TOMATO PRESERVATION TECHNIQUES
Article by Olanrewaju Rukayat Ifedapo
Having left over tomatoes is a common occurrence in homes in Nigeria. I love to take advantage of the lower tomato prices during tomato season to stock up my pantry, and I know that’s true for most of us. But tomatoes, being perishable can’t keep for long period of time without preservation. In most homes, tomatoes are grinded and stored in the refrigerator or freezer but the downside of this method of preservation is that the tomatoes loses both quality and flavor overtime.
Moreover, a great percentage of tomato wastage in Nigeria occur between the market and consumption in the household. This makes it important to find out ways of increasing the shelf life of our household tomato supply. There are simple and innovative ways to preserve our tomatoes, making it available all year round.This methods can be used when there is a glut of tomatoes and it can be commercialized.(Find out how to reduce or avoid tomato wastage by clicking this link https://www.agriculturenigeria.com/research/articles/reducing-tomato-waste )
Freezing bags/ Ziploc bags
Cookie sheets/baking sheets
A clean bowl for washing
A clean knife.
A clean pot.
Containers for freezing
Tomatoes may be frozen whole, sliced, chopped and pureed. It can also be frozen raw or cooked, juiced or sauced. Select firm ripe tomatoes for freezing, wash them in clean water and dry them. When freezing whole tomatoes, cut away the stem scar and place on cookie sheets and freeze, once frozen, transfer in freezer bags or other container (Ziploc bags). Press out as much air as possible to prevent lose flavor. Seal tightly. To use, just defrost.
Tomatoes with the stem scar removed
Source: Farm and dairy
You may also stew your tomatoes before freezing. Dip tomatoes in boiling water for one minute, this splits the skin making it easy to peel off the skin. Cook the tomatoes until tender (10-20mins). Cool the tomatoes by placing the pot in a larger container of cold water. Pack the cooled tomatoes into freezer containers. Avoid overfilling the container, leave room for expansion. Seal and freeze.
Frozen whole tomatoes
A clean pot
Glass jars with covers (mayonnaise jars may be used)
Canner/ Aluminum pot/ Pressure cooker
Ripe, red, and fairly firm tomatoes are the best to use for making tomato preserves. Wash your hands thoroughly without soap. Wash the tomatoes thoroughly. Select the best ones to make whole tomato preserves. Put the selected tomatoes gently in boiling water for 30 seconds, take out the hot tomatoes out of the boiling water with the aid of a sieve. Put immediately in cold water for a few minutes, this loosens the skin for peeling. Peel the tomatoes completely. Don’t leave any skin on them.
Wash the glass jars and lids (old mayonnaise jars) thoroughly with hot water. Fill the cleaned jar with the peeled tomatoes. Ensure they are snuggly packed by tapping the base of the jar carefully. Squeeze some fresh lemon juice without the pips (bottled organic lemon juice may be used). This is to acidify the preserves. One table spoon to half litre /50cl/500ml jar. Add some boiling water to fill up the jar. Avoid overfilling the jar, leave about 1cm of air. Screw the lid tightly, Arrange in the canner and boil for 45mins. Allow the jars to cool. Rinse and dry the jars. Store your canned tomato preserves in a cool, dark place. It can last up to a year unopened but once opened consume within 24hrs or keep left over in the refrigerator.
Source: FAO Canned tomato preserve
I know most of us don’t have a canner, don’t worry an aluminum pot/ pressure cooker and a metal rack can suffice. Just layer the bottom of the pot or pressure cooker with some stray or a metal rack. Arrange the jars on the rack or layer of stray and pour some water (the jar must be at least 2cm immersed in the water). Boil for 45mins for half litre jar (see sterilization time in the table below). Turn off the fire and allow the jar to cool.
A Clean pot
Bottles with lid (old wine bottles can be used)
For this method you can use tomatoes of different sizes. Avoid using squashed or damaged tomatoes. Wash and drain the tomatoes. Wash the bottles thoroughly in hot water. Cut the tomatoes in half and check inside for any that might be rotten. Using an extractor, extract the pulp from the seed and the skin. In the absence of an extractor blend the tomatoes.
Source: FAO; Weston Manual extractor and Strainer
Pour the tomato pulp or blended tomatoes into a cooking pot. Place the pot on low heat and allow the tomatoes to simmer without boiling. Using a funnel, pour a small spoonful of lemon juice into each empty bottle. Fill the bottles with the preheated tomato pulp but leave about 2inches air space. This is to prevent breakage during sterilization. Cover the bottles tightly. Sterilize as with the canned tomato preserves. Allow to cool overnight. Rinse and dry the bottles. Store them in a cool dark place. It can keep for up to a year unopened. Once opened, consume within 24hrs or refrigerate.
Source: FAO Bottled tomato pulp
This method is most suitable for people in the Northern part of Nigeria. It is also suitable for tomato preservation during the dry season.
A clean knife
Preservative (sodium benzoate)
Always use red, ripe undamaged tomatoes of whatever shape and size. Wash your hands thoroughly. Wash the tomatoes. Cut in half and pick out the pip using your fingers without crushing the pulp. You can sundry the pip and keep the seeds to plant your garden or farm. Cut the half tomato into 1cm thick slices. Cut as evenly as possible. Note that the thicker the slices the longer the drying the period. The tomato slices can be dried like this but it will only last for 3 months.
In order to extend the shelf life, add a soup spoonful of salt and a soup spoonful of preservative per litre of water to a pot of water. Put the water to boil then blanch (dip briefly in boiling water for a few minutes then plunged in cold water to halt the cooking process) the tomato slices for 3mins in the boiling (you can use a piece of cloth or a very clean basket) and drain. Your tomato slices are ready to be put in the dehydrator. Spread as evenly as possible. After drying, allow to cool then park in polythene bags or Ziploc bag. Seal tightly and keep in a cool dry place.
In the absence of a dehydrator, this dryer can be constructed. The plastic retains the heat of the sun and the hot air circulates from the bottom of the drier and goes out the top. This is cheaper than the dehydrator.
Locally fabricated dryer
In the dryer, the tomato slices are placed on trays made of slanted plastic and mosquito netting. Spread as evenly as possible. Shut the drier immediately to prevent contamination, flies and dirt. After two and half days the tomatoes are dry. Gather them up and cool off for half an hour in a shady place. Seal in polythene bags or Ziploc bags and keep in a cool dry place.
The dried tomatoes can also be grinded to make tomato powder. This produce can last for a year once kept dry. To use your dried tomatoes, soak in water for 2hrs to rehydrate it before use.
(To learn how start tomatoes production follow this link https://www.agriculturenigeria.com/farming-production/horticulture/tomato )
“Tomatoes with the stem scars removed”. https://www.farmanddairy.com/top-stories/how-to-freeze-whole-tomatoes/275841.html/attachment/tomato-with-stem-scar-removed (October 16, 2018)
“Weston tomato press” https://www.westonsupply.com/Roma-Food-Strainer-Sauce-Maker-p/07-0801.htm (October 15, 2018)
FAO (1998). Preserving tomatoes: 3 home processing and preservation techniques. 35pp. accessed from http://www.fao.org/docrep/s6570e/S6570E00.htm#contents on September 29, 2018.
Parnell T.L., T.V. Suslow, and L.J. Harris (2004). Tomatoes: Safe methods to store, preserve and enjoy. ANR publication 8116. 15pgs.
Vanessa Beaty (2013). Top 8 popular ways to preserve tomatoes for winter. Assessed from www.diycrafts.com/3055/homemade/top-8-most-popular-ways-to-preserve-tomatoes-for-winter on September 28, 2018.