Food pigment

Watanabe, T. and Terabe, S., Analysis of natural food pigments by capillary electrophoresis, J. Chromatogr. A, 880, 311, 2000. 

In this module, an emphasis is placed on the different methods that have been used for assessing the bioavailability of food pigments such as carotenoids. Different in vivo and in vitro approaches can be used to estimate pigment bioavailability from foods in humans. 

Among all food pigments, we have the most knowledge about the carotenoids related to their absorption and metabolism on a molecular basis. 

Simpson, K.L., Chemical changes in natnral food pigments, in Chemical Changes in Food during Processing, Richardson, T. and Finley, J.W., Eds., AVI Pnhhshing, Westport, CT, 1985, 409. 

Replacement of the hydrogen at the 3 or 3 position of the carotene ring with a hydroxyl is the next step in both branches of the pathway. Hydroxylation of the rings of the carotenes leads to biosynthesis of the xanthophylls, including the well-known lutein and zeaxanthin food pigments. Lutein is formed by hydroxylation of a-carotene zeaxanthin is formed by hydroxylation of P-carotene. 

Manley, C.H. and Shubiak, R, High pressure bquid chromatography of anthocyanins [food pigments], Can. Inst. Food Technol., 8, 35, 1975. 

FIGURE 7.3.1 Chemical structures of some synthetic food pigments. 

Horizontal trough mixer, with ribbon blades, paddles or beaters Rotating element produces contra-flow movement of materials Dry and moist powders Chemicals, food, pigments, tablet granulation... 

Because of their high separation capacity, short analysis time, low reagent consumption and simplicity, various electrophoretic methods have found application in the separation and quantitative determination of anthocyanins in various complex matrices [267].The different techniques used for the measurement of anthocyanins in beverages [268], the application of capillary electrophoresis (CE) for the analysis of natural food pigments [269], the use of CE for the determination of anthocyanins in foods [270] and in medicinal plants [271] have been previously reviewed. 

Food pigments, sweeteners and a preservatives were quantitatively determined by TLC in sparkling and non-sparkling drinks. TLC separations were carried out on ready-made silica plates using 2-propanol-12.5 per cent aqueous ammonia (10 2, v/v) and ethanol-2-propanol-12.5 per cent aqueous ammonia (10 40 1, v.v) as mobile phases for the separation of pigments and sweeteners and preservatives, respectively. Samples were used as... 

FOOD PIGMENTS DETECTED AND QUANTIFIED IN THE BEVERAGES ANALYSED... 

Food pigments. Well-described are footh discolorations associated with the consumption of coffee, fea, wine, and betel nuts. This discoloration by food and beverages has been mimicked in vitro with caries lesions (Kidd et al., 1990) and sound teeth (Chan et al., 1981). 

Applications of particle technology in production of pharmaceuticals, chemicals, foods, pigments, structural and functional materials, and in environmental and energy-related areas... 

Simpson, K.L. 1985. Chemical changes in natural food pigments. In Chemical Changes in Food during Processing (T. Richerson and J.W. Finley, eds.) AVI Publishing, Westport, Conn. 

The major constituent in the extract of madder, Rubia tinctorum (Rubiaceae), was identified as lucidin-3-O-primeveroside (342), a commonly used food pigment. It exhibited antifeedant activity against the carpet beetle, Attagenus japonicus 50 This opens the window for using dyes from either R. akane or R. tinctorum to protect textile against these textile pests. 

The solubility diffusion of food pigments is the phenomena responsible for this coloration. It is important to highlight that in the opposite direction, from the packaging to food, substances from the material, of approximately the same size of P-carotene or smaller, can also migrate provided that they are not covalently bonded to the polymer matrix. This contamination of food is usually invisible, without being smelled or tasted, but occurs insidiously. 

---