Combined application of Colocasia esculenta and Eucalyptus globulus leaf extracts for improved preservation of frozen shrimp

Abstract

This study evaluated the efficacy of Colocasia esculenta (CLE) and Eucalyptus globulus (ELE) leaf extracts in preserving the quality of frozen shrimp. Shrimps treated with 1.5% CLE exhibited significantly lower total volatile basic nitrogen (TVB-N) (12.47 mg/100 g), trimethylamine (TMA) (6.85 mg/100 g), and bacterial load (3.94 CFU/ml) compared to lower concentrations and the control. Similarly, 1.5% ELE-treated shrimps showed reduced TVB-N (11.28 mg/100 g), TMA (5.85 mg/100 g), and bacterial load (3.92 CFU/ml). The combined treatment (CLE+ELE, 1:1) was the most effective, yielding the lowest TVB-N (9.69 mg/100 g), TMA (5.08 mg/100 g), and bacterial load (3.78 CFU/ml). Sensory scores declined over the 24-week storage period but remained highest for combined treatment (8.62), followed by ELE (8.55) and CLE (8.42). These findings suggest that the combined CLE+ELE treatment at 1.5% concentration effectively enhances the microbial stability and sensory quality of frozen shrimp, making it a promising natural preservative for commercial applications.