Use of natural brown dye from walnuts in sweets with functional properties

Abstract

Sweets with synthetic dyes have a negative impact on a health, so, according to actual European policies, it is necessary to replace them with inoffensive natural dyes. A good source for obtaining of the natural brown dye can serve the walnut (Juglans regia L) pellicle and septum. R. Moldova produces 50…60 thousand tons of walnuts annually. The results of this study confirm the presence of several important biologically active compounds in the toffee, which provide potential physiological activity: Gallic Acid (λmax. = 271 nm, RT ~ 10 min.), Catechin, Epicatechin (λmax. = 278 nm, RT ~ 15 min., ~ 16 min.), Ellagic Acid (λmax. = 366nm, RT ~ 20min), and their derivates, such as Casuarictin. When analyzing the toffee, an increase of the Ellagic Acid / Casuarictin ratio from 3/1 up to 9/1 is observed. This take place because at high temperatures, Casuarictin turns into Ellagic Acid, Gallic Acid and glucose

by hydrolysis. The addition of the natural coloring from walnuts, contributes to the decrease of titratable acidity from 0.28 ± 0.08 in the control sample to 0.21 ± 0.06 degrees of acidity in the sample with 1.0% of the coloring matter being added. The CIE-Lab chromatic parameters L*, a*, b* of the toffee sample with 0.6% of the brown dye from walnuts are close to the classical toffees. So, the use of natural brown dye from walnut's septum or pellicle in production of toffee with reduced quantity of sugar, substituted by sweeteners, provide synergy of physiological properties. Use of brown natural color maintains the original appearance (for consumers) of the toffee at the same time.