Starchy networks within mungbean starch vermicelli and rice flour noodles are characterized by differential scanning calorimetry, X-ray diffraction, mild acid hydrolysis, and gel permeation studies. In these products, native starch structures disappeared but new crystalline organizations were found. An amylopectin-based crystallinity was evident from its B-type diffraction pattern, melting endotherm at 50°C and high susceptibility towards mild acid hydrolysis. In addition, amylose-based structures were present either in the complexed form (Vtype) in rice flour noodles, or in the retrograded form (B-type) in both pasta-like products. These latter crystallites were highly resistant towards mild acid hydrolysis and melted at high temperatures. Both glutenfree pasta-like products exhibited good cooking behavior which can be attributed to these amylose networks.

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A calorimetric procedure to measure arnylose content of various starchy raw materials has been developed. It is based on the measurement by Differential Scanning Calorimetry (DSC) of the enthalpy change of the formation of complexes between amylose and add phospholipid (L-a-lysophosphatidylcholine from egg yolk) observed during cooling.Contrasting to the colorimetric determination of amylose, the DSC procedure is not influenced by the presence of amylopectin or indigenous lipids. For rice and maize flours, the amylose content determinations are very similar for both colorimetric and DSC methodologies whether the starchy material was raw or pre-cooked. But the DSC methodology is more repeatable and time saving; in particular, the defatting and starch determination steps can be omitted. -~~ ~ Eine schnelle Methode zur Bestimmung des Amylosegehaltes unter Anwendung der Differential-Raster-Calorimetrie. Eln calorimetrisches Verfahren zur Bestimmung des Amylosegehaltes verschiedener starkehaltiger Rohrnaterialien wurde entwickelt. Es basiert auf der Messung durch Differential-Raster-Calorimetrie (DSC) der Enthalpieanderung durch die Bildung von Komplexen zwischen Amylose und den Zusatz von Phospholipid (L-a-lysophosphatidylcholin aus Eigelb), beobachtet wahrend der Abkiihlung. Im Gegensatz zur kolorimetrischen Amylosebestimmung wird das DSC-Verfahren nicht durch die Gegenwart von Amylopektin oder innewohnende Lipide beeinflu&. Bei Reis-und Maismehlen sind die Bestimmungen des Arnylosegehaltes einander sehr ahnlich sowohl fur die kolorirnetrischen als auch fur die DSC-Methodologien, gleichgiiltig ob das starkehaltige Material roh oder vorgekocht war. Jedoch ist die DSC-Methodologie reproduzierbarer und zeitsparend; insbesondere konnen die Entfettungs-und Starkebestimmungs-Stufen wegfallen.