ChemInform Abstract: HPLC OF CAROTENES WITH Ψ‐END GROUPS AND (Z)‐CONFIGURATION AT TERMINAL CONJUGATED DOUBLE BONDS. ISOLATION OF (5Z)‐LYCOPENE FROM TOMATOES

Zumbrunn, Albrecht; Uebelhart, Peter; Eugster, C. H.

doi:10.1002/chin.198550305

Cited by 6 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In various tomato-based foods, the all-trans isomer is comprised of 35 to 96% of total lycopene (Schierle et al, 1996). The 5-cis, 9-cis, and 15-cis isomers of lycopene have been identified in various tomato-based foods and human tissues by NMR spectroscopy (Zumbrunn et al, 1985). The proportion of 5-cis-isomer in tomato-based foods was 4 to 27%, with considerably lower amounts of other isomers (Schierle et al, 1996).…”

Section: Biochemical Propertiesmentioning

confidence: 99%

Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing

Shi¹,

Maguer²

2000

Critical Reviews in Food Science and Nutrition

732

494

View full text Add to dashboard Cite

Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalabili...

show abstract

Section: Biochemical Propertiesmentioning

confidence: 99%

Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing

Shi¹,

Maguer²

2000

Critical Reviews in Food Science and Nutrition

732

494

View full text Add to dashboard Cite

show abstract

“…In aqueous systems, lycopene tends to aggregate and to precipitate as crystals. This behavior is suspected to lower lycopene bioavailability in humans (Zumbrunn et al 1985). Lycopene is the red colored pigment abundantly found in red colored fruits and vegetables such as tomato, papaya, pink grapefruit, pink guava and watermelon (Choudhary et al, 2009;Kong et al, 2010).…”

Section: Carotenoidsmentioning

confidence: 99%

Phenolic compounds in agri-food by-products, their bioavailability and health effects

Shahidi¹,

Varatharajan²,

Oh³

et al. 2019

Journal of Food Bioactives

111

View full text Add to dashboard Cite

Phenolic compounds constitute a large and diverse group of secondary metabolites derived from phenylalanine and tyrosine and are widely distributed throughout the plant kingdom. They could be divided into different classes such as simple phenol, phenyl acetic acid, hydroxybenzoic acid, hydroxycinnamic acid, and other phenylpropanoids as well as condensed tannins (proanthocyanidins) and hydrolysable tannins, among others, depending on their basic carbon skeleton structure. Phenolic compounds in plant-based foods have been suggested to have a number of beneficial health effects including prevention of cancer, cardiovascular disease, diabetes, immune disorders, neurogenerative disease and others. These properties are largely attributable to the antioxidant activity of the phenolic compounds as well as other mechanisms of action. Therefore, nutraceuticals of plant origin may evolve to be considered a vital aspect of dietary-disease preventive food components. Agri-food industries generate substantial quantities of phenolic rich by-products, which could serve as an attractive and commercially viable source of nutraceuticals. This contribution mainly summarizes the occurrence of phenolic compounds and some other bioactives in various Agri-food by-products, their bioavailability and health benefits.

show abstract

“…All solutions were gassed with N 2 for 20 min. The standard assay (200 ll) consisted of liposome suspension containing 1 nmol carotene substrate (typically around 30 ll), 30 lg of cyclase, 10 nmol FAD or FMN, 20 ll hexane [12] and buffer A, added to the final volume of 200 ll. Reducing conditions were achieved with 2 ll of a freshly prepared 0.1 M dithionite solution.…”

Section: Enzymatic Assaysmentioning

confidence: 99%

Reaction specificities of the ε‐ionone‐forming lycopene cyclase from rice (Oryza sativa) elucidated in vitro

Beyer

2012

FEBS Letters

View full text Add to dashboard Cite

a b s t r a c tLycopene cyclases responsible for the formation of e-ionone rings (LCYe) mark a plant-specific bifurcation of carotenogenesis. We investigated purified rice LCYe (OsLCYe) in a liposome-based biphasic assay system. OsLCYe depends on reduced flavin cofactors stabilizing a transient state formed during the non-redox cyclization reaction. In contrast to OsLCYb, OsLCYe produces predominantly monocyclic products and monocyclic carotene intermediates are not suitable substrates. Determination of the OsLCYe reaction specificities and the combined use of OsLCYb allow the characterization of the reaction sequence leading to heterocyclic carotenoids. It was also found that 5-cislycopene, which was thought to be decisive for e-cyclization, was not involved in the reaction, with OsLCYe acting as an exclusion filter for this naturally occurring isomer.

show abstract

ChemInform Abstract: HPLC OF CAROTENES WITH Ψ‐END GROUPS AND (Z)‐CONFIGURATION AT TERMINAL CONJUGATED DOUBLE BONDS. ISOLATION OF (5Z)‐LYCOPENE FROM TOMATOES

Abstract: Aus einem Gemisch der in der vorangegangenen Arbeit synthetisierten Carotine werden die Titelverbindungen (III), (VIIIa), (VIIId) und (XIb) von den Vergleichssubstanzen (VIIIb), (VIIIc), (VIIIc), (XIa) und (XIII) abgetrennt (H PLC‐Daten).

Cited by 6 publications

References 1 publication

Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing

Lycopene in Tomatoes: Chemical and Physical Properties Affected by Food Processing

Phenolic compounds in agri-food by-products, their bioavailability and health effects

Reaction specificities of the ε‐ionone‐forming lycopene cyclase from rice (Oryza sativa) elucidated in vitro

Contact Info

Product

Resources

About