I have been dealing with vegetables all these while for my thesis research :). My job is to compare the difference of total phenolic content and antioxidant activity between organic and conventional vegetables. As organic vegetables are usually more expensive, it is a wonder whether they are really more superior in term of taste, nutrition content and antioxidant content.
I rarely visit the market. Hehe but for my thesis research, I found myself frequenting the tesco vegetable section, selecting vegetables for lab work.
Freshly from the supermarket
Prof wanted me to measure the size of organic and conventional vegetables. It is amazing that organic vegetables are so much shorter! Well, without the aid of pesticide, these organic vege are under so much stress that their focus were shifted to phenolic acid production, thus less growth.
Okra
Choy Sum
Time to get the vege washed and cut :). They look yummy. What a waste, they will soon be blended.
Ready to be blended
The blended vege were then shaken with ethanol solution for 2 hours to extract out its antioxidant content. The extracts were such a lovely shade of green. Looks like some magic potion from Harry Potter's potion class.
Okra extracts
The vege residues formed clumps that floated around. They are unwanted. The extracts wer filtered to obtain clear solutions.
Lovely okra extract
The extracts are concentrated with Rotary Evaporator. It was a cute sight seeing the ball like flask rotating in the water bath.
Unlike okra, the extracts for choy sum is in a much darker shade of green. Looks really acidic:).
Choy Sum extract
These babies are really light sensitive. The antioxidant content within is easily affected by light. For this, I always have to off the light of the lab and work in the dark to protect these babies. Those who shared the lab with me had been very considerate, poor them, haha have to work in the dark as well.
Amber bottles
The test tubes need to be protected by aluminium foils
The extracts were reacted with Folin Ciocalteu's reagent in alkaline solution. They turned blue after 2 hours. The darker the blue, the happier I am because it represents higher content of total phenolics :).
Microplate is such a lovely invention ! It lessens the burden and allow numerous readings to be done simultaneously.
This is the DPPH test where antioxidant activity is measured. The control with no antioxidant activity would remain purple while those with activities would fade to a light yellow colour.
I am thankful that my research doesn't involve those tedious procedures involving high tech machines. Some of the friends have suffered trying to book the equipment or bullied by lab assistants. I am spared of those emotional encounters, but they do gain something too. At least they learn to use HPLC and some unheard machines.
Lab work could be rewarding, but it could turn you nuts too. There are dramas in the lab everyday, you could see the mood swings going up and down like roller coasters among fellow coursemates. A spoilt machine , a spilt sample, a rude lab assistant could make you miserable.
Good luck with my dear coursemates :). Hope we could all complete our lab work soon.