Effects of Blanching with Chemical Preservatives on Functional and Antioxidant Properties of Fluted Pumpkin (<i>Telferia occidentalis</i>) Leaf

Abstract

Fluted pumpkin leaves were blanched with different salt solutions, sodium chloride (FPCT), sodium benzoate (FPNB) and ethylenediamine tetra-acetic acid (FPEB) and combined salt solutions (FPCM), unblanched leaves (FPUB). The samples were evaluated for chemical composition, functional properties, mineral compositions and anti-oxidative properties. The results of the proximate composition showed that the highest protein (36.32%) and ash (9.98%) contents were recorded in FPUB, while the highest fibre content (6.70%) was found in FPCT. The results of functional properties showed that the highest foaming capacity (4.23%) and stability (2.09%) was obtained in FPEB while FPUB had the highest water (364.77 %) and oil absorption (207.66 %) capacity and emulsion capacity (80.80 m2/g). The highest vitamin C content (184.00 mg/100g) was obtained in FPUB. FPED, FPCM, FPCT and FPUB had the highest potassium (3007.50 mg/mg), sodium (2130.80mg/100 g), iron (917.10 mg/100 g) and calcium (388.50 mg/100 g)  contents respectively. FPUB had the highest phenolic content (700.00 mg GAE/100g leaf extract) while FPED exhibited highest free radical scavenging ability (83.50%). In general, blanching of fluted pumpkin leaves with salt solutions resulted in improved nutrient retention capabilities as well as enhancement of some functional properties.

Keywords: Phenolic content, vitamin C, salt solutions, emulsion capacity.