Thermophysical properties of natural food colourants. Part 1. Experi-mental determination of the density of black carrot juice for technologi-cal calculations

For citation: Raudsep V. A., Novotelnova A. V., Chebotar A. V., Novoselov A. G. Thermophysical properties of natural food colourants. Part 1. Experimental determination of the density of black carrot juice for technological calculations. Journal of International Academy of Refrigeration. 2026. No 3. p. 84-91. DOI: 10.17586/1606‑4313‑2026‑25‑3-84-91

Abstract
The study is aimed at the experimental determination of the density of concentrated black carrot juice over a wide temperature range (5–85 °C) and varying soluble solids concentrations, as well as at the development of mathematical relationships required for engineering calculations and the design of thermal equipment in the food industry. The study included density measurements of both undiluted and diluted black carrot juice at different temperatures, determination of soluble solids content, statistical processing of the experimental data, and the derivation of equations describing the dependence of density on temperature and concentration. The results obtained establish quantitative relationships between density, temperature, and soluble solids content, and provide an empirical coefficient for predicting density under various thermophysical conditions. The results form a basis for accurate modeling and engineering calculation of heat and mass transfer processes in the processing of plant-based raw materials, including heat treatment and pasteurization, and can be used to improve the efficiency of technological equipment and to ensure the quality preservation of natural food colorants.