Photo-oxygenation of carotenoids. I. The formation of dihydroactinidiolide and β-ionone from β-carotene

Photodynamics of the Bacteriochlorophyll-Carotenoid System. 1. Bacteriochlorophyll-photosensitized Oxygenation of β-Carotene in Acetone¶

“…There are several reports in the literature on oxidation reactions of Car induced either chemically or photochemically (25)(26)(27)(28)(29)(30) and some of the products of these reactions have been known and identified more than 30 years ago (25,29,46). Still more products of Car oxidation formed upon addition of peroxy radicals, most of them carrying only one oxygen atom, have been described more recently by Yamauchi et al (27,28).…”

“…More exhaustive photooxidation of Car leads eventually to a breakdown of its C 40 -skeleton into a variety of small, colorless end products (29,30). Some of these breakdown products appear to be harmful, their accumulation may cause indirect oxidative damage, e.g.…”

Characterization of carotenoids and their degradation products in oak wood. Incidence on the flavour of wood

“…Light, temperature and oxidation are the three factors mentioned in the literature by different authors [5,6,14,15]. The experimental part was very simple: five solutions at 2 mg l -1 of b-carotene were prepared.…”

“…Aroma compounds are formed during the oxidative degradation of carotenoids. It is also known that carotenoids can lead to the formation of norisoprenoids, compounds that possess distinct aromatic characteristics through oxidative degradation catalysed by light [5] or coupled oxidation [6].…”

Flavours and Fragrances

“…It could be shown experimentally that carotene reacted photochemically with oxygen in the absence of a sensitiser to produce β-ionone and other oxidation products. [54] Also, thermolysis of β-carotene produces β-ionone in significant amounts. [55] Later it has been proven that β-ionone could also be produced enzymatically from carotene.…”