Juice blends, the mixing of juice from different fruits and vegetables, are growing in demand. But some processors may not realize there can be a risk of foodborne pathogens if that juice operation does not handle and process the fruits and vegetables properly. This goes for both when serving juice fresh without any processing treatment, or fresh juice receiving a processing treatment that serves to reduce/eliminate pathogenic microorganisms (a 5 log reduction). According to the Food Code, if a processor does not use a microbial reduction process, that product must be labeled as such. (Consumers should know the difference between these two, because the non treated juice does have a higher risk for foodborne illness, especially when that juice is low acid, and/or stored for any time rather than consumed immediately).
Low acid / high pH juices are the result of using a high proportion of low acid produce such vegetables, including spinach or kale, in the blend These low acid juices, as compared to the higher acid juices, are a bigger concern in that they better able to support the growth of pathogenic bacteria if present (as compared to more acidic juices like apple juice.) When these low acid receive a processing treatment, such as those processed by ultraviolet light (UV) or by high pressure processing, Clostridium botulinum is a risk.
What are the concerns related to juice:
- Incoming contamination – fruits and vegetables can carry bacteria from the harvest areas, including organisms like E. coli (STEC), Salmonella, and Listeria. (Spinach and Salmonella Example) While it is expected that levels of these bacteria should be low, a proper washing and sanitizing step should reduce the risk to safe levels.
- Post-washing contamination – the fruit or the juice can be contaminated after washing if the processing equipment and the environment are not maintained in a sanitary conditions. Organisms like Listeria are known environmental contaminates and can re-contaminate the juice. Proper hold temperature is also important in preventing growth.
- Mold – fruit and vegetables that have rot can contain mold that produces mycotoxins. Mycotoxins are dangerous mold byproducts that can cause liver damage, cancer, and other health issues. Careful culling of damaged fruit must be done prior to pressing.
- Spore-forming pathogens such as Clostridium botulinum can be an issue in low acid juices that are treated, speficially if those juices are not properly acidified to a pH below 4.6. Any juice that is processed must have a pH below 4.6.
There have been some recent issues with juicing operations that highlight these concerns. In January, a company recalled juice blends after the ingredients were found to contain Listeria. This month, FDA issued a warning letter to a processed juice operator for not controlling the pH of their juice blend, thus creating a Clostridium botulinum risk. Another processor recalled product after discovering Listeria in the processing environment.
It is important that juice processors recognize these risks and put in controls to prevent them.
Procurement of produce –Fresh produce can bring in contamination from the field, so it is important that juice establishments source their produce from growers who utilize GAP procedures. The higher the level of contamination, the more difficult it will be to remove all the contamination during the washing and sanitizing wash step.
Using frozen fruit and vegetables - Frozen fruits and vegetables can also harbor pathogenic microorganisms. For example, there have been issues with Hepatitis A in frozen berries. But frozen vegetable can also be a risk. In many cases, frozen vegetables are made to be cooked, and are not produced at the sanitary level required for a truly ready-to-eat food. It is important for juicers to understand the source of their frozen fruits and vegetables and the types of controls used in their production.
Culling of produce – all damaged produce should be removed prior to pressing to minimize the potential for mold to be present.
Washing and sanitizing of produce – it is important that fresh produce be washed and sanitized prior to pressing. Sanitizers must be approved for application and be checked to ensure that they are applied at the required concentration. Produce should be pre-rinsed/washed prior to applying sanitizers because any residual dirt will serve to inactivate sanitizers, thus shielding the microbiological contamination.
Containers / food contact surfaces – Biofilms, thin layers of slime that shield bacteria, can build up on containers, nozzles and other food contact surfaces when those items are not properly washed and sanitized. As part of the cleaning process, it is important to remove residual fruit or vegetable matter that may cake onto the surface. Fruits and vegetables often contain sugars and starches that can build up and be difficult to remove.
Labeling of Bottles – By regulation, bottled juices must be treated (and have a HACCP plan), and if not, they must be labeled that they have not been treated.
Storage of bulk juice overnight – This is especially a concern for low acid juices. Temperature control and cleanliness issues can present the opportunity for organisms like Listeria, Staphylococcus, and Salmonella to grow. Spoilage is also an issue, especially from yeast. Bulk juice held / not bottled immediately, especially juice held overnight, must be labeled with the time and date of processing and when that juice must be used by.
Many establishments are using high pressure processing or UV treatment of juice to achieve a five log reduction of pathogens such as Salmonella. This is fine for high acid, low pH juices. But there is an issue when these juices are not pH 4.6 or lower. We have seen a number of juice operations blending in a sufficiently high percentage of low acid ingredients (kale, spinach, etc), so it is a concern that these products may have a pH above 4.6, thus creating a Clostridium botulinum issue. By regulation, there must be a secondary barrier in addition to refrigeration. Most often, this is done through keeping the pH below 4.6. So it is imperative that anyone processing juice ensure that the juice has a pH that is well below 4.6 and that pH is monitored using a calibrated pH meter is required. If not pH, then there must be validation support - reasons include competitive flora, preservatives, low Aw.