In this Q&A interview, produce packaging expert Shay Zeltzer, founder of Postharvest Hub, shares his concerns over the trend toward paper packaging for produce—a trend adopted to appease consumers’ concerns about plastic, but in many cases fails to protect the product.
Packaging World:
What is your background in the produce industry?
Shay Zeltzer:
I have a bachelor’s and a master’s degree in postharvest. I was dealing with flowers to start with, and just when I was ready to go on to get my PhD, I got a position with a Canadian company called SunBlush. They came to Israel and were looking for someone to run their R&D. Israel at that time was a very big flower exporter, shipping flowers to Europe, mainly to the flower auctions in Holland. The idea was to be able to pack the flowers and move them to sea freight rather than air freight. So all good reasons start with the cost of shipping and the impact on the environment and the volume and so on. I joined the company as R&D director, and later on I managed the company.
We came up with a very good solution when working with the Dutch auctions. We proved that we could keep the flowers in boxes. At that time, we used boxes that were coated on the inside and created a modified atmosphere condition to preserve the freshness of the flowers and allow for the expected vase life after the flowers were unpacked. In early 2000, I moved to a flexible packaging company, StePac, when modified atmosphere packaging [MAP] was really in its infancy.
At that time, there were maybe two or three companies dealing with MAP. It was Amcor in Australia with its LifeSpan brand, and there was StePac in Israel with Xtend. These two companies primarily led the industry with the idea of reducing food waste and successfully delivering fresh produce from one area to another. For example, to export melons from Brazil to Europe, you could do it either by air, which was very pricey, or by using MAP, you would be able to deliver them by boat, which made it a feasible business and also a very successful one.
When you say MAP was in its infancy, do you mean for produce packaging or overall?
For produce it was never used before. At that time, SunBlush was in this business, but it was dealing with MAP packaging or gas-flushed packaging for the fresh-cut industry. The fresh-cut industry at that time also just started. You could see some pineapple chunks from Central America shipped to the U.K., but mainly it was fresh produce.
Seen here is a comparison of broccoli in a commercial PE film versus one wrapped in a specially engineered passive MAP film, ExtendCast Broccoli, from R.O.P. that preserves the freshness, color, and crunch of the produce even after eight days in 61°F.
In addition to that, there is controlled atmosphere, which normally deals with either very large storage rooms or containers where you create the specific atmosphere inside with a combination of oxygen and carbon dioxide. This will allow, for example, apples to be stored almost 12 months under the right conditions. That’s being done by large companies.
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So, back to my experiences: I was working for StePac, and I was relocated to the States and started a business there. One experience I remember from that time is when I was visiting the market in Montreal, the Terminal Market. I was looking at the delivery of bags that weren’t under experiment yet. In talking to one of the melon shippers, I said, “We have a great solution, great packaging for melons, and we’re successfully shipping melons from Brazil to the U.K.” And he said, “I don’t want to hear about bags, and you want to know why? Come with me, and I’ll show you six or 10 pallets with rotten melons.” And I was looking at the pallets, and I said, “Okay, it all depends on which kind of packaging you’re going to use.”
So one bag is different than another bag, and there are so many characteristics within the gas-exchange rate. It’s called the Oxygen Vapor/Transmission Rate, or OV/TR. All of these attributes dictate the outcome of the storage in that particular packaging. So, if you use the right packaging, you could hold these melons for 25 or 30 days, and they will look just as fresh as when they were harvested. But if you put them in a bag that accumulates moisture inside and builds condensation, you’re going to end up with mold growth.
The right plastic packaging can extend the shelf life of cucumbers, which lose 2% of their moisture every day after they are harvested.
After working for StePac, I came back to Israel, and I started my own company working with different packing houses in Israel and abroad, developing protocols for handling fresh produce and working with companies to develop packaging in that particular area.
You have said that the produce industry is moving in the wrong direction by switching from plastic to paper packaging. Can you explain why?
One of the largest fresh produce exhibitions in the world is Fruit Logistica. I’ve been going to the show for about 15 years, and every time I attend, there are new trends, new ideas, normally you’d see new varieties [of produce], new machinery. This time the packaging section was converted, I would say almost all of it, to paper-based packaging.
