Neil Mermelstein

Neil H. Mermelstein

Can foods treated by new nonthermal processes be considered “fresh”? That has been a subject of concern to food companies and equipment manufacturers involved with emerging nonthermal processing technologies.

In 1993, the Food and Drug Administration published a final regulation allowing use of the word “fresh” in labeling if it implies that the food is unprocessed, i.e., not frozen and not thermally treated or otherwise preserved. The following treatments would not preclude the food from bearing the term “fresh”: addition of approved waxes or coatings; postharvest use of approved pesticides; application of a mild chlorine wash or mild acid wash on produce; or treatment of raw foods with ionizing radiation not to exceed the maximum dose of 1 kiloGray. Also, FDA said that use of “fresh” is not precluded when it does not imply that the food is unprocessed; e.g., “fresh” may be used to describe pasteurized whole milk because consumers understand that almost all milk is pasteurized and therefore there is no misleading implication.

Recently, new food processing technologies have been developed as alternatives to thermal processing, such as high-pressure processing, pulsed electric fields, pulsed light, ultraviolet irradiation, and others. FDA contracted with the Institute of Food Technologists to review the scientific information available on these technologies, help evaluate their effectiveness against pathogens of public health concern, and identify research needs. IFT’s report, “Kinetics of Microbial Inactivation for Alternative Food Processing Technologies,” is available on FDA’s Web site at The report is also available on IFT’s Web site at and was published as a 108-p special supplement to the November-December 2000 issue of Journal of Food Science.

Manufacturers using these processes contend that their products maintain the same “fresh” characteristics as unprocessed products and have asked FDA if they may label these products with the term “fresh.” Consequently, FDA held a public meeting in Chicago, Ill., on July 21, 2000, to gather input on whether the use of the term “fresh” is truthful and not misleading on foods processed with these alternative technologies and what type of criteria FDA should use when considering the use of the term with future technologies. The meeting was announced in the Federal Register of July 3, 2000. In its notice, FDA invited comments on specific questions (see sidebar below).

The deadline for written comments was August 21, 2000. An FDA spokesperson said that the comments presented at the public meeting and written comments submitted in response to the Federal Register notice are now being analyzed and no date has been set for issuance of a regulation on the subject. Each year, FDA prioritizes its Center for Food Safety and Applied Nutrition activities for the coming fiscal year and creates an A list and a B list of program priorities. Because of limited staff and resources, the agency intends to complete at least 90% of the A list activities. Activities on the B list are those the agency plans to make progress on during the year but may not complete. In the FY 2001 CFSAN Program Priorities document issued last month, the “fresh” issue remains on the B list for its fiscal year ending September 30, 2001. Under Strategy 1.7 (Education), CFSAN plans to “conduct focus group research on the use of the term ‘fresh’ on food labels or labeling to refer to food products processed using new technologies to ensure safe food.”

The public meeting included a presentation by Charles Sizer of the National Center for Food Safety & Technology on the new processing technologies that are emerging. “We classify them as nonthermal technologies,” he said, “but in fact, with any process we have, there is going to be some effect of temperature on the chemical and biological changes that occur.” He briefly discussed high-pressure processing, high-pressure CO2, UV light processing, different forms of irradiation, chemical treatment, mild thermal treatments, pulsed electric field, and filtration.

From a scientific perspective, he said, a lot of things affect the fresh character. They include microbial spoilage, chemical changes, enzymatic changes, storage conditions, time, temperature, relative humidity, gas composition, and packaging. He added that even raw products eventually reach a point in their life when they’re not fresh, because of the microbiological changes that occur. There’s a need for common agreement of what can be called fresh, he said.

Views expressed at the meeting ranged from those in favor of allowing products treated by the emerging technologies to be labeled fresh to those opposed.

C. Patrick Dunne of the U.S. Army Natick Soldier Center, briefly reviewed the applicability of some of the new processes. High pressure, he said, has very broad capability. It can treat practically any food, as long as it’s in a flexible container, or fluids can be treated and packaged later. Pulsed electric fields are being applied only to pumpable products, mostly vegetable juices and fruit juices. Pulsed light can inactivate all classes of organisms, probably including viruses, but it’s only good at working at surfaces or clear liquids, so the design of the equipment is critical. There’s a whole field of chemistry called photochemistry that can be used to minimize the chemistry involved using very short light pulses. And it must be recognized that both high doses and moderate doses of radiation can control pathogens and spoilage of fresh produce.

Howard Zhang of Ohio State University presented a brief update on pulsed electric fields, using orange juice processing as an example. He said that laboratory studies have shown that it has very good effect in terms of extending shelf life, keeping the food quality. He described OSU’s integrated plant system with pulsed electric field processing and aseptic packaging and said that a consortium of companies is studying commercialization of the process. He concluded by saying that fresh is a term to describe the product rather than something that has to be restricted to the use. If the product has the fresh quality, it should be given the opportunity to be called fresh.

