Abstract:
Sugar beet molasses (SBM) as nutritionally valuable product can easily be
transformed from byproduct to bioproduct. SBM represents rich source of minerals
(Na, K, Ca, Mg) and bioactive compounds (betaine). Although, molasses consists of
high amount of sugar (≤50.0 oS), aw value is still high (≤0.600). Freeze-drying
technique represents one step where biological material was treated before
finalization of the product. SBM was lyophilized at 1 Pa, corresponding temperature
-60oC until dry. Mineral composition of SBM molasses before and after applied
freeze-drying process were determined according to ISO 6869:2008. Quantitative
HPLC method revealed presence of betaine. Influence of freeze-drying on molasses
was expressed in relation to changes of the dry matter, aw value, mineral composition
(Na, K, Ca, Mg, Fe, Zn) and betaine content. Lyophilized SBM with very high
content of dry matter (97.5%) and reduced aw value (from 0.587 to 0.287) implicated
material long-term storage, reduced packaging cost, easier handling and transport
instead of high viscous molasses. All analysed minerals were more concentrated in
the lyophilized molasses expressed on dry matter content, from 4.4% for K to 23.1%
for Mg. Dehydrated molasses concentrated in minerals and betaine represents
nutritive favourable compound for further manipulation and enriching of food
products.