So instead of PET trays there were pulp trays. Or, fiber-based packaging with or without a plastic mesh. I was at one booth, and I was looking at flat green beans, and I told the exhibitor, “The green beans are flabby, they’re not holding up.” And he said to me, “But, if you go to Europe, France, and the U.K, that’s what consumers want now.” In addition, the EU decided they want the industry to stop using plastic altogether, but it’s not protecting the product. That’s the regulation. That’s the trend. That’s where the market goes. People don’t want to see plastic.
You have said that using paper is nothing but a trend that’s leading to ecological disaster and taking a huge toll on the planet earth. Can you expand on that? What do you mean by an ecological disaster?
Yes. You live in the States, right? And when you go to the grocery store, in some cases, where they help you pack your groceries, they’ll ask if you want them in paper or plastic, right? And if you say paper, they’ll take one paper bag and then they’ll put another paper bag inside the first one. So it’ll be a double paper bag. Then they’ll put your groceries in this double paper bag. Why do they do it? Because the paper bag is not as strong as a plastic bag. So they want to be green, but they don’t want your groceries spilling all over the floor. So the first thing is physics. If you want to have the same strength, the same puncture resistance, you have to use much heavier, much thicker paper compared to plastic.
So that’s one thing. With that goes the volume you’re going to ship. Let’s say, in a specific-size case, you can fit 2,000 plastic bags. You can only fit one-quarter of that or even one-fifth of that of paper bags in an equivalent-size case, just because of the volume.
The other thing is that when you cut a corrugated box, there are two sheets, and then there is the fluting in the middle. The fluting is recycled paper, and the other sheets are normally virgin kraft liner. Virgin kraft means it’s the first use of this fiber. When you recycle it, you can only use it for the fluting. Why? Because it’s softer, and it absorbs moisture much, much easier. So if you want to go in the direction of packaging that will not be humidity-sucking paper, you’ll have to opt for the kraft liner. Kraft liner is a single-use paper.
So it’s misleading to say that paper is reusable. You can reuse it, but you can’t reuse it for the same purpose. You can reuse it maybe for books or for newspapers or for egg trays, but you can’t use it for the same purpose. You can’t take a paper bag that was used for fresh produce and make a paper bag again that will be as strong as the original one to be used for the same purpose.
The third issue is with the condition of the produce itself, mostly of fresh produce. If it doesn’t have a specific peel that will resist dehydration, it tends to lose moisture. We’ve done some research on green beans grown in Mexico, shipping them to Canada, and we saw that in order to compensate for the weight loss along the journey, the growers have to pack 10% more product.
Meaning that over the journey of five days from Mexico to Canada, the produce loses about 10% of its weight. So, since the retailers in Canada dictate that they want 30-pound crates, and they’re going to fine the grower if it’s underweight, the grower will overpack it with some extra in order to compensate for that loss.
The loss from moisture?
Mainly from moisture. That’s one major element. I’m calling it the silent thief that steals revenue from the store. Because even produce on the shelf gets dehydrated. And when a retailer buys say 30 pounds of cucumbers, even if they sell everything and nothing goes to waste, they’ll find they only sold 28 pounds. Why? Because two pounds evaporated. When produce loses about 2% of its weight, it becomes soft. And people don’t like to buy soft fruit. Soft, flabby vegetables are especially not wanted—not lettuce, not green beans, not cucumbers, not carrots. If it’s flabby, it’s going to be left on the shelf. So that by itself increases waste because people are not going to purchase it.
A test of lychee fruit in a PET tray versus a molded pulp package demonstrates how the porous nature of fiber-based packaging leads to the growth pathogens that then affect the fruit.
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These are several reasons why moving to paper-based packaging for produce is going to be a disaster. Now also, if you look at the production of paper versus the production of plastics, the production of paper is lengthy and consumes a lot more energy. So let’s say from delivering the wood from wherever it is, to the wood processing facility, and to extract the cellulose, and then turn it into paper, a lot of water is consumed. It’s also a high-energy process versus the production of plastics. So combine all these together, and paper-based packaging is going to take a lot higher toll on planet Earth compared to plastics.
If, by using paper for produce packaging, you’re wasting product, then plastic appears to be the better choice. Yet, the perception by consumers is that paper is more environmentally friendly.
