Abstract:

Effects of rosemary extracts on lipid oxidation, antibacterial activity and quality of cooked pork patties under
vacuum packaging were assessed. Rosemary extracts were added into cooked pork patties at levels of 0.03%, 0.06% and
0.09% compared to a control and a synthetic antioxidant (butylated hydroxytoluene, BHT) treatment. Thiobarbituric acid
reactive substances (TBARS), total bacterial counts, total volatile basic nitrogen (TVB-N), pH values, redness (a*) and
textural characteristics during 10 d of chilled storage were analyzed. The results showed that additions of rosemary extracts
caused significantly lower extent of lipid oxidation than control samples (P < 0.05). Addition of 0.09% rosemary extracts
showed remarkable antibacterial activities throughout the chilled storage compared with control (P < 0.05). After 4 d of
storage, patties with rosemary extracts displayed a significant lower TVB-N than control (P < 0.05). The control samples
from had significantly higher pH values than those prepared with rosemary extracts during the storage (P < 0.05). After 1 d of
storage, supplementation of 0.09% rosemary extracts showed greater a* values than control, while a* values of all treatments
with rosemary extracts were significantly greater compared to control after 7 and 10 d of storage (P < 0.05). In addition, the
chewiness of cooked pork patties added with rosemary extracts increased significantly after 4, 7 and 10 d of storage. After 1
and 10 d of storage, patties with rosemary extracts showed greater hardness than control, while patties with 0.09% rosemary
extracts exhibited significantly higher hardness after 4 and 7 d of storage (P < 0.05). This study reveals that rosemary extracts
could have great antioxidative and antibacterial activities and improve the color and textural characteristics of cooked pork
patties under vacuum packaging.

Key words: rosemary extracts, vacuum-packaged cooked pork patties, lipid oxidation, antibacterial activity, quality