Processing food with minimal heat disruption delivers a fresher, minimally processed food. But its food safety promise has been the greater magnet for interest to date. Virginia Sea Grant, a marine research and advisory group a the University of Virginia at Charlottesville, has sponsored research on high-pressure processing to inactivate hepatitis A virus (HAV) in oysters, opening another door to the technology to enhance the safety of the food supply.
Hormel Foods, Austin, Minn., and Perdue Farms, Salisbury, Md., are employing the process to sterilize lunchmeat, chicken strips, and other meat items and to extend shelf-life to 100 days or longer. Still, with equipment cost on the high end and food safety a constant concern, high-pressure processing has made only limited strides.
Hang on. Better designed, insulated and preheated vessels and better control and monitoring systems have advanced the technology considerably. The process submerges wrapped or packaged product into tanks of pressurized water, killing the food industry’s invisible enemies – salmonella, listeria, e. coli and now even bacterial spores.
“The newest development is a modification of equipment that enables the process to reach higher temperatures,” explains Martin Cole, director of the National Center for Food Safety and Technology, a research consortium among the FDA, Illinois Institute of Technology and the food industry. “This is a big step in preservative technology.”
Cole and colleagues have been testing a 35-liter high-pressure processing system at NCFST’s headquarters, lab and pilot plant in Summit, Ill., where high-pressure studies have been under way for more than five years.
To date, high pressure has been used only in batch processes, but innovations in the technology, including the ongoing development of “tilting vessels,” have helped speed up the process. “The driving force in the development of the technology has been to make it a more fluid process, to move it to an almost continuous process,” says George Allah, senior scientist at Food Products Assn.’s (FPA) Center for Technology.
Though the process has more than doubled the shelf life of meat products, processors have remained cautious, skeptical and divided regarding its efficiency.
Perdue Farms has not extended its date code on products processed with the technology despite highly favorable laboratory results. At least one major processor rejected the process last year for its deli meat operations, complaining that the meat produced was soft and lacking the elastic characteristic of traditionally made deli meats.
More recent developments have yielded more favorable results, however, and Cole and others foresee the industry opening its arms to the process in the not-too-distant future. Some think it will replace the traditional retort canning process.
“A consortium of several food companies has filed an FDA petition to approve the process for food sterilization,” says Cole. “I think we will see it used in the marketplace in the next few years,” says Jeff Barach, vice president and center director of FPA. “The hurdle is consistency and, of course, regulatory matters.”
Bioseparating functional ingredients
Healthful new products. Remarkable functional ingredients. Substantiated label claims to market functional foods to a health-hungry public. All are, as Shakespeare might say, “consummations devoutly to be wished” if you are a food processor.
The functional foods revolution has opened new doors to profit for food processors. But economical extraction of many important functional food ingredients – particularly key phytonutrients credited with health benefits – remains largely unachieved.
Bioseparation of these components is the key. The pharmaceutical industry has the luxury of charging high prices and high profit margins to support the development and implementation of costly technologies.
Not so in the food industry. That’s why more economical technologies to isolate and extract functional food ingredients are so eagerly sought by the industry today.
One such process for bioseparation is based on the 100-year-old technique chromatography. Long employed by the pharmaceutical industry but too dearly priced for the shallow pockets of food processors, chromatography boasts an impressive set of advantages in isolating component elements. First, it is reproducible. Second, it provides good resolution in separating desirable from undesirable components. Third, it is gentle on unstable target components.
The reason for optimism today is the promise of a continuous chromatographic process that is much less costly than the heretofore customary batch chromatographic processes.
The process currently is extracting dairy-based proteins and peptides from milk, colostrum and cheese whey. It also can fractionate dairy proteins into individual isolates, such as alpha lactalbumin and beta lactoglobulin. These whey proteins not only provide valuable functionality in the creation of gels, whips and fat replacers but seem to possess anti-inflammatory and anti-cancer properties as well.
Research has shown that another minor dairy protein, lactoferrin, has useful antimicrobial properties and benefits to bone growth and prevention of osteoporosis, in addition to anti-inflammatory properties. Lactoferrin also may aid skin growth and the healing of burns and wounds.
“We’re looking to leverage the platform for the dairy industry on the meat and horticultural waste streams,” says Geoffrey Smithers, director of international business for Food Science Australia, which provides research to food processors throughout the world. “And we’re looking at techniques to isolate antioxidants from fruit and vegetable streams. Continuous chromatography is the centerpiece of our bio-separation platform.”