Preserving your produce

Press, 14 February 1986, Page 14

Preserving your produce

The Home Science Information Service at the University of Otago has received enquiries during the last twelve months indicating that some homemakers are using risky methods to preserve food. In particular there is an unwillingness to consign surplus catches of fish to the safety of the deep freeze.

Food for future use may be preserved by several different methods. The aim of each method is to control the enzymes and micro-organisms

which spoil perishable foods. Spoilage of preserved foods can be avoided by understanding why it occurs and how to prevent this happening. For safe, successful home preserving of food you must: © stop enzyme action, © destroy micro-organ-isms,

9 prevent the entry of harmful or spoilage organisms into the food, or © provide conditions where these micro-organ-isms cannot grow.

How is this done?

• Enzyme action is stopped by heat, e.g. blanching vegetables before freezing.

© Micro-organisms are destroyed by heating food, e.g. processing fruit packed in jars in a water bath. 1 !

© Further entry of food spoilage organisms is prevented when fruit ;is sealed in glass jars.

• Conditions which prevent growth of micro-or-ganisms are freezing, drying, adding a high concentration of sugar, salt or vinegar as in jam and pickle making.

The Home Science Information Service stresses that the appropriate method of preserving specific foods should be chosen and followed. To help homemakers do this a table giving details of which method to choose

for which food has been included in their new publication "Preserving Food.” This book is available from the Home Science Information Service, University of Otago, P.O. Box 56, Dunedin. Details of preserving foods by freezing, bottling and drying are included; the cost of the book is $5 posted. Freezing This is a safe and convenient method of preserving suited to most foods. It is the only recommended method ol preserving the low acid group of foods which include meat, fish (fresh and saltwater), vegetables and the convenience foods containing pasta. Bottling This is a preserving method which can be

used only for acid foods such as fruit, fruit juices, pulps and purees. Tomatoes may be bottled but as some varieties are low in acid it is recommended that *4 teaspoon citric acid is added to each 500 ml jar of tomatoes before processing. Fruit to be bottled can be cooked as for table use then sealed in sterilized jars (open pan method) or packed raw into jars and processed in a water bath or oven. Drying Herbs, fruits and vegetables can be home preserved by this method. When food is dried the moisture is removed, so preventing the growth of micro-organisms which cause spoilage. Food to be dried must be freshly harvested and in perfect condition.

The Home Science Information Service publication “Jams, Jellies, Pickles and Relishes” costing $2.80 posted from the above address gives recipes for jam and pickle making. The two publications mentioned will be supplied for $7 posted. Jam Fruit that is a little over-ripe or not in perfect condition can be made into jam. To determine when jam is ready to set observe the way in which jam drips from a wooden spoon whilst boiling. When the separate “drips” converge on the spoon and fall in a sheet the jam will set.