Abstract
We investigated the development of water-in-oil (W/O) emulsions just
using CW, evaluating the effect of the water to CW oleogel ratio (40:60,
50:50, 60:40) and, at each ratio, the effect of the CW concentrations
(0.75% to 3%). The emulsions were developed by shearing (60 s at 25°C)
using an ultra-turrax type homogenizer. The emulsions were immediately
evaluated and after 20 days of storage (25°C) for microstructure, water
droplet diameter, emulsion stability through DSC freeze/thaw cycles,
rheological properties, and X-ray measurements. The results showed that,
at all water to oleogel ratios studied the CW developed structured W/O
emulsions where the surface-active components of the CW (i.e.,
triterpenic alcohols, aliphatic alcohols, and fatty acids) stabilized
the oil-water interface, while the n-alkanes and long chain esters
formed an oleogel in the oil phase. Although, independent of the storage
time, all the CW emulsions showed a frequency independent rheological
behavior, after applying a strain above the G’-G” cross point, the
40:60 and 50:50 emulsions with 1.5% to 3% CW concentration showed the
better rheological behavior and were the most stables, even after two
freeze-thaw cycles. In particular, the 40:60 and 50:50 emulsion with
1.5% CW had a recovery profile similar to commercial mayonnaise. In
contrast, independent of the CW concentration, the 60:40 emulsions
showed the lowest recovery profiles and higher instability to
freeze-thaw cycles. These results indicated that the CW is a
multi-functional material able to develop structured W/O emulsions
useful for the formulation of trans-free, stable low-fat edible spreads.