Opportunities in tomato processing

As EU agricultural production subsidies are expected to be entirely phased out by 2013, opportunities for local production and processing may arise for African producers of fruit and vegetable products, which were previously subsidised in the EU. In this regard tomato may be the product with the most potential, especially as it is a most commonly-used ingredient in African cooking and the continent has a tradition of tomato processing.
According to the World Processing Tomato Council, an international non-profit-making organisation for the tomato processing industry, the world processed an average of 33m tons per year of tomatoes in the three years ended 2006; SA (157,000t) and Senegal (70,000t) were the only sub-Saharan African countries which processed more than 15,000t/year in that period.
This was not always the situation. In the early 1970s Senegal promoted the farming of tomatoes and erected processing plants to establish an industry that made Senegal the 23rd largest processor in the world.
A study in 2007 revealed that Senegal’s processing had dropped from 73,000t of concentrate in 1990 to 20,000t in 1996/7, while the EU’s exports of tomato concentrate to Senegal increased from 62t in 1994 to 5,348t in 1996.
Senegalese processors apparently eventually found it was cheaper to buy and dilute Italian paste than purchase tomatoes from local farmers.
For similar reasons, Ghana closed a processing plant that was producing around 100t/day of paste. Ghana is now the largest importer of paste in Africa – it imports 10,000t/year, while the farmers, established to supply the processor, continue to produce a glut, resulting in very low prices for sales to households.
This situation is not unique to Senegal and Ghana, nor to tomatoes. Therefore the new lack of the EU subsidies may offer opportunities.
The key is to produce products which will have shelf life and a market, at a cost that is not inflated by investment in infrastructure and capacity that is under-utilised, while still allowing the existing small farmers to make a return on their investment in production.
For the industrial market, tomato paste is the most important ingredient because it is used as the basis for a wide range of other products such as ketchups, sauces, soups, salsas, tinned meat and fish, etc.
The process
The tomato is washed, sorted and prepared by crushing, peeling or cutting to the required size. Depending on the particular requirements, the prepared tomato then undergoes all/some of the following: heating, refining, pulping, reconditioning, evaporation, pasteurisation and packing.
One of the largest constraints of processing (leading to underutilisation of infrastructure) is short harvest periods, which vary from 60 to 100 days. In Pakistan, projects have focused on proccesing other fruits during the periods when tomatoes are not available.
Constraints on processing cheaply in Africa are the lack of automation in farming, which increases input costs, and the lack of access to capital and qualified technical staff.
Also, the farming sector has generally suffered from the failure in processing, which has meant farmers are unorganised and possibly suspicious. This tends to reduce the assured supply of tomatoes to the processor – until trust can be built again.
Equipment range
Production of concentrated tomato products can be carried out at a range of scales – from small scale (kilograms per hour) to large industrial operations (200-300t/hour) in which both the unit energy consumption and damage to the tomato are vastly reduced.
In the smallest plants, prepared (hand-sorted, washed, peeled and separated) tomato pulps are boiled in open pans over a fire to achieve the required final concentration (44% pulp – 40% puree – 34% concentrated juice, 17-19% juice and 10-12% juice).
At this level the concentration process constrains the product both because of the large cost of energy and the damage to the tomato by uncontrolled heating, which results in darker and duller pastes, often with a stronger cooked taste.
In the largest plants, pulp is prepared via mechanical processes, then vacuum-evaporated; this reduces both the energy required by using evaporated water as heating steam by subjecting the pulp to a lower temperature for a shorter time, which also results in the retention of the traditional bright red colour and a fresher taste.
But there are intermediate processes that can be used:

  • The degree of darkening can be reduced by using steam heating of the pulp in jacketed cooking vessels. However, there is no system to gain the advantages of vacuum evaporation on a small scale.
  • A filtration process was developed in Bangladesh, which produces products that match the colour of commercial pastes. However, only purees can be produced and salt needs to be added to increase the concentration. Gratis Foundation of Ghana has installed one of these plants in Techiman.

Smaller-scale plants have been developed. For example, a Pakistani company produces a plant with capacity to process 2t/hour of tomato. This plant is based on a single-effect, high-vacuum, scraped surface heat exchanger.
A 2003 feasibility study determined a total cost (equipment, land, buildings and installation) for this of around $1.5m – for a capacity to produce 750t/year and 1,900t/year of tomato paste and fruit pulp respectively.
A Chinese plant with a capacity to process 5t/hour of tomato, made by Shanghai Triowin Tech, offers a two-stage, low-vacuum thin film evaporator.
Tomato Puree Filtration – Gratis Foundation in Ghana (253 022 20 4243; fax 233 022 20 4374; gratis@ighmail.com; www.gratisghana.com).
Shanghai Triowin Tech Co Ltd 86 21 5433 1233; 86 21 5433 1011 fax; info@triowinpak.com.cn; www.triowinpak.com.cn
Pakistan Horticulture Development & Export Board; 92 42 111-111-742; fax +92-42-572

In South Africa …

A large tomato paste factory is being planned for the Coega Industrial Development zone in the Eastern Cape.
Funding of $12m is being sought by Post Harvest Technologies (PHT), which initiated the project in conjunction with refrigeration contractors Club Refrigeration and Italian-based food-engineering company, FencoSpA.
It is hoped that about half of the eventual capacity of 50,000t/year of paste will be produced by mid-2008. However, construction of the factory has not yet started, as finances still had to be tied up, according to Gus Robinson, MD of PHT.
If successful, tomato paste will be produced in bulk for the local market as well as for export to the rest of Africa and abroad.
Commercial farmers will be recruited to grow tomatoes in the Sundays River area, which, according to Robinson, is uniquely positioned to produce two growing cycles a year.

In Angola …

The Development Bank of Angola recently approved the funding of a project to install a $10.7m tomato paste factory in Matala district, south Huíla province.
Local newspapers report that the factory will have a capacity of 6t/hr of fresh tomato, to obtain an output of "at least" 1t/hr of tomato paste. It is estimated that the factory will process about 12,500t/year of fresh tomatoes.
The project will reportedly use  Spanish technical assistance.

In Nigeria …

The Sokoto State government in Nigeria is seeking investment for small and medium scale enterprises in tomato juice and puree production. The project involves the construction and operation of the facility.

For this project, contact Alhaji Sani Garba Shuni, Permanent Secretary of Economic Planning, via email: ajiyashuni@yahoo.com