nut pasteurization and how revtech does it well - almonds

RevTech’s Nut Pasteurization

Rachel Lowisz Profiles

RevTech’s Nut Pasteurization

What is nut pasteurization and why is it important?

Over the last 15 years, a series of recalls has plagued the nut industry, from the almond industry to pistachios. When looking at the common link to each of these recalls, a culprit can be traced to each. During these recalls, salmonella contamination was found to be the reason for many of the outbreaks, which was found in what turned out to be products that had not undergone the nut pasteurization process. 

Salmonella can cause stomach cramps, diarrhea, nausea, headache, fever, and chills. In children and the elderly, it can compromise immune systems, and antibiotics may need to be prescribed in order to fully treat the bacteria. In 2004, a salmonella outbreak in almonds caused 25 people to become ill, and the blame ended up being placed on 13 million pounds of compromised almonds. Due to the major liabilities and financial losses, it became clear the nut industry needed to do something to address the ongoing problem.

Almonds Take the Spotlight

The largest offender in the nut family when it comes to bacterial contamination and the potential for outbreaks is the almond. Because of how it’s harvested and processed, the almond ends up spending 8-10 days on the ground to dry after being shaken from its tree. Spending this amount of time on the ground exposes the almond to everything the earth has to offer, from your run-of-the-mill dirt and grime to animal waste.

If you wouldn’t eat your food directly off the forest floor, eating raw almonds in all their natural glory suddenly becomes less than appealing.

In the mid-2000s, it became clear that nut products, specifically from almonds, were causing problems with consumers, and restrictions were put in place to keep everyone safe. This is how the industry began seriously looking into making nut pasteurization the industry standard, decreasing outbreaks and therefore the potential of liabilities and recalls due to losses.

California is the world’s largest producer of almonds, so once the issues with public health crises started happening and being traced back to almonds, the regulatory boards of almonds in California decided to take action to protect this crucial crop and its impact on the economy. In 2004, the Almond Board of California called for the pasteurization of California almonds.  In 2007 the USDA (United States Department of Agriculture) passed the measure, which led to almond growers throughout the country pasteurizing their raw almond products before they hit the shelves. 

Financial restructuring in the nut industry after the salmonella outbreaks was fairly remarkable. In the almond industry alone, about 4 million dollars was spent to improve manufacturing practices sparked the transition that would later become standard to all almonds to the nut pasteurization process. Now all almonds sold must be put through a nut pasteurization process to ensure the safety of all consumers.

Issues Nut Pasteurization Addresses

The most important point to consider when cooking with and consuming nut products is whether the nuts, especially almonds, are going to be eaten as-is and without any other preparation out of the package. If they’re going to be cooked (whether by being part of a stir-fry, baked into a baked good, or cooked in another way), looking out for pasteurization quite isn’t as important. The cooking process will help kill off any harmful bacteria on the nuts, so the nut pasteurization isn’t crucial.

This changes if the nuts in question are going to be eaten without being cooked. In this case, it’s important to make sure the nuts have the least risk of contaminants possible, whether bacterial or otherwise. Nut pasteurization kills harmful bacteria, making raw nuts safe to eat and avoiding the contamination issues that helped contribute to the salmonella outbreaks the industry has experienced in the recent past. 

RevTech: A Leader In Nut Pasteurization Technology

Since its creation in 1997 by founder Martin Mitzkat, Revtech has been an industry leader in both the design and fabrication of installations in the pasteurization technology for food processes all over the world. Revtech is a French company using heat solutions for steam pasteurization to protect against the many health risks associated with eating untreated nuts. In April of 2013, they successfully became the largest certified almond pasteurization system in the world at a factory called Almondco Australia. 

RevTech is intensely committed to quality and offers unique technology to help customers develop exciting projects to tackle their dream projects. According to the company, each project is tackled from an individualized approach with a dedicated team of engineers and technicians to ensure maximum results and innovation. 

In a world where being environmentally conscious is important, Revtech is at the front of the pack. For over 20 years, they’ve focused on creating technology with low energy requirements. They’ve applied this knowledge successfully with over 120 companies. A leader in the pasteurization and food industry, Revtech also specializes in drying and roasting nuts. 

Revtech’s Methods of Nut Pasteurization

The first method of nut pasteurization, which Revtech regularly employs, is called steam pasteurization. During this process, flash heating using natural water steam kills bacteria. Nuts are exposed to steam for eight seconds at temperatures between 210 to 215 degrees Fahrenheit. For 44 seconds they then are moved through a high-heat dehydration tunnel to remove any moisture resulting from the steam. Circulating air temperature at this time is between 391 to 395 degrees Fahrenheit. This process does not change the taste of nuts and is known to eliminate harmful bacteria.

Another method of making nuts safe is roasting the nuts, but this changes both the properties and appearance of the nuts. During this process, hot air temperatures heat nuts to take away any bacteria, but tend to oxidize them and shorten their shelf life. Nuts generally do better when a two-step roasting process is employed to stabilize the microstructure of the nut and generate the desired color and flavor. 

Another tactic employed is blanching. With this, they remove the skin of the nut and put it in hot water. Blanching is a multi-step process whereby a nut is scalded in hot water, and then immediately dipped in cold water to make the skin come off. The nut and skin go through a roller in the factory to separate themselves, and then the nut is dried on a conveyor belt using a special oven. 

