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Summary: Genetic engineering of flower color provides biotechnological products such as blue carnations or roses by accumulating delphinidin‐based anthocyanins not naturally existing in these plant species. Betalains are another class of pigments that in plants are only synthesized in the order Caryophyllales. Although they have been engineered in several plant species, especially red‐violet betacyanins, the yellow betaxanthins have yet to be engineered in ornamental plants.We attempted to produce yellow‐flowered gentians by genetic engineering of betaxanthin pigments. First, white‐flowered gentian lines were produced by knocking out the dihydroflavonol 4‐reductase (DFR) gene using CRISPR/Cas9‐mediated genome editing.Beta vulgaris BvCYP76AD6 and Mirabilis jalapa MjDOD, driven by gentian petal‐specific promoters, flavonoid 3′,5′‐hydroxylase (F3′5′H) and anthocyanin 5,3′‐aromatic acyltransferase (AT), respectively, were transformed into the above DFR‐knockout white‐flowered line; the resultant gentian plants had vivid yellow flowers. Expression analysis and pigment analysis revealed petal‐specific expression and accumulation of seven known betaxanthins in their petals to c. 0.06–0.08 μmol g FW−1.Genetic engineering of vivid yellow‐flowered plants can be achieved by combining genome editing and a suitable expression of betaxanthin‐biosynthetic genes in ornamental plants. [ABSTRACT FROM AUTHOR]

Beetroot was processed into juice and concentrate was obtained using rotary vacuum evaporation. The study investigated the effects of concentration temperature (45C, 50C, 55C and 60C) and time (5-30 min) on total solids, betalain, color, total phenolic content (TPC), antioxidant activity and nitrate content of concentrated beetroot juices. Betalain (composed of betacyanin + betaxanthin) and color value changed significantly ( P < 0.05) with processing temperature and time. Betacyanin and betaxanthin of beetroot juice concentrate (BJC) increased up to concentration temperature of 55C thereafter it decreased notably. Same trends have been followed by total phenolic and nitrate content of BJC. Also, nitrate content varied significantly over vast range nevertheless below the safety range defined by WHO. ' L' and ' a' value of BJC decreased substantially due to loss of the red color as heat destroyed betacyanin pigments. A highly significant correlation ( r2 = 0.9775) was demonstrated between TPC and radical scavenging activity (%RSA) of BJC samples. Practical Applications Preservation of vegetables for consumption exposes the physicochemical, color, antioxidant characteristics to detrimental factors that may lead to alterations in their concentrations and health-related quality. Beetroot (Beta vulgarius) juice contains antioxidants along with nitrates with potential health benefits and hence has an aptitude as functional ingredients. Moreover, pigment (Betalains) found in beetroot juices are well-established colorant for various food uses under regulation, having E.No.-162. Preferably, this study is focused on the determination of the effects of processing temperature and time on the quality components of beetroot juice. The results can be a guide to having a processing method under vacuum that can be used in producing beetroot juice concentrate with good sensory properties and high bioactive compounds. [ABSTRACT FROM AUTHOR]

The pigments of Opuntia ficus-indica fruits, which are derived from the betalain rather than anthocyanin pathway, have an extraordinary range in colour from lime green, orange, red to purple. This is a result from varying concentrations and proportions of about half a dozen betaxanthins and betacyanins. The yellow-orange betaxanthins are derived from spontaneous condensation of betalamic acid with amines or amino acids. The reddish-purple betacyanins are enzymatically formed from betalamic acid and cyclo-dihydroxyphenylalanine (DOPA) yielding betanidin and further glycosylated on either of the two hydroxyls of the cyclo-DOPA moiety. In the present work, degenerated primers were used to obtain partial genomic sequences of two major genes in the biosynthetic pathway for betalains, that is the 4,5-extradiol dioxygenase which forms the betalamic acid responsible for the yellow colour and a putative 5- O-glucosyltransferase which glycosylates betanidin in Dorotheanthus bellidiformis and may be responsible for the red colour. Differences in the genomic DNA between coloured versus non-coloured varieties were not found. Regulatory mechanisms seem to independently control pigmentation of O. ficus-indica fruit tissues for inner core, peel and epidermis. Core pigmentation occurs first and well before fruit maturity and peel pigmentation. Peel pigmentation is fully developed at maturity, presumably related to maximum soluble solids. Epidermal pigmentation appears to be independent of core and peel pigmentation, perhaps because of light stimulation. Similar control mechanisms exist through transcription factors for the major enzyme regulating anthocyanin production in grapes. [ABSTRACT FROM AUTHOR]

In this work, ultrasonic‐assisted extraction was evaluated for obtaining red beet extracts rich in betalains. Experiments evaluated the effects of operating variables (temperature, time, and ratio of ethanol to water) using a Box–Behnken experimental design, allowing the determination of conditions that maximize the removal of betacyanins and betaxanthins. The results indicate that the extracts obtained had higher betacyanins' levels (0.11–4.24 mg/g) than betaxanthins (0.02–2.89 mg/g) for all experimental conditions evaluated. The concentration of ethanol in the extraction solvent had the greatest influence on extraction efficiency, and higher ethanol availability did not favor target compounds removal. Use of higher temperatures impaired betaxanthin extraction but did not affect the removal of betacyanins. The optimum conditions were then evaluated for betalain content, total phenolic compounds, and antioxidant activity, and results were compared with conventional extraction methods. The optimum conditions for the extraction of betacyanins and betaxanthins were determined to be at temperatures 52 and 37 °C, with an extraction time of 90 min, using 25% of ethanol in water as the solvent. Under these conditions, betacyanin (4.2 mg/g) and betaxanthin (2.80 mg/g) concentrations were higher than found in conventional extractions, as were phenolic compound concentrations and antioxidant activity. Practical applications: An ultrasonic‐assisted extraction method for obtaining red beet extracts rich in betalains is demonstrated to be more efficient than the extraction of these compounds by conventional methods. Extracts obtained by this technique had higher betalains and total phenolic contents and greater antioxidant activity. [ABSTRACT FROM AUTHOR]