Preserving Freshness: A Conversation on Innovations and Challenges in the Fresh-Cut Produce and Leafy Green Industries

Hunter Weber

February 15, 2023 at 5:54 pm | Updated February 15, 2023 at 6:00 pm | 17 min read

In today’s world, food waste and the preservation of fresh produce have become increasingly important. The conversation between Eric, the Director of QFresh Lab, and Galen, the Director of Applied Science at Felix Instruments, delves into the challenges and innovations in the fresh-cut produce and leafy green industries. They discuss the impact of microbial growth on produce, the importance of quality for the end consumer, and the focus on preservation to reduce food waste. Join the conversation as they share their expert insights and knowledge on the subject, and explore the latest techniques and technologies that are changing the game for the fresh produce industry. This conversation is a must-read for anyone in the food science, agriculture, and packaging sectors and those passionate about reducing food waste and preserving fresh produce.


Eric’s Insights


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Good morning, Eric. Thank you for taking the time to talk with me today. My name is Galen. I’m the Director of Applied Science at Felix Instruments, and my background is mainly in quality and safety testing in the food, agriculture, produce, and cannabis sectors. 

And at Felix Instruments, I am involved with a lot of the R and D of the instruments, as well as actual deployment of these instruments out in the field and figuring out what kind of applications our instruments are useful for. 

We’re excited to have you on today to discuss your experience using our instruments. So if you can introduce us to who you are, your company, and what you do, we’ll see where the conversation takes us.


Sure. My name is Eric Vandercook. I am the director of the QFresh lab. The QFresh lab was formed about five years ago. We saw a gap in the industry, a knowledge gap. And my business partner has been consulting in the fresh produce space for 20-25 years, primarily around package design, perforations, and how you design a package around fresh produce. 

But what needed to be added was a physical lab space to do the testing. So if you’re a company looking to start a new product, switch packaging, or try a new packaging format, we have the space to bring in your greens, package in various forms, and do shelf-life testing. 

And the Felix O2-CO2 Instrument is vital for us because in fresh produce, the product is still alive, and the product is still breathing. So, understanding how it breathes, its respiration rate, and the residual O2 in the package tells me everything I need to know about how long that leafy green can and will last in that package. 

And it also helps on the back end to redesign that package if we get it wrong in the front end, if the perforations are wrong, or the sizing is wrong, or the respiration rate is a lot higher or lower, all those types of things. 

Our lab here has been dedicated primarily to fresh produce, but we also work in other spaces. We’ve been doing seaweed studies; we’ve been doing fresh fish studies. The State of New York is looking at exciting things around low O2 packaging and the potential for seabot growth.

We’ve done some of that testing as well. So that’s what Qfresh does, and then, on top of that, we do packaging work. So we have various packaging machines to pack either gas-flushed bags, gas-flushed clam shells, or nongas flushed.

On top of that, we have equipment in the lab for measuring perforation, sizing airflow, and the OTR of the package itself. So that’s what Qfresh does in a nutshell. 

My background is in biochemistry and food science. I got my Ph.D. in the real world, working for a salad company that didn’t understand the basic science behind greens. And so I spent years doing exactly that, understanding the basic science behind commercially processed greens and what actually in a commercial setting can extend shelf-life versus the literature telling me what can extend shelf-life. 


Right, there’s a lot of conversation in the food science community. Over the last few years, the discussion has focused on our global food supply chain and how we can reduce food waste. 

And it sounds a lot like what you’re doing. You’re the one-stop shop for figuring out how to keep our produce from going bad so that we can waste less of our food. So I’d like to know what innovations you’re seeing in your packaging sector that are changing the game for how we’re storing our produce and the longevity of our produce. 


Yeah, you hit the nail on the head there. That’s the reason that QFresh Lab was started. We saw a gap in the industry where plenty of great food scientists work for companies that can extend the shelf-life for that specific company. But there wasn’t anyone who was a one-stop shop that had the knowledge and base understanding to look at the whole sector holistically by the company and what works and what won’t work for them. 

So when you talk about innovation, it’s interesting because I’ve tested, you name it, and I’ve tested it. Whether it’s CO2 pads or something unique, we can get more moisture out with this type of valve. It could be a one-way valve that looks at off-gassing CO2. I’m not going to call most of it snake oil, but it just doesn’t quite get you to where you want to be in the industry.

