By:  Nahum Goldberg, LEED GA
Senior Associate – San Francisco, CA

Synopsis:  One area of innovation particularly relevant to my work is that of farm fresh produce sanitizing solutions for medium to small commercial kitchens. This is an up and coming food safety issue as more operations go Farm to Fork.

Why Sanitizing Produce is Becoming More of An Issue

Ready-to-eat packaged produce is being replaced with field fresh items that need deboxing and washing. This takes us back to the days before large produce processing plants began washing, cleaning, cutting and sanitizing our produce and delivering this convenience in sealed bags. Today, most of our clients are looking for fresh, in season, local farm-produced items. Our chef partners and their clients want to see and smell the source of the products. They want to step out into the muddy field and pick it themselves – and then flaunt their muddied field clothes to their clients.  Farm to Fork, transparency, reduced carbon footprint from transportation, greater freshness, local connection to seasonality and nature, social responsibility  – all these points are gaining momentum in the retail and institutional dining food industry and what is better to express these values than to support your local farm. But don’t forget to clean and sanitize the produce because the big daddy packaging plant is moving out of the picture.

Produce + Pathogens = Danger on Your Table

It did not take much research in the matter to learn that during a ten-year period from 1998 – 2007 the Centers for Disease Control recorded 684 outbreaks (an outbreak is more than 2 people sickened by the same source) involving 26,735 cases of illness from pathogen-contaminated produce. Over this period, produce was actually the second most common source of foodborne outbreaks, with total cases of illness nearly equaling all cases from poultry, beef and pork combined! So next time your stomach goes south, don’t necessarily blame that chicken, burger or porkchop because the source might have been the fresh garnish such as a sliced tomato, leaf of lettuce or chopped parsley…

Produce contamination can be very difficult to combat as fruits and vegetables are often served raw, without the heating or cooking which kills most pathogens. On top of that, produce has irregular shapes, oftentimes with nooks and crannies that can harbor  pathogens. And another thing we should know – cutting contaminated produce transfers the problem into the interior so wait until after it is cleaned and sanitized and use sanitized utensils.

So How Do We Set Up A Kitchen to Deal With This Problem?

In my role as a commercial kitchen designer, I am putting in a dedicated produce wash station in almost every application. Kind of reminds me of the days before packaged produce had inundated the commercial market.  Some areas of the world are still like that  -  washing and sanitizing everything – and there is a thriving equipment industry supporting this. Italian Nilma or German Kronen are great examples, both with products serving commercial kitchens and larger industrial applications.

Equipment, Means and Methods

Produce sanitizing options are varied with the most basic equipment solution being a worktable with a 2-compartment sink and a good pre-rinse faucet. Fruit and produce washing and sanitizing must precede slicing, cutting or other mechanical manipulation of the product.   The large packaged salad provider, Fresh Express, sponsored a symposium in Monterey, California in 2008 and presented 12 different research studies, two of which demonstrated how cutting, cubing or slicing prior to surface wash and sanitization enables pathogens to enter the vascular system of the plant. Light removal of outer leaves is  advisable as a first step.

But back to the equipment story… Moving up from the basic sink washing station we see integrated sinks with turbulent water wash pumps, sometimes with water chillers. Cold water is key to keeping the produce firm and better prepared for slicing or other mechanical processing. Continuous temperature control is advisable if the product will not be served for more than 4-6 hours after the processing. Ice is often added to the process water, and one should keep in mind, ice can be a source of contamination if not handled properly. Then there are basket and lift systems. Some systems, like Powersoak’s “Produce Soak” system and Steelkor/Duke’s “Xgreen”, in addition to using sophisticated turbulence pumps, integrate various chemical solutions as sanitizing agents and have procedural aids and monitoring systems built-in that assist in tracking for HACCP and assure a proper process has taken place. Nilma offers a two-basin system with controlled agitation which does not use chemicals, and they tout a very high level of success in removing pathogens. Nilma is reportedly moving forward with additional models for use in the growing US market.

Creating Pathogen Killing…  Water

Perceptions about chemical sanitizing of our fresh produce are sometimes negative. No one wants to tell their client that the lettuce just came out of a sanitizing solution or chemical treatment even if they are FDA approved, organic and totally non toxic.  It seems the next step would naturally be to seek out a solution to sanitizing that eliminates the need for chemicals. Enter Ozone and ECA generators into the produce stations.  San Jamar is offering its Saf-T-Wash System which is an ozone generator that provides ozonated water to rinse produce. No chemicals are used or washed down the drain. This is for soaking and final rinse systems. Produce should be soaked, rinsed and freed of any particles or oils. MVP from Montreal presented a recirculating sink set up with chilled, ozonated water.  They use their GO03 model WMS and also have an acivated carbon recirculating vent system so as ozone is released from the turbulent wash tank, it is drawn into the system and inactivated so staff is not exposed to ozone emissions that can otherwise present adverse health effects. There are Occupational Safety & Health Administration (OSHA) permissable exposure limits for ozone which must be met and the manufacturers must comply. Ozone has been shown to be a highly effective and fast acting oxidizing agent.  But like many things, controls are needed to protect safety and health.

Another “chemical free” system is Electro-Chemical Activation (ECA). These on-site devices use inputs of salt water and low voltage power to produce two non-toxic streams of elecrolytes.  One is a natural surfactant, the other a broad spectrum sanitizer. Coupled to a produce washing process, this rinsing system kills harmful bacteria and inactivates virus in a short time.  Most are inactivated on contact but additional contact time is advisable to better ensure reductions below infective levels.   The washing process may include rubbing, turbulence and spraying. The ECA rinse at the final stage helps seal the deal, reducing chances for cross-contamination. The ECA and ozone generator systems can be used in equipment sanitizing processes as well. Word is there are systems under development integrating the two solutions.

An ultrasonic system, under development in the late 90’s, was shelved when vibrations from the process transmitted through the sinks and tables and had adverse effects on welds and seams and the cost to integrate dampening made this enhancement impractical.  Some entrepreneurial group will likely find a way to overcome those detractions in the future.

Treat Your Produce Well and It Will Last Longer

All of the above solutions claim a longer shelf life is given to produce and that makes lots of sense – wash it properly, remove the  pathogens and it will stay fresher longer. Additionally, drying is a critical step for leafy products and various drying solutions exist from tabletop to large-scale machines.  Several centrifuge type systems exist today, and they are critical to extending shelf life of produce whenever there will be more than a day between processing and consumption.

Produce (Sanitation) is a Growing Issue

So, produce sanitizing is a growing concern.  Most of my clients are totally ‘on board’ with sourcing the local produce, though not all have realized the need for the careful sanitizing process. Others are aware of the threat of contamination, but have not found a viable, safe method or system.  It won’t take long for people to catch on and address the issue a bit more seriously. In the meantime we are designing the eqiupment solutions into our projects and many capable suppliers with varied equipment and peripheral solutions are lining up to meet the needs.

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