Contains Nonbinding Recommendations 
Guidance for Industry 
Measures to Address the Risk for 
Contamination by Salmonella Species in 
Food Containing a Pistachio-Derived 
Product as an Ingredient 
Additional copies are available from: 
Office of Food Safety 
Division of Plant and Dairy Food Safety, HFS-317 
Center for Food Safety and Applied Nutrition 
Food and Drug Administration 
5001 Campus Drive
College Park, MD 20740 
(Tel) 240-402-1700 
http://www.fda.gov/FoodGuidances 
You may submit either electronic or written comments regarding this guidance at any time.  
Submit electronic comments to http://www.regulations.gov.  Submit written comments on the 
guidance to the Division of Dockets Management (HFA-305), Food and Drug Administration, 
5630 Fishers Lane, rm. 1061, Rockville, MD 20852.  All comments should be identified with the 
docket number listed in the notice of availability that publishes in the Federal Register. 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Food Safety and Applied Nutrition 
September 2011  Contains Nonbinding Recommendations 
 
 
Table of Contents 
 
 
I. Introduction
   
II. Discussion
   
A.  Considerations for Evaluating the Effectiveness of Certain Salmonella 
Control Measures 
B.  Recommendations 
III. References
   
 
 
 
 
 
  Contains Nonbinding Recommendations  
 
 
Guidance for Industry1 
 
Measures to Address the Risk for  
Contamination by Salmonella Species in  
Food Containing a PistachioDerived  
Product as an Ingredient 
 
This guidance represents the Food and Drug Administration's (FDA's) current thinking on 
this topic.  It does not create or confer any rights for or on any person and does not operate 
to bind FDA or the public.  You can use an alternative approach if the approach satisfies the 
requirements of the applicable statutes and regulations.  If you want to discuss an alternative 
approach, contact the FDA staff responsible for implementing this guidance.  If you cannot 
identify the appropriate FDA staff, call the telephone number listed on the title page of this 
guidance. 
 
I.  Introduction
 
 
This guidance is intended for manufacturers who use a pistachio-derived product as an ingredient 
in a food product. Pistachio-derived products include roasted in-shell pistachios and shelled 
pistachios (also called kernels) that are roasted or raw.  We are issuing this guidance in light of a 
recent investigation by FDA and the California Department of Public Health of Salmonella 
species (Salmonella spp.) contamination in pistachio-derived products (Refs. 1 and 2).  The 
producer issued a voluntary recall involving a substantial quantity of its products.  Because the 
recalled pistachio-derived products were used as ingredients in a variety of foods, this recall 
affected many products and resulted in additional recalls.     
 
Salmonella can cause serious and sometimes fatal infections in young children, frail or elderly 
people, and others with weakened immune systems.  Healthy persons infected with Salmonella 
often experience fever, diarrhea (which may be bloody), nausea, vomiting, and abdominal pain.  
In rare circumstances, infection with Salmonella can result in the organism getting into the blood 
stream and producing more severe illnesses such as arterial infections (i.e., infected aneurysms), 
endocarditis, and arthritis. 
 
FDA may take enforcement action, including pursuing product seizure, where food has tested 
positive for Salmonella spp. (Refs. 3 and 4).   The circumstances under which food is deemed 
adulterated are set forth in section 402 of the Federal Food, Drug, and Cosmetic Act (FD&C 
Act), and related prohibitions applicable to adulterated food are contained in section 301 (21 
                                                 
1 This guidance has been prepared by the Division of Plant and Dairy Food Safety in the Center for Food Safety and 
Applied Nutrition at the U.S. Food and Drug Administration. 
  1 Contains Nonbinding Recommendations  
 
 
U.S.C. 342 & 331).  Consequences for violations of the FD&C Act include seizure, injunction, 
and criminal prosecution.  (See, e.g., sections 301(a) through (c) and section 303(a) of the FD&C 
Act).   
 
This guidance does not provide recommendations for producers of pistachio-derived products.  
Importantly, this guidance does not diminish the responsibility of producers of pistachio-derived 
products to ensure that foods that they produce are not adulterated under the FD&C Act or 
otherwise in violation of the law.  FDA has contacted producers of pistachio-derived products to 
remind them that our current good manufacturing practice (CGMP) regulations apply to them 
(Ref. 5). 
 
FDAs guidance documents, including this guidance, do not establish legally enforceable 
responsibilities.  Instead, guidances describe the Agency's current thinking on a topic and should 
be viewed only as recommendations, unless specific regulatory or statutory requirements are 
cited.  The use of the word should in Agency guidances means that something is suggested or 
recommended, but not required.  
II.  Discussion 
A.  Considerations for Evaluating the Effectiveness of Certain 
Salmonella Control Measures  
 
Salmonella spp. are bacteria that ordinarily are sensitive to heat and high acidity. This sensitivity 
is often the basis for food processing used to control the presence of the organism.  For example, 
it takes only 3 seconds to achieve a 5-log reduction in Salmonella at 71 C (equivalent to 160 F) 
in fruit juices (Ref. 6). 
 
