The grape seed and pine bark extracts also reduced measures of oxidation and therefore meat spoilage after nine days, whereas the synthetically treated meat showed a more than 200 percent increase in oxidation.
"Results of this work show that ActiVin and Pycnogenol are promising additives for maintaining the quality and safety of cooked beef," said the researchers.
In addition to replacing harmful synthetic preservatives, natural preservatives have the added advantage of actually boosting health. For example, studies have linked grape seed extracts like ActiVin to improved cardiovascular health through its ability to limit oxidation of LDL (bad) cholesterol, and other studies suggest pine bark may improve conditions such as asthma and male infertility, and has improved memory in laboratory mice.
The color of the meats were also affected by the extracts, as grape seed and pine bark both lightened the color of the meat and increased its redness.
"The retention of the red color of cooked beef treated with ActiVin and Pycnogenol may result from their antioxidative effects and their contribution of pigments. The fact that ground beef treated with ActiVin and Pycnogenol retained more redness during cooking may result in consumers avoiding consumption of undercooked meat," the study said.
The researchers noted one possible drawback of using the natural extracts in high concentrations: a negative impact on consumers' perception of taste, color and texture of the meat. The researchers concluded that more research would be needed to see if grape seed and pine bark extracts could be used in high enough concentrations to be effective without impacting flavor and aroma.
"It is vitally important to get cancer-causing additives like sodium nitrite out of processed meats," said Mike Adams, author of Grocery Warning, a book that details the harmful additives and ingredients in everyday foods. "If food processing companies replaced sodium nitrite and other chemical additives with plant-based extracts, it would drastically reduce cancer rates and save tens of thousands of lives a year," he said. "But food companies are more interested in profits than public health, so they continue to use the cheapest additives available, even when they are chemicals with known carcinogenic effects."