Fundamental conditions required in extracting an alpha-amylase from<i> Cadaba farinosa</i> Forsk branches

Abstract

Crude extracts of Cadaba farinosa, Forsk plant are used for their starch-reducing power in most tropic  countries to liquefy/sweeten starch gruels. The extraction process is a time consuming osmotic rehydrating  process characterized by fluctuating extract yield and consequently, an unstable inherent starch-reducing  power. In this study, dried tender branches were ground (O.1 mm) and soaked for 50 min under agitation. The resulting mixture was clarified by centrifugation and tested for total proteins and α-amylase activity.  Preliminary trials preceding extraction, generated process factors which were screened using the Plackett-Burman design. The most significant factors were modeled using Doeh-lertfs design. Four of the eight factors, pH, concentration, velocity gradient of agitation and centrifugal force, were most relevant for extraction.  Statistical analysis of the models of total proteins and total activity suggested a compromise zone where  specific activity is always . 2.1 Umg^-1 under particular prevailing fundamental conditions. The complete  extraction cycle of more than 6 h was now reduced to approximately 60 min. Investigating the marginal starch-reducing power of α-amylase from Cadaba seeds could reveal a better source.

Key words: Cadaba farinosa branches, extraction, fundamental factors, screening, cell-free extract,  α-amylase.