Physiochemical and functional properties of albumin and globulin from amadumbe (Colocasia esculenta) corms

Abstract

Amadumbe (Colocasia esculenta), commonly known as Taro is an indigenous underutilised crop of Southern Africa. Limited utilisation of amadumbe grown in the region may be attributed to the lack of enough information on its corms and storage proteins. In this study, albumin, and globulin fractions from three landraces were investigated for their physicochemical and functional properties. Crude protein contents of amadumbe flours ranged between 2–4%. Amadumbe flours were rich in lysine (5.3 g/100 g) and leucine (9.1 g/100 g). Three major protein families were identified corresponding to albumin and globulin with approximately 55-60 kDa, 20–22 kDa and 14 kDa, respectively. FTIR revealed a protein secondary structure dominated by β-sheets and β-turns. Intrinsic fluorescence results suggested that all albumin and globulin fractions had well-defined tertiary structures. The protein solubility of albumin and globulin fractions were minimal at pH 5. Hydrophobicity data seemed to correlate with emulsification behaviour of the protein fractions. Amadumbe proteins and its albumin and globulin fractions can be a promising source for food protein applications.

Keywords:
characterisation, amadumbe; taro protein; composition; structure