Rutgers University Brings Unique Research To New York Produce Show:
Collaborating Controlled Environment Agriculture And Sensory Science To Develop Better Tasting Leafy Greens
Jim Prevor’s Perishable Pundit, December 9, 2019
We already know that altering the environment can change the nutritional value of some items. For example, the use of UV-B light can enhance the Vitamin-D content of mushrooms.
When we learned that a team from Rutgers was working on a project that might allow us to alter the taste of produce items, especially those grown in controlled environments, we were intrigued. We asked Gill McShane to find out more.
Doctoral Candidate in Food Science
New Brunswick, New Jersey
Dr. Beverly Tepper, Ph. D.
Co-founder and Director of
Center for Sensory Sciences
& Innovation (CSSI)
New Brunswick, New Jersey
Q: Regina, at the New York Produce Show you’ll be giving a talk about controlled environment agriculture (CEA) and the flavor profiles of leafy greens grown using this method. What will be some of the key points you’ll be discussing?
A: My talk will focus on how we can use controlled environment agriculture as a tool to help us understand how we can improve or amplify some of the flavors that are in the leafy greens in order to make them more flavorful and potentially more nutritious.
We’ve been working with AeroFarms, and they’ve manipulated the growing environment to understand how growing conditions are affecting the way the greens taste, because there's a lot of research that's based on leafy greens grown in a field.
When you're growing something in a field, there's a lot of variability in the environment; there's not a lot of control there. Most of the research studies that have looked at the growing environment and its effects on sensory characteristics are not necessarily controlled.
Q: And how long has this research been going on with AeroFarms?
A: We actually have a grant where we are collaborating with AeroFarms. The grant was awarded in 2017, so we're at the end of year two right now.
Q: Okay. What are some of the more enlightening findings that you've had so far?
A: If I can speak generally, we’ve found that you can amplify or you can kind of dial down some of the flavors that are in the greens. You’re not necessarily changing the entire profile of the leafy greens, but you can manipulate how the flavor is either enhanced or subdued.
Q: Is that independent of the actual varieties and the seeds of the leafy greens you’re dealing with?
A: We're seeing a kind of interaction. Depending on what part of the environment they're changing, that's going to have different effects on different types of greens. So not every single type of green is going to respond in the same way to an environmental stress.
Q: There’s also the sensory testing element of the work you’re doing. How is that being done to find that discernible difference of flavor? And are consumers involved?
A: The testing that we're currently doing is not necessarily based on consumers’ liking of it; it's actually based on training a group of people to become very specialized in determining the different flavor profiles within the greens.
They're able to pick up on things like spiciness or bitterness that are present in the greens. They're just looking at intensity right now. We are doing some consumer testing where we will look at consumers and see what their reactions are to two different types of greens… if they prefer maybe one variety over the other, or one profile over the other.
With the consumer testing, we’re not just looking at whether or not they like things, but how it's influenced by their personality and how it's influenced by their genetic response to bitterness. Through that, we're doing something called PROP testing. PROP is a chemical that some people can taste and other people can't taste. So that has been shown to influence people's eating behaviour and influence their liking of different vegetables.
Q: That’s fascinating. So, you start with your trained taste experts who are in-house, and then you go a bit deeper and get consumers involved.
Q: What are the bare basics of that training process so that you can train people to develop finely tuned palates and a better understanding of different flavors?
A: We’re using a technique that's pretty common in sensory science. It's called descriptive analysis. So you recruit a group of maybe 12 to 15 people, and they go through a several month-long training process on all of these specific flavors. You can do this kind of training with any food, but, of course, we're doing this with leafy greens.
They’re given a reference to help them understand what the different flavors are that are present. They really do this through discussion; they're working as a group to identify what the whole profile is of the food that they're working with.
Q: And what’s the plan for consumer testing? When is that going to be kicking off?
