Carrots Subject

As a chemistry undergraduate in the 1960s. .. I learned quantum chemistry as a very theoretical subject. In order to get to grips with the colour of carrots, I knew that I had to somehow understand... 

Intermediary metabolism of irradiated tissues was examined to attempt to explain the increased respiration on the basis of biochemical mechanics. In these experiments carrot disks 0.5 mm. thick were prepared as before and subjected to substrate utilization studies (9). This involved incubating the slices with the appropriately labeled substrate in 0.03M phospate buffer at 25°C. The incubation involves shaking with gentle aeration and trapping the respired CO2 in alkali. Following incubation the slices were removed, washed, ground with 80% ethanol, and filtered, and both the filtrate and residue were assayed for radioactivity. Thus, a measure of substrate absorption and utilization was determined. 

Carotenoids have been the subject of scientific research for the past 160 years. A compound named carotene was isolated from carrots by Wackenroder [33] in 1831. In 1906, Tswett [34] investigated the colored components of leaves and thus invented chromatography. In 1941, Kuhn [35] successfully separated carotene into three separate isomers by liquid adsorption chromatography. 

Facilitating the fermentation in cases where the raw material must be subjected to a heat treatment prior to fermentation. This could for example be necessary to inactivate enzymes causing discolouration or aroma deviations (e.g. chlorophyUase in green vegetables), to destroy or inactivate plant origin toxins (e.g. phasin in beans) or to influence the texture of the vegetable (e.g. beetroot, carrots). 

Lycopersene is the C40 analogue of squalene, and the possibility that it is the first C40 hydrocarbon produced in the biosynthesis of carotenoids instead of phytoene has been the subject of a great deal of discussion. The presence of lycopersene has been reported in N. crassa (Grob and Boschetti, 1962) and in some carrot strains (Nusbaum-Cassuto and Villoutreix, 1965). In addition, the conversion of GGPP to lycopersene by extracts ofN. crassa has been reported (Grob et al., 1%1). In later work, however, the presence of lycopersene was not found (Anderson and Porter, 1%2 Pennock et al., 1962 Beeler e/ al., 1963 Davies et al., 1%3 Mercer et al., 1%3). In studies... 

Liquid crystals were first identified in 1888 ° in a molecule extracted from carrots. The first observed phase was the cholesteric or chiral nematic phase, whose shape is the subject of this chapter. Liquid crystals are made of molecules of particular shapes which, under certain conditions, align to form the phase shown in Figure 17.7. The first synthetic liquid crystals were manufactured in 1889. ° Liquid crystalline phases have been observed in many biopolymers. °... 

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