Questions begging in fresh-cut vegetable industry
- January 21, 2007
It is important to understand that there is no kill step (no boiling, freezing or radiation) in the processing of raw, fresh vegetables, whether it's done in a home kitchen, in a restaurant, in a cafeteria or in a salad-in-a-bag factory.
Fresh means fresh. The freezer pouch and the can or jar are the only zero- tolerance food-safety solutions when it comes to vegetables.
Fresh-cut, salad-in-a-bag vegetables are safer than fresh, off-the-shelf vegetables.
The average cook isn't using any antimicrobial agent in the wash water. The fresh-cut product is washed on the same day it is harvested, not a week later after any pathogens on the product have been reproducing exponentially. The processing plant's wash system will do as good a job or better than a sink and a faucet. What's more, fresh-cut's safety advantage grows with an increase in the number of components in the salad.
Further, if people take the precaution of washing their fresh-cut vegetables before they eat them, then they can give themselves the maximum protection from Mother Nature, the modern factory and human error.
Essential and substantive improvements in the cold chain, distribution, storage, growing and handling of fresh-cut vegetables, and the implementation of HACCP programs from field to fork are the result of the fresh-cut industry's initiative over the last 15 years. The public interest has been well served by these accomplishments.
The fresh vegetable growers are the most committed and diligent link in the fresh-cut industry's chain from field to fork when it comes to food-safety issues and practices - whether or not they got dragged into it kicking and screaming. The growers, many of whom are classic American family farmers, have bent over backwards and spent much money to implement food-safety standards and practices in their growing, harvesting and handling practices. Food-safety and HACCP programs really do start in the field now. Everybody who eats vegetables is better protected now than 15 years ago.
Fresh-cut processors can fairly and credibly claim that their products are safe enough, but not that they are as good as they can be. During the fresh-cut industry's explosive growth period, increasing capacity, productivity and economies of scale were greater priorities than innovation and continuous improvement. Innovation stagnated in the mid-1990s when fresh-cut products became good enough and safe enough to get by. Here are some examples.
Vegetables, like spinach and spring mix lettuces, come into a fresh-cut plant (just like they come into a supermarket) with a little dirt or soil on them. Without filtration, the wash water used for these products becomes increasingly muddy as production progresses. Swimming pool water is cleaner. This practice requires increasingly larger doses of chlorine to combat not only any pathogens (target-demand substances) that might be in the water, but also to overcome the build-up of organic matter (non-target- demand substances) from the soil being washed off the product. But there are a couple of catches with wash-water filtration.
The first catch: The cleaner the wash water is, the more effective any antimicrobial agent will be. Whether it's sodium hypochlorite or chlorine dioxide, and particularly if it's ozone or ultraviolet light, it will work better with fewer non-target-demand substances getting in the way.
The second catch: Filtering the wash water also improves the quality of fresh- cut vegetable products like spinach and spring mixes. These two catches add up to the increased effectiveness of the antimicrobial agent and the improved quality of the product. Do they also add up to safer fresh-cut vegetables?
Ozone as an antimicrobial agent Iceberg, Romaine, radicchio, broccoli florets, kale, mache, spring mix lettuces and green onions smell better, taste better and have better shelf life when ozone is used instead of chlorine as an antimicrobial agent in the wash water in a purpose-built wash system. There is no chemical residue to smell or taste. I think almost everybody in the fresh-cut processing business, especially the big guys, have tested ozone in one way or another and are fully aware of its quality virtues and its application requirements. Reasons for not developing ozone range from the ridiculous (ozone doesn't work because the water's too dirty) to the purely economic (new equipment, upgraded facility). Nobody says it's a bad idea.
My experience with ozone comes from using production-scale wash systems that were either purpose-built to my design or modified to my specs beginning in the early 1990s. The goal of these custom and proprietary wash systems was always to remove as much of the non- target-demand substances from the wash water as possible so the antimicrobial agent could do a better job. These wash systems improved to the point where ozone could be used effectively and economically.
But ozone was just another antimicrobial agent candidate, another of several chlorine alternatives -- until the results came in.
Quality improvements from using ozone instead of chlorine begs the same food-safety questions that the filtering issue does, but it also begs an environmental question: How much residual chlorine would not go down the drain if more fresh-cut products were processed using ozone instead of chlorine-based chemicals?
Perhaps improvements like filtration and ozone are really only about food quality and not about food safety at all. Perhaps it's just budget, initiative, imagination and leadership problems getting in the way of a few quality improvements. Perhaps I'm just some modern manufacturing management freak hooked on strange philosophies like continuous improvement and technical innovation.
Maybe people like me should stop speculating about dialectical food-safety issues and just stick to the business of making better quality products than anybody else.
(Ralph Schneider has been a fresh-cut plant manager, a plant engineer, a partner in small fresh-cut companies and a consultant to more than 20 fresh-cut companies. He is the author of a monograph titled The Practical Utilization of Ozone for the Fresh-cut Vegetable Processor. He can be reached at firstname.lastname@example.org.)