科研之友
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摘要
BackgroundEncapsulation of hydrophobic nutrients can be achieved by freezing and freeze-drying of oil-in-water emulsions containing glass-forming materials. The addition of a polyelectrolyte layer on the protein-stabilised oil droplets may provide better protection to the oil phase against external stresses. %26lt;br%26gt;ResultsSoy protein-trehalose and whey protein-trehalose emulsions with (layer-by-layer, LBL) and without (single-layer, SL) -carrageenan were used as the delivery systems for olive oil with dissolved -tocopherol. Emulsions containing 0.125g kg(-1) protein, 0.42g kg(-1) oil and 150g kg(-1) trehalose with (LBL) or without (SL) 0.25g kg(-1)-carrageenan at pH 3 were frozen and freeze-dried and their state transitions were studied. The stability of -tocopherol in freeze-dried systems at 0 and 0.33 water activity (a(w)) during storage at 55 degrees C was followed. Loss of -tocopherol was found in soy protein-stabilised SL systems at 0.33 a(w), and this loss coincided with trehalose crystallisation. The stability of -tocopherol was retained in soy protein-stabilised LBL and whey protein-stabilised LBL and SL systems at all conditions. Trehalose crystallisation-induced loss of structure was confirmed from changes in emulsion properties and visual appearance. %26lt;br%26gt;ConclusionComponent sugar crystallisation contributed to the loss of sensitive compounds, but the stability of these compounds can be improved by the use of LBL formulations.
- 出版日期2013-8-30
