What is Soil pH and Why is it important in farming? - Chemosmart

               Concept of preservation

                 Preservation of the variety of food material is done by various methods. It depends on for how much period the food material should preserve and type of food material. The different methods of preservation are as follows:

1) Preservation by addition of heat processing in various ways is perhaps the earliest and most common method of preservation. 

2) Drying or dehydration method is another method in which water part removed either by sun-drying or by mechanical method. For example storage of fish, meat, some fruits and vegetables. 

3) Freeze preservation method is used to increase the storage life of fresh fruits and vegetables, and similar other fresh food-stuffs. 

4) Preservation by addition of sugar and application of heat is a highly important method in the case of fruits which are utilized in a very large quantity to make jams, jellies, marmalades and preserves. This method is simple, cheap and easy to adopt. 

5) The use of chemical additives, which are permitted as harmless, within limits is fairy widespread in the case of a variety of squashes, cordials and other beverages. At present, only sulphur dioxide and its salts and benzoic acid and some of its ester derivatives are permitted in food. 

6) Preservation by fermentation is a very ancient and well-known method. Yeast-fermented fruit wines, which contain ethyl alcohol as natural preservative, have been prepared and used for hundreds of years. Such alcoholic liquids undergo further acetic acid fermentation into vinegar, which is an acidulant and is widely employed in pickling. 

7) Preservation by salting or bringing of vegetables and unripe fruits for e.g. Mango, Lime, Lemon etc., is very common in many parts of the world where Indian pickles are well known. 

8) Preservation of friuts and vegetables by application of U.V and ionizing radiation is of recent origin. 

Squash :

                Squash is a type of fruit beverage containing at least 25 percent fruit juice or pulp and 40-50 percent total soluble solids, commercially. It also contains about 1.0 percent acid and 350 ppm sulphur dioxide or 600 ppm sodium benzoate. It is diluted before serving. Mango, orange, and Pineapple are used for making squash commercially. 

              It can also be prepared from lemon, bael, papaya, etc. using potassium metabisulphite (KMS) as preservative of from Jamun, passion-fruit, peach, plum, Raspberry, Strawberry, grapefruit, etc. with sodium benzoate as preservative. Fruit juice are most commonly packed as squashes or cordials. 

Let us take a example of Orange Squash. 

Extraction:

1) Selected tight-skinned oranges or Musambi for extraction. 

2) Cut the fruit in to two halves either with a knife. 

3) The halves are pressed by hand against a revolving burr or rose fitted to a rosing machine. 

4) Collect the reamed juice in a vessel. 

5) It contains plenty of course tissues, seeds etc. To remove these, it is filtered through a net cloth or passed through a sieving machine known as pulper. 

6) The sieved juice is utilized for preparation of Squash. 

7) Ingredients:

Orange juice - 10.00 kg

Sugar - 16.40 kg

Citric acid -0. 498 kg

Essence of Orange - 0.198 kg

Water - 12.70 kg 

Orange color 

Preservative

8) Sugar, citric acid, flavoring materials, color and preservative are added to the juice to the juice in correct proportion. 

9) Sugar, citric acid and water are mixed and heated. Any dirt is skimmed off. 

10) The syrup is cooled slightly and filtered through cloth. 

11) The clean syrup is blended with the juice. 

12) To improve flavor, peal emulsion of 2 to 4 organs for every 100 oranges taken or an appropriate quantity of an essential oil and orange essence is added to the squash. 

13) Edible color can be added if you want provided that it should be resistant to the action of sulphur dioxide. 

14) After mixing all the ingredients, a calculated amount of a chemical preservative, namely potassium metabisulphite, approximately about 28g for every 454g of squash dissolve. 

15) Previously in a small quantity of the juice or water, is added to the squash. 

Flow chart for Squash: