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Titre :
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Physico-chemical characterisation of sage starch
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Auteurs :
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F. Ahmad ;
P. Williams ;
J. Doublier ;
AL Et
|
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Type de document :
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article/chapitre/communication
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|
Année de publication :
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1999
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Format :
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p. 361-370
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Langues:
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= Anglais
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Catégories :
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EAU
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Mots-clés:
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AMIDON
;
PROPRIETE PHYSICOCHIMIQUE
;
CARACTERISATION
;
HUMIDITE
;
COMPOSITION
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Résumé :
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The physico-chemical characteristics of various sago starch samples from South East Asia were determined and compared to starches from other sources. X-ray diffraction studies showed that all the sago starches exhibited a C-type diffraction pattern. Scanning electron microscopy showed that they consist of oval granules with an average diameter around 30 mµ. Proximate composition studies showed that the moisture content in the sago samples varied between 10.6% and 20.0%, ash between 0.06% and 0.43%, crude fat between 0.10% and 0.13%, fiber between 0.26% and 0.32% and crude protein between 0.19% and 0.25%. The amylose content varied between 24% and 31%. The percentage of amylose obtained by colourimetric determination agreed well with the values obtained by fractionation procedures and potentiometric titration. Intrinsic viscosities and weight average molecular weight were determined in 1M KOH. Intrinsic viscosity for amylose from sago starches varied between 310 and 460 ml/g while for amylopectin the values varied between 210 and 250 ml/g. The molecular weight for amylose was found to be in the range of 1.41 x 10(6) to 2.23 x 10(6) while for amylopectin it was in the range of 6.70 x 10(6) to 9.23 x 10(6). The gelatinisation temperature for the sago starches studied varied between 69.4°C and 70.1°C.
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Source :
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Carbohydrate polymers, vol.38
|
