutrient for immune health, normal growth and development, and vision. And so, when you eat a dose of carotenoids, you – it’s a good idea to eat it with a little bit of fat, actually. It can be as low as three grams of fat per serving of your carotenoid-containing food. Because remember, carotenoids are lipid soluble or fat soluble. They want to – they want to be safe in – in their little, surrounded by a lipid. And that’s how your body can properly absorb it as well. So, you eat your carrot with your little olive oil dose, it’s absorbed into your body, and inside your body is where your body can convert that carotenoid or that pro – pro vitamin A. It converts it into the active form of the vitamin, vitamin A –

[Amy Freidig, on-camera]

– or retinol, which your body uses for all those things.

And this pigment has actually taken, plays a role in humanitarian efforts worldwide.

[slide with the word – biofortification – on it in brown letters with an orange outlines]

So, I want to introduce you to biofortification. Has anyone ever heard of this term before? Maybe? So, biofortification –

[Amy Freidig, on-camera]

– is where you’re taking a crop and you are inter – you – you are creating it so that it has a nutrient where it never had it before, or you are increasing the level of a nutrient in-inside that crop. Ramping it up. And it can use either traditional plant breeding techniques or transgenic methods in order to achieve that end. And one really –

[slide featuring a photo of two half bowls of rice – on the left is golden rice and on the right is traditional white rice]

– well-known example is –

[the words – Golden Rice – animate over the top of the bowl filled with golden rice]

– golden rice. And this is – I’m gonna give you the very bare bones story about this. This is a very fascinating, complex story, but this is just the Reader’s Digest version.

So, here is regular rice and un-unbiofortified regular rice. And carotenoids do not naturally accumulate in the grain. Carotenoids are in the rice plant, like the leaves of the rice plant, but not in the grain. So, it is not a good source of vitamin A. So, two European scientists went about biofortification efforts using transgenes. So, they took a gene from a plant and a gene from a – a bacterium, and they inserted it into the rice plant. And they were able to get the rice plant to produce and accumulate carotenoids in the rice grain –

[Amy Freidig, on-camera]

– with the hope that this would be a source of vitamin A for – in – in places where rice is a – a staple crop and where vitamin A deficiency is an issue. So, if this is of interest to you, I really encourage you just, you know, Google it. Find out some more information and read about it because it’s a really, really, interesting, complex story.

And – the – there – biofortification efforts are not just done on rice. Other staple crops are done –

[slide featuring a photo of a young African girl in her mothers papoose with an ear of corn in her hand]

– as well. This is a biofortified maize, biofortified for carotenoids. Sweet potatoes actually have been bred to have higher levels of carotenoids in them. And other crops – other staple crops as well, but like maize, I can’t think of the other ones right now, but including other minerals in these types of staple crops, like zinc or iron for example.

[Amy Freidig, on-camera]

So, biofortification crops – biofortification efforts are happening in many different types of crops.

And I’ve kind of touched on this, but why does this matter that people are working in – in these efforts? And that’s because of deficiency. Vitamin A deficiency –

[slide titled – Deficiency – with the following quote from the World Health organization underneath it – severe visual impairment and blindness and significantly increases the risk of illness and even death from common childhood infections as diarrheal disease and measles. The slide also features an illustrated world map of the prevalence of Vitamin A deficiency from 2009 data and showing Severe Vitamin A deficiency in most of Africa, all of Mexico, parts of South America, India and Southeast Asia, as well as Kazakhstan, Uzbekistan, and parts of Eastern Europe]

– is a humongous problem worldwide, especially for children. It affects over, I – I have the exact numbers here. Over 100 million children, which is an astounding number, are vitamin deficient – vitamin A deficient worldwide. And you can see, on this map here, in the darker green, these are the areas of the world where those – the largest populations of vitamin A deficient children are. And up here on the screen, it – it says the severity of what this deficiency can cause. I’ll read it for you. It says – this is from the World Health Organization – Vitamin A deficiency can cause severe visual impairment and blindness and significantly increases the risk of illness and even death from common childhood infections as diarrheal disease and measles.

[the W.H.O. quote animates off of the slide and is replaced by a photograph of a tribal doctor giving vitamins to a child in their village]

And there have been other efforts to combat this deficiency, for example, using vitamin A supplementation, which has been very successful. But even the World Health Organization still notes –

[Amy Freidig, on-camera]

– the value of eating a carotenoid-rich diet and using the family garden to do so, or attempt to do so, especially in rural areas.

