The goal of this work was to determine if water-in-oil emulsions produced via a lab-scale cross flow membrane emulsification system are suitable for use in the production of melt resistant chocolate. Water-in-oil (w/o) emulsions (30 wt%) were prepared with either polyglycerol ricinoleate (PGPR, 1-6%) or lecithin (1-6 wt%) using a cross-flow membrane homogenizer. PGPR produced stable emulsions with smaller average diameters compared to lecithin. Lecithin produced larger particles that quickly phase separated. Aliquots (2 g) of a stable (2% PGPR-stabilized) and unstable (2% lecithin-stabilized) w/o emulsion were added to a sugar-in-molten confectionery coating fat (CCF) dispersion (50:50 sucrose:lipid, 120 g total) and cooled to produce a solid sample. After washing out the solid fat with hexane, the samples containing added water were found to have formed a self-supporting sucrose skeleton compared to control prepared without water which collapsed. Microscopy revealed the primary mechanism of water-induced sugar crystal adhesion was via capillary forces. The meltability of the solid samples was measured as change in shape following heating at 50 °C (i.e., above the melting point of the CCF). The degree of spread was less for the samples containing water and was affected by the mode of water addition. This work has relevance to the manufacture of melt resistant chocolate where a sugar skeleton is used to maintain a solid product even after the fat has melted.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Food Science
- Applied Microbiology and Biotechnology