Fl-Carotene

Torri, H. and Tasumi, M. Correlation between redshifts and widths of the 0-0 band in the absorption spectra of all-trans-fl-carotene in solution, J.Chem.Phys., 98 (1993), 3697-3702... 

Identify the isoprene units in fl-carotene (see Figure 26.6). Which... 

In this series the achievement of the now well-established industrial syntheses of carotenoids notably that of fl-carotene has been of practical interest because of the permitted colourant nature of the compound and for the legally stipulated vitaminisation... 

Overhauser effects (NOE) for fl-carotene (78) in CDCI3 at various magnetic field strengths ... 

The term bioequivalence, as used here, is chosen to imply a relative efficacy in accretion between two sources of brain DHA, in analogy to the use of the term in reference, for instance, to retinol and fl-carotene. The crucial clinical issue for infant formulations is to establish the amount of DHA to be added to LCP-free formulas as a precursor for neonate brain development. In our neonate study, the commercial formula contained 1.8% of calories as LNA, and the only dietary DHA that these animals consumed was from the dose. Thus, the bioequivalence of 7 1 applies directly to the addition of small amounts of DHA to formula, meaning that the addition of DHA at 0.26% of calories may provide an equal amount of brain DHA as the entire 1.8% calories as LNA. Factors driving the addition of less DHA include possible interference with A A metabolism, the possibility of contaminants added incidentally in DHA oils, and expense. The potency of DHA relative to LNA suggests that the addition of amounts as small as 0.1% of calories would support brain growth, a figure similar to the lowest levels of DHA found inhuman breast milk. Finally, we note that the purely biochemical nature of our studies to date cannot establish whether LNA can completely substitute for DHA. Studies in human preterms suggest that it cannot, whereas those in term infants remain controversial (Cunnane, Francescutti, Brenna, Crawford, 2000). 

The added emulsifiers not only influence stability but also reduce interfacial tension and influence drop-size distribution, hence influencing the creaminess of the product [29]. They can also modify the extent and type of fat crystallization [50]. Mixed gels have also been used [50]. fl-Carotene is often added to produce a yellow colour and provide vitamin A. By varying the amounts of components such as vegetable oils, animal fats and milk fat, a wide range of variations have come into use. Some examples of these spreadable fats include butter, margarine, low-fat spread, vegetable-fat spread, butterfat spread, low-calorie spread, yellow-fat spread, water-continuous spread and so on [50]. The reduced-fat and low-fat spreads tend to have fat contents of 10-79%. Flack [50] provides an illustration of a process plant layout for the manufacture of spreadable fats. 

Activity of vitamin A (antixerophthalmic vitamin) have about 50 other naturally occurring compounds from the group of carotenoids, which are called provitamins A. The most important provitamin A is fl-carotene (5-3). In foods it is often accompanied by other carotenes, namely a-carotene (5-4) and y-carotene (5-5) and xanthophylls, such as fl-cryptoxanthin (5-6) and echinenone (5-7) and other provitamins A. 

The main pigments of depot fats of birds (poultry) and mammals are xanthophylls lutein and zeaxanthin. Also present are small amounts of fl-carotene and other pigments. 

Fig. 6. The fluorescence emission sp>ectra of all-trans fl-carotene (5 p.M) in (A)- (ILl), [C8Hi70CH2-CiIm][BF4] (B)- (IL2), [C6Hi30CH2-CiIm][(CF3S02)2N] (C)- (fL3), [CsHitOCHz-CiIm][(CF3S02)2N] (D)- (IIA), [Cs-Cilm] [BF4] in the standard cuvette and in the 4.-cuvette ...

The main dietary carotenoids are lycopene (linear, no substitutions), fl-carotene and a-carotene (ring closure at both ends, no substitutions), P-cryptoxanthin (ring closure at both ends, substitution in the 3 position), lutein (ring closure at both ends, substitutions in the 3 and 3 positions) and canthaxanthin (ring closure at both ends, [O] substitutions in the 4 and 4 positions). In some tissues, particularly flower petals, the hydroxylated carotenoids may also be present as mono- or di-acyl esters, most commonly with C16 fatty acids. Further oxidation of the terminal ring may occur to produce the mono- and di-epoxides. For an exhaustive list of carotenoids, the Key to Carotenoids (Straub 1987) is a recommended reference source. 

Shiau, A., Mobarhan, S., Stacewicz-Sapuntzakis, M. et aL (1994) Assessment of the intestinal retention of fl-carotene in humans. /. Am. Coll Nutr., 13,369 375. 

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