Antimicrobial activity of a nisin-activated plastic film for food packaging.
OBJECTIVE
To determine the effectiveness of a packaging film coated with nisin to inhibit Micrococcus luteus ATCC 10240 in tryptone soya broth (TSB) and the microbiota of raw milk during storage. A further aim was to examine the release of nisin from the activated film.


RESULTS
An active package, obtained from nisin-treated film, was filled with 1 l of M. luteus ATCC 10240 (ML) suspension in TSB and stored at 4 and 25 degrees C for 2 days. After 24 h at 25 degrees C there was a remarkable reduction of M. luteus ATCC 10240 compared with the control, while at 4 degrees C a slight reduction was observed. Moreover, microbial growth was controlled when 1 l of three different kinds of milk was poured into the active package and stored at 4 degrees C for 7 days. The most significant results were observed in raw milk and pasteurized milk with a reduction of 0.9 log and 1.3 log, respectively. The release experiments showed that nisin release from the film was unpredictable, but it was favoured by low pH and high temperature.


CONCLUSIONS
It appears that nisin-coated films were effective in inhibiting M. luteus ATCC 10240 in TSB and the bacterial flora in milk, and the release of nisin was pH and temperature dependent.


CONCLUSIONS
Nisin-activated film may control bacterial growth, maintaining food quality, safety and extending the shelf-life of food products.
Mauriello
G
G
Dipartimento di Scienza degli Alimenti Università degli Studi di Napoli Federico II, Portici, Italy. giamauri@unina.it
De Luca
E
E
La Storia
A
A
Villani
F
F
Ercolini
D
D
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D016982:Micrococcus luteus / Q000187:drug effects* / Q000254:growth & development; D008892:Milk / Q000382:microbiology; D009561:Nisin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D009561:Nisin