Sevugan Palaniappan of the Minute Maid Co. discussed studies to evaluate alternative technologies to produce good-quality fruit juices. The purpose, he said, was to avoid thermal degradation of sensory and nutritional quality and at the same time assure food safety. One of the ways to let consumers know that the products possess fresh quality is by labeling the product fresh, he said. He reviewed the microbiological, nutritional, and sensory results of new technologies and said that some of these innovative technologies deliver tangible benefits to consumers by producing juice that is safe, pathogen free; retains its original sensory properties; retains its nutrient composition; is less perishable than raw; and is significantly improved over raw juice. He concluded that the treated fruit is not different from untreated juice in terms of physical, biochemical, nutritional, and organoleptic properties. He added that the current fresh regulation is adequate, and it fits the products treated using some of these alternative process technologies. He stated that any food treated to kill pathogens without heating, freezing, or chemical preserving or affecting sensory and nutritional qualities should be considered fresh.

Don Bowden of Avomex said that the guacamole they produce using high-pressure processing provides a significantly longer shelf life without the addition of preservatives. He said they consider this to be a fresh product which should be able to be defined as fresh.

James Curver of Selcor, Inc., described the company’s ultraviolet system for processing juices and other fluid products. He said that the ultraviolet process fits the criteria for freshness. They have tested apple juice, orange juice, carrot juice, other mixed vegetable juices, smoothies, and other products and have found that the vitamin and enzyme content, the organoleptic properties, and the characteristics of the juice appear to be unchanged. There’s definitely a shelf life extension, he said. If objective criteria can be developed that are not too expensive—this could very well be the measurement of a few selected vitamins and enzymes, perhaps acid and alkaline phosphatases—then he would be for the expansion of the term fresh. If this can’t be done, he said, then we should stick with the way it is now.

Dennis Olson of Titan SureBeam Corp., manufacturer of food irradiation facilities using ionizing electrons or X-rays, said that irradiation destroys pathogenic organisms on food without changing the nature of the food. He believes that the term fresh describes a meat and poultry product in its raw state. Of the physical, chemical, sensory, and microbiological properties of a food, we believe it is the physical properties that consumers use to distinguish food from its raw state to a processed state, he said. The primary difference between fresh, cooked, and frozen products is the physical nature or texture of the product. Nonthermal processes that don’t change the physical characteristics of raw products should qualify for using the term fresh.

Edmund Ting of Flow International Corp., manufacturer of high-pressure equipment, said that high-pressure technology is a direct intervention technology that can improve the quality of a fresh product by increasing its safety and its useful shelf life, without significantly changing the sensory and nutritional aspects of the product. Substantial scientific information exists showing that high pressure can leave the taste, color, aroma, mouthfeel, texture, vitamin, and many other nutritional aspects unchanged, he said. He recommended that if the fundamental characteristics of the food are substantially unchanged from fresh, without thermal exposure, then the product should be given the option to be described as fresh.

Regina Hildwine of the National Food Processors Association said that NFPA believes that it is appropriate to allow the use of the term fresh on foods that have been treated to sanitize, phytosanitize, or generally protect products’ organoleptic property characteristics, properties that are characteristic of recent harvesting or preparation, food packaging, or coding methods.

Donald Quass of Imbroglio Cures, Inc., said that in his opinion fresh connotes a flavor attribute. Any food regardless of processing history which carries this desired attribute should be permitted to carry the term fresh. The increase in success of the broad efforts by food preservation scientists in this country and abroad to create viable processing alternatives to thermal processing should not be discarded by preventing the use of the term fresh on the label.

J. Peter Chaires of Florida Fruit Shippers Association, representing the American Fresh Juice Council, said that the council objects to the inclusion of the word fresh in description of these technologies.

Leslie Zinn of Ardeu’s Garden, a fresh juice processor, urged that we keep fresh intact to mean an unprocessed, raw, fresh product.

John Martinelli of Orchid Island Juice Co., said that the term fresh to consumers means washed, extracted, bottled, and refrigerated. To apply the word fresh to a post-extracted treated product would be misleading, he said. He suggested using terms already widely understood like pasteurization, cold pasteurization, minimally pasteurized, ultra lightly pasteurized, flash pasteurized, or gently pasteurized. Fresh should stay synonymous with unadulterated, he said.

Donna Denison of the United Fresh Fruit and Vegetable Association said that the industry strongly supports the present definition of fresh and is very reluctant to endorse any proposed any regulations at this time that seek to make any major changes based on new food processing technologies.

