The physical properties of coffee caviar as influenced by sodium alginate concentration and calcium sources

Coffee caviar is a product of spherification technique, which is one of well-known technique in molecular gastronomy. Spherification is a process when liquid turns into spheres in a bath due to the reaction such as between sodium alginate, calcium chloride, and calcium lactate in the gelation process. The objectives of this study are to know the effect of different formula used for caviar making to the physical characteristics of coffee caviar, and to choose the best formula for coffee caviar. Research was conducted under Randomized Block Design involving two variables i.e. the different concentration of sodium alginate (1%, 1.5% and 2 %) and different calcium sources (calcium lactate or calcium chloride). Evaluation was performed on the coffee-alginate solution (alginate sol) for viscosity, color (L^∗a^∗b^∗), total soluble solids, and pH, while the produced caviar was analyzed for texture, syneresis, as well as sensory properties (appearance, color, aroma, flavor, texture, overall liking, chewiness and gel strength). The result showed that the physical characteristic of the coffee caviars were diverse depending on the different formula used. The sodium alginate concentrations and calcium sources had significant effects (α=0.05) on the caviar texture, chewiness and gel strength. The best proportion for coffee caviar based on Derringer's desirability function was 1.5% concentration of sodium alginate with the use of calcium chloride as calcium ions sources.