Impact of Acetylation and Oxidation on Some Functional, Structural and Pasting Properties of Irish Potato (Solanum tuberosum) starch

Abstract

To meet the demanding technological needs of today, as well as eliminate the
drawbacks, native starches have been chemically modified. Oxidation and
acetylation have been widely employed to alter the chemical structure of starch. In
this study, native Irish potato starch (NIPS) was chemically modified with acetic
anhydride and sodium hypochlorite to produce oxidized (OIPS) and acetylated
(AIPS) starch. The functional and pasting properties of NIPS, OIPS and AIPS
were investigated. Oxidation and acetylation decreased the bulk density, pH, and
water absorption capacity (WAC) of native Irish potato starch whereas an
improvement was observed in the moisture content, the oil absorption capacity
(OAC) and foam capacity with respect to chemical modification. Oxidation and
acetylation increased the OAC of NIPS by 26.7% and 138%, and the foam capacity
by 23.1% and 34.0%. Oxidation and acetylation decreased WAC by 18.75% and
61.27% respectively. Oxidation increased the dispersibility by 1.47% while
acetylation decreased it by 4.94%. Oxidation increased peak and trough viscosities
but reduced breakdown, final and setback viscosities, whereas acetylation
increased peak, trough and breakdown viscosities but reduced final and setback
viscosities. The high peak and final viscosities of NIPS, OIPS, and AIPS suggest
that they could be used as thickeners in sterilizable products such as baby food and
sauces.