So, our next color –

[slide with a red colored background]

– that we’re going to talk about, I’m sure a lot of you are probably seeing a lot of this color in your gardens right now –

[new slide featuring a photo of a bowl of tomatoes on a lawn shot from above and the title – Lycopene – written vertically on the left-hand side within a red stripe]

– is red. Red is the pigment lycopene.

[new slide titled – Lycopene – and featuring the chemical formula for lycopene below it and featuring a bunch of Hydrogen atoms lined up in a row]

And there’s the molecule there. And why this is kind of a cool molecules is – well, first of all, it is actually a member of the carotenoid family, which we were just talking about. But with lycopene, there is a distinction because it’s kind of – so – so, when plants manufacture compounds or molecules inside them, they – you know, they have a – a compound but they rearrange it. They take things off. They add things. They join things. They rearrange things. And that whole process is called a biosynthetic pathway. And so, you kind of got to start with something and then build from it. So, lycopene is a molecule that kind of starts a lot of biosynthetic pathways –

[return to the slide titled – Lycopene – described above]

– and a lot of other different types of molecules are made from that. So, thats – it – its a – its an important and kind of cool molecule of note.

[Amy Freidig, on-camera]

It’s actually in watermelon, apricot, grapefruit –

[slide featuring five photos of fruits in which lycopene appears – (clockwise from top left) watermelon, apricots, grapefruit, tomato, and pink guava]

– pink guava, and of course tomatoes.

[new slide featuring four photos of flowers that contain lycopene – Damask rose, calendula, yew, and saffron]

And here are some flower parts it’s in. Damask rose, calendula, and actually in saffron.

[new slide featuring a macro photo of a honey bee on top of a flowers stamen]

And now’s a good time to talk about one really big reason why plants have pigment at all in the first place, and that has to do with reproduction. So, that – you know, that’s what it’s all about for the plant is reproducing so that your genetic material makes it into the next generation. And so, you need to have a really good advertisement for your pollinators to – to come and visit you. And pigmentation, I – I’m sure you can all think of an example in your garden of – of a plant with unique pigmentation. Thats, you know – it – it’s just an advertisement to get pollinators to come. And there are really cool stories about –

[Amy Freidig, on-camera]

– how different pollinators have evolved with different styles and colors of flowers. Just – they have special relationships. It’s kind of a – there are so many different stories, and I’m only going to share one with you to – to show you how dynamic pigmentation can actually be within a plant, and it’s lantana.

[new slide featuring a photo of the flowers of a lantana plant which have different colored blooms depending on pollination – the flowers in the photo are yellow, orange, and pink]

And if – what this plant does is it changes the pigmentation of the flower based on when it’s ready to pollinate. So, if you’re -youre – youre the pollinator, you’re flying around, you can distinguish, based on what – what color it is, what flower’s too old, what one is too young, and what is ready to go.

[new slide titled – Chromoplast – featuring two photos of the chromoplast of a red pepper fruit where the pigment shows up as little red dots – one photo is at 400 times zoom and the second photo is at 1000 times zoom]

Now, the place where plants store pigment is called – the – the cellular structure is called the chromoplast. And right here, these are – these are cells from a red pepper fruit, and you can see all these little dots. Those – those are – that’s pigment contained in chromoplasts. And its sole job is to just pack in the pigment that the plant makes. And plants can actually turn chloroplasts, they can morph them into chromoplasts.

[new slide featuring a photo of three un-ripened green tomatoes on a vine]

And, again, the tomato gets picked on here again. Oh, that was kind of a bad pun. But –

[laughter]

So, here we have a green chloro-chlorophyll-filled tomato. And as it’s ripening, the – the tomato, the plant is converting its chloroplasts, which contain chlorophyll, into chromoplasts and stuffing it full of that red lycopene. Why would the plant bother to do that in the first place?

[Amy Freidig, on-camera]

Well, does that look particularly appetizing? Compared to that lush, beautiful red fruit that you or I, as a potential seed dispersal agent, might come and, you know, pick that tomato off, eat it, maybe I drop some seeds over here or excrete them in other ways. So, it’s all about reproduction.

[slide featuring a photo of a boiling pot of spaghetti sauce on a stovetop – taken from above]

And I – I eat a lot of spaghetti sauce. I have small children at home, so this is a staple in our diet. And something interesting to share about consuming lycopene in your diet is that, and – and it’s good news. When you cook a lot of plant products, like boiling or steaming, you’re usually losing a percentage of the nutrition in the cooking water or the – it’s breaking down due to cooking.

