Preparation of tomato sauce
Introduction
This model is focused on preparation of tomato sauce, materials and equipment required, ingredients, procedure, bottling, physical and chemical characteristics.
Preparation of tomato sauce
Sauces are thick liquids made from pulped fruit and/ or vegetables, with the addition of salt, sugar, and vinegar. They require pasteurization and are filled while hot. The basic principle of preservation for all of these products is the use of acetic acid (vinegar). Acetic acid preserves the product by making the environment acidic, inhibiting the growth of spoilage and food poisoning microorganisms. Other ingredients such as salts and sugar contribute to the preservative effect.
Materials & equipment:
Stainless steel knives
Stainless steel saucepan
Weighing scale
Blender
Strainer
Refractometer
Bottles and caps
Thermometer
pH meter
Ingredients:
Tomato pulp - 1kg
Vinegar - 25ml
Sugar - 150g
Chili powder - 10g
Onions (optional) - 10g
Salt - 5g
Ginger - 2g
Garlic - 2g
Cloves - 0.5g
Cardamom - 0.5g
Cinnamon - 0.5g
Nutmeg - 0.5g
Pepper - 0.5g
Sodium benzoate - 0.02% of final weight
Procedure:
Preparation of tomato pulp
Tomato pulp should be obtained from sound, wholesome, fully ripe, red tomatoes. The quality of the tomato sauce depends on the quality of the raw material used. Green fruits should be eliminated by careful sorting as the green colour, chlorophyll, would turn brown or brownish-red on cooking. Tomatoes should be free from physical injuries and microbial infections, as this helps lower the initial level of microbial contamination. They should be free from any pest attack and any signs of deterioration. The selected fruits should be thoroughly washed in running water, then chlorinated water, and rinsed in potable water again. This eliminates dust, dirt, and spray residues. The fruit is cut into small pieces using stainless steel knives, and the fruit pulp is obtained using a blender and sieve using a strainer.
Concentration of the pulp
The weighed pulp should be heated by stirring in a stainless steel saucepan and concentrated to half its original volume. Heating should be done as fast as possible after pulp extraction to inactivate enzymes present, which could cause off flavour in the product. Certain heat resistant enzymes, if not inactivated early, would result in pectin breakdown and separation in the final product.
Addition of other ingredients
The spices - cloves, cinnamon, cardamom, nutmeg, and pepper are powdered and placed in a cloth bag, and added to the pulp.
The onions, ginger, and garlic are added to the pulp in a separate cloth bag.
The sugar and salt are added to the pulp after concentration, and the product is cooked.
The chili powder, dissolved in vinegar, is added almost at the end of the process.
The volatile acetic acid in the vinegar would be lost if added early.
The product is cooked to 42° Brix.
Sodium benzoate is added as a preservative at 200 parts per million (ppm) of benzoic acid of the weight of the final product.
Bottling
The mixture is filled hot (82°C) into clean bottles using stainless steel or plastic equipment and capped and allowed to air cool.
Sterilization of empty bottles
Cleaned, washed, empty bottles are sterilized in boiling water for 30 minutes before using.
Physical characteristics
Appearance
The product should have the natural bright red colour of well-ripened tomatoes. It should be free of seeds and seed fragments, pieces of core material, dark specks, or tomato peel. It should also be free from extraneous matter.
Flavour
The product shall have a palatable flavour, basically that of tomato modified by the ingredients added. It should be free from off-flavours or off- odours.
Texture
The product shall have a uniform consistency and shall be free-flowing.
Chemical characteristics
Requirements for the product
Soluble solids content percent by mass, (min) → 25.0
Tomato solids content percent by mass, (min) → 8.0
Total solids content percent by mass, (min) → 30.0
Acidity, as acetic acid percent by mass, (min) → 1.2
Sulphur dioxide content mg/kg, (max)* → 100
Benzoic acid content mg/kg (max)* → 250
*When both benzoic acid and sulphur dioxide are present, the quantity of each preservative expressed as a percentage of the maximum permitted limit of the preservative, shall be calculated. The sum of these percentages shall not exceed 100.
0 Comments