Perception is horrible because we can’t argue with perception. You see it, and it looks fresh, or you see it, and it looks green, and that’s it. And you don’t have to say a word. And then you see the islands of plastic in the ocean or plastic rolling onto beaches, and say no more. Now plastics have to explain themselves and have to go through a lengthy interview and explanations. But paper, you see it and it’s green and it’s wood—it’s plants. It’s so easy to understand why it’s better for the environment
In some cases, paper actually may be the better choice, depending on the product. But in the case of produce, it seems to be defeating the purpose of using the packaging.
There are some produce items that don’t need any packaging, in some cases, paper might be the right solution. But to go across the board and ban plastic and say no more plastic… . I’ve been trying to reply to posts on LinkedIn and articles over the years, but it feels like my voice hasn’t been heard. In the U.K., they were saying that packaging was wasteful, and they were dictating to the growers to stop packaging cucumbers, but cucumbers dehydrate so fast. And I said, it’s only going to increase the waste, and it’s going to increase the waste immediately—not tomorrow, not a year from now, but immediately with the next arrival. If it’s not in the right packaging, it’s going to get dehydrated, 2% every day, and the consumer is going to leave it on the shelf.
Are you seeing other trends in produce packaging, or is the trend really just toward paper?
The change is mainly toward paper, and that was very significant at Fruit Logistica. With that being said, there is one particular machine by a Dutch company called BrimaPack. The owner started the company almost 20 years ago, and year after year, he had the same small booth with one machine. Over the last few years, however, it seems that growers and large shippers have begun to appreciate the benefit of his equipment. It uses a very fine film of about 12 to 15 microns. In terms of mils, I think it’s maybe 0.6, 0.5 mil. It wraps around the product with a very minimal surface area of plastic and creates a heat-seal knot at the bottom of the produce. It’s mainly used for round vegetables, such as iceberg lettuce or cauliflower or broccoli.
Round produce, such as iceburg lettuce, broccoli, or cauliflower, packed using BrimaPack’s system uses 40% less plastic without compromising the freshness of the product.
What do you think about materials such as bio-based or compostable plastics for produce?
That was a trend maybe 10 years ago, when people were looking to replace plastics. One product they looked at was PLA [polylactic acid], which is derived from corn or sugarcane or sugar beet pulp or cassava. The material is clear, it looks like a bag, and it performs like bag. But there were several issues around it. First, because it’s made of a feedstock used for human consumption like corn, it drives the price of corn higher. The other thing is that its weight per volume is about 20% to 40% higher than for the equivalent polypropylene or polyethylene bag.
The other issue is that it’s very susceptible to heat and exposure to UV light, so it deforms very easily. We tried using it as a substitute for trays in Mexico, and if the trays were kept in storage exposed to the sun, not even direct sunlight, but just under the shade where the temperature rises, they deformed over time. So for that reason, and also for the price difference, people are not adopting it. People talk about PLA here and there, but it never catches on.
There is an Israeli company that is using something similar to PLA. I had some experience with this material, and normally it’s thicker, it’s cloudier, so a hazy or a milky color and a lot more pricey than alternative plastics. So again, it’s only for particular applications where people are willing to pay more for the packaging or are willing to compromise on the presentation, because it’s not as clear, and you can’t really see the produce within. But people are really keen to see what they’re buying.
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That’s another reason, by the way, that paper-based packaging is also problematic because you can’t see the product inside. That’s why the some of the paper packaging includes a window with plastic mesh so you can kind of see what’s in the bag, but it’s very likely that people will either care and will check or won’t buy it.
If you were advising produce packagers or any food or beverage company that is thinking about switching from plastic to another material that consumers perceive as more sustainable, what would you say?
The first thing is to work with professionals who specialize in this area. Find out what’s best for the product. We’re investing a lot of effort and money and energy and enthusiasm into growing the best produce. And then, by the same token, we have a post-harvest specialists who know exactly what packaging is most suitable for the product. So work with the professionals and with the companies that specialize in developing and producing packaging that is most suitable for the product. The other thing is to look for the packaging that best fits the product in terms of size and protection.
Mini, or Persian, cucumbers may be more attractive in a heavy-gauge plastic bag with graphics, but, according to Zeltzer, the large amount of plastic used isn’t necessary to keep the products fresh. In addition the use of graphics adds chemicals in the form of ink, while complex closures may hinder the recyclability of the packaging.