[Amy Freidig, on-camera]

In – with lycopene, found in tomatoes, the opposite is true. One study I looked at was – looked at cooked tomatoes and heating them for the amount of time that’s akin to like processing for tomato sauce and heating or cooking tomato sauce that you would eat. And they found that lycopene level, bioavailable lycopene levels increased with heating. Which – bioavailable is a fancy way of saying what your body can actually absorb. So, it’s – its good news that more lycopene is available to you if you heat it. And they – they think this is because, as you heat things, cellular structures are breaking apart. More is just like physically accessible and coming out of the cell.

So, the last color we’re going to talk –

[slide with a beet red colored background]

– about tonight is my personal favorite, beet red. Does everybody like beets in the audience?

[Amy Freidig, on-camera]

I should see, yes, yes, good. Head nodding. So, beet red color is caused by – is – is the betalain family.

[slide titled – betalains – featuring the chemical formulas for two molecules in this family – the beet red betacyanin made up of nitrogen, oxygen, and hydrogen, and the yellow betaxanthin also made up of nitrogen, oxygen, and hydrogen in a slightly different configuration]

And right here, betacyanin is the actual compound that is the beet red color, and there’s also a yellow compound betaxanthin, in this family as well.

[new slide featuring a electro-microscopic image of the inside of a beet with a circular shaped cell with fibers on the inside edge of the circle and a large open area in the middle which is labelled – vacuole]

Unlike the carotenoids we talked about earlier, betalains like to be in water. They’re water soluble. So, you’re looking at a cell here, another electron micrograph, and this big area right here that looks like there’s nothing in it is the vacuole. And that’s a membrane-bound area, and inside it – it – it’s filled with water. But that’s a good place for the plant to put things like toxins, waste products, as well as small molecules or things like betalain pigment.

[new slide titled – Order: Caryophyllales – which has a beet red arrow pointing down to text in a beet red text box that has the words – Contain betalains]

And something that’s just kind of a mystery still and really cool is that these betalain pigments are only found in one order in the plant world. So, remember, you have kingdom, phylum, order. So, it – it’s a big group. But that word, how you say that is caryophyllales. Pretty cool word. So, that is the only order that –

[Amy Freidig, on-camera]

– contains these pigments. So, when you think about that, you know, all the other plant orders they kind of, they share pigments. Theyre – they have that in common. This is the only one with betalain. So, that’s a very interesting thing from an evolutionary perspective. How did that happen? Why did that happen? Why is it nowhere else? I don’t know. It’s a mystery, but it’s really neat.

So, I – I’m –

[slide featuring four photos of plants and flowers that contain the betalain pigment – celosia, four oclocks, moss flower, and bougainvillea]

– glad that this screen shows this color well because you can see, like, pop, wow. These are flowers that contain betalains. Celosia, four o’clocks, moss flower, and bougainvillea.

[new slide that has two photos of vegetables that contain the pigment betalain – Swiss chard, and beets]

And, of course, it’s in beets, a member of the beet family, like a Swiss chard here in petioles and the midvein. That’s all betalains.

[new slide with a photo of a bunch of beets]

So, you might be thinking, Red beet, red pigment, that’s that betacyanin one on the left that she was talking about earlier. Well, actually –

[the slide animates on four bars underneath the photo of the beets – three are the beet red color and one is yellow to show that beets contain both betacyanin and betaxanthin]

– red beets contain both of – of the pigments, in a ratio of about three to one. And when you have a yellow beet, that beet has the genes turned off that manufacture the red pigment. It just makes the yellow pigment. And then the white beet, which I hope you all feel a little bit sad when you think about the white beet.

[laughter]

[Amy Freidig, on-camera]

That has no pigmentation in it whatsoever because the genes to make pigment have been bred – they’ve bred it, so it’s shut off. It does not produce anything.

And beet pigment actually is –

[slide titled – Food colorants – and featuring a photo of a spoon in an open yogurt container]

– an important food colorant. So, in the 1970s, interests arose in creating a natural – natural alternative to petroleum-based food dyes. And so, they started looking at these betalain pigments. But the problem was it was very costly to – to create them because in the beet root you’ve got sugar and water, you have to concentrate it down. It was very expensive. So, at U.W.-Madison, breeding efforts started. And what they were able to do over decades was create lines of beets that had very concentrated pigment. I was actually luck enough to work as a student hourly on the tail end of this project.

