Freshness/spoilage monitoring of rainbow trout (Oncorhynchus mykiss) fillet using pH-sensitive indicator film based on Arabic gum-carboxymethyl cellulose and purple basil (Ocimum basilicum. L) anthocyanin

Rezaie, Amir; Rezaei, Masoud; Alboofetileh, Mehdi

doi:10.48311/jfst.2025.27546

Freshness/spoilage monitoring of rainbow trout (Oncorhynchus mykiss) fillet using pH-sensitive indicator film based on Arabic gum-carboxymethyl cellulose and purple basil (Ocimum basilicum. L) anthocyanin

Document Type : Original Research

Authors

Amir Rezaie ¹

Masoud Rezaei ¹

Mehdi Alboofetileh ²

¹ Department of Seafood Processing, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran

² 2- Persian Gulf and Oman Sea Ecological Research Center, Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research, Education and Extension Organization (AREEO), Bandar Abbas, Iran

10.48311/jfst.2025.27546

Abstract

In the present study, pH-sensitive indicator film based on Arabic gum-carboxymethyl cellulose and purple basil (Ocimum basilicum L.) anthocyanin was prepared and used to monitor the freshness/spoilage of rainbow trout (Oncorhynchus mykiss) fillet during refrigerated storage period. For this purpose, anthocyanin of purple basil were extracted and added to the 100 mL of the Arabic gum-carboxymethyl cellulose film solution at concentrations of 40, 60, and 80 mg. The color change of the prepared films was measured at different pH levels (2-12) and ammonia gas concentrations. Result of this evaluations showed that the color of the indicator films was pink to purple at low pH, colorless at neutral pH, and yellow at high pH. Furthermore, the response of the indicator films in the presence of ammonia gas was similar to high pH, which the color was yellow. During the refrigerated storage period, freshness evaluation indices of the fish fillet, such as pH, total volatile basic nitrogen (TVB-N) and total bacterial count (TVC) were measured in addition to the films color. The TVC, TVB-N and pH were measured at day 0 as 4.8 log cfu/g, 5.2 mg/100g, and 6.7, respectively. These parameters were increased significantly with increasing the 12-day storage period. TVB-N and TVC were exceeded the permissible human consumption limit on day 8. The color of the indicator films was colorless at the beginning of the period (day 0) and it was changed to yellow at day 12, which is a sign of spoilage.

Keywords

Freshness monitoring

Biodegradable films

pH Indicator

Anthocyanin

Storage period

Subjects