It comes back to the basics. It comes back to understanding your specific product and how you interact with it. So, for example, if you’re cutting carrots or bringing in fresh produce from the field. Or you’ve hydroponics, you know, indoor type of growing, and how do you extend the shelf life of something like that?

That industry is exciting because they have perfect control over their product from start to finish, yet they have the most quality issues. What’s driving that? So it goes back to the basics. The basics of understanding your specific product, your geometries, how you process it, what kind of damage you are adding, what sort of temperatures you are changing, and then what type of package you are putting it in ultimately.

If you’re looking at the residual oxygen side of the package, do you need a gas flush or not? Do you need to go really low in O2 or not? Do you need to worry about ethylene? Those are the basics of produce that most people in the industry generally understand, but they don’t truly understand what the drivers are and what kind of levers you can pull.

The types of innovations that we see, especially in the last couple of years, are that most people are moving to a kind of seal-reseal application on leafy greens. They’re moving away from open-air tubs, away from bags, and a little bit towards more lighting film where they can precisely control that atmosphere.

And then on top of that, when a consumer takes it home, opens it, uses one-third of it, and if they seal it back up, it takes a couple of days to bring O2 and CO2 back to that kind of happy medium; and you extend the greens that way. So the major innovation we’re seeing is around packaging and people just understanding more in-depth how important the packaging is.

Then your big innovations are on the other side where you’re looking at external sachets, packets, or something else that can extend the shelf-life. That work in certain realms. You know, that works in strawberries, that works in berries. But for the most part, for most fresh produce, it’s the basics. It’s getting them cold and understanding the package interactions with that product and the residual O2-CO2 levels you reach inside that package.


Yeah. It brings up another interesting point about leafy greens. It has always been the biggest challenge in shelf-life, right there.

We have, for you know, a long time with the deciduous fruits, been able to extend shelf life for quite some time, just with ethylene mitigation strategies and improvements in cold storage. But what are your opinions?

With fruit, it’s also been easy for people to be innovative in the coatings sector. Being able to coat the fruit in something and extending shelf-life through changes in respiration rates and ethylene. With leafy greens, that’s not necessarily something I foresee, as the coatings are not applicable.

But do you do much work? Like, what’s the interplay between that kind of coating strategy and packaging? Are there people that are looking into how those affect each other? Or are you mostly looking at just untreated produce or, you know, just cut produce that solely relies on the packaging for all of the atmospheric control?


Yeah, primarily, when looking at coatings, you’re looking at a long-term kind of moisture ceiling. It is your primary mode of action for extending the shelf-life of anything that’s coated. So you’re trying to reduce the amount of moisture loss, especially in long-term storage applications.

Then those always go hand in hand with a controlled atmosphere long-term storage room. Something like that, where we got it coated, locked in the moisture, and now we need to put that product to sleep. And, each produce item’s a little bit different. You know, apples like 3% O2 and lower CO2 for long-term storage.

The primary mode of action there is temperature. So, it’s more about how cold we can store this product before it gets freeze damage. Different products have different levels because of the different levels of sugars. So that interplay there, there’s not an interplay of those.

It’s more like, hey, here are the best practices for each. Once we got this coated, we got the moisture locked in. Now we need to look at the temperatures that we’re going to store it, at what kind of air we have in that area. Combined with what sort of residual O2-CO2 will prolong this shelf-life as long as possible?


Right. And so going back to when I was talking about leafy greens being a challenge, along with fresh cut produce, I assume that, you know, the quality aspect is essential for the end consumer. But you guys are also more focused or concerned about microbial growth at the beginning stages of storage and throughout storage.

Can you speak more about what kind of work you’re seeing and what challenges you face, especially in the fresh-cut produce and leafy green industries? For example, we’ve had issues with recalls in the past with leafy greens. And you say many quality issues are coming out of the precision ag kind of sectors where they’re, you know, having quality issues.

But are you seeing the same challenges with microbial growth? And how are you studying what kind of packaging will also help mitigate microbial growth?


Yeah, that’s a great question. Microbial growth is interesting, especially in produce, because it’s always there.

You can’t control AP, ABCs, yeast, and molds to the level you’d like, especially if it’s outdoor grown. But even indoors grown, you’re going to have challenges there. It’s interesting because certain items are susceptible to general aerobic plate count bacteria.

And for other ones, it doesn’t affect it whatsoever. An example is primarily in your fresh-cut applications, where you take something and change its geometry. So, for example, fresh sliced apples or fresh cut carrots where it’s more important to get those microbial loads down as low as possible to start.

