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The composition of maturing Omani dates
Author(s) -
Myhara Robert M,
Karkalas John,
Taylor Mark S
Publication year - 1999
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199908)79:11<1345::aid-jsfa366>3.0.co;2-v
Subject(s) - fructose , sucrose , xylose , rhamnose , arabinose , pectin , sugar , chemistry , food science , starch , polysaccharide , dry weight , composition (language) , lactose , botany , biology , biochemistry , fermentation , linguistics , philosophy
The composition of two varieties of Omani dates, fard and khalas , was determined as maturity progressed. Free sugars and dietary fibre content were examined in detail. High‐performance liquid chromatography (HPLC) of the extracts showed that at the early green stage (Arabic kimri ), dates contained small amounts of glucose and fructose. At the intermediate yellow ( khalal ) and red ( rutab ) stages, large amounts (500–565 g kg −1 dry weight) of sucrose had accumulated, but no additional glucose or fructose was detected. At the final mature ( tamar ) stage, all sucrose was converted to glucose and fructose (>800 g kg −1 dry weight). Dietary fibre, determined as non‐starch polysaccharides (NSPs) by gas chromatography (GC), decreased from 250 g kg −1 ( kimri ) to 50 g kg −1 ( tamar ) on a dry weight basis. The principal monomers of NSPs were glucose, galactose, xylose, mannose, arabinose and rhamnose. On a dry weight basis, pectin, protein and ash contents decreased as the dates matured. On a fresh weight basis, changes in NSPs, pectin, protein and ash could be attributed to loss of moisture and the accumulation of sucrose initially, or of invert sugar later as maturation progressed. © 1999 Society of Chemical Industry