Hydroxyethyl cellulose‐based indicator labels to track freshness of anchovy (Engraulis encrasicolus)

In this study, it was aimed to develop a freshness indicator label that changes color with spoilage of fish. Hydroxyethyl cellulose‐based indicator labels were prepared using two different mixed indicator (bromothymol blue/phenol red, cresol red/thymol blue) formulations. The functionality of prepared indicator labels was tested on anchovy (Engraulis encrasicolus) stored at 2°C and 10°C. Changes in total mesophilic aerobic bacteria, Pseudomonas spp., total yeast and mold counts, and total volatile basic nitrogen (TVB‐N) contents of anchovy during storage were examined. Color changes of prepared indicator films were measured by a colorimeter. Correlation between color changes of indicator labels with microorganism growth and content of TVB‐N was investigated. It is concluded that developed indicator labels change color with spoilage of anchovy and can be used as freshness indicator in fish industry.