73D-1 |
Bacteriocin-coated antimicrobial films applied to the packaging of fresh oyster and ground beef |
Y. M. KIM1, H. D. Paik, and D. S. Lee. (1) Division of Life Sciences, Kyungnam University, 449 Wolyoung-dong, Masan, 631-701, South Korea
A packaging film containing an antimicrobial agent in its polymeric surface structure may contribute to the preserved quality of packaged foodstuffs by suppressing microbial activity on the food surface. The use of biologically-derived bacteriocins as antimicrobial additives in the films is desirable because of their potential safety advantages for packaged foods. This research aimed to apply the bacteriocin-coated plastic films to the packaging of fresh oyster and ground beef, and assess their effectiveness in preserving the quality of the fresh foods. Low density polyethylene films coated by 10% bacteriocins of nisin and lacticin NK24 in polyamide binder layer of 11 mm thickness were used for wrapping 70 g of the fresh oyster and ground beef, which were then stored at 3 and 10oC for 25 and 15 days, respectively. Throughout the storage, changes in microbial counts of total aerobic bacteria and coliform group bacteria, pH, thiobarbituric acid (TBA) value and volatile basic nitrogen (VBN) value were monitored to see the effect of the packaging film on the food quality preservation. The bacteriocin-coated films slowed down significantly the microbial quality changes of the packaged oyster and ground beef at both temperatures. Degree of reduced growth in total aerobic bacteria by using the antimicrobial film was about 100 fold for the foods stored for the whole experimental duration at 3 and 10oC. The effect of antimicrobial films on the changes in chemical attributes of TBA and VBN values became apparent later and was less pronounced compared to that in microbial quality changes. There was no difference in the effectiveness of the antimicrobial packaging on the microbial and chemical quality changes between two types of bacteriocin-coated films. The bacteriocin-coated films have shown a potential to be used as packaging films for extending the shelf life of the fresh chilled foods.
Session 73D, Food Packaging
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