How cow's diets influence milk flavour - Prof. Joanne Hort

0:00This is a podcast from Rover. All right, as we know, you are what you eat. Same goes for milk related to what the dairy cows eat. It has an influence on flavour and texture. Very interesting stuff. Sweet, salty, card-boughty, a hint of tello. Those are some of the descriptions that the researchers in this study have come across and would join now by Professor Joanne Hort, who is from Mess University's food experience and sensory-testing lab. Otherwise, no one is feasted. Nice acronym. Go ahead and love it to have you on. How are you? Good, thank you. Yes, and we like a good feast as well. You can imagine we're all food is here. Yes, so the research that we're talking about today is on top of previous research. We know for sure that diet changes how the milk or the meat from an animal is going to taste. But the focus for this project was understanding how if New Zealand moved to a more diverse

1:04pasture for its cows to eat or its sheep to eat and whether it followed contemporary management practices or regenerative management practices, would that actually influence how the meat and the milk was then going to taste? And what I focused on because we haven't done the meat yet is the milk. Well, it's a very good question to be asking as the drums beat for different farming systems. So let's have a look at actually what happened here, in terms of the testing for flavour and perception of texture and things like that. So there were different pasture species in the mix. How did you go about it? Yeah, that's right. So I'm not a pasture specialist, but our experts here at Massey in Agree Culture and Environment, we decided to feed cows in this case on three different pastures. The first was what probably a lot of farmers are doing here was a contemporary management on just a rye grass clover pasture.

2:12And that's really the best practice that is recommended. But then they looked at two diverse pastures. Now, those pastures were very diverse. So they had grasses in there, perennial rye grass, cocks, farts, meadow, fescue, prairie, Persian, lots of legumes, not just white and red clover, but also looser and other clovers, and then some herb, some chiquiri and some plantain. So a much more diverse set of green for the cows to munch on. And they managed that pasture either using contemporary methods or regenerative methods. So we had three different sort of fields of cows for them to feed on. And then what we did was we collected the milk from those cows at each stage of lactation,

3:12so early mid and late, and we sprayed dried the milk. So we have a big food pilot plant here at Massey, and so we sprayed dried the milk. And then we reconstituted it when we were ready with all our consumers to come and taste it. So they could compare the different milks from the different pastures and at different lactation. So it was a lot of milk and a lot of samples. And so all we asked the consumers to do was to come in and do what we call a triangle test. It's called a triangle test, because there's three samples. Two of them are the same and one is different. So they did triangle tests across all the possible combinations of pastures and all the possible combinations of lactation to see if they could spot the odd one out. That's what we asked them to do. Can you tell which is the odd one out? And then we asked them, why did you choose that sample? And if they get it correct, so it's only if they get it correct. Do we look at the terminologies that you were talking about at the start?

4:15Was one more cardboard than the other? Was one good at taste, more animals and the other and so on? And that's how we got to understand whether, with a bit of statistics in there, we used 70 odd people to do the triangle tests. We worked out where we could detect a difference somewhere we couldn't. With those 70 odd people, what was the percentage rather of people that were able to detect something different? Yeah, so it's not quite how we do it. It's not a percentage as such. It's based on how many people you have, so we had 69. And you need about 21 to be able to detect the odd sample correctly, to be statistically sure that the consumer is going to not detect a difference or detect a difference. So we can say with what we say 95% confident that where we could detect a difference between them.

5:18And I tasted them myself and I can see what they were saying. Right, so milk from Hood A was most often described as mouth drying with flavour notes. Rancid, cardboard, cow and stale. Milk from Hood B described as sweeter and creamier with flavours associated with oxidized milk and milk powder. Hood C, sour and salty with a milky flavour and dry after taste. Hood A is racing to be the list desirable ones. Yeah, not quite. So there's a subtle difference. What we were saying it was more cardboardy. So it may still have been acceptable. We don't know that yet. That's where we've got to come on to. But for sure, pasture A, which was the contemporary pasture with just the rye glass and crova, was detected as being had more off notes in it than compared to the other two.