While considered heat sensitive, Salmonella spp. can become heat resistant in dry food products 
such as powdered milk (Ref. 7) or in low water activity products such as chocolate syrup and 
peanut butter (Refs. 8 and 9).  The water activity of pistachios is generally low; for example, 
pistachios may be dried to a water activity of 0.82 for short-term storage or 0.70 for long-term 
storage to prevent mold growth and aflatoxin contamination (Ref. 10).  The relationship of 
Salmonella heat resistance to water activity has been well-studied at water activities between 
0.99 and 0.85. Generally, Salmonella becomes more heat resistant as the water activity of a food 
becomes lower (Refs. 11 and 12). For example, it takes less than 5 minutes to achieve a 5-log 
reduction of Salmonella at 140 F in a food with a water activity of 0.99 (Ref. 13). However, it 
takes 50 minutes to achieve the same reduction of Salmonella at 140 F in a food with a water 
activity of 0.85 (Ref. 14).  
 
The effectiveness of processing conditions used to reduce Salmonella spp. in a particular food 
containing a pistachio-derived product as an ingredient may depend on whether, and to what 
extent, the water activity of the pistachio-derived product changes within the food matrix to 
which it is added.  Any Salmonella in the pistachio-derived product would be expected to 
become relatively less heat resistant if the ingredient attained a higher water activity within the 
food matrix, whereas it would not be expected to respond in this manner if the pistachio-derived 
  2 Contains Nonbinding Recommendations  
 
 
product retained its initial water activity.  Similarly, any Salmonella that might move into a 
higher water activity portion of the food matrix and rehydrate would be expected to become less 
heat resistant.  Therefore, the heat resistance of Salmonella spp. introduced through a pistachio-
derived product will, upon incorporation into a food matrix, depend upon the nature of the food 
and the way in which the food is handled during manufacture.  For example, Salmonella spp. 
originally present in a pistachio-derived product, which is added and thoroughly mixed into a 
food such as a bakery product mix, has the potential to move uniformly in the mix, rehydrate, 
and become less resistant to heat. However, factors affecting the rehydration, such as the amount 
of time between preparing the bakery product mix and cooking it, could affect the susceptibility 
to heat of the Salmonella spp. during the baking process.  In addition, knowing that a baked good 
is heated at an oven temperature such as 375 F for a fixed time (such as 10 minutes) does not 
provide information about the temperature actually achieved at the coldest point in the bakery 
product, the uniformity of the temperature achieved in the bakery product, and the actual 
duration of time that the bakery product experienced its maximum temperature. 
 
B.  Recommendations 
 
Because procedures used to manufacture finished products containing a pistachio-derived 
product as an ingredient may or may not adequately reduce2 the presence of Salmonella spp., 
FDA recommends that: 
 
  Manufacturers of foods containing a pistachio-derived product as an ingredient obtain 
pistachio-derived product only from suppliers with processes in place to adequately 
reduce the presence of Salmonella spp.  
   
  Manufacturers purchasing a pistachio-derived product as an ingredient in a form for 
which no process has been applied to ensure adequate reduction in the presence of 
Salmonella spp. (e.g., raw shelled pistachios), and manufacturers that have purchased a 
pistachio-derived product about which questions have been raised concerning the 
potential presence of Salmonella spp. in a particular lot or lots, ensure that their own 
manufacturing process would adequately reduce the presence of Salmonella spp. (based 
upon a combination of time and temperature, or other means).  In evaluating the ability of 
their manufacturing processes to reduce the presence of Salmonella spp. in the finished 
product, such manufacturers should consider the following:  
 
o  Based on the available data and information, the processing conditions 
appropriate to adequately reduce Salmonella spp. in a particular food product vary 
depending on the specific characteristics of the food product.        
                                                 
2 In this document, we use the phrase adequately reduce to mean capable of reducing the presence of Salmonella 
to an extent sufficient to prevent illness. The extent of reduction sufficient to prevent illness usually is determined by 
the estimated extent to which Salmonella spp. may be present in the food combined with a safety factor to account 
for uncertainty in that estimate.  For example, if it is estimated that there would be no more than 1000 (i.e., 3 logs) 
Salmonella organisms in the food, and a safety factor of 100 (i.e., 2 logs) is employed, a process adequate to reduce 
Salmonella spp. would be a process capable of reducing Salmonella spp. by 5 logs. 
  3 Contains Nonbinding Recommendations  
 
 
o  Determining the processing conditions appropriate to adequately reduce 
Salmonella spp. in a particular food product involves considerable expertise in 
both food microbiology and the physics of heat transfer.       
o  The most reliable way to determine whether a manufacturing process would 
reduce the presence of Salmonella spp. in a food product containing a pistachio-
derived product as an ingredient is to conduct a scientific study to determine the 
death rate of Salmonella spp. in the product using microbiological challenge 
studies, taking into account properties of the food.        
o  A history of negative microbiological tests for Salmonella spp. in the finished 
product, while useful in a verification program for a process, is not sufficient, by 
itself, to determine the adequacy of a process in reducing the presence of 
Salmonella. 
 
