Dude,
I still never understand why anyone would want to start a business in Nigeria that will not be assured of raw materials. Yes, there are tomatoes in Nigeria but the amt of investment in tomato processing equipment will not justy the amt of tomato you can get in Nigeria.
I'm guessing that a processing plant on the cheap will run a minimum of $1-1.5million. You don't just get processing machine. you will need "ancilliary" equipment. Cold Room, Forklift, Trucks, Offices, personnel vehicle (sales, other logistics stuff), Generator (super Duty, No tiger piece of ###

Even if you get all that, you will need a tomato farmer on a large scale for constant supply. Whatta you going to do about Nigeria road
One thing i know about food processing, you need to process the fruits not later than 48hrs after being harvested. Otherwise quality is no good. If you do, people will reject your products and all your investments are down the tube.
I don't mean to be a downer, but you need to work out the logistics, hire a consultant and you're in business.
and lastly, you need hectres upon hectres of farm to supply tomato because the canning machinery works very very very fast producing about .5 to 1million per day. think about it.
its not a small boy business.