Alfalfa sprouts&food safety - EFR 6-14

The following memo sent by the Food and Drug Administration is a helpful reminder that, as people attempt to find "healthy" foods based on vague notions of "natural," the industries that pop (dare I say "sprout"!) up to capitalize on these fears are often less than fastidious when it comes to good manufacturing processes. While part of the memo is the technical stuff related specifically to the problem, it points out that there are regulations and processes that need to be followed to maintain a food supply that presents a very low risk to consumers.

DATE: MARCH 22, 1996
FROM: DIVISION OF FEDERAL-STATE RELATIONS, ORO/ORA/FDA (HFC-150)
SUBJ: ALFALFA SPROUTS

PERSONNEL IN OUR CENTER FOR FOOD SAFETY AND NUTRITION, RECENTLY RESPONDED TO A REQUEST FOR GUIDANCE PERTAINING IN PART TO MICROBIOLOGICAL SAFETY WHEN INDIVIDUALS OR COMPANIES SPROUT ALFALFA SEEDS INTO SPROUTS FOR HUMAN CONSUMPTION.

INFORMATION IS ALSO BEING PROVIDED TO YOU SO THAT YOU CAN BE AWARE OF RECOMMENDED CONTROLS, SALMONELLA OUTBREAKS BEING LINKED EPIDEMIOLOGICALLY TO CONSUMPTION OF ALFALFA SPROUTS, ETC. PERTINENT TEXT/COMMENTS ARE LISTED BELOW FOR YOUR INFORMATION.

". . . Two major outbreaks of salmonellosis have been epidemiologically linked to the consumption of alfalfa sprouts. The first was due to Salmonella stanley and the second due to Salmonella newport. Both outbreaks involved seed imported into the U.S. from Europe. In addition, ... FDA's Seattle District Laboratory has isolated Salmonella agona and a Salmonella Group C2 (speciation not yet available) from unsprouted alfalfa seeds imported from Australia. Thus, it appears that we have a potential public health problem with all unsprouted alfalfa seeds."

"Although the exact nature of the contamination is not known, it is likely that the contamination is on the surface of the seeds themselves. Alfalfa seeds are raw agricultural commodities, and as such as exposed to feral animals in the growing fields, and possibly during storage and shipment. Title 21 of the Code of Federal Regulations is fairly restrictive in what can be used for the washing of fruits and vegetables, sodium hypochlorite being the only practical chemical disinfectant allowed. Section 173.315 of Title 21 is also specific regarding the concentration that may be used: the maximum being 0.2 percent of sodium hypochlorite in wash water (this translates to 2,000 ppm)..."

Some shared university research results concerning the efficacy of chlorine on the disinfection of alfalfa seeds artificially inoculated with Salmonella stanley, indicate that "... it may require washing of the seeds in a highly chlorinated wash water (2,000 ppm available [free] chlorine) for a period of 5 minutes. This should be followed by a rinse with water containing 3-4 ppm of available chlorine."

"This is a high level of sodium hypochlorite and although the research has not yet been performed to demonstrate its efficacy, treatment of the seeds for a longer period of time with lower levels of sodium hypochlorite may provide similar efficacy. A wash in 500 ppm for 30 minutes may provide a mechanism to reduce the level of salmonellae on alfalfa seeds..." The university study has also yielded "an alternative method for disinfection, utilizing heat as the destructive agent..."

The university research data indicated that "... immersion of the seed in water at a temperature of 135 degrees F for 5 minutes is also effective in killing of Salmonella stanley. Periods in excess of 5 minutes at this temperature should be avoided, as reductions in percentage of seeds germinating may result. In my opinion, it would be prudent for alfalfa sprout growers to either treat their seed with at least 500-2,000 ppm of chlorine for 30 minutes (followed by a wash with water containing 3-4 ppm free chlorine) or heat the seed in water at a temperature of 135 degrees F for 5 minutes, prior to sprouting. This is to be considered interim guidance, as research continues to determine additional means to eliminate salmonellae from alfalfa sprouts."

"It should be emphasized, however, that sprouting plants may have salmonellae already introduced into their facilities that may have entered via contaminated seeds used in the past. It should also be emphasized that seed treatment (seed disinfection) does not replace sprouting of the seeds under Good Manufacturing Practices (GMPs), which require proper and adequate cleaning and sanitizing of the food manufacturing facility. Sprouters must sanitize their plant environment prior to the introduction of disinfected seeds to preclude their becoming recontaminated during the sprouting process. This is to include all misting or watering devices and other equipment used in the plant. Water used in the process must also be safe, i.e., potable (generally considered to be water containing 3-4 ppm available chlorine). These are requirements for food manufacturers under Title 21 of the CFR, Section 110..."