Sometimes nuts are fumigated for bacteria by the final type of nut pasteurisation used by Revtech, which is propylene oxide pasteurization.  Propylene oxide is a registered fumigant in the United States for the reduction of bacteria, yeasts, and mold on raw nut meats. Typically, the procedure is done at over 86 degrees Fahrenheit and has been in regulation standards with the FDA since 2004

Revtech’s Nut Pasteurization Technology and Process

revtech's nut pasteurization gourmet nuts and dried fruit

In a recent talk given by Celia Schlosser of RevTech, their technology and how it’s used in nut pasteurization was broken down and explained.

For proper pasteurization of a product, temperatures must exceed 180 degrees Fahrenheit in a process that requires several steps. Revtech’s temperatures slightly exceed that amount of heat to make sure nuts pasteurized using their technology are as safe as possible for the public. From the bottom of the base of the tower of their pasteurization machine, a preheating stage is completed before every pasteurization process. 

The Revtech pasteurization technology is based on a heating tower, which serves as the support structure. A stainless steel tube is then run and coiled around that support structure. The products, which in this case are nuts, are heated and distributed through the tube from the bottom to the top. The nuts then enter the system through the bottom and are heat-treated up through the top of the system. 

revtech's nut pasteurization gourmet nuts and dried fruit

Three basic steps are used when applying techniques of transportation and sterilization to the products through the pasteurization system. The first step is the mixing of the nuts and transporting them by vibration. Two off-balance motors create vibration at the base of the structure. This allows the product to move from the bottom to the top. The second step is direct heat by coming into contact with a hot surface. This is achieved through an electrical current running to the tube of the structure. Finally, as the last principle, hot air or steam is injected into the product in a confined atmosphere, helping to reduce the micro load in each batch of nut products. This set of steps ensures that each batch of products is safe and secure for the general public to safely enjoy. 

revtech's nut pasteurization gourmet nuts and dried fruit

When the product leaves the pasteurizing machine, it then is passed through a drying spiral, again through vibrations which dry the product completely. Cool air is then blown onto the product in order to cool it off for storage, packaging, and shipment to wherever the nuts are off to next. Thanks to the nut pasteurization process, this could be directly (and safely!) into the palm of a hungry snacker!

Product Appearance 

revtech's nut pasteurization gourmet nuts and dried fruit

Revtech’s process of steam pasteurization does not change the appearance or texture of the product. When looking at one nut that has been through the process and one that has not, it is impossible for most to actually be able to tell the difference. However, there is one way to tell if your nuts have been pasteurized, and this is by soaking them.

It should be known that almonds in the United States may be labeled “raw” on the shelves, even though they have been pasteurized. You can tell the difference between pasteurized and raw nuts by soaking them in water. Pasteurized almonds will not sprout when soaked in water, and will in fact grow moldy. Other raw nuts are great for soaking, as they release various beneficial chemicals from the process. 

“Are all nuts in the U.S. pasteurized,” some health enthusiasts might ask. The answer is complicated. Many commercial companies, even those who are not required to engage in pasteurization, including companies that produce products like brazil nuts, are likely to engage in the practice. For instance, brazil nuts pasteurized that on the shelves and products like pasteurized macadamia nuts are desirable to big manufacturers because they are likely to keep for a longer period of time. 

Small of steam added to each batch of nuts that are pasteurized, and then packed and stored. Many businesses say that they use it in order to increase their profit, even if pasteurization is not required under their current regulations and guidelines. 

Pasteurized nuts should keep for at least six months or more on the shelf if they are stored in airtight containers and kept in a cool and dark place. In this way, it can save consumers money, as they know nuts that are treated when bought in bulk will stand the test of time. Nuts are traditionally a product that keeps on the shelves for a long time, and the process of keeping them safe does not affect how long they are able to be sold to consumers.

Only when they want to change the properties, texture or taste does Revtech engage in the roasting of nuts. To achieve this, Revtech simply adjusts the temperature in the tube of the same machine the pasteurization takes place in and increases the time in which the nuts are engaged in this process. This decreases the moisture in the product and further develops the taste and color. The process of roasting only takes slightly longer than pasteurization, and steam is not injected during the process. 

Pasteurization has scientifically shown to not affect the nutrients found in nuts, so those ingesting them will still get the vitamins and nutrients they are looking for in these products. There are small studies suggesting that roasting nuts may take out slight nutrients in the products, but there is only a small amount of evidence of this as of yet. 

The U.S. Food and Drug Administration and other food quality organizations said that the loss of nutritional benefits from pasteurizing nuts is so small that it certainly does not outweigh the risks involved from not protecting against many dangerous bacteria and pathogens. 

Revtech’s Global Reach

revtech's nut pasteurization gourmet nuts and dried fruit

Currently, RevTech has over 120 projects installed in multiple factories all over the globe. They mostly work with nuts and various kinds of cereals, including wheat, corn, and barley. In addition to these initiatives, they also work with the pasteurization of herbs and spices, particularly in India, though they are headquartered in Europe. In the United States and Canada, Revtech’s work extends to deal mostly with almonds and peanuts, as well as seeds and a few types of cereals. 

Many large companies install multiple units of RevTech’s machinery for both pasteurization and roasting. Though the equipment is known to be quite expensive, it is also at the forefront of food safety, distribution, and processing. They say that while they are interested in working with large companies, Revtech is also open to relationships with cooperatives and all kinds of different farmers who wish to have a clean and safe product. 

Based on patented innovations and a wealth of experience in design, the company is devoted to pushing the envelope in continuing to develop excellence in heat treatment and pasteurization to a host of nuts and other dry ingredients. As regulations change and consumers become more educated about what they are putting into their bodies, it is important that companies remain transparent about their processes and their commitment to keeping bacteria out of important food sources. Revtech’s innovative, eco-friendly, and health-conscious initiatives are a prime example of a company with its values in the right place.