Poindexter Nut improves food safety with installation of second pasteurization unit

Testing shows the shelf life of walnuts can be extended as much as 40% through this natural pasteurization process; plus the process is organic which is preferred by customers and consumers alike.

In the past handful of years, some recalls and foodborne illness outbreaks have been traced to tree nuts and related commodities. Whether the packaging or ingredient label omitted a nut advisory or the so-called nut-free product was produced on machinery that previously manufactured foods with nuts, this particular allergen has been the source of widespread consumer concern. 

As a result, the almond industry began mandatory pasteurization of U.S. domestic product in 2007. That’s why companies like Poindexter Nut Co. go to great lengths to ensure the safety and quality of their nut products.

For instance, in August 2011, Poindexter Nut became what is said to be the first in the walnut industry to invest in a natural pasteurization process. This system, manufactured by Napasol, based in Switzerland, produced a maximum capacity of 1.6 million kernel pounds of walnuts a month. In November 2016, the Selma, Calif.-based walnut processor installed a purpose-built structure to house the second Napasol unit, which today produces approximately 9 million kernel pounds of walnuts a month.

“The purpose-built structure is actually a new walnut shelling and sorting facility that was designed from the ground up to process walnuts as gently as possible while maximizing the quality and freshness, and also doing so with the highest standards of food safety in our industry,” says Mike Poindexter, chief executive officer. “Every process was designed with food safety, traceability, efficiency and preservation of quality in mind.”

And, the only way to properly pasteurize walnuts is prior to packaging, according to Poindexter, making any third-party treatment impossible to do without the quality of the product suffering.

“Walnuts are a very fragile nut with delicate oils containing omega-3 fatty acids that other nuts do not have. This poses unique challenges that make the current third-party pasteurization services built for the almond industry an inadequate option for walnuts,” he adds.

In the natural pasteurization process, walnuts enter the silo tank farm, where they are fumigated and then fed into the 150,000-sq.-ft. plant. The facility features air systems that direct air upstream to maintain a clean room environment, thus trapping the loudest and dustiest portions of the process for occupational safety and plant cleanliness. Walnuts convey through the walls into the next rooms, which use mechanical, optical and laser sorting for removal of shells, defects and foreign materials.

Then, walnuts convey into a temperature-controlled inspection room where they undergo a final visual and manual inspection before passing through an X-ray machine and a new pasteurizer. Once treated, the walnuts are unloaded into a positive air pressure clean room, where they are packaged and conveyed to a palletizing robot that stacks the cases, wraps the pallets and moves them via forklift into the company’s 54,000-sq.-ft. cold storage facility. Walnuts rotate through a first-in, first-out racking process, so walnuts are kept as fresh as possible.

“Walnuts are best pasteurized without chemicals, so the Napasol system applies heat to the walnuts using dry steam in controlled atmospheric conditions that allow the temperature to be closely regulated while keeping the walnuts from picking up moisture,” says Poindexter. “We have also done testing that shows the shelf life to be extended as much as 40% through this process. Numerous blind taste tests showed that a majority of people could not discern a difference, while those that stated they could tell a difference preferred the pasteurized sample by a substantial margin. It’s also an organic process, which is preferred over the chemical process of propylene oxide (PPO) nearly unanimously from our customer and consumer base.”

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