Isolation and Isomerization of Lycopene from Tomato Paste free essay sample

To extract the carotenoid pigments from canned tomato paste and separate them by column chromatography to obtain a solution that contains lycopene. Then record the ultraviolet-visible spectrum of this solution and analyze it for evidence of isomerization. Calculation List of Materials 4. 0g tomato paste screw cap vial Chromatography column 25ml buret 50ml flask ring stamd and clamp 50% mixture of acetone and low boiling petroleum ether 5ml extraction solvent 0ml 10% aqueous solution and 20ml of saturated sodium chloride Procedure Wash combined extracts with 20ml potassium carbonate followed by 20ml of saturated sodium chloride solution. Dry w/ lycopene Concentrate the pigment solution to a volume of . 5ml by evaporation OP-19. SEPARATION fill chromatography column with hexanes and let liquid drain until its surface just disappears into the sand layer. Transfer the pigment to the top of the column Keep liquid level in column constant When yellow carotene band begins to drain out of the column, replace the beaker by the collection vial and elute the lycopene band, collecting a 5. We will write a custom essay sample on Isolation and Isomerization of Lycopene from Tomato Paste or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 0ml sample of eluate. Use the midband lycopene sample for spectral analysis as soon as possible record spectrum midband lycopene sample over the 600-400nm range. Add a drop of . 025% iodine solution to the lycopene solution and leave it in the sample beam for about 2 mins. Turn in your lycopene solution in a labeled vial Estimate the percentage of all-trans lycopene in your midband sample before isomerizaion. B) Lycopene is a micronutrient with important health benefits, because it appears to protect both men and women from a broad range of cancers. Lycopene in tomatoes is 90% all-trans, but human tissues contain mostly cis-lycopene isomers. This suggests either that the cis-isomers are more readily absorbed by the body or that an enzyme in the body converts all-trans-lycopene to the cis-isomer. So, although the presence of a significant amount of 13-cis-lycopene in tomato paste suggests that some degradation has taken place during processing, that may not be a bad thing hen considering its health benefits. I would think the green features are ones that can be recycled and do not harm the environment. These could be the use of sand and alumina as a filtration for the chromatography. These are things that can be disposed of without having to worry about hurting the environment. The use of petroleum ether and acetone wouldnt be as green b/c they are potentially harmful chemicals. Lycopene o xidizes slowly in the presence of oxygen, so we want to try to record its UV-VIS spectrum on the same day that we isolate the lycopene solution. This oxidation may alter its spectrum if left out for too long in the refrigerator. Because Lycopene has 13 carbon-carbon double bonds, it is one of the most unsaturated compounds in nature. Most of the double bonds are conjugated, so it absorbs radiation at long wavelengths; which gives it its orange-red color. B-Carotene has a similar all-trans structure that happens naturally, much like Lycopenes. This helps give B-carotene its yellow-orange structure. This is why their colors are similar. Discussion The goal of this experiment was to extract the pigments of carotenoids from canned tomato paste through chromatography. We did this by setting up a chromatography column by packing sand and alumina into a long filtration column. We then prepared a 8g sample of tomato paste by adding 10ml acetone and mixing. This step removed any excess water. We then dried the paste with filter paper and paper towels. 10 ml of 1:1 petroleum ether was added to the tomato paste, along with a scoop of magnesium sulfate, and filtered into a small beaker. The tomato paste extract was then placed by pipette into the top of our chromatography column and allowed to trickle down. We then added a few mL of petroleum ether to elute the B-carotene band. This was a bright yellow liquid at the bottom. We then added a 9:1 petroleum/acetone to elute the red-orange lycopene band. This liquid was a darker yellow/orange color. Conclusion The sand filter alumina helped to separate the different particles so that we could extract the different colors. It did this by allowing the different size particles to get caught in the grains of sand and forced them to take different amounts of time to filter. The B-carotene is less polar, so it moved down faster than the lycopene.