Jim Gorny of the International Fresh-cut Produce Association said that the association defines fresh-cut produce as any fresh-cut fruit or vegetable or combination that has been physically altered but remains in the fresh state, meaning that it is still alive, actively respiring, and carrying out the metabolic and biochemical activities we call life. IFPA supports the use of new and emerging technologies that may more effectively maintain or enhance quality and/or safety of fresh produce products, but feels that use of the term fresh must be reserved for fruit and vegetable products which meet the criteria of being alive and respiring.

Jur Strobos of The Fresh Juice Co. said that fresh citrus juice represents a special circumstance. He said that FDA requires fruit juices to be pasteurized or, if not, to have a 5-log reduction in pathogens or be labeled with a warning label. Since fresh citrus juice is the only commodity covered by this rule that is currently able to demonstrate the 5-log reduction, the meaning of fresh within this subcategory of juices should be preserved and uniquely made available to the companies that are able to do this 5-log reduction. He concluded that the word fresh as applied to fresh citrus juice should apply only to juice that has undergone no post-extraction processing.

Harriet Adams of Juice Tree, Inc., manufacturer of juice extracted on site in supermarkets and juice bars, asked that FDA leave the definition of fresh alone so that the consumer would not be misled or misinformed.

John Veldhuis of Florida Citrus Packers said that he supports FDA’s current position and that to change things now to allow some of these products to be called fresh is premature. He said that more research, time, and duplication of research is necessary to award a title as precious as fresh.

Mary Grace Sexton of Orchid Island Juice Co. stressed the need for honesty on the label, saying that consumers have the right to know what has been done to the products they buy.

A complete transcript of the proceedings of the public meeting is available on the Internet at

IFT’s Nonthermal Processing Division sub-sequently submitted written comments to FDA (see sidebar on page 66). The division has also scheduled a workshop on March 26–28, 2001, in Newark, Del., hosted by the University of Delaware. According to C. Patrick Dunne, chair of the division, the workshop would represent a first step in a process leading to publication of standards for nonthermal processing research in appropriate journals.

The first day will feature presentations on nonthermal processing compared to thermal inactivation; bacterial inactivation kinetics and mechanisms; standards for nonthermal processing research; enzyme inactivation kinetics; and breakout sessions on methodology/future research needs for predicting inactivation with specific nonthermal processing.

The second day will cover synergy among nonthermal methods in association with conventional methods; consumer acceptance issues; case studies on process/product introduction; updates and case studies on current developments; updates on minimal processes for treating “fresh foods”; and breakout sessions on developing specific research protocols, standards for publication, marketing strategies, etc.

The third day will cover reports from breakout sessions; nonthermal processing implementation strategy; and potential needs for the future of nonthermal processing.

Details are available on the division’s Web site at

FDA’s Questions Regarding “Fresh” Labeling
1. Do consumers associate the term “fresh” with organoleptic characteristics, nutritional characteristics, or some other characteristics?

2. Do consumers want a way to identify foods that taste and look fresh but have been processed to control pathogens?

3. What does industry think the term “fresh” means?

4. Is the term “fresh” when applied to foods processed with the new technologies misleading to consumers?

5. Do the new technologies preserve the foods?

6. Are the new technologies truly nonthermal?

7. Are there quantifiable parameters, e.g., level of nutrients, vitamins etc., that could be measured to determine if a food is “fresh?”

8. Is there a term other than “fresh” that can be used for foods processed with the new technologies?

9. Would consumers understand a new term?

10. What is the economic impact of allowing use of the term “fresh” for foods processed with the new technologies?

11. Would allowing the term “fresh” on foods processed with new technologies place small firms not able to use these technologies at an economic disadvantage? 

IFT’s Comments to FDA Regarding “Fresh” Labeling
The Institute of Food Technologists (IFT) appreciates the opportunity to offer comments to FDA as the agency considers use of the term “fresh” in labeling of foods processed with alternative nonthermal technologies. As the society for food science and technology with 29,000 members working in the food industry, academia, and government, IFT commends the agency for convening the July 3 public meeting to discuss this issue and solicit comment on several questions. Members of IFT’s Nonthermal Food Processing Division, several of whom participated in the July meeting, are keenly interested in this issue. A small group of the Division’s members drafted the comments below.

IFT believes that future implementation of new food processing technologies will be important to enhance food safety and consumer welfare. To assist commercialization and improve consumer awareness and understanding of these new technologies, IFT encourages FDA to clarify the important trade issues related to applying the term “fresh” to foods processed with new technologies (i.e., alternatives to thermal processing). Rapid and effective resolution of these issues will promote the availability of higher quality and more nutritious safe food products than thermally processed food products.

IFT believes that it would be appropriate to use the term “fresh” for products that are “not detectably different” (from their counterparts) as a result of the application of a specific alternative nonthermal technology to reduce spoilage or pathogenic microorganisms. With concern for the public welfare, it is the agency’s responsibility to base the definition of “not detectably different” on reasonable interpretations that are consistent with both scientific state-of-knowledge and established regulations. Use of an alternative nonthermal technology that enhances food safety and enhances or extends product quality should not bar the products from being associated with the “fresh” identifier.

