Quality attributes of halva by utilization of proteins, non-hydrogenated palm oil, emulsifiers, gum arabic, sucrose, and calcium chloride

Emulsion stability (oil separation) in halva is a major problem that affects quality upon storage. Emulsion instability results in toughness, oil separation, and oil contamination on packaging materials. The objective of this study was to evaluate the effectiveness of improving halva quality by incorporating non-hydrogenated palm oil, glycerol, soy protein concentrate, gelatin, lecithin, pectin, gum Arabic, sugar powder, and calcium chloride. Halva was produced by heating sugar (sucrose) solution (65%) containing citric acid (0.65%) and heating to reach 105 degrees C, adding halva root (Saponaria officinalis) extract solution (5.6%) and continuing heating for 60-70 min. This is followed with cooling at room temperature for 15 min and adding tahinia (sesame paste) (1:1) and mixing for 10 min. The additives to improve the quality of halva were incorporated with the sugar solution, during cooking, and with tahinia. The quality of halva was evaluated by measuring the amount of oil separation, microscopic examination, and oil viscosity. Microscopic examination of halva showed a porous non-crystalline sugar melt particles surrounded by a precipitated protein layer originating from tahinia. The oil was found as free non-emulsified fluid, filling in the spaces between solid particles. The saponin (from halva root extract) possibly precipitated the colloidal proteins of tahinia, and contributed to a fragile structure. Soy protein concentrate, gelatin, glycerol, and lecithin incorporation did not improve emulsion stability. However, calcium chloride, sugar powder, gum Arabic, and pectin minimized emulsion instability. Furthermore, 1.0% or 2.5% of non-hydrogenated palm oil increased viscosity of the oil phase and contributed to emulsion stability.