The motto of Consumers Union, the publisher of Consumer Reports, is "working for a fair, just and safe marketplace for all."  The motto of Jim Prevor’s Perishable Pundit is "where the subject may be perishable but the insight isn’t."  When Consumer Reports publishes a report, it nearly always becomes widespread news.  When Jim Prevor publishes a report, it will be carefully read and commented upon within the confines of the produce industry, but it is not often that it reaches national attention.  Let us now match the insight of Jim Prevor against the values of Consumers Union.  The subject:  bagged salad.

Bagged salad is one of the most successful take-home convenience foods ever.  The produce industry loves it, because it greatly expands the market for fresh produce.  The packaging industry loves it, because it only works with special packaging that extends the product’s shelf life.  The grocery industry loves it, because it is high-margin, high-volume product that goes in the produce aisle.  And consumers love fresh salad they don’t need to prepare.  Win-win-win-win. 

Until Consumers Union comes along.

Consumers Union has published a report that is entitled, "Bagged Salad:  Better Standards and Enforcement Needed."  A shorter article is in the March issue of Consumer Reports, entitled, "Bagged Salad:  How Clean?"  Both are based on a study, funded in part by Pew Health Group, that examined samples of bagged salad purchased, as Consumers Union ordinarily does, in grocery stores near its Yonkers, New York headquarters.   It found levels of bacteria they called "indicator organisms" that exceeded standards set by a number of other countries, since there is no federal standard in the United States.  No E Coli O157:H7, listeria or salmonella was found. 

From the study, Consumers Union concluded that the United States needed to adopt food safety legislation pending in Congress (about which we reported here), needs to declare known pathogens in leafy greens "adulterants" (even though the study didn’t find any), and set satefy standards for indicator organisms.  In addition, Consumer Reports recommended that consumers should:

  1. Buy packages as far from their use-by date as possible
  2. Even if the salad is pre-washed, wash it again
  3. Prevent cross-contamination with other foods (although the link the article does not, as it appears to promise, go straight to a how-to list for that)

Since this is of great concern to the produce industry, Jim Prevor sent the report to Dr. Trevor Suslow of the University of California at Davis., a plant pathologist.  Apparently a number of other readers of the report did so as well, because Dr. Suslow’s response printed in the Perishable Pundit is broader than Jim’s questions.  Dr. Suslow makes some very cogent points about the Consumers Union report.

  • "We eat lots and lots of microbes all the time."  And generally don’t die from them.  Leafy greens are colonized by microbiota, not contaminated by them.
  • The specific number of microbes on a leaf do not relate well to risk of illness.
  • Higher numbers closer to the use-by date are expected, particularly if the product was subject to significant changes in termperature.  More specifically,

Because all the samples were taken from retail stores, the numbers of bacteria (not that fact that they were present) may tell us more about the temperature history of the product than provide clear evidence of poor sanitation.

  • Additional washing of pre-washed greens can lead to cross-contamination and is not recommended.  He cited a 2007 study to that effect which concluded,

additional washing of ready-to-eat green salads is not likely to enhance safety. The risk of cross contamination from food handlers and food contact surfaces used during washing may outweigh any safety benefit that further washing may confer

His ultimate recommendation was that a consumer should check both the way the bagged salads are placed in the store (vertical in a row, not placed on top of one another in a stack) and get a feel for the temperature at which they are stored (both the air and the bag should feel "very cool"). 

As I read the report and the rejoinder from Dr. Suslow, it would seem the Perishable Pundit has the better of it.  What Consumers Union proposed would seem to lead to a lot of regulation and attendant expense, leading to a false sense of security in consumers.  What Dr. Suslow proposed would seem to enable consumers to make senisible choices for themselves.