High Pressure Processing for the Food Industry

(from Avure.com/Avure Technologies)

High Pressure Processing (HPP) for the food industry uses water under very high hydrostatic pressure to produce packaged foods that are safer, longer lasting, and better tasting.  This process is also called High Hydrostatic Pressure and High Pressure Pasteurization.

Pressures up to 700 mPa (100K psi) are used to destroy food-born pathogens such as listeria, E. coli and salmonella with little or no change in organoleptic properties or nutritional value.  HPP kills other microorganisms that cause spoilage, resulting in the doubling of the shelf life of most foods.

The trend is toward fewer to no artificial ingredients being added to foods. HPP can reduce and even eliminate the need to add chemical preservatives to food.  It is cost saving and responsive to the market for organic, all natural and clean label products.

Foods tend to taste better when processed in this fashion because they are not subjected to high temperatures.  Foods retain more of their natural color, texture and nutrients.

The market for HPP foods is reaching $2 billion annually.  The applications include ready-to-eat meats, fruits and vegetables; juices and smoothies; deli salads and dips; meat and dairy products. The process is also used for shellfish shucking and meat retrieval.

In 2009 the National Center for Food Safety and Technology (NCFST) announced the FDA had accepted the Illinois Institute of Technology’s research filing of the new food sterilization process.

HPP of seafood results easy extraction of product from shellfish, a high yield of product and a longer chilled shelf life.  It is less expensive than conventional food processing.  Maple Lodge Farms, a Brampton Ontario-based producer of poultry products, uses HPP.

The Big Mother Shucker or “Avure 215l-600” shucks a lobster or other shellfish with high pressure water (40K psi) and it kills all bacteria with 6,000 times normal air pressure.

Hormel Natural Choice Meats, using HPP, created a line of all natural luncheon meats that are free of preservatives, artificial ingredients, gluten, MSG nitrites and nitrates.  There are also many fewer returns of their products due to spoilage.  For companies that use this process, sales have risen substantially and returns are almost at zero.

Products are loaded into the pressure vessels, submerged in water and subjected to high pressure and temperatures that are elevated, but not too high.  Since it’s not a heat treatment there are limited effects on taste, texture and nutritional value of food products.

(from CanadianPoultryMagazine.com)

Consumers are much more aware of food safety these days.  Ninety-two percent of consumers surveyed reported food safety as a top consideration regarding the product they buy.  In the past only 20-25% of those surveyed were concerned with the issue.

For deli meats, the products are cooked, packaged, and then loaded into the HPP.  Water is pumped in and pressurized.  The pressure is applied in all directions uniformly so the product suffers no damage.

(from Avure.com news, 12/22/09)

The NCFST High Pressure Research Consortium’s (HPRC) members include Basic American Foods, Campbell’s Soup, Michael Foods, PepsiCo, U.S. Army Naich Soldier Research Center, and Avure Technologies. Avure Technologies manufactures food processing chambers for cold pasteurization, which cuts the use of salt, sugar, and fat—another market trend.

HPP leads to up to 80% yield improvement in shucking crab.  The capital cost of the equipment is high (between $300K and $1 million) but costs are recovered in about 2 years.

Fresherized Foods’ store-bought guacamole, Wholly Guacamole, has a shelf life of about 42 days.  This Saginaw, TX company controls 83% of the market share.

Virginia Tech in Blacksburg, VA, has a high pressure processing laboratory studying the effects of pressure in inactivating the Norwalk virus in seafood.  The $600,000 study is funded by the U.S. Department of Agriculture’s Cooperative Extension Service.  The lab is a facility of the Department of Food Science and Technology. Virginia Tech will collaborate with the USDA Aquaculture Center in Dover, DE and the Rollins School of Public Health at Emory University in Atlanta, GA.

Norwalk and Norwalk-like viruses are also called noroviruses and are responsible for most food-bourne disease outbreaks in the US.  Twenty-two million cases are reported annually.  These viruses are resistant to detergents, solvents, high temperatures and freezing.  The symptoms are nausea and gastroenteritis and usually last for two to three days. Most cases are linked to raw oysters and clams, contaminated water, raw salads and ready-to-eat foods.

(from The Business Journal – 2/7/10 – serving greater Milwaukee)

American Pasteurization Co. specializes in HPP.  The company has gone from processing 250,000 pounds of food to 20 million pounds in 2009.  This phenomenal growth is thought to be due to increasing concerns about food safety and recalls.