Effects of Hot-Water Extracts from Myrtle, Rosemary, Nettle and Lemon Balm Leaves on Lipid Oxidation and Color of Beef Patties during Frozen Storage

Abstract

The effects of hot-water extracts from myrtle, rosemary, nettle and lemon balm leaves on lipid oxidation and the color properties of beef patties during frozen storage were studied. Ground beef was treated with salt (1.5%) and five types of samples were prepared: control (no extract), 10% myrtle extract added, 10% rosemary extract added, 10% nettle extract added and 10% lemon balm extract added. Each group was adjusted to a fat content of 20% by the addition of backfat. Patties (25 g) were wrapped with polyethylene film and stored at -20 ± 2C for 120 days. Oxidative and sensory changes were evaluated after 0, 30, 60, 90 and 120 days of storage. Hot-water extracts from myrtle, rosemary, nettle and lemon balm leaves affected peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), color (except L value) and sensory properties of beef patties. Hot-water extracts from myrtle, rosemary, nettle and lemon balm leaves slowed down the lipid oxidation of beef patties. While myrtle and rosemary extracts showed the highest antioxidant effects, the effects of nettle and lemon balm extracts were lower. Myrtle extract protected the color properties of frozen beef patties. In terms of overall acceptability, myrtle and rosemary extracts were given the highest points by the panelists. Storage time affected pH, POV, TBARS, color (except L and b values) and sensory properties of beef patties. The addition of hot-water extracts from myrtle leaves at 10% ratio to the frozen storage of beef patties prevents development of oxidative processes in lipids and changes in color. PRACTICAL APPLICATIONS Lipid oxidation is one of the primary causes of quality losses in frozen stored meat and meat products. One of the methods for protection against oxidation is to use antioxidants. Hot-water extracts from myrtle and rosemary slowed down the lipid oxidation and prevented color changes of beef patties. According to these results, hot-water extracts of myrtle and rosemary can be used to extend the shelf life of meat patties and other meat products. © 2008, Blackwell Publishing.