All You Want to Know About Sprouts

In 2016, FDA codified the growing and handling of all produce (the FSMA Rule) with a special section addressing (some of—I’ll get back to this) the unique qualities of sprouts. Upon issuance of the final Rule, the Task Force went into its third revision of the “Standard” to incorporate the appropriate elements for the applicable FSMA regulations (Produce Safety Rule, Sanitary Transport, and Intentional Adulteration). The Task Force will evaluate need for a fourth revision when the 2017 Draft FDA Guidance for Sprout Operations is finalized.

Concurrent with the development of sprout safety standards by industry and regulatory, in 2003 the Food Marketing Institute developed a Safe Quality Food (SQF) audit, within the framework of the Global Food Safety Initiative, which has become the primary food safety standard for many of the larger retailers.

Recently, SQF created a draft Sprout Module, using the language of the Sprout Standard. At the same time, due to budget concerns, the USDA has tabled the next round of beta testing and auditor training for their Sprout Safety Audit until they see more interest from growers, or industry QA, for a less expensive, thorough audit, based on the Sprout Safety Standard. Contact Ken Petersen, branch chief of specialty crops inspection division, Audit Services Branch, USDA-AMS, at [email protected] if you are interested in pursuing this option.

During the summer of 2017, the FDA released its Draft Guidance for Sprout Growers, a 123-page document with details appropriate to specific kinds of sprouting equipment (more or less costly to growers depending on the type of equipment they use) and in some cases containing unclear or insufficient scientific or statistical rationale for the specific recommendations given. Although the sprout industry and the public were given the opportunity to comment on both the FSMA Rule and the Guidance, the process of deliberation and decision does not involve further sprout grower input, and will at some point be published as “final” Guidance.

Sprout Sampling

Back to FSMA, there are several areas where regulators have codified practices for the sprout industry that are based on “the way things have been defined” and not on a scientific questioning of the applicability to the unique qualities of sprouts. For example, FDA classified sprouts as “Time/Temperature Control” for safety. It is expensive to growers and retail stores and ignores one of the most promising characteristics of sprouts. From the earliest guidance in 1999, the FDA has suggested sampling and testing of sprout irrigation water (SIW) for Salmonella and E. coli O157:H7, at about 48 hours from planting of every batch of sprouts grown (see graph).

Microbial growth in two types of samples ~30 CFU/g: seed and sprout samples (black circles) or irrigation water samples (clear circles). Solid line represents the logistic regression line from total aerobic growth.(A) Growth of E. aerogenes at ~30 CFU/g during the sprouting process. (B) Growth of Salmonella Stanley at ~30 CFU/g during the sprouting process. (Republished with permissions of Journal of Food Protection, from Quantitative Analysis of the Growth of Salmonella Stanley during Alfalfa Sprouting and Evaluation of Enterobacter aerogenes as Its Surrogate, Bin Liu and Donald W. Schaffner, Vol 70, Issue 2, 2007; permission conveyed through Copyright Clearance Center, Inc.)

Notice that the population of bacteria on the sprout increases from about 3.6 log cfu/g at the start of sprouting (about 600 cfu) to about 9 log cfu/g (100 million cfu) in 24 to 48 hours, after which it shows no further growth, and possibly a slight decline in population. Every experiment we have seen tracking normal or pathogenic bacterial growth in sprouts has almost the identical growth curve.