A: I’m glad you asked. Actually, we’ve just started some consumer testing. We’re doing a short study first and trying to do almost like a proof-of-concept kind of study, and then we'll move on and have a larger group of people that's maybe more representative of the actual population.
Q: You mentioned how people have different responses to bitterness. How can produce marketers or retailers work with that information?
A: It can be used by marketers, and we are looking at demographic information as well. It could potentially be used by marketers to understand the different consumer segments that exist and what types of people like specific types of greens.
Q: In the course of your work with AeroFarms and the sensory testing, what have been some of the biggest challenges along the way for you?
A: One of the things that's really difficult is the fact that these are natural products that we're working with. All of the greens kind of taste a little bit different from each other. When you get a shipment of greens, you might have different leaves that taste differently from each other. So natural products are a challenge to work with for sure.
Q: Looking at the actual controlled environment agriculture, now I know there are limits about what you can say about specific aspects of the testing, but could either of you go into a little bit of depth about the kind of elements that can be altered in the CEA space to change flavor?
Beverly: Broadly speaking when they modify various controls in this type of agriculture, they're talking about abiotic stressors. This could be changing something about the light regimen, changing something about the nutrient regimen, and so on.
Q: And water, for example.
Beverly: Yes. We have some very specific conditions that AeroFarms has manipulated in this project, but it's along the lines of water, light and nutrients. They really tightly control the environment: the humidity is controlled, the temperature is controlled and all of that.
Q: I'd like to get to the bigger picture about why do a test like this and ultimately what is the overall objective? How do you think the impact will be on the produce sector, on retail and consumers?
Beverly: We are often asked that kind of question, and I would answer it this way: sensory testing is very well developed in the food industry, particularly the food processing industry. There is a sensory analyst, sometimes a sensory group, that works with product developers to bring new products to market to make sure products are consistent and so on.
Every technique that the sensory scientist has can be used for that purpose. I am a scientific editor at Journal of Food Science, and what I've been seeing lately is many more projects working with natural products — produce — where breeders and scientists try to develop new varieties.
Instead of just taking a shot at it and breeding what they think is good and bringing that to market, they are using some of those same sophisticated techniques of sensory testing to help or to develop a strategy to bring these products to market.
I've seen this happening with, for example, kale, with arugula, with grapefruit and other citrus fruits. They're using very, very sophisticated techniques hand-in-hand with breeders, growers and producers, to get the best products out there.
So, it's really utilizing a series of sensory tools that have existed for a long time, but utilizing them in this space to add value.
Q: And it's funny because at the end of the day, it's so much work yet the consumer probably doesn't realize it.
Beverly: Exactly. It should look like it just showed up on the shelf, but there's actually a lot of work that goes behind developing that variety with the hope of success.
It is commonplace today to hear people say that breeding has traditionally been done with grower concerns in mind: yield, storage, ease of transport etc. and that flavor was neglected. This is true, though somewhat overstated. Afterall, if anyone believed that consumers would pay a premium for a certain variety, then lower yields, lower storage capacity, etc., would have been acceptable. The complaint, maybe better stated, is that in breeding there was not a good system for evaluating what consumers would or would not pay for, but it was pretty easy to judge what farmers would pay for.
Even recognizing this and even changing this, it is very tough to use breeding to make produce more flavorful, and thus increase consumption. Indeed, we first got involved with the Culinary Institute of America and created the Ideation Fresh Foodservice Forum because we saw culinary technique as a way to improve flavor that would not take 20 years as it often does to develop and commercialize new varieties of produce.
Now Dr. Tepper and Ms. O’Brien are suggesting a third path – use the environment to change the flavor profile of the produce.
It is fascinating work with many important implications. Much of the produce trade’s consumption-improvement efforts are built around sweet fruit, but much of the nutritional value of produce comes from the more harsh-tasting greens. If we could modify that flavor, make it more appealing to people, especially children, we might really change health outcomes.
So, come join us in New York to review this fascinating research and reflect on the prospects it may hold for the future.
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