Isolation and Partial Characterisation of αAmylase from Two Vegetables Consumed in Sokoto Metropolis

Abstract

Leaves of cabbage and spinach are edible vegetables eaten all year round in
regions of northern Nigeria for nutritional purposes. α-amylase are enzymes that
catalyze the breakdown of carbohydrates into soluble absorbable molecules. In
this research, α-amylase was isolated and partially characterised from leaves of
cabbage and spinach. Conventional methods of protein purification were
adopted using successive stepwise purification steps including ammonium
sulfate precipitation, dialysis and gel filtration to obtain a corresponding enzyme
purification fold of 1, 1.8, 2.2 and 5.7 for Brassica (cabbage) and 1, 1.5, 2.3 and
5.1 for Spinachia (spinach) respectively. The purified α-amylase from the
cabbage and spinach leaves had an optimum pH of 5.5 and 5.1, optimum
temperature of 58°C and 60°C, Km of 2.5 mg/mL and 4.2 mg/mL, and Vmax of
0.24 and 0.20 respectively. The physico-chemical properties and kinetics
obtained for the α-amylase from these vegetables may justify that cabbage and
spinach can help to improve nutritional availability of foods such as simple
absorbable carbohydrates particularly for protein energy malnourished children
by facilitating food digestibility and release of macro nutrients.