Lycopene (Z) – isomers enrichment and separation

Abstract

Summary (All‐E)‐ Lycopene undergoes geometrical isomerisation into (Z)‐lycopene isomers with thermal treatment. Influence of three isomerisation methods including ethyl acetate reflux, microwave‐assisted reflux and ultrasound/microwave‐assisted reflux, and isolation of (all‐E)‐lycopene from other carotenoids and (Z) lycopene isomers through selective inclusion by deoxycholic acid (3α, 12α dihydroxy‐5βcolan‐24‐oic‐acid, DCA) were investigated. The results showed that microwave and ultrasound/microwave‐assisted reflux were not significantly different at P < 0.05, but both were significantly different (P < 0.05) over refluxing in ethyl acetate, proportion of (Z)‐lycopene isomers reached 54% after refluxing for 5 h. Heterogeneous mixture of isomerised tomato oleoresin containing 54% (Z)‐lycopene isomers and 40% (all‐E)‐lycopene and deoxycholic acid in dichloromethane was incubated at 25 °C for 2 h. Then, the mixture was filtered and from the filtrate 96.6% (Z)‐isomers enriched lycopene was obtained. The processes can be used in the production of enriched (Z)‐lycopene isomers for food supplements and functional food industry as a natural bioactive ingredient.

Microwave‐Accelerated Z‐Isomerization of (all‐E)‐Lycopene in Tomato Oleoresin and Enhancement of the Conversion by Vegetable Oils Containing Disulfide Compounds

“…Therefore, the microwave‐induced Z ‐isomerization of lycopene is considered to be more efficient than the conventional heat‐induced isomerization. Kessy et al have also reported that the efficiency of lycopene Z ‐isomerization by microwave irradiation was higher than that of conventional heating. They carried out the isomerization tests in ethyl acetate, while our study showed that Z ‐isomerization of lycopene proceeds efficiently without using such organic solvents.…”

“…Microwave irradiation can be expected to be an alternative procedure. Several studies have reported that carotenoids such as astaxanthin and lycopene were isomerized by this treatment . The conventional heating method for Z ‐isomerization of lycopene has been conducted by heat conduction and convection, using a water or oil bath .…”

Tomato peel drying and carotenoids stability of the extracts

“…Tomato skin contains large amounts of valuable compounds, including carotenoids, mainly in the form of lycopene (80–90% of total carotenoids), an orange/red pigment, and β‐carotene, which accounts for around 2–3% of total carotenoids (Dumas et al ., ; Riggi et al ., ). Lycopene and β‐carotene are plant pigments that have been widely accepted as natural food colourants (Mortensen, ; Kessy et al ., ). Many researchers have investigated the role lycopene plays in improving human health due to their strong antioxidant activity (AA) (Yang et al ., ; Dehghan‐Shoar et al ., , ).…”

“…For this reason, pomace is often preserved by drying; however, drying and subsequent storage is expensive and results in the degradation of the lycopene (Lavelli & Torresani, ; Oludemi & Akanbi, ). The first stage of degradation, during the drying and storage of tomato powders, is the reversible isomerisation of all‐trans lycopene to less coloured, more oxidisable cis‐isomers (Boskovic, ; Kessy et al ., ). The preferences of consumers towards environmentally friendly products drive the food industry in the development of new natural colourants in the continuing replacement of synthetic food dyes, because natural products are associated with high quality, whereas synthetic pigments are critically assessed by consumers (Dawson, ; Shahid et al ., ).…”

New Developments in Lycopene Analysis by Spectroscopic and Chromatographic Techniques, Accompanied With Mathematical Modelling

“…Oxidation may also take place by the action of lipoxygenase, with the formation of hydroperoxides, and the presence of some antioxidants may inhibit this reaction. These processes may be reduced by using techniques that avoid contact with oxygen in air, such as freeze-drying, microwave, or others [25,26,[52][53][54][55][56][57][58].…”