Beet Powder Research Articles

COLOR STABILITY OF BEET POWDERS

Color thermal stability kinetics tests of the major beet pigments, betanine and vulgaxanthin (I), were conducted in beet powder during storage (25, 31, 35, 40 and 45°C) and in its reconstituted solution (40 and 86°C heat treatment at pH 4.0, 5.7 and 6.8). The powders evaluated were produced by two different drying methods — drum drying and the conventional cube dehydration. Pigment degradation rates generally followed a first order reaction with an energy of activation of 7.0 and 8.0 Kcal/mole for betanine and 6.2 and 6.4 Kcal/mole for vulgaxanthin for drum and air dehydrated powders, respectively. Optimal pigment stability in the reconstituted juice was obtained at pH 5.7 for both the high and low tested temperatures (40 and 86°C). Freeze dried powder (used as a control), although having a higher initial pigment concentration, showed a markedly higher degradation rate in its reconstituted juice at the 40°C temperature, thus suggesting an enzymatic pigment degradation activity in the native beet.

Qualitative Tests for Added Coloring Matter in Meat Products

The rapid qualitative detection of coal tar dyes, chemicals added to color meat products, and some natural coloring materials was investigated through extraction and subsequent identification by spectrophotometric, paper chromatographic, and specific reaction techniques. These techniques will detect the presence of coal tar dyes, imidazole, histamine, histidine, cochineal, beet powder, annatto, alkanet, carotene, paprika, saffron, turmeric, and materials causing discoloration in meats.

Betalaines as Colorants in Dairy Products

Color in foods is one of the most important attributes and is subject to great changes that are not easily controlled. Therefore, to control appearance of food, artificial dyes often need to be added. In recent years the safety of artificial dyes has been questioned and, as a result, their use in the future will be limited if not eliminated. It is for this reason that interest has developed in obtaining pigments from natural sources. The red beet is a rich source of pigments, which warrant investigation in dairy products. In addition, beet powder is permitted as a colorant under the 1960 Color Additive Amendment. The term betalaine refers to the class of pigments found in the beet which contains both betacyanines (red) and betaxanthines (yellow). The betanine content (major red pigment) in beets is in excess of 100 mg/100 g fresh weight and juice concentrates and powders available range in dye content between 0.2 and 1%. Use of betalaines as colorant and color stability of betalaines in yogurt, ice cream, and sherbet has been evaluated. Subjective and objective color values were measured and, as an example, yogurt colored with 45 ppm pigment, calculated as betanine, was judged to compare favorably with a black cherry shade.