Stabilization of melon cloudy juice with biopolymer agar

Abstract

In the production of natural fruit juices, the uniform distribution of fruit pulp particles in the volume is of great importance, which determines the aggregate stability of the system. To maintain the aggregate stability of fruit juices, stabilizers are used, which are polymers or surfactants. In this regard, the influence of natural polymer agar on the stability of melon juice containing particles of melon pulp has been studied. The initial melon juice had a pH of 5.78 and a titrated acidity of 970.29 mg of citric acid/L, the content of soluble solids in it corresponded to 10.08 TSS Brix. Samples of melon juice with concentrations of 50, 70 and 90 % were used for research. The study of the stability of melon juice in the presence of agar was carried out for 6 days on the Turbiscan device (France). It is shown that at concentrations of agar introduced into melon juice of 0.005 % and 0.01 %, the system retains its aggregate stability, but when switching to a concentration of 0.02 %, the stability of the system decreases. The size of melon pulp particles changes accordingly. If the addition of agar concentration of 0.05 % and 0.01 % to the melon pulp reduces the particle size of the melon pulp, then an increase in the agar concentration to 0.02 % causes a certain increase in the particle size of the fruit pulp. This effect of agar concentration on the aggregate stability of melon juice is explained by the fact that at low concentrations, polymer macromolecules, covering the surface of melon pulp particles, protect them from sticking. When the polymer concentration increases, melon pulp particles begin to stick together due to the coupling of loops and tails of agar macromolecules adsorbed on their surface