6:21So the B pasture, which was said to be sweeter and creamier, but did still have some off notes like oxidize or cooked. And the cook comes in because we spray dried the milk, it's not fresh. That was the diverse pasture with regenerative management. So it did really well. Yeah, and part of this is to see whether the results that people have seen in America with this kind of diverse regenerative practice. Is the same in New Zealand because we have different soil, obviously. And see which was a slightly sour and saltier and more stringent was still the diverse pasture. But with contemporary management. Now, we don't know yet whether these differences are going to impact the consumer. You know, is it going to make them not want to drink the milk or drink one more than the other?

7:22That's the next step. This was the first stage to see, actually, if you can tell the difference and you can. So now we need to move on to see, does that matter to the consumer? Okay, so just to clarify, diverse pasture regeneratively farmed, that was group B. That was her being, that was the most, that was the creamier stuff. Well, it was creamier. Yes, again, I note the nuance in the Saturday given the parameters that the study was taking place within that would seem to be the most desirable of the hoods in terms of their milk output. Possibly. Yeah, yeah, possibly. Yeah. Yeah, well, I'd take creamier over, you know, cardboardy and salty any day, but hey, that's just me. How much did you do? New Zealand milk is all cardboardy and anomaly to me. I don't like it because I'm from the UK, where they are different diets. So it's all down to the consumer and whether that's too much for them to take or whether it's fine.

8:23Yeah, right. Okay, that's interesting. Yeah, it is. It's complex. Well, it's very complex. Yeah, yeah, yeah. They sound like fighting words between the Zealand and the UK. Yeah. So in terms of the lactation, then how did the lactation affect what the testers were tasting in relation to those three hoods? Yeah, I mean, and there's been lots of studies and we know that there's a big difference in lactation periods between the cows because the milk is being produced. So that for the calf ultimately and it's different nutritional needs and most studies show differences. We didn't see so much difference detected between early and mid lactation. It was that late lactation milk, which is often thinner. So thinner milk, so you probably get more of the flavours coming through. You generally find that late lactation milk is more sour and salty and perhaps has those animal notes, tallow notes in New Zealand.

9:29And so they were probably easier to detect during that late lactation period and those differences would be more obvious between the pastures from the compared to the earlier mid lactation milks. Interesting. Okay. So where do we go from here? Okay. So what does that tell us then about the, let's say, the regenerative method? It's obviously got some, it's got some legs. Possibly. Yeah. Obviously the whole project is looking just, is looking beyond just the sensory perception of the milk. Although ultimately that's going to be important to be to be businesses or consumers. But it's also looking at how the regenerative practices and the diverse pastures impacting the soil are impacting the animal itself. I mean this and also impacting the yield and the nutritional value of the milk.

10:34So there's a lot of different people working on different aspects of the project to understand what the benefits are at each of the different stages right from the roots of the, the grasses and the legumes through to the animal and through to the consumer. So at the moment we're seeing positive results in the sensory space. And we need to now see whether the consumer, you know, engages with that because they'll engage with the messaging as well that comes from perhaps more regenerative animal friendly, climate friendly, soil friendly. Also even the wildlife around regenerative and diverse pastures is probably more diverse than in standard practice. It's kind of going to the whole system rather than just the milk and the yield. You know, it's a different approach.

11:34Yeah, no, it definitely is. And yeah, that's an interesting thing from an NZ ink point of view just thinking more broadly here as well. Yeah, yeah, we have, you know, we already have quite a bit of kudos, particularly in Asia with our milk. You can be saved as even though it's not fresh fresh and natural because it's often powdered or or you H T treated. But you know, in that idea of the naturalness for many of our Asian markets is really important to them. And this will just build on that in terms of the farming practices that are carried out here. So it's interesting that March is the month for at least consistent milk type. So apparently November and January milk from those months was found to be relatively similar with the within each past your type. But the milk produced in March was very different.

