| Abstract
| - Identification and quantification of starch used as thickening andgelling agent (TGA) in sweetenedfruit preparations (SFP) are difficult because of the low levels ofconcentration and the heterogeneous,gelified, and highly sweetened nature of the medium. A method isproposed that overcomes thosedifficulties. In a first step, starches are identified by opticalmicroscopy and acetyl and hydroxypropylmodifications are characterized by Fourier transform infraredspectroscopy (FT-IR). Starchquantification requires high purification, achieved by dialysis toremove most of the sucrose. Theexperimental conditions of this step are optimized. A previousgelatinization treatment, theconditions of which are studied here, improves significantly theenzymatic hydrolysis of starch andthe quantification of the released glucose. The method proposed,applied to 15 different SFP, allowsan accurate and repeatable determination of distarch phosphate,acetylated distarch phosphate,and acetylated distarch adipate. It provides, furthermore, anappropriate tool for the special caseof a hydroxypropylated distarch phosphate. Keywords: Sweetened fruit preparation; Fourier transform infrared;dialysis; starch identificationand determination
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