surface with protrusions, causing an unattractive and sensory unacceptable
product. Whereas the addition of freeze dried extract did not
cause any significant differences in the chocolate surface (Fig. 3d and l),
the addition of concentrated raspberry leaf extract induced significant
bloom development (small whitish spots of liquid and re-crystallized
fat on the product surface). As previously indicated this might be due
to the thickening and agglomeration of solid particles upon the addition
of water. Namely, the relatively larger capillary pores created within the
particulate structures of products containing higher water content
were suspected to be the key factor facilitating their rate of bloom
development, relative to the smaller pores with smaller particle
size in products. As can be seen in Fig. 3c, g and k, the chocolates
enriched with 3% of concentrated extract had an uneven, heterogeneous
microstructure in which some areas displayed large inclusions of fat,
connected by large irregular domains. Semisweet chocolate added with
freeze dried extract had an even, homogeneous microstructure, with
small inclusions of liquid fat depicted by the small white spots in Fig. 3h.