12:34Yeah, that's the late lactation. Yeah, so what you tend to find is that there's a lot of the early milk is very nutrient dense. It'll have more sort of metabolites in there and bioactives for in the milk itself, whereas in the late lactation, it's a much thinner. I mean, it depends what the cow is feeding on. So in our diverse pastures, they were consuming a lot more different bioactive compounds, which then would be transferred into the into the milk. But also you see different levels of oxidation of fatty acids in the milk during early versus late lactation. And that gives rise to the different aromas and flavors that you get in the milk anyway.

13:34It's very interesting stuff because yeah, well for a whole variety of reasons really, but this is as you said at the start part of a much bigger. A set of data that you're looking to accumulate here. Lots of people are fun working in this sort of area. Is it in the whole team together doing various aspects of this kind of work? I think it's fun, but I think it's necessary. I think I was a conference just a couple of weeks ago. The Red Institute AgriFood Summit and one of the speakers there was saying that if we fail at food, we fail at everything. And the only real way we can understand food is to bring in all of the expertise we have from the different disciplines, from agriculture to culture through to the consumer and sensory science. So yes, it's fun and it means I get to learn a lot about grass and pasture that I never knew before I thought a plant lane was a Madonna.

14:35So yes, it's fun, but I think from a serious perspective, if we don't understand the whole life cycle of our food products and we don't understand how it affects the nutritional value and then the taste for the consumer, then we're not going to be successful because we've got a unique position here in New Zealand, but the rest of the world is catching up. And so we need to make sure that we have that full understanding of the whole production through manufacture to the consumer. And that's what this project is enabling us to do. And specifically, what's your area of expertise? So I'm a sensory scientist, so sort of trained as a food scientist, but sensory science, which is about understanding how people perceive flavor, texture, appearance of food products or how though those sensory properties interact with the packaging and the messaging that we might give. So that's a bit of psychology. So I'm a cross between a psychologist and a neuroscientist and a food scientist, which is why that I enjoy cross disciplinary work.

15:47Yeah, yeah, it's like when I find bits of apricot and chicken or something like that, or salt, and a salad or something like that. So you're the same as me. So at Feast, we're really interested in understanding how different food formulations or food pairings or different ingredients impact how consumers respond and how we respond differently. So I don't do sweet with with savory meat like yourself or foreigners in salads, but some people who are much more who prefer sweetness, they would really love those combinations. So we're physiologically different. That's why we all have different preferences and we have arguments over the dinner table as to, you know, why don't you eat that? Oh, I love this. No, it's terrible. All choosing wine, everything because our genetics and our experiences change how we see food.

16:48Wow, that's really interesting. Yeah. Well, I mean, the sultana people are just playing weird. I don't think they're right. I agree. It's interesting when you are sitting around the dinner table or you say to kids or something, I'll try this. How do you not like it? Why don't you like it? It's like, well, clearly because people have different palettes and different reactions with all the facets that you've just mentioned. It's not as simple as going, well, I like it before everyone must. Correct. Yeah, no, it's very the genetics. It's also children. This is genetic trait, but some children are more near phobic, which means they don't like new foods. And so you take different approaches with children who are near phobic to children who will who will eat anything, you know, so. I raised two of them. Yeah. They've done tomato sauce for about 15 years. Yeah. Yeah. Yeah. Yeah. But it's all down to our genetics and our culture as to what we perceive to be preferable.

17:50Yeah. And I, you know, I made a career out of understanding that. So that's what I do. Well, that sounds like that sounds right. We need to have another chat more generally. Yeah. That's fascinating actually. So, um, we'll finish this one here because that's really interesting. When are we going to see it? So this is obviously ongoing. You'll co-late that data and you'll, what's the time line or anything? Yeah. So the next study, which is the key one around the consumer preferences of the, of the milks. Obviously, we need to go through a whole new, um, sort of round of lactation. Sorry, it'll be another year or so. So probably early 2028, when we've got the final findings and for the rest of the project as well, it's they'll have more findings around that. Yeah. Well, we'll talk before then anyway, but lovely, lovely to have you on the show. Appreciate your time. You're welcome anytime. Yeah. You should come and visit us at feast.

18:50We're at, we're at, we're at feast based. Palmerston North. Of course. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. Yeah. So if you ever, you know, traveling through, come and come and see us. It's something to see as well as talk about. Yeah.