African Journal of
Pure and Applied Chemistry

  • Abbreviation: Afr. J. Pure Appl. Chem.
  • Language: English
  • ISSN: 1996-0840
  • DOI: 10.5897/AJPAC
  • Start Year: 2007
  • Published Articles: 357

Article in Press

Comparative study of oxidation, acetylation and boric acid treatment with various concentrations of NaOH/alcohol on cold water solubility (CWS), amylopectin and amylose content of starches from cassava, potato and corn

Department of Biochemistry, University of Nigeria, Nsukka, Enugu State, Nigeria.

The effect of oxidation, acetylation and boric acid treatment and varying concentrations (30, 40 and 50%) of alcohol-alkaline (NaOH/alcohol) modifications on the cold water solubility (CWS), amylopectin and amylose content of starches extracted from cassava, potato and corn were evaluated and compared. The studies were carried out using the determination of cold water solubility (CWS), amylose-amylopectin content and light transmittance. Acetylation and oxidation of different starches resulted in CWS of 60, 27 and 39% for cassava, corn and potato starches and 21, 56 and 30%, of CWS starches for cassava, corn and potato, respectively. While boric acid modification yielded starches with 2% CWS for potato and 1% CWS for both cassava and corn. The results of amylopectin content after acetylation of different starches were 65, 80 and 68% for cassava, corn and potato, respectively. Also, oxidation treatments yielded 71, 80 and 80%, of amylopectin content for cassava, corn and potato starches, boric acid treatment produced amylopectin content of 69, 74 and 72%, respectively. The acetylation treatment was found to be more efficient in the production of high amylose rich starch and cold water soluble starch as compared to oxidation and boric acid treatments. Oxidation treatment was not efficient in the production of CWS starches from these sources but was efficient in the production of amylopectin rich starch. The results of alcohol-alkaline modifications at 30% showed CWS of 88, 86 and 91% for cassava, corn and potato, respectively. 40% concentration yielded 98, 61 and 98% for cassava, corn and potato, respectively. Similarly, 50% concentration yielded 86, 97 and 80% from sources. The amylose content of 30% concentration modifications were 20, 27 and 23% for cassava, corn and potato, 40% yielded 23% for cassava and 33% for both corn and potato, respectively. The amylopectin content of the samples was analyzed. The light transmittance of the treated starches increased with corresponding increase in cold water solubility. Hence, 40% alcohol-alkaline modification was more effective in the production of cold water soluble starch from cassava and potato, while 50% concentration was most suitable for corn starch.

Keywords: Oxidation, acetylation, boric acid treatment, starch, alcohol, NaOH.