Premium
Water Mobility and Crystallization Action of Lactose‐water Systems by Oxygen‐17 and Carbon‐13 NMR
Author(s) -
LAI HSIMEI,
SCHMIDT SHELLY J.
Publication year - 1990
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1990.tb03952.x
Subject(s) - mutarotation , lactose , chemistry , crystallization , supersaturation , carbon 13 nmr , analytical chemistry (journal) , chromatography , stereochemistry , organic chemistry
Systems ranging in concentration from 10‐60g lactose/100g water were investigated by fully proton decoupled 17 O and fully proton decoupled 13 C Nuclear Magnetic Resonance (NMR). The relation between 17 O NMR transverse relaxation rate measurements and lactose concentration showed water mobility decreased linearly with increasing lactose concentration up to 25g lactose/100g water and decreased rapidly and nonlinearly above that level. Water mobility was used to monitor lactose crystallization in supersaturated solutions with time. The 13 C NMR showed no significant differences in chemical shifts of carbon atom peaks in lactose molecules during crystallization. However, depending on the method of sample preparation, mutarotation could be observed.