Fruits and vegetables are processed to avoid wastage throughout the food chain since they are perishable. Processing can be done in different ways to give whole, pulped or extracted products that include dried fruits and vegetables, wine, vinegar, sauerkraut, pickles, sauces, ketchups, jam, marmalade and juices. Acidity plays a big role in determining the processing method.
Fruits are more acidic compared to vegetables and unlikely to be contaminated by illness causing germs. The acidity can, however, support growth of yeasts and molds.
Fruits and vegetables are bulky and most processing methods will involve removal of water, hence site the factory near where they are grown.
This will save on transport costs, have less handling of raw fruits and vegetables that would lead to bruising. In rural areas, land will be cheaper and air cleaner than in town.
However, there may not be reliable power supply, portable water, sewerage system, accessible roads, housing and amenities.
Lack of housing and amenities impact on the labour as especially young skilled people will prefer to be in town.
Insects, birds and stray animals are also abundant in rural settings and have to be controlled or eliminated.
Factory layout and design
Factory must be designed to give a hygienic look and use materials that enable easy cleaning. Built a size based on capacity and expected profit.
The building should be cool by ensuring enough ventilation and adequate insulation of steam pipes. Adequate light is important in all sections.
Have screen vents with mesh to keep out insects and birds.
Walls, windows and doors
Walls should be plastered and rendered with concrete and should have easy to clean smooth surfaces. The lower surfaces; up to 1.5m can be tiled or painted with water proof white or off white gloss paint.
Higher up use good quality white emulsion paint. The number and size of windows will depend on perceived security threats and type of product.
No windows for storerooms. Window sills should slope to allow water on them to drain and doors should not have gaps underneath them to keep of rodents.
Floor should be of good quality concrete and smooth finish for easy cleaning. Spillages should be wiped off especially if acidic as they will react with concrete.
Red wax household flour polish should not be used as they wear away easily and rub out on the product package besides contaminating the products.
Floors should be curved up and not sharp edged to meet wall for easy cleaning. They should also slope to a drainage channel that is fitted with metal grating that has a wire mesh to avoid pests getting into the factory.
Power and lighting
Fluorescent tubes though expensive are preferred to light bulbs. Electric points should be at least a metre above ground and one power source per machine to avoid overloading.
Use waterproof sockets if possible. There should be no exposed wires at any connection. Always consider safety before money or saving time.
Water supply and sanitation
Portable water should be used as ingredient and for washing (flowing or tap in processing room). Boreholes provide alternative sources of water.
Dams, lake and river waters may be contaminated. Schedule checks on the water quality and keep records. Treat water by use of chlorine at 0.5ppm for water used as ingredient and at 200ppm for that used for sterilising reasons.
Chlorine can damage the skin so take care and warn staff.
Dr Ngoda is based Department of Dairy, Food Science and Technology, Egerton University.