And then the lower you get it to start, the longer you can push out that lag phase of growth of bacteria and keep that produce longer. So, for example, when you’re looking at something like a fresh sliced apple, produce count or APC kind of yeast mold counts under 50 is what you’re targeting.

And that’s not that simple to get low numbers through a standard commercialization process. For example, dropping fresh slice apples directly into something like a PAA or a chlorine bath does a great job of knocking that initial load down. But then you have several transfer conveyor belts. You’ve got your drop, you’ve got your packaging, and you’ve got people sorting in between. They are all sources of increasing bacteria load. Post-wash, pre-packaged. Every single produce item is going to face some similar challenges to that.

When you move towards something like baby greens, your baby spinach, your baby arugula, or maybe chopped romaine, bacteria doesn’t seem to be as big a problem. It’s not the primary mode of action for that product not making shelf-life. Typically the primary mode of action is some oxidation reaction. So it’s premature yellowing in the product where the chlorophyll depletes or pinking on a main where you didn’t get the residual O2 in the package low enough to stop that phenolic compound reaction from occurring.

And so, it varies space by space, and as far as controlling it, it again primarily goes back to the basics. So it’s getting cold, keeping it cold. It’s making sure that your wash plumes are doing a good job. Making sure that you have adequate oxygenation in there, not too much, too bitty, and you got the correct PAA or chlorine levels throughout time. Because anyone who’s worked in the wash line knows that chlorine can deplete almost instantaneously when you dump in a high bacterial load or a high electrical conductivity load; maybe, say, you brought in dirty spinach. So that soil combined with whatever microbes are on that spinach going through a wash flume, even if you have an adequate amount of water, and even if you start with an adequate amount of sanitizer, that sanitizer can be used up very, very rapidly.

So it’s the basics there. Combined, there’s been some innovation in the packaging space, especially when looking at CO2 off-gassing valves. But primarily, people have looked at different types of substrates for the plastic itself.

Not only from a sustainability standpoint but from a, hey, can we put some nano gold or some sort of small particle embedded into the package that might reduce or stop microbial growth? So there’s been some work in that space. However, people need to come up with something commercial, and, primarily, these types of things don’t go commercial. Because the cost of them becomes so high of a barrier of entry that it’s, hey, sure, we can get an extra two days of shelf life, but at that cost, what kind of trade-offs do we get for that type of product?

So the innovations and the research is ongoing. So I stay up on the science; I read up on it. But when it comes down, you know when it’s time to hit the road and see if there is a viable product here.

We are typically on the front end of that type of testing for those companies, but ultimately there’s generally some hangup that kind of knocks it out of the market. And, primarily, it’s cost combined with what’s your market share.

A lot of it’s very targeted. It might work on carrots, but it might not do anything for produce, for spinach. Or it might do something for spinach and not for 90% of the other fruits and vegetables, limiting its uses.


You briefly mentioned the microbial growth stage. There are all these chances, you know, for additional microbial growth on these surfaces after the wash, before you are packaging, where inoculation could happen, and microbial growth could start up again.

Do you guys, in your lab, try to mimic that exactly when you’re testing your packaging? Are you trying to emulate that whole process? Or are you already receiving stuff that’s already gone through the wash from whomever you’re doing your research for, and then you’re just testing it after you’ve received it? I am assuming it’s gone through the same process that it usually would have up until the packaging.


That’s a great question. The answer is both. We will take produce that has been processed by someone else, and we’ll take that and run it as a shelf life trial. Or we also do our own processing. I’ve got a significant kind of three-tier stainless steel sink, and then it’s an understanding of their process. And then we try and mimic as well as possible.

So, for example, we wash and dry pack leafy greens here all the time. And then we’re using chlorinated water. We’re using agitation. We’re using packaging; we perforate packaging ourselves to match. Then, we’ll do a respiration rate study before we take/get the produce. So we are left with a baseline understanding of how the produce breeds, and then we match the packaging to that produce through the process.

So that’s one thing that we do. And then we’ll also take product that’s been through the process. Generally, that’s looking at different packaging or just understanding what their current produce is doing, what kind of modes of action, of decay, or yellowing, or discoloration, or whatever else it may be. Whether it’s a plant pathogen or we’re seeing mold growth or whatever it may be. Taking that through shelf-life and coming back and going, well, if you guys tweaked this, this, and this, you’d get three, four extra days of shelf life based on these results. Because you know it’s not being handled properly or there are certain points in the system breaking that type of product down.

And then, as far as you know, the testing phase. What’s interesting for us is that we don’t want to be a microbiology lab. We don’t want to do microbiology; we don’t want to do wet chemistry. I am a biochemist and can do those things, but I don’t want to staff people to do that.

So we partnered with Eurofins, so we have a strategic partnership with Eurofins, a very large Microbiology lab and Chemistry labs across the globe. And any testing that we need to do, we send to them. And we remain a one-stop shop because you can come to us and run challenge studies. You can come to us and run microbial studies, and we’ll be the ones designing them. We’ll be the ones executing it, but we can send those samples off to Eurofins for any microbiology or chemistry-type-related results.

And they’ve got a phenomenal reporting system, internal labs all over the country, where that work can be done. And so that’s how we handle that type of work.


That’s smart, honestly, on your part. Eurofins, you know, offers every test under the sun in their analytical testing profile.

So if you, whatever your customer wants a test for, they either already do it or are willing to get that method up and running. That’s smart to do. Continuing with your current lab practices kind of discussion, curious to bring it back to the instrument you’re using.

Gas analysis typically requires sampling from the bag and then throwing it into a gas chromatograph. Were you doing that before, or did you jump right into using this technology so that you didn’t have to purchase a hundred thousand dollars instrument and get it set up or get and maintain your flame ionization detector and all that stuff?


Yeah, you know, only through school did I play with all that type of equipment. So I knew, well, maybe not right away, but when I first got into produce, I took my kind of scientific mind and all of that type of equipment and started thinking about, what can I use where?  

Certain things are useful—for example, volatiles, you know, especially when discussing packaging. But you know, when we ran that type of testing, for example, contamination in a package, for example, from a supplier, we’d send it off for gas chromatography type of work. And the gas chromatography becomes overwhelmed instantaneously. Again, this is because there are so many volatile compounds in there. So there’s almost no way to figure out which applies to us.

We’ve looked at GC, GCMS type of work, and companies do olfactory with that. Someone can smell the compound being alluded to and get a GC kind of MS reading of that. We tried that with some greens to understand what type of volatiles we see during the breakdown. What kind when a leafy green breaks down, what does it put off?

Again, there were so many compounds through the system, and in that machine that read it, we didn’t know how to interpret the results. And so that quickly turned into, okay, what practical solutions can we look at here? And O2 and CO2 measurements quickly became just an unbelievable bevy of information. So there’s much more to it than getting an O2 and a CO2 reading off a package or understanding O2 and CO2. There’s a lot more nuance to how leafy greens and fruit or produce respond to a change in the residual O2 post-harvest.

It’s an unexplored space in terms of understanding its depth. That’s what I learned very early that O2 and CO2 measurements could tell me pretty much everything I need to know about why this produce item might be going bad prematurely and what types of levers I can pull to extend that shelf-life.

99 times out of a hundred, just simply understanding the current O2 and CO2 you’re getting in your package, understanding how to get to the ideal O2 and CO2 and what that is by produce item, connect you almost every single time, four to five days of shelf life. So when I’ve got a powerful lever that I can pull for companies that don’t fully understand it but think they do, I’ve got a piece of equipment that can open up doors for me.

That’s where O2, CO2, and ethylene understandings were my primary. Once I started to get into that and started to understand how respiration rate changes in a package and how different processing can affect respiration rate. Then also, once you put it into a package, how different O2 and CO2, and residual O2 and CO2 inside of that package can change the physiology of the greens; that’s where I spent all my time.

So having an accurate O2 and CO2 meter is tantamount to me. I’ve tested several over the years that give varying degrees of accuracy and start going bad prematurely with an O2 sensor, internally, inside of those types of equipment to make sure that I consistently have a meter that I believe. Because I take so many O2, CO2 measurements, and ethylene of so many different produce items that, when I get a funky result, nine times out of 10, it’s the meter, and it’s not the produce doing something. It’s the meter starting to go bad, but, you know, still being in warranty or still being within, whatever the calibration period for that equipment is, I know almost immediately something’s wrong here.

One interesting thing I’ve only recently learned about is how volatiles can affect O2 and CO2. Different items put off a different amount of volatiles, volatile organic carbons, and they could be different VOCs. And I’m starting to find VOCs from fish or seaweed interact differently than VOCs from leafy greens, fruits, or veggies, which is fascinating.