FDA is aware that the Grocery Manufacturers Association (GMA), collaborating with other food 
industry organizations in a Salmonella Control Task Force and a Nut Safety Task Force, has 
recently published two industry guidance documents.  The first document reviews and 
synthesizes information about industry programs in place to control Salmonella spp. and help 
ensure the safety of low-moisture food products (Refs. 15 and 16).  The second document (Ref. 
17) builds upon the first and provides a comprehensive handbook on the control of food safety 
hazards for peanut and tree nut shellers, hullers, processors, and manufacturers.  Manufacturers 
that use a pistachio-derived product as an ingredient in a food product may find GMAs 
documents useful.  Please be aware that FDA is not responsible for the content of GMAs 
documents, which FDA did not create and has not verified. 
III.  References 
We have placed the following references on display in the Division of Dockets Management, 
Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852. You may 
see them at that location between 9 a.m. and 4 p.m., Monday through Friday. As of August 17, 
2011, FDA had verified the Web site address for the references it makes available as hyperlinks 
from the Internet copy of this guidance, but FDA is not responsible for any subsequent changes 
to Non-FDA Web site references after August 17, 2011. 
 
1.  FDA.  2009.  Update on Pistachio Product Recall. 
 
2.  FDA.  2009.  Pistachio Product Recalls.  
 
3.  FDA.  2005.  Compliance Policy Guide Sec. 527.300, Dairy Products - Microbial 
Contaminants and Alkaline Phosphatase Activity (PDF, 103KB).   
 
4.  FDA.  1995.  Compliance Policy Guide Sec. 555.300 Foods, Except Dairy Products - 
Adulteration with Salmonella (7120.20). 
 
5.  FDA.  2009.  April 3, 2009 FDA Letter to Processors About Current GMPs.  Updated 
June 18, 2009. 
  4 Contains Nonbinding Recommendations  
 
 
 
6.  Mazzotta, A.S.  2001.  Thermal Inactivation of Stationary-Phase and Acid-Adapted 
Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in Fruit Juices.  
Journal of Food Protection 64:315-320. 
 
7.  Dega, C.A., J.M. Goepfert, and C.H. Amundson.  1972.  Heat Resistance of Salmonellae 
in Concentrated Milk.  Applied Microbiology 23:415420. 
 
8.  Goepfert J.M. and R.A. Biggie.  1968.  Heat Resistance of Salmonella typhimurium and 
Salmonella seftenberg 775W in Milk Chocolate.  Applied Microbiology 16:1939-1940.   
  
9.  Shachar D. and S. Yaron.  2006.  Heat Tolerance of Salmonella enterica Serovars Agona, 
Enteritidis, and Typhimurium in Peanut Butter.  Journal of Food Protection 11:2687-
2691.     
  
10. Aktas, T. and R. Polat.  2007.  Changes in the Drying Characteristics and Water Activity 
Values of Selected Pistachio Cultivars During Hot Air Drying.  Journal of Food Process 
Engineering 30:607-624. 
 
11. Corry J.  1976.  The Safety of Intermediate Moisture Foods with Respect to Salmonella.  
In Intermediate Moisture Foods, eds R. Davies, G. Birch and K. Parker, 215-238. 
London: Applied Science Publishers Ltd.    
  
12. D'Aoust J.-Y.  1989.  Salmonella.  In Foodborne Bacterial Pathogens, ed M Doyle, 327-
445. New York: Marcel Dekker.     
 
13. Baird-Parker A.C., M. Boothroyd, and E. Jones.  1970.  The Effect of Water Activity on 
the Heat Resistance of Heat Sensitive and Heat Resistant Strains of Salmonellae.  Journal 
of Applied Bacteriology 33:515-522.      
 
14. Gibson B.  1973.  The Effect of High Sugar Concentrations on the Heat Resistance of 
Vegetative Microorganisms. Journal of Applied Bacteriology 36:365-376.   
   
15. Grocery Manufacturers Association.  2009.  Control of Salmonella in Low-Moisture 
Foods.  (available in PDF).  
 
16. Grocery Manufacturers Association. 2009. Annex to Control of Salmonella in Low-
Moisture Foods.  (available in PDF).   
 
17. Grocery Manufacturers Association.  2010.  Industry Handbook for Safe Processing of 
Nuts.  (available in PDF). 
 
 
 
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