Physicochemical parameters of food emulsion products with summer savory (Satureja hortensis L.) essential oil

¹ Department of Technology of Tobacco, Sugar, Vegetable and Essential Oils, University of Food Technologies, 4002 Plovdiv, Bulgaria
² Department of Tourism and Culinary Management, University of Food Technologies, 4002 Plovdiv, Bulgaria
³ Department of Analytical and Physical Chemistry, University of Food Technologies, 4002 Plovdiv, Bulgaria

^* Corresponding author: antondlazarov@gmail.com

Abstract

Summer savory (Satureja hortensis L.) is a plant source of essential oil belonging to the Lamiaceae family, widely used in the food industry. The present work aims to determine the physicochemical parameters of food emulsions containing the essential oil. The summer savory essential oil with main components carvacrol (63.71%), γ-terpinene (20.47%), and p-cymene (5.08%) was used in this study. Several model variants of emulsions have been developed with varying amounts of emulsifier (2 and 3% soy protein isolate), oil phase (20 and 40% sunflower oil), and essential oil (0.2 and 0.4%). The following physicochemical parameters of the emulsion were determined: Gibbs free energy, enthalpy, and entropy. This parameter was used to determine the thermal effect of the system. The process was determined as exothermic with the negative enthalpy. Emulsions prepared with 2% soybean protein isolate, 40% oil phase, and 0.4% essential oil were characterized by some good results with high equilibrium constants and high Gibbs energies. Model variants of salad diet dressings had also been developed, with 0.2 and 0.3% essential oil, which were qualified by sensory analysis. The overall evaluation of salad dressings showed that the evaluators perceived with best sensory properties in those with 0.2% essential oil.