I was asked to help solve a problem concerning cross contamination and product quality control in one of the smaller fruit juice factories in our area yesterday. The factory in question has a capacity to produce 72,000 liters of various fruit juices, fruit drinks and fruit nectar and ice teas. The factory basically consists of two departments, a mixing department and a bottling department. The products are either packed in glass bottles, plastic bottles or tetra pak cartons.
All of the concentrates are poured into the 18,000 liter vats via a barrel tipping machine and a suction device for rotoplasts. The concentrates are pumped through a pipe console which directs the concentrates in to one of four vats in the mixing department.
The factory had started producing tomato juice several months ago and since the onset of this production the company has been experiencing problems with the shelf life and color of products. They had tried every way they could imagine to clean the pipes leading into the tanks but to no avail. Tomato paste is very thick and viscose which makes it a difficult product to work with. Tomato paste tends to travel through pipes in pulses and because of this it coats the pipes evenly from the inside. Thinner and less solid substances such as caustic soda solution tends to run along the bottom of pipes and will only reach the top extremities for brief moments. This makes cleaning tomato paste particularly problematic.
I could smell the presence of tomato concentrate coming out of all of the pipes. There was no question that there was a grave danger of the tomato residue in the pipes fermenting. After a little thought this was my solution to the problem:
1) only to use two of the tanks for producing tomato paste. The effect this would have would be to reduce any possible risk by 50% from the outset.
2) to install separate feed pipes into those two tanks for tomato paste. This would leave the pipes for other products uncontaminated by tomato paste.
3) To dilute the tomato paste with 50% chilled water in a 500 liter mixing tank which was already on site.(2 degrees centigrade) prior to being pumped into the tanks. This would cause the concentrate to be less viscose and much easier to clean during the CIP process.
4)To dissemble and to clean the pump on the barrel tipping machine after every use.
5) To dissemble all pipes weekly and to immerse them in caustic soda solution.
6) To clean all pneumatic valves with a special industrial pipe cleaning brush from all directions.
At the end of the meeting with the department head, production manager, head of quality control and the general manager, all my suggestions were accepted and will be implemented within one working week. I will conduct a follow up check one month from today.