Process for obtaining natural brown dye from walnut kernel extract

Abstract

The invention relates to the food industry, namely to a process for obtaining a natural brown dye from walnut kernel extract to produce a harmless brown dye. Protecting the natural colour of the food product is of interest and necessity in food processing in the food industry. Food colours have an important impact on the external appearance of food when restoring the colour of food during processing, storage, packaging or distribution. Food colours also impact improving the sensory qualities, harmlessness and quality of food products. The essence of the invention consists in the 1:2...1:3 hydromodal extraction of walnut kernels with a solution containing 25-30% ethyl alcohol, and 1% anhydrous sodium carbonate, assisted by 37MHz ultrasound at 40-45°C for 10-15 minutes, followed by distillation of the alcohol at a temperature of 60...65°C at a pressure of 0.09...0.11 atmospheres, treatment of the aqueous extract concentrate obtained with a saturated solution of calcium chloride, separation of the brown dye obtained in solid form and drying at 60...65°C at a pressure of 0.09...0.11 atmospheres. The result of the invention is a natural brown dye in solid form, which can be used for colouring confectionery and sweets.