Yeah. I mean, what you mentioned about practicality, the rabbit hole, you started going down with using the electronic nose, the sniffer on the GC, and all that stuff, you know, people have to understand that in the industry, you are trying to do research for the industry.

Academics have the time and resources to look at all these thousands of volatile compounds and determine the most important ones. We can then apply that knowledge in a practical way, you know, deploying technology like the F-950, the F-940, the F-960, the three gas meters.

We’re getting the same kind of information that we would from these larger pieces of equipment that take a lot longer—but being able to get that information way faster, at a more rapid rate, and then applying that knowledge to help with providing solutions for all these people, as you’ve mentioned.

I mean, that’s incredible. That is, understanding what CO2 and O2 alone can provide up to four or five days extra shelf-life is critical. And it’s mind-blowing that the people in the industry think they understand but don’t quite understand. So yeah, that’s pretty awesome that you’ve been able to use this instrument in such an incredible way with all this packaging innovation.

And what you guys are doing is, honestly, something that is so needed in this time of being concerned about climate change and, you know, disruptions to our supply chain, food waste, all these things combined, giving us this sense of doom that makes you ask, is food going to become more scarce? Do we have to figure out ways to keep it longer?

And so, what the research that you guys are doing and helping out all these current manufacturers and producers, distributors, people that are responsible for getting this food to us have it be of high quality and have it be safe, is such a vital thing that you guys are doing.

I’m excited that you were able to find our instrument and get reliable and accurate results. With the VOCs, that is also exciting because, with the technology we’re using in our sensors, we’re using electrochemical and infrared sensors for the ethylene, CO2, and oxygen.

So volatiles, you know, there’s no technology yet specific to a singular molecule. The infrared sensor is closest to a molecule-specific sensor for these portable, fast technologies. So, ways of mitigation that we’ve researched, when we were doing our R & D for our instruments, we were using things like our polar cept filter. This simple DI water filter can filter out many VOCs if you’re looking to eliminate those from your readings and get a more reliable reading of only the target molecule you’re looking for, whether it be CO2, O2, or ethylene.

But there’s research also looking at other filtering technologies to eliminate the volatiles but maintain that target molecule when you’re measuring. And so this industry is still evolving, just like the packaging industry, to get better and better, faster and more reliable technology. So it’s just exciting to see the interplay between using technology geared towards food and agriculture on people also developing technology and packing in a different sector, tech-like packaging, for you.

So, I want to thank you for all the insight you’ve provided today. It’s been fantastic talking to you, and I’m excited to hear more about what you guys do in the future with all the packaging innovation and testing. If people are listening to this and you are concerned about your packaging, I recommend getting in touch with Eric.

And Eric, if you are comfortable, we can talk after the interview about putting your contact information in this as well because it seems like you provide a valuable service that many people could benefit from in the fresh produce industry.


Yeah. And, you know, that’s why we started, what we started.

I realized, hey, I could have a good effect at this company, but it’s about as far as they go, as everybody’s a little secretive. Everybody keeps their secrets close to their chest; what worked for them can work for most others, extending that shelf life. Keep that product longer. As we advance, they’re vital to food waste and food security. And so anything I can do to help companies extend that, you know, is what we do.


Awesome. Well, I want to say thank you again for this interview opportunity. I’m happy that you can utilize our technology to help you with your research and, ultimately, help us keep our food for longer and waste less. And help relieve all the current stress on our industry, especially with all the eyes watching us about all the food waste and supply chain issues.

I’m excited to see where the future takes the packaging and testing technology industry. Hopefully, we’ll get to a point where no food is wasted. 0%. That’s the goal. So, maybe one day, but for now, we’ll take an extra four or five days of shelf life over nothing.

In conclusion, the conversation between Galen and Eric provides valuable insights into the challenges and innovations in the fresh-cut produce and leafy green industries. They discuss the importance of preserving produce to reduce food waste, the impact of microbial growth on produce and the role of packaging in extending shelf-life. Eric’s expertise as the Director of QFresh Lab, along with Galen’s insights as the Director of Applied Science at Felix Instruments, offer a detailed view on the subject. They both highlighted the importance of keeping produce cold, adequate sanitation and the utilization of latest technologies and innovations such as CO2 off-gassing valves and different types of plastic substrates to increase the shelf-life of fresh produce. This conversation highlights the ongoing efforts to reduce food waste and preserve fresh produce for a sustainable future.

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