California raisins make safe and tasty preservative in jerky

May 12, 2003

CORVALLIS - California raisins may soon be starring in a new role: keeping beef jerky tasty, more nutritious and safe.

Food science researchers at Oregon State University have determined that raisins are a great substitute for sodium nitrite, a preservative commonly used in beef jerky.

Mark Daeschel, an OSU food scientist, is a specialist in natural "antimicrobials" - natural substances added to food that inhibit the growth of harmful microorganisms. He and OSU research assistants Karl Schilke and Cindy Bower have completed research indicating that ground up raisins work just as well as the preservative sodium nitrite, typically used as a processed meat preservative by the food industry.

The research results will be published in an upcoming issue of the Journal of Food Science.

Daeschel and his colleagues found that adding raisins to jerky inhibited bacterial growth, especially the types prevalent in food borne illness: E. coli, Staphylococcus aureus and Listeria monocytogenes.

"Raisins performed as an antimicrobial at least as well as sodium nitrite in jerky," said Daeschel.

Sodium nitrite has been found to break down into cancer-causing chemicals during digestion. In addition inhibiting bacterial growth, raisins bring multiple nutritional benefits to jerky over jerky made with typical preservatives.

"First, when you add raisins to jerky, it means there is less fat in the jerky," he said. "Plus, raisins are high in antioxidants and have lots of fiber. Consumers are looking for all these characteristics - low fat, high fiber and antioxidants."

Raisin additives may be of benefit especially to those on sodium-restricted diets, he said. "Traditionally, high sodium foods such as beef jerky are restricted for patients on low salt diets," he said. "The substitution of raisins for a high nitrite curing mix may make beef jerky accessible to these people again."

Why do raisins work so well as a preservative in jerky?

Raisins are high in sugar, which inhibits microbial growth associated with spoiled food and food borne illness, explained Daeschel. "The sugar makes the water in food less available to microbes."

And raisins are acidic, which also discourages microbes.

With a grant from the California Raisin Board, Daeschel and his colleagues in OSU's Department of Food Science and Technology evaluated the taste, texture, antioxidant potential and antimicrobial properties of jerky made with ground beef. They compared these properties of the raisin jerky to typical commercial-type jerky made with sodium nitrite and jerky made without any preservatives.

In blind taste tests, a scientific panel in OSU's Sensory Research Laboratory in Corvallis evaluated the three types of jerky for flavor, texture, chewiness, overall liking and appearance.

"Panelists ranked the 10 percent raisin jerky as superior to the nitrite control in terms of overall liking, flavor, texture, and appearance," said Daeschel. "They said sweet and tangy flavor imparted by the raisins was pleasing and that it made the jerky seem less salty."

Why did he use raisins?

"The raisin industry is always looking for new uses for its product," he said. "We tried to come up with some type of food product whose flavor would be compatible with raisins. Then we came up with beef jerky. It's sweet and sour.

"Raisins have showed us they offer multiple benefits as an additive," added Daeschel. "People liked the texture and flavor, they inhibited bacterial growth and added nutrition. Plus raisins can be used in place of more harmful preservatives. Another benefit is that the high antioxidant levels in raisins may decrease off-flavors associated with oxidation or rancidity. We'd like to investigate that next."

Daeschel thinks that raisins may also prove valuable in vegetarian products such as meatless burgers and sausage.

Author: Carol Savonen
Source: Mark Daeschel