Lycopene the structure of the molecule was determined by 1931. In its natural, all-"trans" form, the molecule is long and straight, constrained by its system of 11 conjugated double bonds. Each extension in this conjugated system reduces the energy required for electrons to transition to higher energy states, allowing the molecule to absorb visible light of progressively longer wavelengths. Lycopene absorbs all but the longest wavelengths of visible light, so it appears red. Plants and photosynthetic bacteria naturally produce all-"trans" lycopene. When exposed to light or heat, lycopene can undergo isomerization to any of a number of "cis"-isomers, which have a
Diarylide pigment t, being diarylide yellows. The diarylide yellows are the most common yellow pigments used in printing as well as a wide variety of other applications. Due to their stability, diarylide yellows are used in inks, coatings, and as plastic colorants. The pigment is insoluble. It is a standard pigment used in printing ink and packaging industry. The diarylide yellow pigment Yellow 12 is one of the three main colored pigments used in the four color process of color printing. As such, its use is ubiquitous in printing both in commercial applications and in home color printers, as well as in