[Amy Freidig, on-camera]

And those – those breeding lines are still in use today. And it – it was very successful, so much so that in 2008 it was only two-and-a-half times more expensive to use – to – to manufacture a beet food dye than it was synthetic food dye. And you may know this from firsthand experience, you go in the yogurt aisle and you’re looking at, like, the strawberry yogurt you may see, you know, colored with beet juice or something like that. You may have already seen that. And one thing to note is that these food dyes, betalain food dyes, are only in things that are kept cool. They’ll degrade when they’re heated. So, they’re going to be found in things like ice cream and yogurt, cosmetics and meat products, powdered drink mixes, for example. So, in encourage you to go home and take a look. It’s – its cropping up more and more. I mean, they’re even using it in my kid’s Goldfish crackers, I think, so – or maybe some other vegetable dyes. But it’s really cool.

So, now –

[new slide titled – Plant pigments and health – with white lettering on an orange background]

– we’ve talked about our four – four colors tonight and some of the really neat science stories behind it. And now I want to kind of pull back and look – talk to you guys about plant pigments and health, human health.

[return to the multicolored slide with the health benefits of Chlorophyll (green), Carotenoids (orange), Lycopene (red), Betalains (beet red), and Anthocyanins (blue) described above]

So, here’s this slide again with the individual plant colors and the various health claims associated with eating them. And I don’t want to talk about, focus on these individually right now. I want to think of them as a whole. So, I’m gonna talk about plant pigments in terms of eating a more colorful diet. A diet rich in fruits and vegetables.

[new slide titled – Oxygen Radical Absorbance Capacity (ORAC) – featuring a table of various vegetables and the number of micrograms per 100 grams – the higher the number the more antioxidantal properties they have – Garlic/2000; Kale/1770; Spinach/1260; Alfalfa sprouts/930; Broccoli/ 890; Beet/840; Onion/450]

And so, there’s a lot of research that goes on today looking at these types of things. So, I have an example on the board for you right now. In 2010, the U.S.D.A. published this information. They published the O.R.A.C. database, which O.R.A.C. stands for Oxygen Radical Absorbance Capacity. And what they did was they looked at a bunch of different foods and they, in the laboratory, they subjected them to a lab test to see how they behaved as an antioxidant. And they got these numbers, and here are some of the values for just some vegetables that I picked out there.

[Amy Freidig, on-camera]

So, this is one example of some of the research that’s going on.

[slide featuring three photos illustrating the types of research going on – one of a Petri dish labelled – In vitro, one of a silhouette of a rat labelled – in vivo, and one of a long line of people waiting for a store to open labelled – Epidemiological]

And that’s a type of in vitro or research which means like in a test tube, in a lab, in a Petri dish. Other types of research that go on are in vivo, meaning like in a body system, like in mammal or in a human, and then there’s also epidemiological research, which is more at the population level.

[new slide with the following statement in white letters on a green background – The trouble with pigments in foods – Its hard to attribute a particular health function to a pigment]

But the trouble with studying plant pigments is it’s really hard to attribute a particular health function to a pigment.

[new slide titled – Why? – and the following bulleted list (also in white lettering on a green background) – large, complex molecules; break down during analysis; highly metabolized; act in concert]

Because these are very large, complex molecules, they break down during analysis, they’re highly metabolized by your body, and they’re often acting in concert –

[Amy Freidig, on-camera]

– with another molecule found in the food matrix where that pigment originated.

So, there’s a lot of research going out there, and there’s a lot of misuse of research going out there to make health claims. So much so –

[slide featuring a screenshot of the U.S.D.A. website with the headline of an article titled – Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 (2010)]

– that, in 2012, the U.S.D.A. took that O.R.A.C. database information down. And I gotta – I’ll read this to you. So, on their website here, you can’t read that cause it’s too small, they said, The data for antioxidant capacity of foods generated by in vitro or test tube methods cannot be extrapolated in vivo or human effects, and the clinical trials to test benefits of dietary antioxidants have produced mixed results. So, they’re saying there that –

[Amy Freidig, on-camera]

– the – they’re saying that – that the data on how antioxidants affect your health, there’s information for and against it. But still they noted that there are a number of bioactive –

[return to the slide with the screenshot of the U.S.D.A. website, described above]

– compounds which are theorized to have a role in preventing or ameliorating various chronic diseases, such as cancer, coronary vascular disease, Alzheimer’s, and diabetes. However, the associated metabolic pathways are not completely understood, and non-antioxidant mechanisms still undefined may be responsible. Which –

[Amy Freidig, on-camera]

– is a long way of saying, like, we think these types of compounds may have a human health benefit, but we don’t really know how it works.

