Cis-Trans Isomers of .BETA.-Carotene in Fresh Vegetables and Fruits.

Kon, Masayo; Takahashi, Bunjiro; Hirota, Saishi

doi:10.3136/fstr.5.308

Cited by 6 publications

(9 citation statements)

References 10 publications

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“…Levels of cis-β-carotene and cis-lutein increased only marginally in the standard solutions. These results comply well with previous reports (16,20,43) showing insignificant isomerization after light exposure of dissolved all-trans-β-carotene. Because cis isomers were detected in the photosynthetic apparatus, carotenoid isomerization in the presence of chlorophylls was concluded (43).…”

Section: Discussionsupporting

confidence: 93%

“…In yellow and red vegetables, thermal processing of food facilitated the formation of 13- cis isomers, while illumination induced 9- cis isomerization ( 9 , 10 , 17 , 18 ). These results comply with studies with pure carotenoids yielding similar isomeric composition ( , ). In contrast, in green-colored vegetables and fruits, 9- cis -β-carotene was found to be the major cis isomer ().…”

Section: Introductionsupporting

confidence: 91%

“…These results comply with studies with pure carotenoids yielding similar isomeric composition (16,19). In contrast, in green-colored vegetables and fruits, 9-cis-β-carotene was found to be the major cis isomer (16). Mixtures of pure all-trans-β-carotene and chlorophyll fractions showed an increase in 9-cis stereoisomers after illumination, explaining the elevated content of 9-cis isomers in raw green vegetables (20).…”

Section: Introductionsupporting

confidence: 88%

“…In previous studies, cis stereoisomers were shown to be concomitant with all-trans carotenoids in raw vegetables and fruits (16). In yellow and red vegetables, thermal processing of food facilitated the formation of 13-cis isomers, while illumina-tion induced 9-cis isomerization (9,10,17,18).…”

Section: Introductionmentioning

confidence: 90%

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Effects of Heating and Illumination on Trans−Cis Isomerization and Degradation of β-Carotene and Lutein in Isolated Spinach Chloroplasts

Aman

Schieber

Carle

2005

J. Agric. Food Chem.

133

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The influence of thermal treatment and light exposure on degradation and isomerization of the predominant carotenoids (lutein and beta-carotene) occurring in green leafy vegetables was assessed. The effect of lipid addition on carotenoid stability was also evaluated. For the first time, the stabilities of pure carotenoids and chloroplast-bound carotenoids were compared. Besides degradation, heating caused carotenoid isomerization in all samples. Whereas pure carotenoids favor 13-cis isomers, in native chloroplasts and heated chloroplasts 9-cis isomers were predominant. Illumination of freshly prepared chloroplast isolates caused an initial increase in the level of lutein (9.6%) and beta-carotene (29.8%), while pure carotenoids exhibited time-dependent degradation. The addition of lipids to chloroplast preparations had the reverse effects on the retention of both carotenoids after heating; isomerization was not significantly affected. It was demonstrated that carotenoid stability has to be evaluated for every individual pigment in its genuine environment. Stability data based on model systems (e.g., pure carotenoids) may not be transferred to complex food matrices without intensive investigation.

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Section: Discussionsupporting

confidence: 93%

Section: Introductionsupporting

confidence: 91%

Section: Introductionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 90%

See 2 more Smart Citations

Effects of Heating and Illumination on Trans−Cis Isomerization and Degradation of β-Carotene and Lutein in Isolated Spinach Chloroplasts

Aman

Schieber

Carle

2005

J. Agric. Food Chem.

133

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“…Of the two cis-BC isomers examined in the present study, 9-cis-BC represented a greater contribution to the overall BC content of the four raw and cooked green vegetables. The present study supports previous literature which reports that fresh green fruits and vegetables contain more 9-cis-than 13-cis-BC (Watanabe, Masayo, Takahashi & Hirota, 1999). Broccoli and kale had similar profiles for each of the three BC isomers before and after the vegetables were cooked ( Fig.…”

Section: Bc Profile Of Raw and Cooked Green Vegetablessupporting

confidence: 94%