neoxanthin and beta-damascenone

Red pepper (Capsicum annuum L.) has been used as one of key ingredients in certain fermented foods due to it providing a unique hot and spicy sensation. In this study, volatile compounds-including degradation compounds of carotenoids-in fermented red pepper inoculated with Lactobacillus parabuchneri were investigated. In total, the contents of certain alcohols, benzene and its derivatives, esters, hydrocarbons, lactones, pyrazines, and terpenes were increased in red pepper inoculated with L. parabuchneri, while those of aldehydes, sulfur-containing compounds, and ketones decreased during the fermentation period. The contents of some degradation compounds of carotenoids (β-ionone, β-cyclocitral, α-ionone, and β-damascenone) increased significantly with the fermentation period. In particular, the content of β-damascenone-which could form by the degradation of neoxanthin-increased gradually during fermentation, but this compound was not detected in 0-day samples. These findings indicate that the contents of certain volatiles-including degradation compounds of carotenoids-in fermented red pepper inoculated with L. parabuchneri can change markedly during the fermentation process.. This study investigated the changes of volatiles and carotenoids degradation compounds in fermented red pepper inoculated with Lactobacillus parabuchneri during fermentation. These results could be used to improve the quality of red pepper-based products and in the development of certain fermented foods, including Gochujang (fermented red pepper paste) and kimchi.

Topics: Alcohols; Aldehydes; Benzene; Capsicum; Carotenoids; Esters; Fermentation; Hydrocarbons; Ketones; Lactobacillus; Norisoprenoids; Sulfur Compounds; Terpenes; Volatile Organic Compounds; Xanthophylls

Developmental changes in the carotenoids and volatile compounds of Pinot noir grape berries were investigated in this study from pea size to harvest during 2012. HPLC analysis showed continued decrease of lutein, β-carotene, neochrome a and neoxanthin continued to decrease during berry development, with rapid decrease of lutein and (9'z)-neoxanthin occurred two weeks before véraison. Neochrome b and violaxanthin accumulated at early development and started to decrease two weeks before véraison. Volatile analysis demonstrated that total β-damascenone, TDN and vitispirane all increased dramatically, especially at later stage of ripening, whereas the changes for α-ionone and β-ionone were not obvious. The correlation between carotenoids and C13-norisoprenoids in the grape berries was compound-dependent, suggesting dependency on enzyme activity and specificity. In addition, C6-alcohols accumulated before véraison and decreased towards maturation, and 3-isobutyl-2-methoxyprazine decreased with increasing maturity.

Topics: Alcohols; beta Carotene; Carotenoids; Chromatography, High Pressure Liquid; Fruit; Lutein; Norisoprenoids; Taste; Vitis; Volatile Organic Compounds; Wine; Xanthophylls

The potent odorant beta-damascenone was formed directly from 9'-cis-neoxanthin in a model system by peroxyacetic acid oxidation and two-phase thermal degradation without the involvement of enzymatic activity. Beta-damascenone formation was heavily dependent on pH (optimum at 5.0) and temperature, occurring over the two sequential phases. The first was incubation with peroxyacetic acid at 60 degrees C for 90 min, and the second was at above 90 degrees C for 20 min. Only traces of beta-damascenone were formed on application of only one of the two phases. Formate and citrate solutions produced a much better environment for beta-damascenone formation than acetate and phosphate. About 7 microg/L beta-damascenone was formed from 5.8 mg/L 9'-cis-neoxanthin under optimal experimental condition. The detailed pathway by which beta-damascenone is formed remains to be elucidated.

Topics: Buffers; Chromatography, High Pressure Liquid; Hot Temperature; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Models, Chemical; Norisoprenoids; Odorants; Oxidation-Reduction; Oxygen; Peracetic Acid; Time Factors; Xanthophylls