And here’s another example of some research.

[slide titled – Boffeta, Paolo et. al. 2010. Fruit and Vegetable Intake and Overall Cancer Risk in the European Prospective Investigation Into Cancer and Nutrition (EPIC) – and featuring a myriad of photos and illustrations of fruits and vegetables at the bottom of the slide]

This – this is a citation up here for a study that was released in 2010, and it was published in the Journal of the National Cancer Institute. It did receive some popular press, so you may – may remember it. It’s fruit and vegetable intake and overall cancer risk in the European perspective investigation into cancer and nutrition. So, the story behind this is in the ’90s, recommendations started to come out –

[Amy Freidig, on-camera]

– you know, that to eat a high – a diet high in fruits and vegetables in the hopes that it would lead to a decrease in overall cancer risk. And since then, institutions have really backed off of that. And this study was kind of addressing that. So, they looked at the relationship between eating a diet high in fruits and vegetables with overall cancer risk. And it’s important to note it’s overall cancer risk. Not saying, you know, associating eating one particular type of food with a health effect on a particular type of cancer. This is overall. So, they – this was a huge study – over 400,000 participants across 10 countries in Europe from – it was 1992 to 2000. It was very, very large. So, what they found was that –

[slide with two bulleted findings from the above mentioned study – Eating a high amount of fruits and vegetables only contributed a modest preventative effect toward decreasing overall cancer risk; very weak association between overall cancer risk and high fruit/vegetable comsumption]

– eating a high amount of fruits and vegetables only contributed to a modest preventative effect toward decreasing overall cancer risk. And it was – there was a very weak association between overall cancer risk and high fruit and vegetable consumption.

[Amy Freidig, on-camera]

So, that’s kind of a bummer, huh?

[laughter]

So – I’m sharing with you that there’s lots of research out there, so – so, in both – with results that go in both directions.

[slide featuring a black question mark on a green background]

And you might sit there and say, Well, there – there’s all this research. Some of this research is being misused by certain companies for, you know, to sell a product.

[Amy Freidig, on-camera]

It – it’s all kind of a downer. What can we say? What can we say?

We’re still saying eat –

[slide that has the statement – Eat a colorful diet – inside a blue circle – to the left of the blue circle are an orange, green stripe and to the right of the circle are a beet red and yellow stripe]

– a colorful diet. We are still recommending that because of the vast potential benefits. A diet – fruits and vegetables are low in calories, high in fiber, low in cholesterol. They’re –

[Amy Freidig, on-camera]

-very nutrient-dense. Eating a diet high in fruits and vegetables may reduce the risk for heart disease, including heart attack and stroke. It may protect against certain types of cancers. It may reduce the risk of heart disease, obesity, and Type 2 diabetes. It may lower blood pressure and may also reduce the risk of developing kidney stones, may help to decrease bone loss. So, you may have noticed a lot of “may contribute” type of language there. And I think that really highlights that we don’t know a lot for certain but due to the vast potential benefits, we are still recommending it, and it is still important.

And it’s also really important to mention that –

[slide featuring a macro photo of succotash with the word – YUM! – in red superimposed on top of it]

– a lot of these benefits due to various compounds are because you’re eating the compound in the food matrix in which it occurs. That means, like, eating the broccoli as opposed to taking a broccoli supplement, okay? So, I share that with you just so that you’re – youre aware of that –

[Amy Freidig, on-camera]

– because there – there are many health claims out there, and it’s important to do your research and – and understand that concept.

So, to kind of wrap things up, I really like –

[slide featuring three multicolored words on a lime green background – Protective (purple), Preventative (red), Human health maintenance (orange)]

– these words on the board in terms of eating a colorful diet. Eating a high fruit and vegetable diet may have protective and preventative health effects, especially in relation to chronic or aging related diseases. And in terms, its a – its a – it could have a vast benefit in terms of overall human health maintenance. So, again, I encourage you –

[Amy Freidig, on-camera]

– to up the colorfulness of your diet. And I want to thank you for having –

[slide featuring a photo of a garden with a myriad of different colored flowers in it]

– me out tonight, and if you have any questions, I will try to answer them now or go and do some more research and get back to you. So, thank you.

[applause]