IFT suggests that application of new nonthermal processing technologies and the phrase “not detectably different” as a result of the specific process be evaluated using precedence already established by FDA. Fruit juice, for example, is extracted (with a number of nonthermal processing steps) from the natural fruit, yet chilled “fresh” juice is sold to consumers.

Furthermore, FDA currently allows the use of the term “fresh” on fruits and vegetables treated by less than 1 kGy irradiation, a method of inactivating pathogenic and spoilage microorganisms with little to no impact on product taste and nutrient content. Pasteurized milk is also allowed to be labeled as “fresh.” Some manufacturers currently add a microfiltration step to prolong the shelf life of “fresh” pasteurized milk. Consequently, IFT believes that other nonthermal technologies that also result in “not detectably different” products should likewise be allowed to use the “fresh” identifier.

IFT offers the following specific responses to three selected questions raised by FDA:

Question #5: Do the new technologies preserve the foods?

As described in several peer-reviewed technical articles, the new alternative nonthermal technologies are food preservation methods. An intended result of the application of these alternative technologies to fresh foods is the reduction of both pathogenic and spoilage microorganisms, thus extending the time frame of acceptability for the fresh products. Substantial evidence exists for the extension of shelf life with many new processes applied to a wide variety of food products. The specific increase in shelf life, accompanied by enhanced product safety, is very product and process specific, however. The ultimate goal of any food preservation method is to extend product shelf life without quality deterioration and compromised food safety. Alternative nonthermal or minimal-thermal processing technologies address consumers’ desire for high quality products that are safe to eat.

Question #6: Are the new technologies truly nonthermal?

Because some form of energy is applied in any intervention method, there is usually some measurable thermal component. The new alternative intervention methods, however, do not rely on the thermal component as a primary inactivation mechanism for controlling pathogenic or spoilage microorganisms. The primary advantage of the nonthermal technologies is that products processed with them may be pasteurized without reaching standard thermal pasteurization temperature and time conditions. Achieving a five-log cycle reduction in pathogens of concern in fruit juices using nonthermal technologies is an example.

IFT noted in a report to FDA [“Kinetics of Microbial Inactivation for Alternative Food Processing Technologies,” March 2000, pp. 283-286.] that much more research and data on new nonthermal processing technologies are needed. For example, more research is needed to determine if the thermal and nonthermal effects of high pressure and pulsed electric fields are simply additive or synergistic. Food processors must understand such interactions and be able to control and measure any temperature rise associated with the process. IFT clearly recognizes that shelf-stable foods produced by any process with a thermal component in a critical step will be regulated according to 21 CFR 113, 114 for low-acid foods and acidified foods, respectively.

Question #7: Are there quantifiable parameters, e.g., level of nutrients, vitamins, etc. that could be measured to determine if a food is “fresh?”

Yes, quantifiable parameters exist; this question, however, is of such scientific complexity that any simple tests of “freshness,” for regulatory purposes, may be precluded. There are many constituents that could be measured with very sophisticated quantitative instrumental or sensory tests to assess the technically defined “freshness” of a food product. The measurable level of any selected critical parameter, however, would vary with a number of factors including product, variety, location, season, and most importantly time and storage conditions after harvesting. “Fresh” would then be a relative descriptor that could be quantified by scientific measurements during the time between product manufacture and sale and consumption. The ultimate measurement of “fresh,” however, is likely to be based on an individual consumer’s own sensory perception. Consumers are likely to compare products that are labeled “fresh” to similar products that they have become accustomed to purchasing with that label. The consumer’s ultimate satisfaction with the product involves a comparison of expected sensory quality (based on previous “fresh” label product experience) with the actual product characteristics.

In conclusion, the U.S. government has the responsibility to issue regulations that benefit and protect the U.S. public. Such regulations ultimately may also impact consumers worldwide. In addition to setting policies that ensure food safety and promote public welfare, regulators should also promote policies that clearly help consumers understand the characteristics of the food they purchase. IFT embraces the agency’s partnering with academia and industry in the development of improved food processing technologies. Further, additional labeling information may either be required or found to be desirable by manufacturers for a specific new technology; such a question should be considered separately from “fresh” labeling.

In accordance with the above comments, IFT encourages FDA to make this issue—use of the term “fresh” for foods processed with alternative nonthermal technologies—a high priority during the next year, to help consumers understand the implications of the new high quality foods that are becoming available to them. IFT would be pleased to participate in further dialogue within the scientific community to help clarify this important issue.

Senior Editor

About the Author

IFT Fellow
Editor Emeritus of Food Technology
[email protected]
Neil Mermelstein