Application of curcumin-based pH-sensitive film for freshness assessment of Indian carp species

Abstract:

The present study explore the application of a curcumin-based pH-sensitive colourimetric film as an intelligent indicator for freshness assessment of Indian carps species. The film was developed by incorporating curcumin, a natural polyphenolic pigment into biodegradable polymer matrix of sodium alginate, enabling visible colour transitions in response to pH changes associated with fish spoilage. Fresh Indian carps Rohu (Labeo rohita), and Mrigal (Cirrhinus mrigala) were stored under controlled conditions, and periodic analysis of physicochemical and microbial parameter, including pH, total volatile basic nitrogen (TVBN), and total plate count were conducted. Simultaneously, the colour response of the developed film was monitored and correlated with spoilage indicators. The film exhibited a distinct colour change from yellow to orange-red with increasing pH, corresponding to the accumulation of basic volatile compounds during storage. A strong correlation was observed between film colour variation and convectional freshness indices, confirming its reliability as real-time freshness indicators. The results demonstrate that the curcumin-based film is a cost effective, eco-friendly, and non-destructive tool for monitoring fish freshness. This study highlights its potential application in intelligent food packaging system to enhance quality control and consumer safety in the seafood industry.