Comparative Study on the Physico-Chemical Characteristics of Different Juice Varieties

Abstract

Orange juice is one of the most consumed natural beverages worldwide, due to its high content of vitamin C, phenolic compounds, and aromatic substances. During the processes of extraction, transportation, storage, and packaging, the physicochemical properties of the juice play a crucial role in maintaining its quality and stability. Physico-chemical analyses represent an important stage in the quality control of food products. In the food industry, the quality of a product is not limited to its organoleptic appearance (taste, smell, color, texture), but is also defined by physico-chemical parameters such as pH, density, sugar content. The properties of liquids such as viscosity and surface tension are two fundamental parameters that influence fluid behavior, and in the case of orange juice, they contribute to pulp stability, the degree of homogenization, foaming, as well as the sensory perception of the product. The study of these quantities allows the characterization of orange juice as a complex, non-ideal fluid, with non-Newtonian behavior in some cases. In this work, 4 types of commercially purchased orange juice were analyzed and a comparison was made between the results obtained from them and those from natural orange juice. Five samples of orange juice were analyzed over three days, investigating parameters such as density, pH, sugar concentration, surface tension and viscosity. The results revealed significant changes in density and viscosity, correlated with composition and sugar concentration. Surface tension varied significantly between the five types of juice. In parallel, data obtained from a questionnaire on consumption preferences provided a complementary perspective on consumer behavior. The study highlights the importance of physico-chemical characterization of juices in order to choose products that have a lower sugar content and that help to properly hydrate the body.