Package design and cold chain management go hand in hand

Fresh-cut produce is the fastest growing segment of the produce industry, and customers are looking for convenience, freshness, quality and safety when they purchase fresh-cut products.

But the produce packaging is often the last step a company takes in preparing a new product for the market, said Jeff Brandenburg, packaging consultant and president of The JSB Group, Greenfield, Mass. Attention is paid to developing safe products, extending shelf life and managing field to fork progress, but less is paid to the bag or carton that the produce is stored in from the time it’s processed until it’s opened by the customer.

Brandenburg said clients often ask him at the tail end of development for a generic package that will improve the quality of their produce. That’s not a question he likes to hear, because all a package can do is extend shelf life.

“The packaging will never improve quality,” he said. “Start thinking of packaging a bit earlier on in the process.”

He said packaging should be developed in parallel with the product itself.

“Right now, it’s much more linear,” he said.

Quantifying Produce

The first thing Brandenburg tells his customers is that they need to design the package around the produce they’re packing. He calls it a “symbiotic” relationship between the packaging materials and the product inside.

Packaging considerations should start with a quantitative measurement of the product’s respiration rate. There’s no generic rate that can be applied to produce; each fruit and vegetable breathes at its own rate and that needs to be taken into account.
Brandenburg developed procedures for his customers that quantify the respiration rates of their produce. That information becomes the company’s proprietary information and is used to design the packaging.

“It’s not about one kind of packaging over another; it’s about the product you’re packing. You design the package around the product and the respiration of that product,” Brandenburg said.

The next step is to determine the “business” side of the product, which includes variables such as shelf life. For products that will have only a five- to six-day shelf life, there are many packaging options. If you go up to 10 days, there are fewer options, and if you want a 15-day shelf life, there are even fewer, and all of the variables must be controlled.

That means everything from Good Agricultural Practices to the chill chain have to be effectively monitored because the quality of the final product is only as good as what goes into the package. And as you extend shelf life, the cold chain becomes more important.

“The problem for the processors is not in their facilities, but once it leaves their facilities,” he said. “Ultimately, what that means is the longer the shelf life, the more things have to be in control. You can’t look at it at the eleventh hour.”
Brandenburg cautions his clients against relying too much on their cold chains.

“Packaging can do more harm than good if there’s not good chill chain management,” he said. “If you don’t have good temperature control, then your package will not do anything for you.”

If a package is designed around a specific temperature, then it has to be cooled to that temperature before it’s packaged. With modified atmosphere packaging the gases can act as an insulator, and if a product isn’t cooled going in it’s not going to cool down.

“If you go up to 7° C, then that respiration rate can double or triple,” he said. “You end up going anaerobic.”

On the other hand, that insulation can prevent small spikes in temperature from raising the temperature of the product.
The growth of ready-to-eat meals and fruit and vegetable combinations compounds the number of variables that have to be quantified.

Companies combining fruit or vegetable varieties have to look at the individual respiration rates and a weighted average, then develop a package based on the shelf life.

“Sometimes you come back and say ‘these vegetables shouldn’t be together,’” he said. “At that point, it becomes a business decision.”

Brandenburg was a presenter at Fresh Cut Europe in November, and while in London he saw a fresh-cut product that had kiwi, mango and papaya packaged together. He also saw more combinations of vegetables than is common in the United States.

European Fresh-Cut

Brandenburg said the packaging of fresh-cut produce is more important in Europe than it is in the United States. Europe has never focused on cold chain management because of its demographic and geographic differences.

European customers shop more often than U.S. customers and don’t keep food as long. They’ll visit a market two to three times a week, a higher rate than customers in the United States. Europe is much smaller, so there isn’t the challenge of moving product that U.S. processors have.

“They’re just dealing with the issues that we’ve been dealing with for a long time,” Brandenburg said.

That goes against the common perception that European fresh-cut processors are more advanced than their U.S. counterparts.
“When it comes to leakers, shelf life and cold chain management, North America is ahead,” he said.

European packaging is notorious for leaking modified atmosphere gases. When that happens, shelf life is reduced and so is the visual quality of the produce.

“You can design the sexiest package in the world, but if it leaks it’s all for naught,” Brandenburg said. “If you have a leak, you are therefore out of control.”