Abstract:

Effects of different amounts of rosemary extract on lipid oxidation, antibacterial activity and quality of pork
patties during refrigerated (4 ℃) storage were assessed. Rosemary extract was added into pork patties at levels of 0.03%,
0.06% and 0.09%, respectively. Thiobarbituric acid reactive substances (TBARS), total bacterial count, pH value, color
(L*, a*, and b* values), cooking yield and sensory attributes of these patties during a storage period of 10 d were analyzed.
The results showed that the patties with rosemary extract exhibited significantly lower extent of lipid oxidation and higher
cooking yield than control samples (no added rosemary extract) (P < 0.05). It was commensurate with patties added with
0.02% butylated hydroxytoluene (BHT). Addition of 0.06% and 0.09% rosemary extract showed remarkable antibacterial
activities after 7 d of chilled storage (P < 0.05), while the pH values of these two treatments during storage were lower than
those of the control (P < 0.05). Addition of 0.06% rosemary extract exhibited significantly higher a* values after 4 d of
refrigerated storage as compared to the control (P < 0.05), 0.09% rosemary extract displayed significantly lower L* values
during the storage period (P < 0.05) and the b* values of these two treatments were both significantly higher than that of
the control (P < 0.05) during the refrigerated storage. No significant differences in flavor, texture or overall acceptability of
pork patties among treatments were observed with increasing rosemary extract addition (P > 0.05). This study shows that
rosemary extract has great anti-oxidative and antibacterial activities in pork patties. The color of pork patties also can be
improved by rosemary extract while having no negative influence on the sensory quality.

Key words: rosemary extract, pork patties, lipid oxidation, antibacterial activity, quality