Effect of different blanching methods on kinetics of physico-chemical, functional properties, and enzyme inactivation in baby corn

Abstract

Baby corn, characterized by its high water activity and elevated respiration rate, poses a formidable obstacle to prolonged storage under standard ambient conditions and necessitates specialized treatments for transportation to distant locations. One of the primary postharvest challenges associated with baby corn is the occurrence of brown pigment formation because of enzymatic browning at the apex of its immature ovules, cut surfaces, and silk attached to the young ears. The present study was undertaken to investigate the effect of different blanching treatments on peroxidase inactivation, physicochemical properties, and functional properties of baby corn. The treatments applied were hot water blanching (HWB) at temperatures ranging from 70°C to 90 °C for 30-240 s, steam blanching (SB) for 30-240 s, and microwave blanching (MWB) at power levels of 360 W-900 W for 30-300 s. Results indicated that 90 % peroxidase enzyme inactivation occurred under different methods as 90 °C for 60 s for HWB, 100 °C for 60 s for SB, and 540 W for 30 s for MWB. These blanching methods have shown significant effects on the properties under investigation. MWB demonstrated the highest retention of ascorbic acid (94.15 %) and minimal color changes (ΔE = 5.72) in comparison to hot water and steam blanching. Similarly, the result for total flavonoid content for 540 W, 90 °C and 100 °C for 30, 60, and 60 s were found to be 3.01,1.99 and 2.10 mg QE/100g, phenols 48.98, 47.99 and 48.03 mg GAE/100g and DPPH (%) 42.55, 34.20 and 37.08 % respectively. The findings suggest that microwave blanching of baby corn at 540 W for 30 s holds promise to inactivate the peroxidase enzyme with better retention of physicochemical and functional properties.

Keywords: Antioxidant; Baby corn; Blanching; Peroxidase; Physical chemical properties.

Fig. 1

a Effect of hot water and steam blanching on shrinkage %, b Effect of microwave blanching on shrinkage % c Effect of hot water and steam blanching on bulk density (g/cc) d Effect of microwave blanching on bulk density (g/cc) e Effect of hot water and steam blanching on true density (g/cc) f Effect of microwave blanching on true density (g/cc) g Effect of hot water and steam blanching on porosity (%) and h. Effect of microwave blanching on porosity (%).

Fig. 2

a Effect of hot water and steam blanching on the TSS (°Brix), b Effect of microwave blanching on TSS (°Brix), c Effect of hot water and steam blanching on ascorbic acid (mg/100 g) d Effect of microwave blanching on ascorbic acid (mg/100 g) e Effect of hot water and steam blanching on enzyme inactivation(%) and f. Effect of microwave blanching on enzyme inactivation(%).