Levels of sugars in milk products in Lebanon
Loiselet, J.; Jarjouhi, L.
Le Journal Medical Libanais. Lebanese Medical Journal 28(2): 319-334
1975
ISSN/ISBN: 0023-9852 PMID: 1185763 Document Number: 83531
2 methods were used to measure lactose and galactose in Lebanese dairy products. The 1st is based on the measurement of reducing sugars with the Folin phosphomolybdic-Cu reagent, monosaccharides (galactose and glucose) being measured in acetate-lactate buffer and total sugars (lactose + glucose + galactose) in an alkaline medium. In the 2nd method, lactose is hydrolysed with HCl and the resulting glucose + galactose are measured by the ferricyanide reduction method using a Technicon Auto-Analyzer. Treatment of a portion of hydrolysate with baker's yeast (to remove glucose) enables galactose to be estimated separately. Similar results obtained using the 2 methods showed that 33% of the lactose present in milk was hydrolysed during the manufacture of Laban (yoghurt). Labne, a soft white cheese prepared from Laban, contained only 15 g lactose/kg, the major part of the residual lactose and galactose being present in the whey. The preference for fermented dairy products in the Lebanon may be due to high level of lactose intolerance in the adult population [see DSA 39, 5789 & 5790].