Development of Banana Pseudostem Incorporated Heat-Induced Surimi Gel from Nemipterus Japonicus and its Characterisation

Abstract

The present study aimed at developing a fibre-incorporated surimi gel with improved functional properties by incorporating banana pseudostem flour (BPF), an abundant agro-industrial waste, into Nemipterus japonicus (Japanese threadfin bream) surimi. Surimi gel with varying concentrations of BPF (0-5%) was prepared using trial and error method and named as S1 (0%), S2 (1%), S3 (2.5%), and S4 (5%). Results indicated that S4 significantly improved (p < 0.05) gel strength, water-holding capacity, and sensory acceptability of the gel, although it caused a slight reduction in whiteness. The incorporation of 5% BPF (S4) was found to be optimal for enhancing the dietary fibre content without compromising the quality of the surimi gel. The total dietary fibre content of S4 was 2.52 ± 0.06%. Addition of BPF also significantly improved the thermal stability of surimi gel, as evidenced by an increase in the first endothermic peak temperature from 33.67 °C in S1 to 50.71 °C in S4 in Differential Scanning Calorimetry (DSC) analysis. Thermal stability analysis and structural characterisation were performed to compare the differences between S1 and S4. Scanning electron microscopy revealed a denser, more heterogeneous structure in S4 than in S1. Addition of BPF modified the surimi microstructure by promoting protein–fibre interactions, resulting in a more integrated network that enhances gel strength and waterholding capacity. Fourier transform infrared spectroscopy (FTIR) results confirm that BPF incorporation does not disrupt the fundamental protein structure but rather promotes intermolecular interactions, thereby improving gel network stability and functional properties. Overall, this study demonstrates that banana pseudostem flour, a valuable secondary raw material, can be effectively utilised at an optimal level of 5% to enhance the functional properties of surimi gel.