Adding 0.02 per cent of the extract to ground pork meat reduced the lipid oxidation in processed meat that can lead to the formation of off-odours associated, says the research published in the Journal of Food Science.
Furthermore, the extract performed at least as well as the more established synthetic preservatives such as like butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT), said the researchers from the University of Illinois.
According to a 2003 report by Frost and Sullivan, the synthetic antioxidant market is in decline, while natural antioxidants, such as herb extracts, tocopherols (vitamin E) and ascorbates (vitamin C) are growing, pushed by consumer desire acceptance and easier market access.
The research adds to previous reports from the same researchers published in the same journal that adding the phenolic-rich grape-seed extract at a concentration of 0.02 per cent reduced the formation of off-odours associated with lipid oxidation in processed meat without affecting the colour of the product.
The researchers, led by Susan Brewer, investigated the effect of various antioxidants on the oxidative and colour stability of pre-cooked pork patties. They used grape seed extract (Gravinol Super, Kikkoman), oleoresin rosemary (Herbalox Seasoning HT-25, Kalsec Inc.), water-soluble oregano extract (Origanox WS, RAD Natural Technologies), propyl gallate (Sigma), BHA (Sigma), and BHT (Sigma). All the compounds were used at a concentration of 0.02 per cent.
After storing the patties for six months at minus 18 degrees Celsius, they found that pork that was not treated with any antioxidant developed a rancid odour between the first and second months of storage. Furthermore, so-called cardboard flavours were significantly higher after four months of storage, compared to the start of the study.
On the other hand, when the grape seed extract was added to the patty, lower rancid odour scores were obtained. Moreover, these scores were lower that the BHT-, oleoresin rosemary-, and BHA-containing samples.
The degree of lipid oxidation was measured using the thiobarbituric acid-reactive substances (TBARS) assay, and this found that the grape seed extract had the best antioxidant activity.
“Grape seed extract has the potential to inhibit oxidative rancidity as well as current synthetic antioxidants,” wrote the researchers.
“Grape seed extract has the potential to be as powerful an antioxidant as synthetic antioxidants that are currently used in cooked, frozen meat products without adversely affecting meat colour,” they concluded.
Source: Journal of Food SciencePublished online ahead of print, doi: 10.1111/j.1750-3841.2008.00979.x“Effect of Natural and Synthetic Antioxidants on the Oxidative Stability of Cooked, Frozen Pork Patties”Authors: A. Sasse, P. Colindres, M.S. Brewer