# Monitoring the quality of Beluga fish (Huso huso) during cold storage using pH indicator patches: a comprehensive evaluation of chemical, microbial, and sensory changes

## TL;DR

This study tested pH indicator patches to monitor Beluga fish quality during cold storage, tracking chemical, microbial, and sensory changes over time.

## Contribution

The study introduces pH-sensitive nanofibrous patches as a novel tool for real-time fish quality monitoring during cold storage.

## Key findings

- G0 and G1 patches showed clearer and sharper color changes compared to G2, indicating higher sensitivity.
- Increases in TVB-N and microbial counts correlated with significant spoilage and quality decline by day 14.
- Sensory attributes like color, odor, and texture deteriorated over time, confirming spoilage progression.

## Abstract

This study evaluated the effectiveness of pH indicator patches in monitoring the quality of Beluga fish (Huso huso) stored at 4 °C for 3, 7, and 14 days, assessing changes in chemical, microbial, and sensory properties. Three polymer solutions (G0, G1, G2) were used to create nanofibrous patches via electrospinning. The fish were stored, and chemical analyses (peroxide value (PV) and total volatile basic nitrogen (TVB-N)), sensory evaluation (texture, color, odor), and microbial counts (psychrophilic and thermophilic bacteria) were conducted. On day 3, G0 and G1 exhibited clearer color changes compared to G2, with G1 showing sharper shifts. By day 14, G0 and G1 exhibited a slight decrease in the a* value, whereas G2 showed greater variation. PV and TVB-N increased significantly, indicating oxidative spoilage and protein degradation. Sensory evaluation revealed a decline in color, odor, texture, and acceptability. The pH-sensitive patches effectively monitored fish quality, but further optimization is needed.

Unlabelled Image

•pH-sensitive patches showed clear color transitions under varying pH conditions (5–9).•G0 and G1 patches showed sharper color shifts, indicating greater sensitivity than G2.•Significant color changes correlated with increases in TVB-N, reflecting protein degradation.•Psychrophilic and thermophilic bacteria increased, supporting spoilage progression.•Significant decline in color, smell, texture, and acceptability on day 14, confirming spoilage.

pH-sensitive patches showed clear color transitions under varying pH conditions (5–9).

G0 and G1 patches showed sharper color shifts, indicating greater sensitivity than G2.

Significant color changes correlated with increases in TVB-N, reflecting protein degradation.

Psychrophilic and thermophilic bacteria increased, supporting spoilage progression.

Significant decline in color, smell, texture, and acceptability on day 14, confirming spoilage.