Effect of different roasting techniques on techno-functional properties, bioactive constituents and morphological characteristics of muskmelon seeds
摘要
This study aimed to investigate the impact of different roasting techniques on the functionality of muskmelon seeds, where seeds were roasted using conventional techniques such as pan (6 min), sand (4 min), oven (200 °C for 15 min), as well as advanced techniques including microwave (360 W for 5 and 7 min, 700 W for 3 and 5 min) and electric roaster (150 °C for 4 and 6 min, 180 °C for 2 and 4 min) under different time and temperature conditions. The roasted seeds were extensively analysed for compositional, bioactive, functional, color and organoleptic properties and structural characterization. The results revealed a significant (p < 0.05) increase in water absorption capacity (200.74 to 224.37 g/g100 g), oil absorption capacity (188.25 to 217.17 g/100 g), emulsifying capacity (0.00 to 4.57%), reducing power (216.10 to 267.81 mg AAE/100 g), browning index (36.54 to 68.09) and sensory score. On the other hand, there was a significant decline in physical and bioactive properties, nitrogen solubility index, foaming capacity (24.83 to 9.52%), water solubility index (15.49 to 5.83%) and lightness value (75.51 to 68.05). Scanning electron microscopy illustrated the separation of the lipid layer, resulting in the disruption of the protein matrix and reduction in size of starch granules due to the application of thermal treatment. Fourier transform infrared spectra depicted the increase in intensity of peaks at different regions of absorption, especially 800 –650 cm− 1, representing the production of esters due to the Maillard reaction and gelatinisation of starch molecules. The results suggest that advanced techniques such as electric and microwave roasting are among the most effective techniques for roasting muskmelon seeds.