3.2. Microbiological analysis
Microbial counts of the control and the other samples packaged with three active LDPE films were shown in Table 2. The initial total bacterial count of the control was 3.20 lg cfu g1, then improved to 6.19 lg cfu g1 after 6 days. This value has exceeded the acceptable limit (6.0 lg cfu g1) reported in many previous studies (Cao et al., 2013; Jeon, Kamil, & Shahidi, 2002). The control sample only had a shelf life of 6 days. However, total bacterial counts of the samples treated with 112 nm CE-NPs. 215 nm CE-NPs and 527 nm CE-NPs coatings decreased to 7.61, 7.14 and 6.60 lg cfu g1 on day 15 (P < 0.001). This indicated that the shelf-life of the chilled pork treated with 527 nm CE-NPs could be extended to 15 days of storage.