Betalains beets, extraction from

Despite their potential health-promoting effects as dietary antioxidants, the fate of betalains in humans has been poorly studied. Betalain bioavailability was first demonstrated in humans by the appearance of betacyanins in urines after ingestion of beetroot extract" and red beet juice," indicating that these compounds are indeed absorbed. Although intact betacyanins (betanin and isobetaiun) appeared rapidly in human urine with a maximum excretion rate observed within 2.5 to 8 hr," betacy-anin recoveries in human urine were usually low (< 1% of the dose) over 24 hr postdose, suggesting that either the bioavailabifity of betacyaiuns from red beetroot is low or that renal clearance is a minor excretion route for these compounds. 

Support Protocol Extraction of Betalains from Beets F3.1.4... 

In addition, a protocol describing the extraction of betalains from beets is provided (see Support Protocol). 

The documented use of betalain pigments as food colorants dates back at least one century, when inferior red wines were colored with betalain-containing juices (e.g., red beet juice). This common practice was, however, soon prohibited, and the application of betalain colorants was widely replaced by artificial dyes, which displayed better stability, at a lower price, and with higher purity. But in recent years the interest in natural food colorants has been renewed, mainly because of consumers concerns about the safety of some artificial colorants, which may be hazardous to human health (234). As a result, the number of permitted artificial dyes has been markedly reduced, and new efforts had to be made to develop natural food colorants (235). However, current legislation restricts the application of betalain colorants to concentrates or powders (E 162) obtained from aqueous extracts of beets (211). 

Fig. 22 HPLC separation of betalains in fermented red beet root extract, (a) Detection of betacyanins at 538 nm. Peaks 1 = betanin, 2 = isobetanin, 3 = betanidin, 4 = isobetanidin, 5 = prebetanin. (b) Detection of betaxanthins at 477 nm. Peaks 1 = vulgaxanthin I, 2 = vulgaxanthin II, 3 = betanin, 4 = isobetanin, 5 = betanidin, 6 = isobetanidin, 7 = prebetanin. (From Ref. 239.)...

Betalains have received much attention from the food industry as natural colour additives (Adams et at, 1976 Pourrat et at, 1983). The betacyanins from red beet are used for colouring ice cream, jam and fruit conserves. Earlier interest in betacyanins came from their use in colouring red wine, although this was prohibited by law in 1892 due to the use of the apparently harmful pokeberry Phytolacca americana, extract (Dreiding, 1961). 

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