Colorado State University Extension
SafeFood Rapid Response Network
Go to Table of Contents for this issue
IN THE NEWS
PEANUT BUTTER: FRIEND OR FOE?
By Adesuwa Elaiho, CSU Food Science StudentPeanut butter has been an American staple since the late 1800s, but this popular comfort food is now the unlikely main character in a foodborne illness outbreak and unprecedented product recall. Peanut butter and peanut butter paste contaminated with Salmonella Typhimurium have been the source of almost 700 illnesses and the cause of a record-breaking recall of more than 3,800 products. In 2007, Peter Pan peanut butter was implicated in an outbreak of Salmonella Tennessee that infected 425 people, 71 requiring hospitalization. These outbreaks have caused consumers to question whether peanut butter is truly our friend or an unexpected foe.
Salmonella is a rod-shaped enterobacteria and its discovery also dates back to the late 1800s. This pathogen has been associated with fresh poultry, meats, eggs, shrimp, and tomatoes and responsible for numerous outbreaks of foodborne illness. Common symptoms include diarrhea, fever, and abdominal cramps. Onset of the illness usually occurs within 12 to 72 hours following consumption and most people recover within 4 to 7 days without treatment. In severe cases, hospitalization may be required to maintain hydration. Infants, the elderly and immune compromised individuals are more likely to experience severe illness. The first documented outbreak of salmonellosis associated with peanut butter occurred in 1996 and was attributed to Salmonella Mbandaka.
The peanut plant is unusual in that it flowers above the soil but fruits below the surface. Runner and Spanish peanuts are the types generally used in making peanut butter. After reaching peak ripeness, peanuts are harvested, shelled, roasted, cooled, blanched, and sorted. During the grinding stages, the peanuts are heated up to about 170C and then emulsifiers are often added to help maintain consistency and prevent separation. Peanut butter paste is 100% ground peanuts and is supplied to food processors for use in products such as crackers, cereal, and candy bars.
Peanut butter is a colloidal suspension of lipid and water and has traditionally been considered low-risk when compared to many other foods. This lunchbox favorite does not usually require refrigeration and has a fairly long shelf life. This is due in part to the low water activity of peanut butter, reported to be 0.7 or below, which indicates there is a limited amount of water available to support the growth of microorganisms. A water activity of 0.70 means the vapor pressure is 70% of pure water. Most foods have a water activity above 0.95. Ironically, some studies have shown that Salmonella may exhibit more heat resistance in foods with low water activity and high fat, such as peanut butter and chocolate. Experiments with highly contaminated peanut butter samples indicate that normal heat treatments may not be adequate to destroy Salmonella. If contaminated after processing, studies have shown that Salmonella can survive in peanut butter for at least 24 weeks and possibly the duration of the expected shelf life.
To help consumers determine if they have purchased recalled peanut products, the U.S. Food and Drug Administration (FDA) has created a searchable database and is advising consumers to check it often. The data base is available at: http://www.accessdata. fda.gov/scripts/peanutbutterrecall/index.cfm. Consumers who do not have internet access can get information by calling FDA's Information line at 1-888-SAFEFOOD or the Center for Disease Control and Prevention (CDC) at 1-800-CDC-INFO.
Sources:FEWER CRACKED EGGS ON THE WAY?
Thanks to USDA Agriculture Research Service (ARS) researchers, a new technology has been developed using slight vacuum pressure and special lights to spot microcracks in eggshells prior to packaging. According to ARS, the new method has an accuracy rating of 99.4%, as compared to current practice of professional human checkers (94.2%). As one ARS staffer stated, "this could provide a tool that egg graders can use to consistently identify cracked eggs and improve the quality of the eggs that reach the consumer." To read the news release, "A Better Way to Spot Eggshell Cracks," visit the ARS' Web site at: http://www.ars.usda.gov/is/AR/archive/feb09/eggshell0209.htm.
ERYTHRITOL-SWEET JUST GOT BETTER
Label readers may have noticed lately the addition of a new sweetener on product ingredient lists. Although Erythritol was deemed safe by the FDA more than a decade ago, only recently is it gaining attention in products like chewing gum, candy, ice cream, baked goods and fruit spreads, as well as in some oral care and cold products.
A polyol, Erythritol is less likely to cause diarrhea than other sugar alcohols like sorbitol since it is digested primarily in the large rather than small intestine. It is 70% as sweet as table sugar, but it provides zero calories and is found naturally in some fruits like pears, melons and grapes. Costly to produce, price is a major drawback and thus why it is often used in combination with other sweeteners.
Erythritol can be used for baking and is available as a tabletop sweetener under the names Sweet Simplicity and Smart Sweet (both 100% erythritol), Sun Crystals (80% erythritol, 20% sugar), and truvia (erythritol and stevia, another newly approved sweetener).
Source:SURVEY ANYONE?
The National Agricultural Library's Food Safety Information Research Office (FSIRO) is seeking input to improve their website. The mission of FSRIO is supporting the research community by collecting, organizing and disseminating food safety research information. To participate, go to http://fsrio.nal.usda.gov/ and click on survey.
The information available through this Web site is provided as a public service and for educational purposes only. All efforts have been made to ensure the material on this information system is accurate and up to date. However, Colorado State University Extension and SafeFood cannot be held responsible for any circumstances resulting from its use, unavailability, or possible inaccuracy. Also, reference in this Web to any specific commercial products, process, service, manufacturer, or company does not constitute its endorsement or recommendation.