By Theresa Siebert
You can earn more for your produce than the current market prices. If you add value to your produce by processing and packaging it, you can increase your profit by selling processed condiments at higher prices. In the previous edition of this series we covered peach chutney. This month the focus will be on tomato chutney.
Chutney is a sweet, tangy condiment that is served with curries, hot and cold meats and savouries. Tomato chutney may be prepared from both green and ripe tomatoes, along with onion, sugar, vinegar and various other ingredients, including spices. It is packaged in glass bottles and has a shelf-life of several months at cool temperatures.
For green tomato chutney, the tomatoes are picked at full size, just prior to it turning colour. It should be free from rot and disease. Minor blemishes can be tolerated as these are easily trimmed away. When ripe tomatoes are used, the tomatoes are picked in the firm-ripe stage. Selective hand picking enables the fruit to be sorted in the field. Any sunburnt, overripe and infected tomatoes are discarded.
Peeled, chopped onion, brown sugar and vinegar are basic ingredients of any chutney. Peeled, chopped apples (preferable Granny Smith) and sultanas are popular additions to tomato chutney. A wide selection of spices can be Chutneyadded. Green tomato chutney favours the addition of mustard, cinnamon, cloves, cayenne pepper, chillies, and garlic. Ripe tomato chutney blends well with allspice, curry powder, garlic, chilli powder, cinnamon, ginger, and cloves. (Please consult recipe books for precise chutney formulations.)
It is always better to wash the tomatoes before using them in a recipe, especially if the tomatoes are soiled or have been sprayed with chemical pesticides. Washing takes place in a water bath with the assistance of soft brushes. Peeling tomatoes are easy to do when following this simple hint.
The tomatoes are scalded for approximately 1 minute in hot water or steam at 98 to 100 °C. The tomatoes are then given a cold water dip or spray. This rapid drop in temperature helps to loosen the skin for easy peeling without loss of sub-surface tissue. The cooled tomatoes are given a shallow slit at the blossom-end and the peel is pulled off using a sharp knife.
Onions are topped and tailed and given a lateral slit before the outer shell is peeled off. Apples are peeled and cored by hand or special hand-driven apparatus.
Chopping of tomatoes and other fruit is done by hand using stainless steel knives, hand driven apparatus or small electric food processors. The size of the fruit pieces will have a great effect on the consistency of the end product.
During the cooking process, all the ingredients are combined in a large saucepan or batch cooker and slowly heated until all the sugar has dissolved. The heat is turned up to bring the mixture to boil and then left to simmer (uncovered) until the moisture starts to thicken (usually after about 45 minutes). Occasional stirring is required to prevent pieces from settling on the bottom and burning.
Glass jars used for the preservation of food should be of high quality, without any cracks or chips and should form tight seals. These are various methods of sterilising jars involving either dry or moist heat.
Oven method: The clean jars are placed upright in a cold oven, allowing an even spacing between the jars. The temperature is set on 160 °C and the jars are left to spend a minimum of 30 minutes in the oven. The hot bottles are removed from the oven using gloves and tongs.
•Boiling method: The clean jars are placed lying down in a deep pot and covered with cold water. The water is brought to boil. After 10 minutes of boiling, the jars are
removed using gloves and tongs. The jars are placed upright on a wooden board and are ready to fill.
•Steam method: Jars can be sterilised by saturating the interior with steam. This can be done by simply holding the open neck of the jar over the spout of a steam generator, water boilers or even kettles for 1 minute. Tongs or clams are necessary to handle the hot jars.
NB: Take note that as a general rule, hot food goes into hot jars and cold food into cold jars.
Filling involves displacing the air in the container with a food product prior to sealing. The hot chutney is filled into the hot, sterilised jars, leaving virtually no room on top. This is important since the hot chutney shrinks upon cooling.
The filled jars are left to cool before they are sealed with suitable, tight-fitting lids. Metal lids are generally not suitable since the high acid content would cause corrosion of the metal, leaving the product inedible. Specially lined or lacquered lids are required.
The containers are labelled and coded so that the product contains all the necessary information. The labelling of these containers should be done in accordance with the labelling legislation of Zambia to ensure that the correct product details and nutritional information is displayed.
The chutney is stored in a cool, airy, dark place. Once the seal has been broken, it requires refrigerated storage.
Next month we shall take a look at the production of ginger oil. Published with acknowledgement to the ARC Agricultural Engineering for the use of their manuals. Visit www.arc.agric.za for more information.
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2. Arthley, D. & Ashurts, P.R. (eds) 1996. Fruit Processing. London: Blackie Academic & Professional.
3. Fellows, P. 1988. Food Processing Technology: Principles and Practice. Chichester: Ellis Horwood, Ltd.
4. Macrae, R. et al. 1993. Encyclodaedia of Food Science, Food Technology and Nutrition. pp. 2960 – 2966
5. Potter, N.N. & Hotchkiss, J.H. 1995. Food Science. 5th ed. New York: Chapman & Hall.
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7. Gould, W.A. 1992. Tomato Production, Processing & Technology. 3rd ed. Timonium, Maryland: CTI Publications, Inc.
8. Somogyi, L P, Ramaswamy, H S & Hui, Y H. 1996. Processing fruits: Science and Technology: Vol 1 & 2. Lancaster: Technomic Publishing Co.